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>
And delete them from asm_go.
Change-Id: I0057cbd90ca55fa51c596e32406e190f3866f93e
Reviewed-on: https://go-review.googlesource.com/99815
Reviewed-by: Keith Randall <khr@golang.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
And remove them from ssa_test.
Change-Id: I3efac5fea529bb0efa2dae32124530482ba5058e
Reviewed-on: https://go-review.googlesource.com/98815
Reviewed-by: Keith Randall <khr@golang.org>
And remove them from ssa_test.
Change-Id: Ib5de5c0d908f23915e0847eca338cacf2fa5325b
Reviewed-on: https://go-review.googlesource.com/98795
Reviewed-by: Giovanni Bajo <rasky@develer.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
The signature of the mapassign_fast* routines need to distinguish
the pointerness of their key argument. If the affected routines
suspend part way through, the object pointed to by the key might
get garbage collected because the key is typed as a uint{32,64}.
This is not a problem for mapaccess or mapdelete because the key
in those situations do not live beyond the call involved. If the
object referenced by the key is garbage collected prematurely, the
code still works fine. Even if that object is subsequently reallocated,
it can't be written to the map in time to affect the lookup/delete.
Fixes#22781
Change-Id: I0bbbc5e9883d5ce702faf4e655348be1191ee439
Reviewed-on: https://go-review.googlesource.com/79018
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
CL 76551 modified inline_callers.go to build everything, including the
runtime, with -l=4. While that works in most places (and ideally
should work everywhere), it blows out the nosplit stack on
solaris/amd64.
Fix this by only building the test itself with -l=4.
This undoes some of the changes to this test from CL 73212, which
originally changed the go tool to rebuild all packages with the given
flags. This change modified the expected output of this test, so now
that we can go back to building only the test itself with inlining, we
revert these changes to the expected output. (That CL also changed
log.Fatalf to log.Printf, but didn't add "\n" to the end of the lines,
so this CL fixes that, too.)
Fixes#22797.
Change-Id: I6a91963a59ebe98edbe0921d8717af6b2c2191b0
Reviewed-on: https://go-review.googlesource.com/79197
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Improve the error message for wrong
case-field names in composite literals,
by mentioning the correct field name.
Given the program:
package main
type it struct {
ID string
}
func main() {
i1 := &it{id: "Bar"}
}
just like we do for usage of fields, we now
report wrongly cased fields as hints to give:
ts.go:8:14: unknown field 'id' in struct literal of type it (but does have ID)
instead of before:
ts.go:8:14: unknown field 'id' in struct literal of type it
Fixes#22794
Change-Id: I18cd70e75817025cb1df083503cae306e8d659fd
Reviewed-on: https://go-review.googlesource.com/78545
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This test fails on 1.9.2, but is ok on tip.
CL 77331 has both the 1.9.2 fix and this test, and is on the 1.9 release branch.
This CL is just the test, and is on HEAD. The buggy code doesn't exist on tip.
Update #22683
Change-Id: I04a24bd6c2d3068e18ca81da3347e2c1366f4447
Reviewed-on: https://go-review.googlesource.com/77332
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also, with this change, error locations don't print absolute positions
in [] brackets following positions relative to line directives. To get
the absolute positions as well, specify the -L flag.
Fixes#22660.
Change-Id: I9ecfa254f053defba9c802222874155fa12fee2c
Reviewed-on: https://go-review.googlesource.com/77090
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
It has always been problematic that there was no way to specify
tool flags that applied only to the build of certain packages;
it was only to specify flags for all packages being built.
The usual workaround was to install all dependencies of something,
then build just that one thing with different flags. Since the
dependencies appeared to be up-to-date, they were not rebuilt
with the different flags. The new content-based staleness
(up-to-date) checks see through this trick, because they detect
changes in flags. This forces us to address the underlying problem
of providing a way to specify per-package flags.
The solution is to allow -gcflags=pattern=flags, which means
that flags apply to packages matching pattern, in addition to the
usual -gcflags=flags, which is now redefined to apply only to
the packages named on the command line.
See #22527 for discussion and rationale.
Fixes#22527.
Change-Id: I6716bed69edc324767f707b5bbf3aaa90e8e7302
Reviewed-on: https://go-review.googlesource.com/76551
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Plain blocks that contain only uninteresting instructions
(that do not have reliable Pos information themselves)
need to have their Pos left unset so that they can
inherit it from their successors. The "uninteresting"
test was not properly applied and not properly defined.
OpFwdRef does not appear in the ssa.html debugging output,
but at the time of the test these instructions did appear,
and it needs to be part of the test.
Fixes#22365.
Change-Id: I99e5b271acd8f6bcfe0f72395f905c7744ea9a02
Reviewed-on: https://go-review.googlesource.com/74252
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
They could get picked up by reflect code, yielding the wrong type.
Fixes#22605
Change-Id: Ie11fb361ca7f3255e662037b3407565c8f0a2c4c
Reviewed-on: https://go-review.googlesource.com/76315
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Be more pessimistic when parsing if/switch/for headers for better error
messages when things go wrong.
Fixes#22581.
Change-Id: Ibb99925291ff53f35021bc0a59a4c9a7f695a194
Reviewed-on: https://go-review.googlesource.com/76290
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Updates #21317
@mdempsky fixed issue #21317 with CL 66810,
so lock a test in to ensure we don't regress.
The test is manual for now before test/run.go
has support for matching column numbers so do
it old school and match expected output after
an exec.
Change-Id: I6c2a66ddf04248f79d17ed7033a3280d50e41562
Reviewed-on: https://go-review.googlesource.com/76150
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently, assigning a []T where T is a go:notinheap type generates an
unnecessary write barrier for storing the slice pointer.
This fixes this by teaching HasHeapPointer that this type does not
have a heap pointer, and tweaking the lowering of slice assignments so
the pointer store retains the correct type rather than simply lowering
it to a *uint8 store.
Change-Id: I8bf7c66e64a7fefdd14f2bd0de8a5a3596340bab
Reviewed-on: https://go-review.googlesource.com/76027
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Updates #22389
@mdempsky's CL 70850 fixed the unnecessary
compile stack trace printing during ICE diagnostics.
This CL adds a test to lock in this behavior.
Change-Id: I9ce49923c80b78cb8c0bb5dc4af3c860a43d63ba
Reviewed-on: https://go-review.googlesource.com/74630
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
CL 65071 enabled inlining for local closures with no captures.
To determine safety of inlining a call sites, we check whether the
variable holding the closure has any assignments after its original
definition.
Unfortunately, that check did not catch OAS2MAPR and OAS2DOTTYPE,
leading to incorrect inlining when a variable holding a closure was
subsequently reassigned through a type conversion or a 2-valued map
access.
There was another more subtle issue wherein reassignment check would
always return a false positive for closure calls inside other
closures. This was caused by the Name.Curfn field of local variables
pointing to the OCLOSURE node instead of the corresponding ODCLFUNC,
which resulted in reassigned walking an empty Nbody and thus never
seeing any reassignments.
This CL fixes these oversights and adds many more tests for closure
inlining which ensure not only that inlining triggers but also the
correctness of the resulting code.
Updates #15561
Change-Id: I74bdae849c4ecfa328546d6d62b512e8d54d04ce
Reviewed-on: https://go-review.googlesource.com/75770
Reviewed-by: Hugues Bruant <hugues.bruant@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Instead of trying to validate map key types eagerly in some
cases, delay their validation to the end of type-checking,
when we all type information is present.
Passes go build -toolexec 'toolstash -cmp' -a std .
Fixes#21273.
Fixes#21657.
Change-Id: I532369dc91c6adca1502d6aa456bb06b57e6c7ff
Reviewed-on: https://go-review.googlesource.com/75310
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Handle make(map[any]any) and make(map[any]any, hint) where
hint <= BUCKETSIZE special to allow for faster map initialization
and to improve binary size by using runtime calls with fewer arguments.
Given hint is smaller or equal to BUCKETSIZE in which case
overLoadFactor(hint, 0) is false and no buckets would be allocated by makemap:
* If hmap needs to be allocated on the stack then only hmap's hash0
field needs to be initialized and no call to makemap is needed.
* If hmap needs to be allocated on the heap then a new special
makehmap function will allocate hmap and intialize hmap's
hash0 field.
Reduces size of the godoc by ~36kb.
AMD64
name old time/op new time/op delta
NewEmptyMap 16.6ns ± 2% 5.5ns ± 2% -66.72% (p=0.000 n=10+10)
NewSmallMap 64.8ns ± 1% 56.5ns ± 1% -12.75% (p=0.000 n=9+10)
Updates #6853
Change-Id: I624e90da6775afaa061178e95db8aca674f44e9b
Reviewed-on: https://go-review.googlesource.com/61190
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The test was skipped because it did not work on AMD64 with
frame pointer enabled, and accidentally skipped on other
architectures. Now frame pointer is the default on AMD64.
Update the test to work with frame pointer. Now the test
is skipped only when frame pointer is NOT enabled on AMD64.
Fixes#18317.
Change-Id: I724cb6874e562f16e67ce5f389a1d032a2003115
Reviewed-on: https://go-review.googlesource.com/68610
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This cuts 6 seconds off all.bash with the new go command.
Not a ton, but also an easy 6 seconds to grab.
The -tags=use_go_run in the misc/cgo tests is just some
go command flag that will make run.go use go run,
but without making everything look stale.
(Those tests have relative imports,
so go tool compile+link is not enough.)
Change-Id: I43bf4bb661d3adde2b2d4aad5e8f64b97bc69ba9
Reviewed-on: https://go-review.googlesource.com/73994
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This CL changes the go command to base all its rebuilding decisions
on the content of the files being processed and not their file system
modification times. It also eliminates the special handling of release
toolchains, which were previously considered always up-to-date
because modification time order could not be trusted when unpacking
a pre-built release.
The go command previously tracked "build IDs" as a backup to
modification times, to catch changes not reflected in modification times.
For example, if you remove one .go file in a package with multiple .go
files, there is no modification time remaining in the system that indicates
that the installed package is out of date. The old build ID was the hash
of a list of file names and a few other factors, expected to change if
those factors changed.
This CL moves to using this kind of build ID as the only way to
detect staleness, making sure that the build ID hash includes all
possible factors that need to influence the rebuild decision.
One such factor is the compiler flags. As of this CL, if you run
go build -gcflags -N cmd/gofmt
you will get a gofmt where every package is built with -N,
regardless of what may or may not be installed already.
Another such factor is the linker flags. As of this CL, if you run
go install myprog
go install -ldflags=-s myprog
the second go install will now correctly build a new myprog with
the updated linker flags. (Previously the installed myprog appeared
up-to-date, because the ldflags were not included in the build ID.)
Because we have more precise information we can also validate whether
the target of a "go test -c" operation is already the right binary and
therefore can avoid a rebuild.
This CL sets us up for having a more general build artifact cache,
maybe even a step toward not having a pkg directory with .a files,
but this CL does not take that step. For now the result of go install
is the same as it ever was; we just do a better job of what needs to
be installed.
This CL does slow down builds a small amount by reading all the
dependent source files in full. (The go command already read the
beginning of every dependent source file to discover build tags
and imports.) On my MacBook Pro, before this CL all.bash takes
3m58s, while after this CL and a few optimizations stacked above it
all.bash takes 4m28s. Given that CL 73850 cut 1m43s off the all.bash
time earlier today, we can afford adding 30s back for now.
More optimizations are planned that should make the go command
more efficient than it was even before this CL.
Fixes#15799.
Fixes#18369.
Fixes#19340.
Fixes#21477.
Change-Id: I10d7ca0e31ca3f58aabb9b1f11e2e3d9d18f0bc9
Reviewed-on: https://go-review.googlesource.com/73212
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
If the go install doesn't use the same flags as the main build
it can overwrite the installed standard library, leading to
flakiness and slow future tests.
Force uses of 'go install' etc to propagate $GO_GCFLAGS
or disable them entirely, to avoid problems.
As I understand it, the main place this happens is the ssacheck builder.
If there are other uses that need to run some of the now-disabled
tests we can reenable fixed tests in followup CLs.
Change-Id: Ib860a253539f402f8a96a3c00ec34f0bbf137c9a
Reviewed-on: https://go-review.googlesource.com/74470
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The test for #18902 reads the assembly stream to be sure
that the line number does not change too often (this is an
indication that debugging the code will be unpleasant and
that the compiler is probably getting line numbers "wrong").
It checks that it is getting "enough" input, but the
compiler has gotten enough better since the test was written
that it now fails for lack of enough input. The old
threshould was 200 instructions, the new one is 150 (the
minimum observed input is on arm64 with 184 instructions).
Fixes#22494.
Change-Id: Ibba7e9ff4ab6a7be369e5dd5859d150b7db94653
Reviewed-on: https://go-review.googlesource.com/74357
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
KeepAlive needs to introduce a use of the spill of the
value it is keeping alive. Without that, we don't guarantee
that the spill dominates the KeepAlive.
This bug was probably introduced with the code to move spills
down to the dominator of the restores, instead of always spilling
just after the value itself (CL 34822).
Fixes#22458.
Change-Id: I94955a21960448ffdacc4df775fe1213967b1d4c
Reviewed-on: https://go-review.googlesource.com/74210
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
Currently copy and append for types containing only scalars and
notinheap pointers still get compiled to have write barriers, even
though those write barriers are unnecessary. Fix these to use
HasHeapPointer instead of just Haspointer so that they elide write
barriers when possible.
This fixes the unnecessary write barrier in runtime.recordspan when it
grows the h.allspans slice. This is important because recordspan gets
called (*very* indirectly) from (*gcWork).tryGet, which is
go:nowritebarrierrec. Unfortunately, the compiler's analysis has no
hope of seeing this because it goes through the indirect call
fixalloc.first, but I saw it happen.
Change-Id: Ieba3abc555a45f573705eab780debcfe5c4f5dd1
Reviewed-on: https://go-review.googlesource.com/73413
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Currently (*Type).HasHeapPointer only ignores pointers go:notinheap
types if the type itself is a pointer to a go:notinheap type. However,
if it's some other type that contains pointers where all of those
pointers are go:notinheap, it will conservatively return true. As a
result, we'll use write barriers where they aren't needed, for example
calling typedmemmove instead of just memmove on structs that contain
only go:notinheap pointers.
Fix this by making HasHeapPointer walk the whole type looking for
pointers that aren't marked go:notinheap.
Change-Id: Ib8c6abf6f7a20f34969d1d402c5498e0b990be59
Reviewed-on: https://go-review.googlesource.com/73412
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The current go:nowritebarrierrec checker has two problems that limit
its coverage:
1. It doesn't understand that systemstack calls its argument, which
means there are several cases where we fail to detect prohibited write
barriers.
2. It only observes calls in the AST, so calls constructed during
lowering by SSA aren't followed.
This CL completely rewrites this checker to address these issues.
The current checker runs entirely after walk and uses visitBottomUp,
which introduces several problems for checking across systemstack.
First, visitBottomUp itself doesn't understand systemstack calls, so
the callee may be ordered after the caller, causing the checker to
fail to propagate constraints. Second, many systemstack calls are
passed a closure, which is quite difficult to resolve back to the
function definition after transformclosure and walk have run. Third,
visitBottomUp works exclusively on the AST, so it can't observe calls
created by SSA.
To address these problems, this commit splits the check into two
phases and rewrites it to use a call graph generated during SSA
lowering. The first phase runs before transformclosure/walk and simply
records systemstack arguments when they're easy to get. Then, it
modifies genssa to record static call edges at the point where we're
lowering to Progs (which is the latest point at which position
information is conveniently available). Finally, the second phase runs
after all functions have been lowered and uses a direct BFS walk of
the call graph (combining systemstack calls with static calls) to find
prohibited write barriers and construct nice error messages.
Fixes#22384.
For #22460.
Change-Id: I39668f7f2366ab3c1ab1a71eaf25484d25349540
Reviewed-on: https://go-review.googlesource.com/72773
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
...because that's an illegal addressing mode.
I double-checked handling of this code, and 387 is the only
place where this check is missing.
Fixes#22429
Change-Id: I2284fe729ea86251c6af2f04076ddf7a5e66367c
Reviewed-on: https://go-review.googlesource.com/73551
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If n.Type==nil after typechecking, then we should have already
reported a more useful error somewhere else. Just return 0 in
evalunsafe without trying to do anything else that's likely to cause
problems.
Also, further split out issue7525.go into more test files, because
cmd/compile reports at most one typechecking loop per compilation
unit.
Fixes#22351.
Change-Id: I3ebf505f72c48fcbfef5ec915606224406026597
Reviewed-on: https://go-review.googlesource.com/72251
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Robert Griesemer <gri@golang.org>
Fine-tune skipping of tokens after missing closing parentheses in lists.
Fixes#22164.
Change-Id: I575d86e21048cd40340a2c08399e8b0deec337cf
Reviewed-on: https://go-review.googlesource.com/71250
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Follow CL 41477 and add two more line position tests for yyerror calls
in the typechecker which are currently not tested.
Update #19683
Change-Id: Iacd865195a3bfba87d8c22655382af267aba47a9
Reviewed-on: https://go-review.googlesource.com/70251
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Previously, we were treating cross-package function calls as free for
inlining budgeting.
In theory, we should be able to recompute InlCost from the
exported/reimported function bodies. However, that process mutates the
structure of the Node AST enough that it doesn't preserve InlCost. To
avoid unexpected issues, just record and restore InlCost in the export
data.
Fixes#19261.
Change-Id: Iac2bc0d32d4f948b64524aca657051f9fc96d92d
Reviewed-on: https://go-review.googlesource.com/70151
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Calls to a closure held in a local, non-escaping,
variable can be inlined, provided the closure body
can be inlined and the variable is never written to.
The current implementation has the following limitations:
- closures with captured variables are not inlined because
doing so naively triggers invariant violation in the SSA
phase
- re-assignment check is currently approximated by checking
the Addrtaken property of the variable which should be safe
but may miss optimization opportunities if the address is
not used for a write before the invocation
Updates #15561
Change-Id: I508cad5d28f027bd7e933b1f793c14dcfef8b5a1
Reviewed-on: https://go-review.googlesource.com/65071
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hugues Bruant <hugues.bruant@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
It should be skipped on 32-bit architectures.
Change-Id: If7a64b9e90e47c3e8734dd62729bfd2944ae926c
Reviewed-on: https://go-review.googlesource.com/70071
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
If the stack frame is too large, abort immediately.
We used to generate code first, then abort.
In issue 22200, generating code raised a panic
so we got an ICE instead of an error message.
Change the max frame size to 1GB (from 2GB).
Stack frames between 1.1GB and 2GB didn't used to work anyway,
the pcln table generation would have failed and generated an ICE.
Fixes#22200
Change-Id: I1d918ab27ba6ebf5c87ec65d1bccf973f8c8541e
Reviewed-on: https://go-review.googlesource.com/69810
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This re-enables functionality that inadvertently was disabled in the
(long) past.
Also, don't perform branch checks if we had errors in a function
to avoid spurious errors or (worst-case) crashes.
Slightly modified test/fixedbugs/issue14006.go to make sure the
test still reports invalid label errors (the surrounding function
must be syntactically correct).
Change-Id: Id5642930877d7cf3400649094ec75c753b5084b7
Reviewed-on: https://go-review.googlesource.com/69770
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We've supported inlining methods called as functions for a while now.
Change-Id: I53fba426e45f91d65a38f00456c2ae1527372b50
Reviewed-on: https://go-review.googlesource.com/69530
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Keep left-to-right order when referring to the number of
variables and values involved.
Fixes#22159.
Change-Id: Iccca12d3222f9d5e049939a9ccec07513c393faa
Reviewed-on: https://go-review.googlesource.com/68690
Reviewed-by: Russ Cox <rsc@golang.org>
C_PPAUTO was matching offsets that is a multiple 8. But this
condition is dropped in CL 55610, causing unaligned offset
between 256 and 504 mistakenly matched to some classes, e.g.
C_UAUTO8K. This CL restores this condition, also fixes an
error that C_PPAUTO shouldn't match C_PSAUTO, because the
latter is not guaranteed to be multiple of 8. C_PPAUTO_8 is
unnecessary, removed.
Fixes#21992.
Change-Id: I75d5a0e5f5dc3dae335721fbec1bbcd4a3b862f2
Reviewed-on: https://go-review.googlesource.com/65730
Reviewed-by: David Chase <drchase@google.com>
Historically, gc optimistically parsed the left-hand side of
assignments as expressions. Later, if it discovered a ":=" assignment,
it rewrote the parsed expressions as declarations.
This failed in the presence of dot imports though, because we lost
information about whether an imported object was named via a bare
identifier "Foo" or a normal qualified "pkg.Foo".
This CL fixes the issue by specially noding the left-hand side of ":="
assignments.
Fixes#22076.
Change-Id: I18190ecdb863112e7d009e1687e6112eec559921
Reviewed-on: https://go-review.googlesource.com/66810
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Use entire inlining call stack to decide whether two panic calls
can be merged. We used to merge panic calls when only the leaf
line numbers matched, but that leads to places higher up the call
stack being merged incorrectly.
Fixes#22083
Change-Id: Ia41400a80de4b6ecf3e5089abce0c42b65e9b38a
Reviewed-on: https://go-review.googlesource.com/67632
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Very similar fix to the one made in golang.org/cl/65655. This time it's
for switches on interface values, as we look for duplicates in a
different manner to keep types in mind.
As before, add a small regression test.
Updates #22001.
Fixes#22063.
Change-Id: I9a55d08999aeca262ad276b4649b51848a627b02
Reviewed-on: https://go-review.googlesource.com/66450
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
If we have
y = <int16> (MOVBQSX x)
z = <int32> (MOVWQSX y)
We used to use this rewrite rule:
(MOVWQSX x:(MOVBQSX _)) -> x
But that resulted in replacing z with a value whose type
is only int16. Then if z is spilled and restored, it gets
zero extended instead of sign extended.
Instead use the rule
(MOVWQSX (MOVBQSX x)) -> (MOVBQSX x)
The result is has the correct type, so it can be spilled
and restored correctly. It might mean that a few more extension
ops might not be eliminated, but that's the price for correctness.
Fixes#21963
Change-Id: I6ec82c3d2dbe43cc1fee6fb2bd6b3a72fca3af00
Reviewed-on: https://go-review.googlesource.com/65290
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is a regression introduced by myself in golang.org/cl/41852,
confirmed by the program that reproduces the crash that can be seen in
the added test.
Fixes#21988.
Change-Id: I18d5b2b3de63ced84db705b18490b00b16b59e02
Reviewed-on: https://go-review.googlesource.com/65655
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The compiler generates wrapper methods to forward interface method
calls (which are always pointer-based) to value methods. These
wrappers appear in the call stack even though they are an
implementation detail. This leaves ugly "<autogenerated>" functions in
stack traces and can throw off skip counts for stack traces.
Fix this by considering these runtime frames in printed stack traces
so they will only be printed if runtime frames are being printed, and
by eliding them from the call stack expansion used by CallersFrames
and Caller.
This removes the test for issue 4388 since that was checking that
"<autogenerated>" appeared in the stack trace instead of something
even weirder. We replace it with various runtime package tests.
Fixes#16723.
Change-Id: Ice3f118c66f254bb71478a664d62ab3fc7125819
Reviewed-on: https://go-review.googlesource.com/45412
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The existing logic tried to advance the offset for each variable's
width, but then tried to undo this logic with the array and struct
handling code. It can all be much simpler by only worrying about
computing offsets within the array and struct code.
While here, include a short-circuit for zero-width arrays to fix a
pedantic compiler failure case.
Passes toolstash-check.
Fixes#20739.
Change-Id: I98af9bb512a33e3efe82b8bf1803199edb480640
Reviewed-on: https://go-review.googlesource.com/64471
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Previously, after inlining a call, we made a second pass to rewrite
the AST's position information to record the inlined stack frame. The
call arguments were part of this AST, but it would be incorrect to
rewrite them too, so extra effort was made to temporarily remove them
while the position rewriting was done.
However, this extra logic was only done for regular arguments: it was
not done for receiver arguments. Consequently if m was inlined in
"f().m(g(), h())", g and h would have correct call frames, but f would
appear to be called by m.
The fix taken by this CL is to merge setpos into inlsubst and only
rewrite position information for nodes that were actually copied from
the original function AST body. As a side benefit, this eliminates an
extra AST pass and some AST walking code.
Fixes#21879.
Change-Id: I22b25c208313fc25c358d3a2eebfc9b012400084
Reviewed-on: https://go-review.googlesource.com/64470
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Previously, we used OXFALL vs OFALL to distinguish fallthrough
statements that had been validated. Because in the Node AST we flatten
statement blocks, OXCASE and OXFALL needed to keep track of their
block scopes for this purpose.
Now that we have an AST that keeps these separate, we can just perform
the validation earlier.
Passes toolstash-check.
Fixes#14540.
Change-Id: I8421eaba16c2b3b72c9c5483b5cf20b14261385e
Reviewed-on: https://go-review.googlesource.com/61130
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
By setting both a valid size and alignment for broken recursive types,
we can appease some more safety checks and prevent compiler crashes.
Fixes#21882.
Change-Id: Ibaa137d8aa2c2a9d521462f144d7016c4abfd6e7
Reviewed-on: https://go-review.googlesource.com/64430
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Refactor walkrange to treat "for _ = range a" as "for range a".
This avoids generating some later discarded nodes in the compiler.
Passes toolstash -cmp.
Change-Id: Ifb2e1ca3b8519cbb67e8ad5aad514af9d18f1ec4
Reviewed-on: https://go-review.googlesource.com/61017
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Currently, we handle "x op= y" by rewriting as "x = x op y", while
ensuring that any calls or receive operations in 'x' are only
evaluated once. Notably, pointer indirection, indexing operations,
etc. are left alone as it's typically safe to re-evaluate those.
However, those operations were interleaved with evaluating 'y', which
could include function calls that might cause re-evaluation to yield
different memory addresses.
As a fix, simply ensure that we order side-effecting operations in 'y'
before either evaluation of 'x'.
Fixes#21687.
Change-Id: Ib14e77760fda9c828e394e8e362dc9e5319a84b2
Reviewed-on: https://go-review.googlesource.com/60091
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Do the similar thing to CL 55143 to reduce IMUL.
Change-Id: I1bd38f618058e3cd74fac181f003610ea13f2294
Reviewed-on: https://go-review.googlesource.com/56252
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The assembler barfs on large offsets. Make sure that all the
instructions that need to have their offsets in an int32
1) check on any rule that computes offsets for such instructions
2) change their aux fields so the check builder checks it.
The assembler also silently misassembled offsets between 1<<31
and 1<<32. Add a check in the assembler to barf on those as well.
Fixes#21655
Change-Id: Iebf24bf10f9f37b3ea819ceb7d588251c0f46d7d
Reviewed-on: https://go-review.googlesource.com/59630
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
For code like the following (where x escapes):
x := []int{1}
We're currently generating a nil check. The line above is really 3 operations:
t := new([1]int)
t[0] = 1
x := t[:]
We remove the nil check for t[0] = 1, but not for t[:].
Our current nil check removal rule is too strict about the possible
memory arguments of the nil check. Unlike zeroing or storing to the
result of runtime.newobject, the nilness of runtime.newobject is
always false, even after other stores have happened in the meantime.
Change-Id: I95fad4e3a59c27effdb37c43ea215e18f30b1e5f
Reviewed-on: https://go-review.googlesource.com/58711
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This is a crude compiler pass to eliminate stores to auto variables
that are only ever written to.
Eliminates an unnecessary store to x from the following code:
func f() int {
var x := 1
return *(&x)
}
Fixes#19765.
Change-Id: If2c63a8ae67b8c590b6e0cc98a9610939a3eeffa
Reviewed-on: https://go-review.googlesource.com/38746
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Where possible generate calls to runtime makemap with int hint argument
during compile time instead of makemap with int64 hint argument.
This eliminates converting the hint argument for calls to makemap with
int64 hint argument for platforms where int64 values do not fit into
an argument of type int.
A similar optimization for makeslice was introduced in CL
golang.org/cl/27851.
386:
name old time/op new time/op delta
NewEmptyMap 53.5ns ± 5% 41.9ns ± 5% -21.56% (p=0.000 n=10+10)
NewSmallMap 182ns ± 1% 165ns ± 1% -8.92% (p=0.000 n=10+10)
Change-Id: Ibd2b4c57b36f171b173bf7a0602b3a59771e6e44
Reviewed-on: https://go-review.googlesource.com/55142
Reviewed-by: Keith Randall <khr@golang.org>
If an error was already printed during LHS conversion step, we don't reprint
the "cannot convert" error.
In particular, this prevents `_ = int("1")` (and all similar casts) from
resulting in multiple identical error messages being printed.
Fixes#20812.
Change-Id: If6e52c59eab438599d641ecf6f110ebafca740a9
Reviewed-on: https://go-review.googlesource.com/46912
Reviewed-by: Robert Griesemer <gri@golang.org>
There are a few cases where this can be useful. Apart from the obvious
(and silly)
100*n + 200*n
where we generate one IMUL instead of two, consider:
15*n + 31*n
Currently, the compiler strength-reduces both imuls, generating:
0x0000 00000 MOVQ "".n+8(SP), AX
0x0005 00005 MOVQ AX, CX
0x0008 00008 SHLQ $4, AX
0x000c 00012 SUBQ CX, AX
0x000f 00015 MOVQ CX, DX
0x0012 00018 SHLQ $5, CX
0x0016 00022 SUBQ DX, CX
0x0019 00025 ADDQ CX, AX
0x001c 00028 MOVQ AX, "".~r1+16(SP)
0x0021 00033 RET
But combining the imuls is both faster and shorter:
0x0000 00000 MOVQ "".n+8(SP), AX
0x0005 00005 IMULQ $46, AX
0x0009 00009 MOVQ AX, "".~r1+16(SP)
0x000e 00014 RET
even without strength-reduction.
Moreover, consider:
5*n + 7*(n+1) + 11*(n+2)
We already have a rule that rewrites 7(n+1) into 7n+7, so the
generated code (without imuls merging) looks like this:
0x0000 00000 MOVQ "".n+8(SP), AX
0x0005 00005 LEAQ (AX)(AX*4), CX
0x0009 00009 MOVQ AX, DX
0x000c 00012 NEGQ AX
0x000f 00015 LEAQ (AX)(DX*8), AX
0x0013 00019 ADDQ CX, AX
0x0016 00022 LEAQ (DX)(CX*2), CX
0x001a 00026 LEAQ 29(AX)(CX*1), AX
0x001f 00031 MOVQ AX, "".~r1+16(SP)
But with imuls merging, the 5n, 7n and 11n factors get merged, and the
generated code looks like this:
0x0000 00000 MOVQ "".n+8(SP), AX
0x0005 00005 IMULQ $23, AX
0x0009 00009 ADDQ $29, AX
0x000d 00013 MOVQ AX, "".~r1+16(SP)
0x0012 00018 RET
Which is both faster and shorter; that's also the exact same code that
clang and the intel c compiler generate for the above expression.
Change-Id: Ib4d5503f05d2f2efe31a1be14e2fe6cac33730a9
Reviewed-on: https://go-review.googlesource.com/55143
Reviewed-by: Keith Randall <khr@golang.org>
The gofmt bug in question seems to be fixed (at least gofmt doesn't
complain), so reenable the commented-out ... test.
Change-Id: Icbfe0511160210557894ec8eb9b206aa6133d486
Reviewed-on: https://go-review.googlesource.com/55030
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
https://golang.org/cl/37508 added an escape analysis test for #12397 to
escape2.go but missed to add it to escape2n.go. The comment at the top
of the former states that the latter should contain all the same tests
and the tests only differ in using -N to compile. Conform to this by
adding the function issue12397 to escape2n.go as well.
Also fix a whitespace difference in escape2.go, so the two files match
exactly (except for the comment at the top).
Change-Id: I3a09cf95169bf2150a25d6b4ec9e147265d36760
Reviewed-on: https://go-review.googlesource.com/54610
Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
It is possible to have an unexported name with a nil package,
for an embedded field whose type is a pointer to an unexported type.
We must encode that fact in the type..namedata symbol name,
to avoid incorrectly merging an unexported name with an exported name.
Fixes#21120
Change-Id: I2e3879d77fa15c05ad92e0bf8e55f74082db5111
Reviewed-on: https://go-review.googlesource.com/50710
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Load/store-merging and move optimizations can result in unaligned
memory accesses. This is fine so long as the load/store instruction
used does not take a relative offset. In the SSA rules this means we
must not merge (MOVDaddr (SB)) ops into loads/stores unless we can
guarantee the alignment of the target.
Fixes#21048.
Change-Id: I70f13a62a148d5f0a56e704e8f76e36b4a4226d9
Reviewed-on: https://go-review.googlesource.com/49250
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Framepointer is the default now. Only print an X: list
if the settings are _not_ the default.
Before:
$ go tool compile -V
compile version devel +a5f30d9508 Sun Jul 16 14:43:48 2017 -0400 X:framepointer
$ go1.8 tool compile -V
compile version go1.8 X:framepointer
$
After:
$ go tool compile -V
compile version devel +a5f30d9508 Sun Jul 16 14:43:48 2017 -0400
$ go1.9 tool compile -V # imagined
compile version go1.9
$
Perpetuates #18317.
Change-Id: I981ba5c62be32e650a166fc9740703122595639b
Reviewed-on: https://go-review.googlesource.com/49252
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
On a slow or distracted machine, 0.1s is sometimes
not long enough for a non-blocking function call to complete.
This causes rare test flakes.
They can be easily reproduced by reducing the wait time to (say) 100ns.
For non-blocking functions, increase the window from 100ms to 10s.
Using different windows for block and non-blocking functions,
allows us to reduce the time for blocking functions.
The risk here is false negatives, but that risk is low;
this test is run repeatedly on many fast machines,
for which 10ms is ample time.
This reduces the time required to run the test by a factor of 10,
from ~1s to ~100ms.
Fixes#20299
Change-Id: Ice9a641a66c6c101d738a2ebe1bcb144ae3c9916
Reviewed-on: https://go-review.googlesource.com/47812
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
