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2991 Commits

Author SHA1 Message Date
Bryan Chan
625f2dccd4 cmd/compile/internal/ssa: handle symbol address comparisons consistently
CL 38338 introduced SSA rules to optimize two types of pointer equality
tests: a pointer compared with itself, and comparison of addresses taken
of two symbols which may have the same base. This patch adds rules to
apply the same optimization to pointer inequality tests, which also ensures
that two pointers to zero-width types cannot be both equal and unequal
at the same time.

Fixes #24503.

Change-Id: Ic828aeb86ae2e680caf66c35f4c247674768a9ba
Reviewed-on: https://go-review.googlesource.com/102275
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-31 21:37:13 +00:00
Alberto Donizetti
3b0b8bcd68 test/codegen: port stack-related tests to codegen
And delete them from asm_test.

Change-Id: Idfe1249052d82d15b9c30b292c78656a0bf7b48d
Reviewed-on: https://go-review.googlesource.com/103315
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-30 08:08:06 +00:00
Alberto Donizetti
56eaf574a1 test/codegen: match 387 ops too for GOARCH=386
Change-Id: I99407e27e340689009af798989b33cef7cb92070
Reviewed-on: https://go-review.googlesource.com/103376
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-29 20:05:40 +00:00
Alberto Donizetti
aacf7a1846 test: avoid touching GOOS/GOARCH in codegen driver
This change modifies the codegen test harness driver so that it no
longer modifies the environment GOOS/GOARCH, since that seems to cause
flakiness in other concurrently-running tests.

The change also enables the codegen tests in run.go.

Fixes #24538

Change-Id: I997ac1eb38eb92054efff67fe5c4d3cccc86412b
Reviewed-on: https://go-review.googlesource.com/103455
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-29 19:00:10 +00:00
Alberto Donizetti
04e993f953 test: update list of escape reasons
The escape_because.go test file (which tests the "because" escape
explainations printed by `-m -m`) cointains a machine-generated list
of all the escape reasons seen in the escape tests.

The list appears to be outdated; moreove a new escape reason was added
in CL 102895. This change re-generates the list.

Change-Id: Idc721c6bbfe9516895b5cf1e6d09b77deda5a3dd
Reviewed-on: https://go-review.googlesource.com/103375
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-29 14:17:40 +00:00
Alberto Donizetti
360c19157a cmd/compile: print accurate escape reason for non-const-length slices
This change makes `-m -m` print a better explanation for the case
where a slice is marked as escaping and heap-allocated because it
has a non-constant len/cap.

Fixes #24578

Change-Id: I0ebafb77c758a99857d72b365817bdba7b446cc0
Reviewed-on: https://go-review.googlesource.com/102895
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-03-28 16:56:03 +00:00
Matthew Dempsky
7b177b1a03 cmd/compile: fix method set computation for shadowed methods
In expandmeth, we call expand1/expand0 to build a list of all
candidate methods to promote, and then we use dotpath to prune down
which names actually resolve to a promoted method and how.

However, previously we still computed "followsptr" based on the
expand1/expand0 traversal (which is depth-first), rather than
dotpath (which is breadth-first). The result is that we could
sometimes end up miscomputing whether a particular promoted method
involves a pointer traversal, which could result in bad code
generation for method trampolines.

Fixes #24547.

Change-Id: I57dc014466d81c165b05d78b98610dc3765b7a90
Reviewed-on: https://go-review.googlesource.com/102618
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-03-27 18:56:36 +00:00
Alberto Donizetti
a27cd4fd31 test/codegen: port tbz/tbnz arm64 tests
And delete them from asm_test.

Change-Id: I34fcf85ae8ce09cd146fe4ce6a0ae7616bd97e2d
Reviewed-on: https://go-review.googlesource.com/102296
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-24 09:35:53 +00:00
Giovanni Bajo
79112707bb cmd/compile: add patterns for bit set/clear/complement on amd64
This patch completes implementation of BT(Q|L), and adds support
for BT(S|R|C)(Q|L).

Example of code changes from time.(*Time).addSec:

        if t.wall&hasMonotonic != 0 {
  0x1073465               488b08                  MOVQ 0(AX), CX
  0x1073468               4889ca                  MOVQ CX, DX
  0x107346b               48c1e93f                SHRQ $0x3f, CX
  0x107346f               48c1e13f                SHLQ $0x3f, CX
  0x1073473               48f7c1ffffffff          TESTQ $-0x1, CX
  0x107347a               746b                    JE 0x10734e7

        if t.wall&hasMonotonic != 0 {
  0x1073435               488b08                  MOVQ 0(AX), CX
  0x1073438               480fbae13f              BTQ $0x3f, CX
  0x107343d               7363                    JAE 0x10734a2

Another example:

                        t.wall = t.wall&nsecMask | uint64(dsec)<<nsecShift | hasMonotonic
  0x10734c8               4881e1ffffff3f          ANDQ $0x3fffffff, CX
  0x10734cf               48c1e61e                SHLQ $0x1e, SI
  0x10734d3               4809ce                  ORQ CX, SI
  0x10734d6               48b90000000000000080    MOVQ $0x8000000000000000, CX
  0x10734e0               4809f1                  ORQ SI, CX
  0x10734e3               488908                  MOVQ CX, 0(AX)

                        t.wall = t.wall&nsecMask | uint64(dsec)<<nsecShift | hasMonotonic
  0x107348b		4881e2ffffff3f		ANDQ $0x3fffffff, DX
  0x1073492		48c1e61e		SHLQ $0x1e, SI
  0x1073496		4809f2			ORQ SI, DX
  0x1073499		480fbaea3f		BTSQ $0x3f, DX
  0x107349e		488910			MOVQ DX, 0(AX)

Go1 benchmarks seem unaffected, and I would be surprised
otherwise:

name                     old time/op    new time/op     delta
BinaryTree17-4              2.64s ± 4%      2.56s ± 9%  -2.92%  (p=0.008 n=9+9)
Fannkuch11-4                2.90s ± 1%      2.95s ± 3%  +1.76%  (p=0.010 n=10+9)
FmtFprintfEmpty-4          35.3ns ± 1%     34.5ns ± 2%  -2.34%  (p=0.004 n=9+8)
FmtFprintfString-4         57.0ns ± 1%     58.4ns ± 5%  +2.52%  (p=0.029 n=9+10)
FmtFprintfInt-4            59.8ns ± 3%     59.8ns ± 6%    ~     (p=0.565 n=10+10)
FmtFprintfIntInt-4         93.9ns ± 3%     91.2ns ± 5%  -2.94%  (p=0.014 n=10+9)
FmtFprintfPrefixedInt-4     107ns ± 6%      104ns ± 6%    ~     (p=0.099 n=10+10)
FmtFprintfFloat-4           187ns ± 3%      188ns ± 3%    ~     (p=0.505 n=10+9)
FmtManyArgs-4               410ns ± 1%      415ns ± 6%    ~     (p=0.649 n=8+10)
GobDecode-4                5.30ms ± 3%     5.27ms ± 3%    ~     (p=0.436 n=10+10)
GobEncode-4                4.62ms ± 5%     4.47ms ± 2%  -3.24%  (p=0.001 n=9+10)
Gzip-4                      197ms ± 4%      193ms ± 3%    ~     (p=0.123 n=10+10)
Gunzip-4                   30.4ms ± 3%     30.1ms ± 3%    ~     (p=0.481 n=10+10)
HTTPClientServer-4         76.3µs ± 1%     76.0µs ± 1%    ~     (p=0.236 n=8+9)
JSONEncode-4               10.5ms ± 9%     10.3ms ± 3%    ~     (p=0.280 n=10+10)
JSONDecode-4               42.3ms ±10%     41.3ms ± 2%    ~     (p=0.053 n=9+10)
Mandelbrot200-4            3.80ms ± 2%     3.72ms ± 2%  -2.15%  (p=0.001 n=9+10)
GoParse-4                  2.88ms ±10%     2.81ms ± 2%    ~     (p=0.247 n=10+10)
RegexpMatchEasy0_32-4      69.5ns ± 4%     68.6ns ± 2%    ~     (p=0.171 n=10+10)
RegexpMatchEasy0_1K-4       165ns ± 3%      162ns ± 3%    ~     (p=0.137 n=10+10)
RegexpMatchEasy1_32-4      65.7ns ± 6%     64.4ns ± 2%  -2.02%  (p=0.037 n=10+10)
RegexpMatchEasy1_1K-4       278ns ± 2%      279ns ± 3%    ~     (p=0.991 n=8+9)
RegexpMatchMedium_32-4     99.3ns ± 3%     98.5ns ± 4%    ~     (p=0.457 n=10+9)
RegexpMatchMedium_1K-4     30.1µs ± 1%     30.4µs ± 2%    ~     (p=0.173 n=8+10)
RegexpMatchHard_32-4       1.40µs ± 2%     1.41µs ± 4%    ~     (p=0.565 n=10+10)
RegexpMatchHard_1K-4       42.5µs ± 1%     41.5µs ± 3%  -2.13%  (p=0.002 n=8+9)
Revcomp-4                   332ms ± 4%      328ms ± 5%    ~     (p=0.720 n=9+10)
Template-4                 48.3ms ± 2%     49.6ms ± 3%  +2.56%  (p=0.002 n=8+10)
TimeParse-4                 252ns ± 2%      249ns ± 3%    ~     (p=0.116 n=9+10)
TimeFormat-4                262ns ± 4%      252ns ± 3%  -4.01%  (p=0.000 n=9+10)

name                     old speed      new speed       delta
GobDecode-4               145MB/s ± 3%    146MB/s ± 3%    ~     (p=0.436 n=10+10)
GobEncode-4               166MB/s ± 5%    172MB/s ± 2%  +3.28%  (p=0.001 n=9+10)
Gzip-4                   98.6MB/s ± 4%  100.4MB/s ± 3%    ~     (p=0.123 n=10+10)
Gunzip-4                  639MB/s ± 3%    645MB/s ± 3%    ~     (p=0.481 n=10+10)
JSONEncode-4              185MB/s ± 8%    189MB/s ± 3%    ~     (p=0.280 n=10+10)
JSONDecode-4             46.0MB/s ± 9%   47.0MB/s ± 2%  +2.21%  (p=0.046 n=9+10)
GoParse-4                20.1MB/s ± 9%   20.6MB/s ± 2%    ~     (p=0.239 n=10+10)
RegexpMatchEasy0_32-4     460MB/s ± 4%    467MB/s ± 2%    ~     (p=0.165 n=10+10)
RegexpMatchEasy0_1K-4    6.19GB/s ± 3%   6.28GB/s ± 3%    ~     (p=0.165 n=10+10)
RegexpMatchEasy1_32-4     487MB/s ± 5%    497MB/s ± 2%  +2.00%  (p=0.043 n=10+10)
RegexpMatchEasy1_1K-4    3.67GB/s ± 2%   3.67GB/s ± 3%    ~     (p=0.963 n=8+9)
RegexpMatchMedium_32-4   10.1MB/s ± 3%   10.1MB/s ± 4%    ~     (p=0.435 n=10+9)
RegexpMatchMedium_1K-4   34.0MB/s ± 1%   33.7MB/s ± 2%    ~     (p=0.173 n=8+10)
RegexpMatchHard_32-4     22.9MB/s ± 2%   22.7MB/s ± 4%    ~     (p=0.565 n=10+10)
RegexpMatchHard_1K-4     24.0MB/s ± 3%   24.7MB/s ± 3%  +2.64%  (p=0.001 n=9+9)
Revcomp-4                 766MB/s ± 4%    775MB/s ± 5%    ~     (p=0.720 n=9+10)
Template-4               40.2MB/s ± 2%   39.2MB/s ± 3%  -2.47%  (p=0.002 n=8+10)

The rules match ~1800 times during all.bash.

Fixes #18943

Change-Id: I64be1ada34e89c486dfd935bf429b35652117ed4
Reviewed-on: https://go-review.googlesource.com/94766
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-24 02:38:50 +00:00
Alberto Donizetti
fc6280d4b0 test/codegen: port direct comparisons with memory tests
And remove them from asm_test.

Change-Id: I1ca29b40546d6de06f20bfd550ed8ff87f495454
Reviewed-on: https://go-review.googlesource.com/102115
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-22 17:20:09 +00:00
Alberto Donizetti
be371edd67 test/codegen: port comparisons tests to codegen
And delete them from asm_test.

Change-Id: I64c512bfef3b3da6db5c5d29277675dade28b8ab
Reviewed-on: https://go-review.googlesource.com/101595
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-20 19:38:06 +00:00
Michael Munday
ae10914e67 cmd/compile: mark LAA and LAAG as clobbering flags on s390x
The atomic add instructions modify the condition code and so need to
be marked as clobbering flags.

Fixes #24449.

Change-Id: Ic69c8d775fbdbfb2a56c5e0cfca7a49c0d7f6897
Reviewed-on: https://go-review.googlesource.com/101455
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-20 09:44:50 +00:00
Vladimir Kuzmin
c12b185a6e cmd/compile: avoid mapaccess at m[k]=append(m[k]..
Currently rvalue m[k] is transformed during walk into:

        tmp1 := *mapaccess(m, k)
        tmp2 := append(tmp1, ...)
        *mapassign(m, k) = tmp2

However, this is suboptimal, as we could instead produce just:
        tmp := mapassign(m, k)
        *tmp := append(*tmp, ...)

Optimization is possible only if during Order it may tell that m[k] is
exactly the same at left and right part of assignment. It doesn't work:
1) m[f(k)] = append(m[f(k)], ...)
2) sink, m[k] = sink, append(m[k]...)
3) m[k] = append(..., m[k],...)

Benchmark:
name                           old time/op    new time/op    delta
MapAppendAssign/Int32/256-8      33.5ns ± 3%    22.4ns ±10%  -33.24%  (p=0.000 n=16+18)
MapAppendAssign/Int32/65536-8    68.2ns ± 6%    48.5ns ±29%  -28.90%  (p=0.000 n=20+20)
MapAppendAssign/Int64/256-8      34.3ns ± 4%    23.3ns ± 5%  -32.23%  (p=0.000 n=17+18)
MapAppendAssign/Int64/65536-8    65.9ns ± 7%    61.2ns ±19%   -7.06%  (p=0.002 n=18+20)
MapAppendAssign/Str/256-8         116ns ±12%      79ns ±16%  -31.70%  (p=0.000 n=20+19)
MapAppendAssign/Str/65536-8       134ns ±15%     111ns ±45%  -16.95%  (p=0.000 n=19+20)

name                           old alloc/op   new alloc/op   delta
MapAppendAssign/Int32/256-8       47.0B ± 0%     46.0B ± 0%   -2.13%  (p=0.000 n=19+18)
MapAppendAssign/Int32/65536-8     27.0B ± 0%     20.7B ±30%  -23.33%  (p=0.000 n=20+20)
MapAppendAssign/Int64/256-8       47.0B ± 0%     46.0B ± 0%   -2.13%  (p=0.000 n=20+17)
MapAppendAssign/Int64/65536-8     27.0B ± 0%     27.0B ± 0%     ~     (all equal)
MapAppendAssign/Str/256-8         94.0B ± 0%     78.0B ± 0%  -17.02%  (p=0.000 n=20+16)
MapAppendAssign/Str/65536-8       54.0B ± 0%     54.0B ± 0%     ~     (all equal)

Fixes #24364
Updates #5147

Change-Id: Id257d052b75b9a445b4885dc571bf06ce6f6b409
Reviewed-on: https://go-review.googlesource.com/100838
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-20 01:47:07 +00:00
Alberto Donizetti
5a4e09837c test/codegen: port maps test to codegen
And delete them from asm_test.

Change-Id: I3cf0934706a640136cb0f646509174f8c1bf3363
Reviewed-on: https://go-review.googlesource.com/101395
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-19 13:39:34 +00:00
Alberto Donizetti
b61b1d2c57 test/codegen: port structs test to codegen
And delete them from asm_test.

Change-Id: Ia286239a3d8f3915f2ca25dbcb39f3354a4f8aea
Reviewed-on: https://go-review.googlesource.com/101138
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-18 16:53:53 +00:00
Alberto Donizetti
cceee685be test/codegen: port floats tests to codegen
And delete them from asm_test.

Change-Id: Ibdaca3496eefc73c731b511ddb9636a1f3dff68c
Reviewed-on: https://go-review.googlesource.com/100915
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-15 18:05:59 +00:00
Giovanni Bajo
a35ec9a59e cmd/compile: implement CMOV on amd64
This builds upon the branchelim pass, activating it for amd64 and
lowering CondSelect. Special care is made to FPU instructions for
NaN handling.

Benchmark results on Xeon E5630 (Westmere EP):

name                      old time/op    new time/op    delta
BinaryTree17-16              4.99s ± 9%     4.66s ± 2%     ~     (p=0.095 n=5+5)
Fannkuch11-16                4.93s ± 3%     5.04s ± 2%     ~     (p=0.548 n=5+5)
FmtFprintfEmpty-16          58.8ns ± 7%    61.4ns ±14%     ~     (p=0.579 n=5+5)
FmtFprintfString-16          114ns ± 2%     114ns ± 4%     ~     (p=0.603 n=5+5)
FmtFprintfInt-16             181ns ± 4%     125ns ± 3%  -30.90%  (p=0.008 n=5+5)
FmtFprintfIntInt-16          263ns ± 2%     217ns ± 2%  -17.34%  (p=0.008 n=5+5)
FmtFprintfPrefixedInt-16     230ns ± 1%     212ns ± 1%   -7.99%  (p=0.008 n=5+5)
FmtFprintfFloat-16           411ns ± 3%     344ns ± 5%  -16.43%  (p=0.008 n=5+5)
FmtManyArgs-16               828ns ± 4%     790ns ± 2%   -4.59%  (p=0.032 n=5+5)
GobDecode-16                10.9ms ± 4%    10.8ms ± 5%     ~     (p=0.548 n=5+5)
GobEncode-16                9.52ms ± 5%    9.46ms ± 2%     ~     (p=1.000 n=5+5)
Gzip-16                      334ms ± 2%     337ms ± 2%     ~     (p=0.548 n=5+5)
Gunzip-16                   64.4ms ± 1%    65.0ms ± 1%   +1.00%  (p=0.008 n=5+5)
HTTPClientServer-16          156µs ± 3%     155µs ± 3%     ~     (p=0.690 n=5+5)
JSONEncode-16               21.0ms ± 1%    21.8ms ± 0%   +3.76%  (p=0.016 n=5+4)
JSONDecode-16               95.1ms ± 0%    95.7ms ± 1%     ~     (p=0.151 n=5+5)
Mandelbrot200-16            6.38ms ± 1%    6.42ms ± 1%     ~     (p=0.095 n=5+5)
GoParse-16                  5.47ms ± 2%    5.36ms ± 1%   -1.95%  (p=0.016 n=5+5)
RegexpMatchEasy0_32-16       111ns ± 1%     111ns ± 1%     ~     (p=0.635 n=5+4)
RegexpMatchEasy0_1K-16       408ns ± 1%     411ns ± 2%     ~     (p=0.087 n=5+5)
RegexpMatchEasy1_32-16       103ns ± 1%     104ns ± 1%     ~     (p=0.484 n=5+5)
RegexpMatchEasy1_1K-16       659ns ± 2%     652ns ± 1%     ~     (p=0.571 n=5+5)
RegexpMatchMedium_32-16      176ns ± 2%     174ns ± 1%     ~     (p=0.476 n=5+5)
RegexpMatchMedium_1K-16     58.6µs ± 4%    57.7µs ± 4%     ~     (p=0.548 n=5+5)
RegexpMatchHard_32-16       3.07µs ± 3%    3.04µs ± 4%     ~     (p=0.421 n=5+5)
RegexpMatchHard_1K-16       89.2µs ± 1%    87.9µs ± 2%   -1.52%  (p=0.032 n=5+5)
Revcomp-16                   575ms ± 0%     587ms ± 2%   +2.12%  (p=0.032 n=4+5)
Template-16                  110ms ± 1%     107ms ± 3%   -3.00%  (p=0.032 n=5+5)
TimeParse-16                 463ns ± 0%     462ns ± 0%     ~     (p=0.810 n=5+4)
TimeFormat-16                538ns ± 0%     535ns ± 0%   -0.63%  (p=0.024 n=5+5)

name                      old speed      new speed      delta
GobDecode-16              70.7MB/s ± 4%  71.4MB/s ± 5%     ~     (p=0.452 n=5+5)
GobEncode-16              80.7MB/s ± 5%  81.2MB/s ± 2%     ~     (p=1.000 n=5+5)
Gzip-16                   58.2MB/s ± 2%  57.7MB/s ± 2%     ~     (p=0.452 n=5+5)
Gunzip-16                  302MB/s ± 1%   299MB/s ± 1%   -0.99%  (p=0.008 n=5+5)
JSONEncode-16             92.4MB/s ± 1%  89.1MB/s ± 0%   -3.63%  (p=0.016 n=5+4)
JSONDecode-16             20.4MB/s ± 0%  20.3MB/s ± 1%     ~     (p=0.135 n=5+5)
GoParse-16                10.6MB/s ± 2%  10.8MB/s ± 1%   +2.00%  (p=0.016 n=5+5)
RegexpMatchEasy0_32-16     286MB/s ± 1%   285MB/s ± 3%     ~     (p=1.000 n=5+5)
RegexpMatchEasy0_1K-16    2.51GB/s ± 1%  2.49GB/s ± 2%     ~     (p=0.095 n=5+5)
RegexpMatchEasy1_32-16     309MB/s ± 1%   307MB/s ± 1%     ~     (p=0.548 n=5+5)
RegexpMatchEasy1_1K-16    1.55GB/s ± 2%  1.57GB/s ± 1%     ~     (p=0.690 n=5+5)
RegexpMatchMedium_32-16   5.68MB/s ± 2%  5.73MB/s ± 1%     ~     (p=0.579 n=5+5)
RegexpMatchMedium_1K-16   17.5MB/s ± 4%  17.8MB/s ± 4%     ~     (p=0.500 n=5+5)
RegexpMatchHard_32-16     10.4MB/s ± 3%  10.5MB/s ± 4%     ~     (p=0.460 n=5+5)
RegexpMatchHard_1K-16     11.5MB/s ± 1%  11.7MB/s ± 2%   +1.57%  (p=0.032 n=5+5)
Revcomp-16                 442MB/s ± 0%   433MB/s ± 2%   -2.05%  (p=0.032 n=4+5)
Template-16               17.7MB/s ± 1%  18.2MB/s ± 3%   +3.12%  (p=0.032 n=5+5)

Change-Id: I6972e8f35f2b31f9a42ac473a6bf419a18022558
Reviewed-on: https://go-review.googlesource.com/100935
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-15 16:41:59 +00:00
Geoff Berry
e244a7a7d3 cmd/compile/internal/ssa: add patterns for arm64 bitfield opcodes
Add patterns to match common idioms for EXTR, BFI, BFXIL, SBFIZ, SBFX,
UBFIZ and UBFX opcodes.

go1 benchmarks results on Amberwing:
name                   old time/op    new time/op    delta
FmtManyArgs               786ns ± 2%     714ns ± 1%  -9.20%  (p=0.000 n=10+10)
Gzip                      437ms ± 0%     402ms ± 0%  -7.99%  (p=0.000 n=10+10)
FmtFprintfIntInt          196ns ± 0%     182ns ± 0%  -7.28%  (p=0.000 n=10+9)
FmtFprintfPrefixedInt     207ns ± 0%     199ns ± 0%  -3.86%  (p=0.000 n=10+10)
FmtFprintfFloat           324ns ± 0%     316ns ± 0%  -2.47%  (p=0.000 n=10+8)
FmtFprintfInt             119ns ± 0%     117ns ± 0%  -1.68%  (p=0.000 n=10+9)
GobDecode                12.8ms ± 2%    12.6ms ± 1%  -1.62%  (p=0.002 n=10+10)
JSONDecode               94.4ms ± 1%    93.4ms ± 0%  -1.10%  (p=0.000 n=10+10)
RegexpMatchEasy0_32       247ns ± 0%     245ns ± 0%  -0.65%  (p=0.000 n=10+10)
RegexpMatchMedium_32      314ns ± 0%     312ns ± 0%  -0.64%  (p=0.000 n=10+10)
RegexpMatchEasy0_1K       541ns ± 0%     538ns ± 0%  -0.55%  (p=0.000 n=10+9)
TimeParse                 450ns ± 1%     448ns ± 1%  -0.42%  (p=0.035 n=9+9)
RegexpMatchEasy1_32       244ns ± 0%     243ns ± 0%  -0.41%  (p=0.000 n=10+10)
GoParse                  6.03ms ± 0%    6.00ms ± 0%  -0.40%  (p=0.002 n=10+10)
RegexpMatchEasy1_1K       779ns ± 0%     777ns ± 0%  -0.26%  (p=0.000 n=10+10)
RegexpMatchHard_32       2.75µs ± 0%    2.74µs ± 1%  -0.06%  (p=0.026 n=9+9)
BinaryTree17              11.7s ± 0%     11.6s ± 0%    ~     (p=0.089 n=10+10)
HTTPClientServer         89.1µs ± 1%    89.5µs ± 2%    ~     (p=0.436 n=10+10)
RegexpMatchHard_1K       78.9µs ± 0%    79.5µs ± 2%    ~     (p=0.469 n=10+10)
FmtFprintfEmpty          58.5ns ± 0%    58.5ns ± 0%    ~     (all equal)
GobEncode                12.0ms ± 1%    12.1ms ± 0%    ~     (p=0.075 n=10+10)
Revcomp                   669ms ± 0%     668ms ± 0%    ~     (p=0.091 n=7+9)
Mandelbrot200            5.35ms ± 0%    5.36ms ± 0%  +0.07%  (p=0.000 n=9+9)
RegexpMatchMedium_1K     52.1µs ± 0%    52.1µs ± 0%  +0.10%  (p=0.000 n=9+9)
Fannkuch11                3.25s ± 0%     3.26s ± 0%  +0.36%  (p=0.000 n=9+10)
FmtFprintfString          114ns ± 1%     115ns ± 0%  +0.52%  (p=0.011 n=10+10)
JSONEncode               20.2ms ± 0%    20.3ms ± 0%  +0.65%  (p=0.000 n=10+10)
Template                 91.3ms ± 0%    92.3ms ± 0%  +1.08%  (p=0.000 n=10+10)
TimeFormat                484ns ± 0%     495ns ± 1%  +2.30%  (p=0.000 n=9+10)

There are some opportunities to improve this change further by adding
patterns to match the "extended register" versions of ADD/SUB/CMP, but I
think that should be evaluated on its own.  The regressions in Template
and TimeFormat would likely be recovered by this, as they seem to be due
to generating:

    ubfiz x0, x0, #3, #8
    add x1, x2, x0

instead of

    add x1, x2, x0, lsl #3

Change-Id: I5644a8d70ac7a98e784a377a2b76ab47a3415a4b
Reviewed-on: https://go-review.googlesource.com/88355
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-15 14:10:41 +00:00
Alberto Donizetti
ded9a1b372 test/codegen: port len/cap pow2 div tests to codegen
And delete them from asm_test.

Change-Id: I29c8d098a8893e6b669b6272a2f508985ac9d618
Reviewed-on: https://go-review.googlesource.com/100876
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-15 13:34:01 +00:00
Ilya Tocar
644d14ea0f Revert "cmd/compile: implement CMOV on amd64"
This reverts commit 080187f4f7.

It broke build of golang.org/x/exp/shiny/iconvg
See issue 24395 for details

Change-Id: Ifd6134f6214e6cee40bd3c63c32941d5fc96ae8b
Reviewed-on: https://go-review.googlesource.com/100755
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-14 21:21:23 +00:00
Alberto Donizetti
cd3aae9b81 test/codegen: port all small memmove tests to codegen
This change ports all the remaining tests checking that small memmoves
are replaced with MOVs to the new codegen test harness, and deletes
them from the asm_test file.

Change-Id: I01c94b441e27a5d61518035af62d62779dafeb56
Reviewed-on: https://go-review.googlesource.com/100476
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-14 15:57:07 +00:00
Alberto Donizetti
858042b8fd test/codegen: add codegen tests for div
Change-Id: I6ce8981e85fd55ade6078b0946e54a9215d9deca
Reviewed-on: https://go-review.googlesource.com/100575
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-14 15:56:46 +00:00
Tobias Klauser
d32018a500 test: check that size argument errors are emitted at call site
Add tests for the "negative size argument in make.*" and "size argument
too large in make.*" error messages to appear at call sites in case the
size is a const defined on another line.

As suggested by Matthew in a comment on CL 69910.

Change-Id: I5c33d4bec4e3d20bb21fe8019df27999997ddff3
Reviewed-on: https://go-review.googlesource.com/100395
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-03-14 08:36:15 +00:00
Matthew Dempsky
e601c07908 cmd/compile: reject type switch with guarded declaration and no cases
Fixes #23116.

Change-Id: I5db5c5c39bbb50148ffa18c9393b045f255f80a3
Reviewed-on: https://go-review.googlesource.com/100459
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-03-13 22:02:46 +00:00
Robert Griesemer
363bcd7b4f cmd/compile: use key position for key:val elements in composite literals
Fixes #24339.

Change-Id: Ie47764fed27f76b480834b1fdbed0512c94831d9
Reviewed-on: https://go-review.googlesource.com/100457
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-03-13 21:44:12 +00:00
Matthew Dempsky
09d4455f45 cmd/compile: enable inlining variadic functions
As a side effect of working on mid-stack inlining, we've fixed support
for inlining variadic functions. Might as well enable it.

Change-Id: I7f555f8b941969791db7eb598c0b49f6dc0820aa
Reviewed-on: https://go-review.googlesource.com/100456
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-13 20:34:03 +00:00
Vladimir Kuzmin
7395083136 cmd/compile: avoid extra mapaccess in "m[k] op= r"
Currently, order desugars map assignment operations like

    m[k] op= r

into

    m[k] = m[k] op r

which in turn is transformed during walk into:

    tmp := *mapaccess(m, k)
    tmp = tmp op r
    *mapassign(m, k) = tmp

However, this is suboptimal, as we could instead produce just:

    *mapassign(m, k) op= r

One complication though is if "r == 0", then "m[k] /= r" and "m[k] %=
r" will panic, and they need to do so *before* calling mapassign,
otherwise we may insert a new zero-value element into the map.

It would be spec compliant to just emit the "r != 0" check before
calling mapassign (see #23735), but currently these checks aren't
generated until SSA construction. For now, it's simpler to continue
desugaring /= and %= into two map indexing operations.

Fixes #23661.

Change-Id: I46e3739d9adef10e92b46fdd78b88d5aabe68952
Reviewed-on: https://go-review.googlesource.com/91557
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-03-12 19:27:44 +00:00
isharipo
85a8d25d53 cmd/compile/internal/ssa: emit IMUL3{L/Q} for MUL{L/Q}const on x86
cmd/asm now supports three-operand form of IMUL,
so instead of using IMUL with resultInArg0, emit IMUL3 instruction.

This results in less redundant MOVs where SSA assigns
different registers to input[0] and dst arguments.

Note: these have exactly the same encoding when reg0=reg1:
      IMUL3x $const, reg0, reg1
      IMULx $const, reg
Two-operand IMULx is like a crippled IMUL3x, with dst fixed to input[0].
This is why we don't bother to generate IMULx for the case where
dst is the same as input[0].

Change-Id: I4becda475b3dffdd07b6fdf1c75bacc82af654e4
Reviewed-on: https://go-review.googlesource.com/99656
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-12 19:02:36 +00:00
Giovanni Bajo
080187f4f7 cmd/compile: implement CMOV on amd64
This builds upon the branchelim pass, activating it for amd64 and
lowering CondSelect. Special care is made to FPU instructions for
NaN handling.

Benchmark results on Xeon E5630 (Westmere EP):

name                      old time/op    new time/op    delta
BinaryTree17-16              4.99s ± 9%     4.66s ± 2%     ~     (p=0.095 n=5+5)
Fannkuch11-16                4.93s ± 3%     5.04s ± 2%     ~     (p=0.548 n=5+5)
FmtFprintfEmpty-16          58.8ns ± 7%    61.4ns ±14%     ~     (p=0.579 n=5+5)
FmtFprintfString-16          114ns ± 2%     114ns ± 4%     ~     (p=0.603 n=5+5)
FmtFprintfInt-16             181ns ± 4%     125ns ± 3%  -30.90%  (p=0.008 n=5+5)
FmtFprintfIntInt-16          263ns ± 2%     217ns ± 2%  -17.34%  (p=0.008 n=5+5)
FmtFprintfPrefixedInt-16     230ns ± 1%     212ns ± 1%   -7.99%  (p=0.008 n=5+5)
FmtFprintfFloat-16           411ns ± 3%     344ns ± 5%  -16.43%  (p=0.008 n=5+5)
FmtManyArgs-16               828ns ± 4%     790ns ± 2%   -4.59%  (p=0.032 n=5+5)
GobDecode-16                10.9ms ± 4%    10.8ms ± 5%     ~     (p=0.548 n=5+5)
GobEncode-16                9.52ms ± 5%    9.46ms ± 2%     ~     (p=1.000 n=5+5)
Gzip-16                      334ms ± 2%     337ms ± 2%     ~     (p=0.548 n=5+5)
Gunzip-16                   64.4ms ± 1%    65.0ms ± 1%   +1.00%  (p=0.008 n=5+5)
HTTPClientServer-16          156µs ± 3%     155µs ± 3%     ~     (p=0.690 n=5+5)
JSONEncode-16               21.0ms ± 1%    21.8ms ± 0%   +3.76%  (p=0.016 n=5+4)
JSONDecode-16               95.1ms ± 0%    95.7ms ± 1%     ~     (p=0.151 n=5+5)
Mandelbrot200-16            6.38ms ± 1%    6.42ms ± 1%     ~     (p=0.095 n=5+5)
GoParse-16                  5.47ms ± 2%    5.36ms ± 1%   -1.95%  (p=0.016 n=5+5)
RegexpMatchEasy0_32-16       111ns ± 1%     111ns ± 1%     ~     (p=0.635 n=5+4)
RegexpMatchEasy0_1K-16       408ns ± 1%     411ns ± 2%     ~     (p=0.087 n=5+5)
RegexpMatchEasy1_32-16       103ns ± 1%     104ns ± 1%     ~     (p=0.484 n=5+5)
RegexpMatchEasy1_1K-16       659ns ± 2%     652ns ± 1%     ~     (p=0.571 n=5+5)
RegexpMatchMedium_32-16      176ns ± 2%     174ns ± 1%     ~     (p=0.476 n=5+5)
RegexpMatchMedium_1K-16     58.6µs ± 4%    57.7µs ± 4%     ~     (p=0.548 n=5+5)
RegexpMatchHard_32-16       3.07µs ± 3%    3.04µs ± 4%     ~     (p=0.421 n=5+5)
RegexpMatchHard_1K-16       89.2µs ± 1%    87.9µs ± 2%   -1.52%  (p=0.032 n=5+5)
Revcomp-16                   575ms ± 0%     587ms ± 2%   +2.12%  (p=0.032 n=4+5)
Template-16                  110ms ± 1%     107ms ± 3%   -3.00%  (p=0.032 n=5+5)
TimeParse-16                 463ns ± 0%     462ns ± 0%     ~     (p=0.810 n=5+4)
TimeFormat-16                538ns ± 0%     535ns ± 0%   -0.63%  (p=0.024 n=5+5)

name                      old speed      new speed      delta
GobDecode-16              70.7MB/s ± 4%  71.4MB/s ± 5%     ~     (p=0.452 n=5+5)
GobEncode-16              80.7MB/s ± 5%  81.2MB/s ± 2%     ~     (p=1.000 n=5+5)
Gzip-16                   58.2MB/s ± 2%  57.7MB/s ± 2%     ~     (p=0.452 n=5+5)
Gunzip-16                  302MB/s ± 1%   299MB/s ± 1%   -0.99%  (p=0.008 n=5+5)
JSONEncode-16             92.4MB/s ± 1%  89.1MB/s ± 0%   -3.63%  (p=0.016 n=5+4)
JSONDecode-16             20.4MB/s ± 0%  20.3MB/s ± 1%     ~     (p=0.135 n=5+5)
GoParse-16                10.6MB/s ± 2%  10.8MB/s ± 1%   +2.00%  (p=0.016 n=5+5)
RegexpMatchEasy0_32-16     286MB/s ± 1%   285MB/s ± 3%     ~     (p=1.000 n=5+5)
RegexpMatchEasy0_1K-16    2.51GB/s ± 1%  2.49GB/s ± 2%     ~     (p=0.095 n=5+5)
RegexpMatchEasy1_32-16     309MB/s ± 1%   307MB/s ± 1%     ~     (p=0.548 n=5+5)
RegexpMatchEasy1_1K-16    1.55GB/s ± 2%  1.57GB/s ± 1%     ~     (p=0.690 n=5+5)
RegexpMatchMedium_32-16   5.68MB/s ± 2%  5.73MB/s ± 1%     ~     (p=0.579 n=5+5)
RegexpMatchMedium_1K-16   17.5MB/s ± 4%  17.8MB/s ± 4%     ~     (p=0.500 n=5+5)
RegexpMatchHard_32-16     10.4MB/s ± 3%  10.5MB/s ± 4%     ~     (p=0.460 n=5+5)
RegexpMatchHard_1K-16     11.5MB/s ± 1%  11.7MB/s ± 2%   +1.57%  (p=0.032 n=5+5)
Revcomp-16                 442MB/s ± 0%   433MB/s ± 2%   -2.05%  (p=0.032 n=4+5)
Template-16               17.7MB/s ± 1%  18.2MB/s ± 3%   +3.12%  (p=0.032 n=5+5)

Change-Id: Ic7cb7374d07da031e771bdcbfdd832fd1b17159c
Reviewed-on: https://go-review.googlesource.com/98695
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-03-12 18:01:33 +00:00
Giovanni Bajo
f7ac70a566 test: move rotate tests to top-level testsuite.
Remove old tests from asm_test.

Change-Id: Ib408ec7faa60068bddecf709b93ce308e0ef665a
Reviewed-on: https://go-review.googlesource.com/100075
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
2018-03-11 10:08:18 +00:00
Alberto Donizetti
8e427a3878 test/codegen: add README file for the codegen test harness
This change adds a README file inside the test/codegen directory,
explaining how to run the codegen tests and the syntax of the regexps
comments used to match assembly instructions.

Change-Id: Ica4eb3ffa9c6975371538cc8ae0ac3c1a3a03baf
Reviewed-on: https://go-review.googlesource.com/99156
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-09 18:38:53 +00:00
Alberto Donizetti
5f541b11aa test/codegen: port MULs merging tests to codegen
And delete them from asm_go.

Change-Id: I0057cbd90ca55fa51c596e32406e190f3866f93e
Reviewed-on: https://go-review.googlesource.com/99815
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-09 17:01:56 +00:00
Alberto Donizetti
cde34780b7 test/codegen: port math/bits.RotateLeft tests to codegen
Only RotateLeft{64,32} were tested, and just for ppc64. This CL adds
tests for RotateLeft{64,32,16,8} on arm64 and amd64/386, for the cases
where the calls are actually instrinsified.

RotateLeft tests (the last ones for math/bits functions) are deleted
from asm_test.

This CL also adds a space between the "//" and the arch name in the
comments, to uniform this file to the style used in all the other
files.

Change-Id: Ifc2a27261d70bcc294b4ec64490d8367f62d2b89
Reviewed-on: https://go-review.googlesource.com/99596
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-09 10:53:38 +00:00
Austin Clements
6436270dad cmd/compile: add fence-post implications to prove
This adds four new deductions to the prove pass, all related to adding
or subtracting one from a value. This is the first hint of actual
arithmetic relations in the prove pass.

The most effective of these is

   x-1 >= w && x > min  ⇒  x > w

This helps eliminate bounds checks in code like

  if x > 0 {
    // do something with s[x-1]
  }

Altogether, these deductions prove an additional 260 branches in std
and cmd. Furthermore, they will let us eliminate some tricky
compiler-inserted panics in the runtime that are interfering with
static analysis.

Fixes #23354.

Change-Id: I7088223e0e0cd6ff062a75c127eb4bb60e6dce02
Reviewed-on: https://go-review.googlesource.com/87480
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
2018-03-08 22:25:28 +00:00
Austin Clements
941fc129e2 cmd/compile: derive unsigned limits from signed limits in prove
This adds a few simple deductions to the prove pass' fact table to
derive unsigned concrete limits from signed concrete limits where
possible.

This tweak lets the pass prove 70 additional branch conditions in std
and cmd.

This is based on a comment from the recently-deleted factsTable.get:
"// TODO: also use signed data if lim.min >= 0".

Change-Id: Ib4340249e7733070f004a0aa31254adf5df8a392
Reviewed-on: https://go-review.googlesource.com/87479
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-08 22:25:27 +00:00
Austin Clements
669db2cef5 cmd/compile: make prove pass use unsatisfiability
Currently the prove pass uses implication queries. For each block, it
collects the set of branch conditions leading to that block, and
queries this fact table for whether any of these facts imply the
block's own branch condition (or its inverse). This works remarkably
well considering it doesn't do any deduction on these facts, but it
has various downsides:

1. It requires an implementation both of adding facts to the table and
   determining implications. These are very nearly duals of each
   other, but require separate implementations. Likewise, the process
   of asserting facts of dominating branch conditions is very nearly
   the dual of the process of querying implied branch conditions.

2. It leads to less effective use of derived facts. For example, the
   prove pass currently derives facts about the relations between len
   and cap, but can't make use of these unless a branch condition is
   in the exact form of a derived fact. If one of these derived facts
   contradicts another fact, it won't notice or make use of this.

This CL changes the approach of the prove pass to instead use
*contradiction* instead of implication. Rather than ever querying a
branch condition, it simply adds branch conditions to the fact table.
If this leads to a contradiction (specifically, it makes the fact set
unsatisfiable), that branch is impossible and can be cut. As a result,

1. We can eliminate the code for determining implications
   (factsTable.get disappears entirely). Also, there is now a single
   implementation of visiting and asserting branch conditions, since
   we don't have to flip them around to treat them as facts in one
   place and queries in another.

2. Derived facts can be used effectively. It doesn't matter *why* the
   fact table is unsatisfiable; a contradiction in any of the facts is
   enough.

3. As an added benefit, it's now quite easy to avoid traversing beyond
   provably-unreachable blocks. In contrast, the current
   implementation always visits all blocks.

The prove pass already has nearly all of the mechanism necessary to
compute unsatisfiability, which means this both simplifies the code
and makes it more powerful.

The only complication is that the current implication procedure has a
hack for dealing with the 0 <= Args[0] condition of OpIsInBounds and
OpIsSliceInBounds. We replace this with asserting the appropriate fact
when we process one of these conditions. This seems much cleaner
anyway, and works because we can now take advantage of derived facts.

This has no measurable effect on compiler performance.

Effectiveness:

There is exactly one condition in all of std and cmd that this fails
to prove that the old implementation could: (int64(^uint(0)>>1) < x)
in encoding/gob. This can never be true because x is an int, and it's
basically coincidence that the old code gets this. (For example, it
fails to prove the similar (x < ^int64(^uint(0)>>1)) condition that
immediately precedes it, and even though the conditions are logically
unrelated, it wouldn't get the second one if it hadn't first processed
the first!)

It does, however, prove a few dozen additional branches. These come
from facts that are added to the fact table about the relations
between len and cap. These were almost never queried directly before,
but could lead to contradictions, which the unsat-based approach is
able to use.

There are exactly two branches in std and cmd that this implementation
proves in the *other* direction. This sounds scary, but is okay
because both occur in already-unreachable blocks, so it doesn't matter
what we chose. Because the fact table logic is sound but incomplete,
it fails to prove that the block isn't reachable, even though it is
able to prove that both outgoing branches are impossible. We could
turn these blocks into BlockExit blocks, but it doesn't seem worth the
trouble of the extra proof effort for something that happens twice in
all of std and cmd.

Tests:

This CL updates test/prove.go to change the expected messages because
it can no longer give a "reason" why it proved or disproved a
condition. It also adds a new test of a branch it couldn't prove
before.

It mostly guts test/sliceopt.go, removing everything related to slice
bounds optimizations and moving a few relevant tests to test/prove.go.
Much of this test is actually unreachable. The new prove pass figures
this out and doesn't try to prove anything about the unreachable
parts. The output on the unreachable parts is already suspect because
anything can be proved at that point, so it's really just a regression
test for an algorithm the compiler no longer uses.

This is a step toward fixing #23354. That issue is quite easy to fix
once we can use derived facts effectively.

Change-Id: Ia48a1b9ee081310579fe474e4a61857424ff8ce8
Reviewed-on: https://go-review.googlesource.com/87478
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-08 22:25:25 +00:00
Alberto Donizetti
3772b2e1d5 test/codegen: port 2^n muls tests to codegen harness
And delete them from the asm_test.go file.

Change-Id: I124c8c352299646ec7db0968cdb0fe59a3b5d83d
Reviewed-on: https://go-review.googlesource.com/99475
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-08 16:30:14 +00:00
Matthew Dempsky
88466e93a4 cmd/compile: mark anonymous receiver parameters as non-escaping
This was already done for normal parameters, and the same logic
applies for receiver parameters too.

Updates #24305.

Change-Id: Ia2a46f68d14e8fb62004ff0da1db0f065a95a1b7
Reviewed-on: https://go-review.googlesource.com/99335
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-08 00:20:01 +00:00
Alberto Donizetti
c028958393 test/codegen: fix issue with arm64 memmove codegen test
This recently added arm64 memmove codegen check:

  func movesmall() {
    // arm64:-"memmove"
    x := [...]byte{1, 2, 3, 4, 5, 6, 7}
    copy(x[1:], x[:])
  }

is not correct, for two reasons:

1. regexps are matched from the start of the disasm line (excluding
   line information). This mean that a negative -"memmove" check will
   pass against a 'CALL runtime.memmove' line because the line does
   not start with 'memmove' (its starts with CALL...).
   The way to specify no 'memmove' match whatsoever on the line is
   -".*memmove"

2. AFAIK comments on their own line are matched against the first
   subsequent non-comment line. So the code above only verifies that
   the x := ... line does not generate a memmove. The comment should
   be moved near the copy() line, if it's that one we want to not
   generate a memmove call.

The fact that the test above is not effective can be checked by
running `go run run.go -v codegen` in the toplevel test directory with
a go1.10 toolchain (that does not have the memmove-elision
optimization). The test will still pass (it shouldn't).

This change changes the regexp to -".*memmove" and moves it near the
line it needs to (not)match.

Change-Id: Ie01ef4d775e77d92dc8d8b7856b89b200f5e5ef2
Reviewed-on: https://go-review.googlesource.com/98977
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-07 16:41:24 +00:00
Kunpei Sakai
b75e8a2a3b cmd/compile: prevent detection of wrong duplicates
by including *types.Type in typeVal.

Updates #21866
Fixes #24159

Change-Id: I2f8cac252d88d43e723124f2867b1410b7abab7b
Reviewed-on: https://go-review.googlesource.com/98476
Run-TryBot: Kunpei Sakai <namusyaka@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-03-07 01:26:00 +00:00
ChrisALiles
42ecf39e85 cmd/compile: improve compiler error on embedded structs
Fixes #23609

Change-Id: I751aae3d849de7fce1306324fcb1a4c3842d873e
Reviewed-on: https://go-review.googlesource.com/97076
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-06 21:06:46 +00:00
Alberto Donizetti
8516ecd05f test/codegen: port math/bits.ReverseBytes tests to codegen
And remove them from ssa_test.

Change-Id: If767af662801219774d1bdb787c77edfa6067770
Reviewed-on: https://go-review.googlesource.com/98976
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-06 20:34:33 +00:00
Wei Xiao
05962561ae cmd/compile/internal/ssa: improve store combine optimization on arm64
Current implementation doesn't consider MOVDreg type operand and fail to combine
it into larger store. This patch fixes the issue.

Fixes #24242

Change-Id: I7d68697f80e76f48c3528ece01a602bf513248ec
Reviewed-on: https://go-review.googlesource.com/98397
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-06 20:29:04 +00:00
Balaram Makam
0e8b7110f6 cmd/compile/internal/ssa: inline small memmove for arm64
This patch enables the optimization for arm64 target.

Performance results on Amberwing for strconv benchmark:
name             old time/op  new time/op  delta
Quote             721ns ± 0%   617ns ± 0%  -14.40%  (p=0.016 n=5+4)
QuoteRune         118ns ± 0%   117ns ± 0%   -0.85%  (p=0.008 n=5+5)
AppendQuote       436ns ± 2%   321ns ± 0%  -26.31%  (p=0.008 n=5+5)
AppendQuoteRune  34.7ns ± 0%  28.4ns ± 0%  -18.16%  (p=0.000 n=5+4)
[Geo mean]        189ns        160ns       -15.41%

Change-Id: I5714c474e7483d07ca338fbaf49beb4bbcc11c44
Reviewed-on: https://go-review.googlesource.com/98735
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-06 18:37:19 +00:00
Alberto Donizetti
18ae5eca3b test/codegen: port math/bits.OnesCount tests to codegen
And remove them from ssa_test.

Change-Id: I3efac5fea529bb0efa2dae32124530482ba5058e
Reviewed-on: https://go-review.googlesource.com/98815
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-06 17:53:00 +00:00
Alberto Donizetti
85dcc709a8 test/codegen: port math/bits.TrailingZeros tests to codegen
And remove them from ssa_test.

Change-Id: Ib5de5c0d908f23915e0847eca338cacf2fa5325b
Reviewed-on: https://go-review.googlesource.com/98795
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-06 11:48:37 +00:00
Alberto Donizetti
83e41b3e76 test/codegen: port math/bits.Leadingzero tests to codegen
Change-Id: Ic21d25db5d56ce77516c53082dfbc010e5875b81
Reviewed-on: https://go-review.googlesource.com/98655
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-05 19:52:04 +00:00
Alberto Donizetti
c1806906d8 test: port bits.Len intrinsics tests to the new codegen harness
This change move bits.Len* intrinsification tests to the new codegen
test harness, removing them from the old ssa_test file. Five different
test functions (one for each bit.Len function tested) was used, to
avoid possible unwanted interactions between multiple calls inside one
function.

Change-Id: Iffd5be55b58e88597fa30a562a28dacb01236d8b
Reviewed-on: https://go-review.googlesource.com/98156
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-03-05 18:01:19 +00:00
Giovanni Bajo
89ae7045f3 test: convert all math-related tests from asm_test
Change-Id: If542f0b5c5754e6eb2f9b302fe5a148ba9a57338
Reviewed-on: https://go-review.googlesource.com/98443
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-04 16:52:33 +00:00
Giovanni Bajo
fad31e513d test: move load/store combines into asmcheck
This CL moves the load/store combining tests into asmcheck.
In addition at being more compact, it's also now easier to
spot what it is missing in each architecture.

While doing so, I think I uncovered a bug in ppc64le and arm64
rules, because they fail to load/store combine in non-trivial
functions. Not sure why, I'll open an issue.

Change-Id: Ia1572d53c0553d9104f3e52b95e4d1768a8440a3
Reviewed-on: https://go-review.googlesource.com/98441
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-04 16:52:03 +00:00
Giovanni Bajo
80bfb75c42 test: in asmcheck, dump only the functions which fail
Before this change, in case of any failure, asmcheck was
dumping to stderr the whole output of compile -S, which
can be very long if it contains multiple functions.

Make it so it filters the output to only display the
assembly output of functions for which at least one opcode
check failed. This greatly simplifies debugging.

Change-Id: I1bbf54473b8252a3384e2c1dade82d926afc119d
Reviewed-on: https://go-review.googlesource.com/98444
Run-TryBot: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-04 01:05:02 +00:00
Giovanni Bajo
8ce74b7d11 test: port a nil-check interface test from asm_test
Change-Id: I69c1688506d1aeca655047acf35d1bff966fc01e
Reviewed-on: https://go-review.googlesource.com/98442
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-03 20:20:54 +00:00
Giovanni Bajo
ec0b8c0585 test: use the version of Go used to run run.go
Currently, the top-level testsuite always uses whatever version
of Go is found in the PATH to execute all the tests. This
forces the developers to tweak the PATH to run the testsuite.

Change it to use the same version of Go used to run run.go.
This allows developers to run the testsuite using the tip
compiler by simply saying "../bin/go run run.go".

I think this is a better solution compared to always forcing
"../bin/go", because it allows developers to run the testsuite
using different Go versions, for instance to check if a new
test is fixed in tip compared to the installed compiler.

Fixes #24217

Change-Id: I41b299c753b6e77c41e28be9091b2b630efea9d2
Reviewed-on: https://go-review.googlesource.com/98439
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-03 19:52:00 +00:00
Alberto Donizetti
644b2dafc2 test/codegen: add copyright headers to new codegen files
Change-Id: I9fe6572d1043ef9ee09c0925059ded554ad24c6b
Reviewed-on: https://go-review.googlesource.com/98215
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-02 20:13:13 +00:00
Cherry Zhang
2baed3856d cmd/asm: fix assembling return jump
In RET instruction, the operand is the return jump's target,
which should be put in Prog.To.

Add an action "buildrundir" to the test driver, which builds
(compile+assemble+link) the code in a directory and runs the
resulting binary.

Fixes #23838.

Change-Id: I7ebe7eda49024b40a69a24857322c5ca9c67babb
Reviewed-on: https://go-review.googlesource.com/94175
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-03-01 21:11:16 +00:00
Giovanni Bajo
f16cc298d3 test: implement negative rules in asmcheck
Change-Id: I2b507e35cc314100eaf2ec2d1e5107cc2fc9e7cf
Reviewed-on: https://go-review.googlesource.com/97818
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-01 18:15:24 +00:00
Giovanni Bajo
0bcf8bcd99 test: in asmcheck, regexp must match from beginning of line
This avoid simple bugs like "ADD" matching "FADD". Obviously
"ADD" will still match "ADDQ" so some care is still required
in this regard, but at least a first class of possible errors
is taken care of.

Change-Id: I7deb04c31de30bedac9c026d9889ace4a1d2adcb
Reviewed-on: https://go-review.googlesource.com/97817
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-01 18:14:54 +00:00
Giovanni Bajo
879a1ff1e4 test: improve asmcheck syntax
asmcheck comments now support a compact form of specifying
multiple checks for each platform, using the following syntax:

   amd64:"SHL\t[$]4","SHR\t[$]4"

Negative checks are also parsed using the following syntax:

   amd64:-"ROR"

though they are still not working.

Moreover, out-of-line comments have been implemented. This
allows to specify asmchecks on comment-only lines, that will
be matched on the first subsequent non-comment non-empty line.

    // amd64:"XOR"
    // arm:"EOR"

    x ^= 1

Change-Id: I110c7462fc6a5c70fd4af0d42f516016ae7f2760
Reviewed-on: https://go-review.googlesource.com/97816
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-01 18:10:48 +00:00
Josh Bleecher Snyder
aa9c1a8f80 runtime: fix amd64p32 indexbytes in presence of overflow
When the slice/string length is very large,
probably artifically large as in CL 97523,
adding BX (length) to R11 (pointer) overflows.
As a result, checking DI < R11 yields the wrong result.
Since they will be equal when the loop is done,
just check DI != R11 instead.
Yes, the pointer itself could overflow, but if that happens,
something else has gone pretty wrong; not our concern here.

Fixes #24187

Change-Id: I2f60fc6ccae739345d01bc80528560726ad4f8c6
Reviewed-on: https://go-review.googlesource.com/97802
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-01 16:53:33 +00:00
Giovanni Bajo
c9438cb198 test: add support for code generation tests (asmcheck)
The top-level test harness is modified to support a new kind
of test: "asmcheck". This is meant to replace asm_test.go
as an easier and more readable way to test code generation.

I've added a couple of codegen tests to get initial feedback
on the syntax. I've created them under a common "codegen"
subdirectory, so that it's easier to run them all with
"go run run.go -v codegen".

The asmcheck syntax allows to insert line comments that
can specify a regular expression to match in the assembly code,
for multiple architectures (the testsuite will automatically
build each testfile multiple times, one per mentioned architecture).

Negative matches are unsupported for now, so this cannot fully
replace asm_test yet.

Change-Id: Ifdbba389f01d55e63e73c99e5f5449e642101d55
Reviewed-on: https://go-review.googlesource.com/97355
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
2018-03-01 07:59:54 +00:00
Matthew Dempsky
b3f00c6985 cmd/compile: fix unexpected type alias crash
OCOMPLIT stores the pre-typechecked type in n.Right, and then moves it
to n.Type. However, it wasn't clearing n.Right, so n.Right continued
to point to the OTYPE node. (Exception: slice literals reused n.Right
to store the array length.)

When exporting inline function bodies, we don't expect to need to save
any type aliases. Doing so wouldn't be wrong per se, but it's
completely unnecessary and would just bloat the export data.

However, reexportdep (whose role is to identify types needed by inline
function bodies) uses a generic tree traversal mechanism, which visits
n.Right even for O{ARRAY,MAP,STRUCT}LIT nodes. This means it finds the
OTYPE node, and mistakenly interpreted that the type alias needs to be
exported.

The straight forward fix is to just clear n.Right when typechecking
composite literals.

Fixes #24173.

Change-Id: Ia2d556bfdd806c83695b08e18b6cd71eff0772fc
Reviewed-on: https://go-review.googlesource.com/97719
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-02-28 20:18:37 +00:00
Daniel Martí
1e308fbc1a cmd/compile: improved error message when calling a shadowed builtin
Otherwise, the error can be confusing if one forgets or doesn't know
that the builtin is being shadowed, which is not common practice.

Fixes #22822.

Change-Id: I735393b5ce28cb83815a1c3f7cd2e7bb5080a32d
Reviewed-on: https://go-review.googlesource.com/97455
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-02-28 19:39:52 +00:00
Robert Griesemer
0c884d0810 cmd/compile, cmd/compile/internal/syntax: print relative column info
This change enables printing of relative column information if a
prior line directive specified a valid column. If there was no
line directive, or the line directive didn't specify a column
(or the -C flag is specified), no column information is shown in
file positions.

Implementation: Column values (and line values, for that matter)
that are zero are interpreted as "unknown". A line directive that
doesn't specify a column records that as a zero column in the
respective PosBase data structure. When computing relative columns,
a relative value is zero of the base's column value is zero.
When formatting a position, a zero column value is not printed.

To make this work without special cases, the PosBase for a file
is given a concrete (non-0:0) position 1:1 with the PosBase's
line and column also being 1:1. In other words, at the position
1:1 of a file, it's relative positions are starting with 1:1 as
one would expect.

In the package syntax, this requires self-recursive PosBases for
file bases, matching what cmd/internal/src.PosBase was already
doing. In src.PosBase, file and inlining bases also need to be
based at 1:1 to indicate "known" positions.

This change completes the cmd/compiler part of the issue below.

Fixes #22662.

Change-Id: I6c3d2dee26709581fba0d0261b1d12e93f1cba1a
Reviewed-on: https://go-review.googlesource.com/97375
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-28 03:51:23 +00:00
Keith Randall
2413b54888 cmd/compile: mark the first word of an interface as a uintptr
The first word of an interface is a pointer, but for the purposes
of GC we don't need to treat it as such.
 1. If it is a non-empty interface, the pointer points to an itab
    which is always in persistentalloc space.
 2. If it is an empty interface, the pointer points to a _type.
   a. If it is a compile-time-allocated type, it points into
      the read-only data section.
   b. If it is a reflect-allocated type, it points into the Go heap.
      Reflect is responsible for keeping a reference to
      the underlying type so it won't be GCd.

If we ever have a moving GC, we need to change this for 2b (as
well as scan itabs to update their itab._type fields).

Write barriers on the first word of interfaces have already been removed.

Change-Id: I643e91d7ac4de980ac2717436eff94097c65d959
Reviewed-on: https://go-review.googlesource.com/97518
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-02-27 22:58:32 +00:00
Matthew Dempsky
d7cd61ceaa cmd/compile: fix inlining of constant if statements
We accidentally overlooked needing to still visit Ninit for OIF
statements with constant conditions in golang.org/cl/96778.

Fixes #24120.

Change-Id: I5b341913065ff90e1163fb872b9e8d47e2a789d2
Reviewed-on: https://go-review.googlesource.com/97475
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-27 19:27:32 +00:00
Robert Griesemer
515fa58ac9 cmd/compile: track line directives w/ column information
Extend cmd/internal/src.PosBase to track column information,
and adjust the meaning of the PosBase position to mean the
position at which the PosBase's relative (line, col) position
starts (rather than indicating the position of the //line
directive). Because this semantic change is made in the
compiler's noder, it doesn't affect the logic of src.PosBase,
only its test setup (where PosBases are constructed with
corrected incomming positions). In short, src.PosBase now
matches syntax.PosBase with respect to the semantics of
src.PosBase.pos.

For #22662.

Change-Id: I5b1451cb88fff3f149920c2eec08b6167955ce27
Reviewed-on: https://go-review.googlesource.com/96535
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-26 18:32:03 +00:00
Ian Lance Taylor
9fba50545d test: add test case where gccgo incorrectly rejected aliases
Updates #23912

Change-Id: I50d06506a8ac91ed99a761a9ff3fd0b03d4c8121
Reviewed-on: https://go-review.googlesource.com/94995
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-20 01:57:14 +00:00
Keith Randall
4313d7767d cmd/compile: reset branch prediction when deleting a branch
When we go from a branch block to a plain block, reset the
branch prediction bit. Downstream passes asssume that if the
branch prediction is set, then the block has 2 successors.

Fixes #23504

Change-Id: I2898ec002228b2e34fe80ce420c6939201c0a5aa
Reviewed-on: https://go-review.googlesource.com/88955
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2018-02-20 00:56:13 +00:00
Austin Clements
2b415549b8 runtime: use sparse mappings for the heap
This replaces the contiguous heap arena mapping with a potentially
sparse mapping that can support heap mappings anywhere in the address
space.

This has several advantages over the current approach:

* There is no longer any limit on the size of the Go heap. (Currently
  it's limited to 512GB.) Hence, this fixes #10460.

* It eliminates many failures modes of heap initialization and
  growing. In particular it eliminates any possibility of panicking
  with an address space conflict. This can happen for many reasons and
  even causes a low but steady rate of TSAN test failures because of
  conflicts with the TSAN runtime. See #16936 and #11993.

* It eliminates the notion of "non-reserved" heap, which was added
  because creating huge address space reservations (particularly on
  64-bit) led to huge process VSIZE. This was at best confusing and at
  worst conflicted badly with ulimit -v. However, the non-reserved
  heap logic is complicated, can race with other mappings in non-pure
  Go binaries (e.g., #18976), and requires that the entire heap be
  either reserved or non-reserved. We currently maintain the latter
  property, but it's quite difficult to convince yourself of that, and
  hence difficult to keep correct. This logic is still present, but
  will be removed in the next CL.

* It fixes problems on 32-bit where skipping over parts of the address
  space leads to mapping huge (and never-to-be-used) metadata
  structures. See #19831.

This also completely rewrites and significantly simplifies
mheap.sysAlloc, which has been a source of many bugs. E.g., #21044,
 #20259, #18651, and #13143 (and maybe #23222).

This change also makes it possible to allocate individual objects
larger than 512GB. As a result, a few tests that expected huge
allocations to fail needed to be changed to make even larger
allocations. However, at the moment attempting to allocate a humongous
object may cause the program to freeze for several minutes on Linux as
we fall back to probing every page with addrspace_free. That logic
(and this failure mode) will be removed in the next CL.

Fixes #10460.
Fixes #22204 (since it rewrites the code involved).

This slightly slows down compilebench and the x/benchmarks garbage
benchmark.

name       old time/op     new time/op     delta
Template       184ms ± 1%      185ms ± 1%    ~     (p=0.065 n=10+9)
Unicode       86.9ms ± 3%     86.3ms ± 1%    ~     (p=0.631 n=10+10)
GoTypes        599ms ± 0%      602ms ± 0%  +0.56%  (p=0.000 n=10+9)
Compiler       2.87s ± 1%      2.89s ± 1%  +0.51%  (p=0.002 n=9+10)
SSA            7.29s ± 1%      7.25s ± 1%    ~     (p=0.182 n=10+9)
Flate          118ms ± 2%      118ms ± 1%    ~     (p=0.113 n=9+9)
GoParser       147ms ± 1%      148ms ± 1%  +1.07%  (p=0.003 n=9+10)
Reflect        401ms ± 1%      404ms ± 1%  +0.71%  (p=0.003 n=10+9)
Tar            175ms ± 1%      175ms ± 1%    ~     (p=0.604 n=9+10)
XML            209ms ± 1%      210ms ± 1%    ~     (p=0.052 n=10+10)

(https://perf.golang.org/search?q=upload:20171231.4)

name                       old time/op  new time/op  delta
Garbage/benchmem-MB=64-12  2.23ms ± 1%  2.25ms ± 1%  +0.84%  (p=0.000 n=19+19)

(https://perf.golang.org/search?q=upload:20171231.3)

Relative to the start of the sparse heap changes (starting at and
including "runtime: fix various contiguous bitmap assumptions"),
overall slowdown is roughly 1% on GC-intensive benchmarks:

name        old time/op     new time/op     delta
Template        183ms ± 1%      185ms ± 1%  +1.32%  (p=0.000 n=9+9)
Unicode        84.9ms ± 2%     86.3ms ± 1%  +1.65%  (p=0.000 n=9+10)
GoTypes         595ms ± 1%      602ms ± 0%  +1.19%  (p=0.000 n=9+9)
Compiler        2.86s ± 0%      2.89s ± 1%  +0.91%  (p=0.000 n=9+10)
SSA             7.19s ± 0%      7.25s ± 1%  +0.75%  (p=0.000 n=8+9)
Flate           117ms ± 1%      118ms ± 1%  +1.10%  (p=0.000 n=10+9)
GoParser        146ms ± 2%      148ms ± 1%  +1.48%  (p=0.002 n=10+10)
Reflect         398ms ± 1%      404ms ± 1%  +1.51%  (p=0.000 n=10+9)
Tar             173ms ± 1%      175ms ± 1%  +1.17%  (p=0.000 n=10+10)
XML             208ms ± 1%      210ms ± 1%  +0.62%  (p=0.011 n=10+10)
[Geo mean]      369ms           373ms       +1.17%

(https://perf.golang.org/search?q=upload:20180101.2)

name                       old time/op  new time/op  delta
Garbage/benchmem-MB=64-12  2.22ms ± 1%  2.25ms ± 1%  +1.51%  (p=0.000 n=20+19)

(https://perf.golang.org/search?q=upload:20180101.3)

Change-Id: I5daf4cfec24b252e5a57001f0a6c03f22479d0f0
Reviewed-on: https://go-review.googlesource.com/85887
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2018-02-15 21:12:23 +00:00
Robert Griesemer
33eb0633e1 cmd/compile/internal/syntax: don't assume (operator) ~ means operator ^
The scanner assumed that ~ really meant ^, which may be helpful when
coming from C. But ~ is not a valid Go token, and pretending that it
should be ^ can lead to confusing error messages. Better to be upfront
about it and complain about the invalid character in the first place.

This was code "inherited" from the original yacc parser which was
derived from a C compiler. It's 10 years later and we can probably
assume that people are less confused about C and Go.

Fixes #23587.

Change-Id: I8d8f9b55b0dff009b75c1530d729bf9092c5aea6
Reviewed-on: https://go-review.googlesource.com/94160
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-15 16:41:24 +00:00
Ian Lance Taylor
0849dfd4a3 test: add new test that gccgo failed to compile
Updates #22305

Change-Id: I0e6bbd880599fc1b70d0378b746d162d4a846c65
Reviewed-on: https://go-review.googlesource.com/91556
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-15 03:37:20 +00:00
Robert Griesemer
1a22738749 cmd/compile/internal/syntax: more tolerant handling of missing function invocation in go/defer
Assume that an expression that is not a function call in a defer/go
statement is indeed a function that is just missing its invocation.
Report the error but continue with a sane syntax tree.

Fixes #23586.

Change-Id: Ib45ebac57c83b3e39ae4a1b137ffa291dec5b50d
Reviewed-on: https://go-review.googlesource.com/94156
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-15 01:48:16 +00:00
Matthew Dempsky
d3f6d11d84 cmd/compile: fix typechecking of untyped boolean expressions
Previously, if we typechecked a statement like

    var x bool = p1.f == p2.f && p1.g == p2.g

we would correctly update the '&&' node's type from 'untyped bool' to
'bool', but the '==' nodes would stay 'untyped bool'. This is
inconsistent, and caused consistency checks during walk to fail.

This CL doesn't pass toolstash because it seems to slightly affect the
register allocator's heuristics. (Presumably 'untyped bool's were
previously making it all the way through SSA?)

Fixes #23414.

Change-Id: Ia85f8cfc69b5ba35dfeb157f4edf57612ecc3285
Reviewed-on: https://go-review.googlesource.com/94022
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2018-02-15 01:00:06 +00:00
Kunpei Sakai
bcb563f4db cmd/compile: allow converting defined string types to []rune
Fixes #23298

Change-Id: I107c6f3a80db83f063c0daf262c6e7f7492e4d4c
Reviewed-on: https://go-review.googlesource.com/87695
Run-TryBot: Kunpei Sakai <namusyaka@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-15 00:25:21 +00:00
Cherry Zhang
beeab6ac02 cmd/compile: fix go:uintptrescapes tag for unnamed parameters
The tag was overwritten by the code for special handling unnamed
parameters.

Fixes #23045.

Change-Id: Ie2e1db3e902a07a2bbbc2a3424cea300f0a42cc3
Reviewed-on: https://go-review.googlesource.com/82775
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-14 21:41:39 +00:00
Ian Lance Taylor
d1f679a6af test: add test case for incorrect gccgo compilation error
Updates #23489

Change-Id: Ie846ccfe4c4d9295857f5da6863ac8f2ac0f2f6a
Reviewed-on: https://go-review.googlesource.com/89935
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-14 20:13:22 +00:00
Ian Lance Taylor
034aca1cbb test: add a test that gccgo miscompiled
Updates #20923

Change-Id: Ia1210ea3dec39e5db2521aeafca24d6e731f0c93
Reviewed-on: https://go-review.googlesource.com/91657
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-14 20:13:07 +00:00
Ian Lance Taylor
d9fc1929e9 test: add test for rounding to positive zero
Per the language spec clarification in https://golang.org/cl/14727.

Updates #12576
Updates #12621

Change-Id: I1e459c3c11a571bd29582761faacaa9ca3178ba6
Reviewed-on: https://go-review.googlesource.com/91895
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-14 20:13:05 +00:00
Keith Randall
755b36aa53 cmd/compile: fix constant folding of right shifts
The sub-word shifts need to sign-extend before shifting, to avoid
bringing in data from higher in the argument.

Fixes #23812

Change-Id: I0a95a0b49c48f3b40b85765bb4a9bb492be0cd73
Reviewed-on: https://go-review.googlesource.com/93716
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-14 00:03:36 +00:00
Emmanuel Odeke
25d22d9aba cmd/compile: report the struct type in invalid number of initializer values
Fixes #23732

Disambiguate "too few" or "too many" values in struct
initializer messages by reporting the name of the literal.

After:
issue23732.go:27:3: too few values in Foo literal
issue23732.go:34:12: too many values in Bar literal
issue23732.go:40:6: too few values in Foo literal
issue23732.go:40:12: too many values in Bar literal

Change-Id: Ieca37298441d907ac78ffe960c5ab55741a362ef
Reviewed-on: https://go-review.googlesource.com/93277
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-13 19:42:15 +00:00
Austin Clements
2010189407 runtime: remove legacy eager write barrier
Now that the buffered write barrier is implemented for all
architectures, we can remove the old eager write barrier
implementation. This CL removes the implementation from the runtime,
support in the compiler for calling it, and updates some compiler
tests that relied on the old eager barrier support. It also makes sure
that all of the useful comments from the old write barrier
implementation still have a place to live.

Fixes #22460.

Updates #21640 since this fixes the layering concerns of the write
barrier (but not the other things in that issue).

Change-Id: I580f93c152e89607e0a72fe43370237ba97bae74
Reviewed-on: https://go-review.googlesource.com/92705
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-13 16:34:46 +00:00
Keith Randall
23e8e197b0 cmd/compile: use unsigned loads for multi-element comparisons
When loading multiple elements of an array into a single register,
make sure we treat them as unsigned.  When treated as signed, the
upper bits might all be set, causing the shift-or combo to clobber
the values higher in the register.

Fixes #23719.

Change-Id: Ic87da03e9bd0fe2c60bb214b99f846e4e9446052
Reviewed-on: https://go-review.googlesource.com/92335
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-02-06 18:24:33 +00:00
Cherry Zhang
43288467d2 test: add test for gccgo bug 23545
The fix is CL 91035.

Build only with gccgo at the moment, as it hits issue #23546.

Updates #23545.

Change-Id: I3a1367bb31b04773d31f71016f8fd7bd1855d7b5
Reviewed-on: https://go-review.googlesource.com/89735
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-01-31 20:03:31 +00:00
Keith Randall
7eaa8efbe4 cmd/compile: don't let spills clobber arguments
The compiler allows code to have multiple differently-typed views of a
single argument. For instance, if we have

func f(x float64) {
   y := *(*int64)(unsafe.Pointer(&x))
   ...
}

Then in SSA we get two OpArg ops, one with float64 type and one with
int64 type.

The compiler will try to reuse argument slots for spill slots. It
checks that the argument slot is dead by consulting an interference
graph.

When building the interference graph, we normally ignore cross-type
edges because the values on either end of that edge can't be allocated
to the same slot. (This is just a space-saving optimization.) This
rule breaks down when one of the values is an argument, because of the
multiple views described above. If we're spilling a float64, it is not
enough that the float64 version of x is dead; the int64 version of x
has to be dead also.

Remove the optimization of not recording interference edges if types
don't match. That optimization is incorrect if one of the values
connected by the edge is an argument.

Fixes #23522

Change-Id: I361f85d80fe3bc7249014ca2c3ec887c3dc30271
Reviewed-on: https://go-review.googlesource.com/89335
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-01-23 21:51:55 +00:00
Kunpei Sakai
e858a6b9f0 all: use Fatalf instead of Fatal if format is given
Change-Id: I30e9b938bb19ed4e674c3ea4a1cd389b9c4f0b88
Reviewed-on: https://go-review.googlesource.com/86875
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-01-10 01:35:45 +00:00
Cherry Zhang
7f1c4b3afb cmd/compile: disable "redundant zeroextensions" optimization for Select on AMD64
A Select Op could produce a value with upper 32 bits NOT zeroed,
for example, Div32 is lowered to (Select0 (DIVL x y)).

In theory, we could look into the argument of a Select to decide
whether the upper bits are zeroed. As it is late in release cycle,
just disable this optimization for Select for now.

Fixes #23305.

Change-Id: Icf665a2af9ccb0a7ba0ae00c683c9e349638bf85
Reviewed-on: https://go-review.googlesource.com/85736
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-01-02 21:08:35 +00:00
Than McIntosh
841d865a56 cmd/compile: second attempt at fix for issue 23179
My previous fix for issue 23179 was incomplete; it turns out that if
an unnamed parameter is below a specific size threshold, it gets
register-promoted away by the compiler (hence not encountered during
some parts of DWARF inline info processing), but if it is sufficiently
large, it is allocated to the stack as a named variable and treated as
a regular parameter by DWARF generation. Interestingly, something in
the ppc64le build of k8s causes an unnamed parameter to be retained
(where on amd64 it is deleted), meaning that this wasn't caught in my
amd64 testing.

The fix is to insure that "_" params are treated in the same way that
"~r%d" return temps are when matching up post-optimization inlined
routine params with pre-inlining declarations. I've also updated the
test case to include a "_" parameter with a very large size, which
also triggers the bug on amd64.

Fixes #23179.

Change-Id: I961c84cc7a873ad3f8f91db098a5e13896c4856e
Reviewed-on: https://go-review.googlesource.com/84975
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2017-12-20 20:39:16 +00:00
Than McIntosh
0447216316 cmd/compile: fix corner case in DWARF inline info generation
The helper routine for returning pre-inlining parameter declarations
wasn't properly handling the case where you have more than one
parameter named "_" in a function signature; this triggered a map
collision later on when the function was inlined and DWARF was
generated for the inlined routine instance.

Fixes #23179.

Change-Id: I12e5d6556ec5ce08e982a6b53666a4dcc1d22201
Reviewed-on: https://go-review.googlesource.com/84755
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-12-19 19:00:42 +00:00
Russ Cox
c6ea277ac1 test: skip "# package/path" output from cmd/go in errchk
This allows errchk to be used with "go vet" output (as opposed to "go tool vet").

Change-Id: I0009a53c9cb74accd5bd3923c137d6dbf9e46326
Reviewed-on: https://go-review.googlesource.com/83836
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-12-13 21:32:01 +00:00
Matthew Dempsky
13bf4ada80 cmd/compile: remove broken inlining accounting code
We can't currently inline functions that contain closures anyway, so
just delete this budgeting code for now. Re-enable once we can (if
ever) inline functions with nested closures.

Updates #15561.
Fixes #23093.

Change-Id: Idc5f8e042ccfcc8921022e58d3843719d4ab821e
Reviewed-on: https://go-review.googlesource.com/83538
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-12-12 20:26:33 +00:00
Matthew Dempsky
840fad13ec cmd/compile: fix unsafe.Pointer liveness for Syscall-like functions
The package unsafe docs say it's safe to convert an unsafe.Pointer to
uintptr in the argument list to an assembly function, but it was
erroneously only detecting normal pointers converted to unsafe.Pointer
and then to intptr.

Fixes #23051.

Change-Id: Id1be19f6d8f26f2d17ba815191717d2f4f899732
Reviewed-on: https://go-review.googlesource.com/82817
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-08 21:34:24 +00:00
Keith Randall
4c800f03c9 cmd/compile: fix large load/store offsets on 386
Pointer arithemetic is done mod 2^32 on 386, so we can just
drop the high bits of any large constant offsets.

The bounds check will make sure wraparounds are never observed.

Fixes #21655

Change-Id: I68ae5bbea9f02c73968ea2b21ca017e5ecb89223
Reviewed-on: https://go-review.googlesource.com/82675
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-12-08 03:53:18 +00:00
Keith Randall
dd7cbf3a84 cmd/compile: fix map assignment with panicking right-hand side
Make sure that when we're assigning to a map, we evaluate the
right-hand side before we attempt to insert into the map.

We used to evaluate the left-hand side to a pointer-to-slot-in-bucket
(which as a side effect does len(m)++), then evaluate the right-hand side,
then do the assignment. That clearly isn't correct when the right-hand side
might panic.

Fixes #22881

Change-Id: I42a62870ff4bf480568c9bdbf0bb18958962bdf0
Reviewed-on: https://go-review.googlesource.com/81817
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-12-05 00:10:10 +00:00
Matthew Dempsky
2b9e7c1864 test: disable broken test for 1.10
This test was added recently as a regress test for the spec relaxation
in #9060, but doesn't work correctly yet. Disable for now to fix noopt
builders.

Updates #22444.

Change-Id: I45c521ae0da7ffb0c6859d6f7220c59828ac6149
Reviewed-on: https://go-review.googlesource.com/81775
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-12-04 19:29:14 +00:00
Than McIntosh
88c2fb9d04 cmd/compile: fix bug in DWARF inl handling of unused autos
The DWARF inline info generation hooks weren't properly
handling unused auto vars in certain cases, triggering an assert (now
fixed). Also with this change, introduce a new autom "flavor" to
use for autom entries that are added to insure that a specific
auto type makes it into the linker (this is a follow-on to the fix
for 22941).

Fixes #22962.

Change-Id: I7a2d8caf47f6ca897b12acb6a6de0eb25f5cac8f
Reviewed-on: https://go-review.googlesource.com/81557
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-12-04 18:36:11 +00:00
Robert Griesemer
088a9ad543 cmd/compile: permit indices of certain non-constant shifts
Per the decision for #14844, index expressions that are non-constant
shifts where the LHS operand is representable as an int are now valid.

Fixes #21693.

Change-Id: Ifafad2c0c65975e0200ce7e28d1db210e0eacd9d
Reviewed-on: https://go-review.googlesource.com/81277
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-12-01 20:39:50 +00:00
Than McIntosh
9372166faa cmd/compile: fix DWARF type symbol buglet
The code that generates the list of DWARF variables for a function
(params and autos) will emit a "no-location" entry in the DWARF for a
user var that appears in the original pre-optimization version of the
function but is no longer around when optimization is complete. The
intent is that if a GDB user types "print foo" (where foo has been
optimized out), the response will be "<optimized out>" as opposed to
"there is no such variable 'foo'). This change fixes said code to
include vars on the autom list for the function, to insure that the
type symbol for the variable makes it to the linker.

Fixes #22941.

Change-Id: Id29f1f39d68fbb798602dfd6728603040624fc41
Reviewed-on: https://go-review.googlesource.com/81415
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-12-01 18:52:50 +00:00
Cherry Zhang
dbb1d198ab cmd/compile: fix loop depth of range expression in escape analysis
ORANGE node's Right node is the expression it is ranging over,
which is evaluated before the loop. In the escape analysis,
we should walk this node without loop depth incremented.

Fixes #21709.

Change-Id: Idc1e4c76e39afb5a344d85f6b497930a488ce5cf
Reviewed-on: https://go-review.googlesource.com/80740
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-11-30 13:45:18 +00:00
Matthew Dempsky
2f588ff08f cmd/compile: make -asmhdr work with type aliases
For "type T = U" we were accidentally emitting a #define for "U__size"
instead of "T__size".

Fixes #22877.

Change-Id: I5ed6757d697753ed6d944077c16150759f6e1285
Reviewed-on: https://go-review.googlesource.com/80759
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-29 20:40:41 +00:00
Matthew Dempsky
71a9c4430f cmd/compile: fix infinite recursion in isdirectiface
Fixes #22904.

Change-Id: Id504504eda7275c10d3c665add8b7ccd23f65820
Reviewed-on: https://go-review.googlesource.com/80301
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-11-28 21:58:16 +00:00