Avoid targeting a partial register with load;
ensure source of load (writebarrier) is aligned.
Better yet would be "CMPB $1,writebarrier" but that requires
wrestling with flagalloc (mem operand complicates moving
instruction around).
Didn't see a change in time for
benchcmd -n 10 Build go build net/http
Verified that we clean the code up properly:
0x20a8 <main.main+104>: mov 0xc30a2(%rip),%eax
# 0xc5150 <runtime.writeBarrier>
0x20ae <main.main+110>: test %al,%al
Change-Id: Id5fb8c260eaec27bd727cb0ae1476c60343b0986
Reviewed-on: https://go-review.googlesource.com/19998
Reviewed-by: Keith Randall <khr@golang.org>
Exposed data already in sdom to avoid recreating it in prove.
Change-Id: I834c9c03ed8faeaee013e5a1b3f955908f0e0915
Reviewed-on: https://go-review.googlesource.com/19999
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
* It does very simple bounds checking elimination. E.g.
removes the second check in for i := range a { a[i]++; a[i++]; }
* Improves on the following redundant expression:
return a6 || (a6 || (a6 || a4)) || (a6 || (a4 || a6 || (false || a6)))
* Linear in the number of block edges.
I patched in CL 12960 that does bounds, nil and constant propagation
to make sure this CL is not just redundant. Size of pkg/tool/linux_amd64/*
(excluding compile which is affected by this change):
With IsInBounds and IsSliceInBounds
-this -12960 92285080
+this -12960 91947416
-this +12960 91978976
+this +12960 91923088
Gain is ~110% of 12960.
Without IsInBounds and IsSliceInBounds (older run)
-this -12960 95515512
+this -12960 95492536
-this +12960 95216920
+this +12960 95204440
Shaves 22k on its own.
* Can we handle IsInBounds better with this? In
for i := range a { a[i]++; } the bounds checking at a[i]
is not eliminated.
Change-Id: I98957427399145fb33693173fd4d5a8d71c7cc20
Reviewed-on: https://go-review.googlesource.com/19710
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add the max arg length to opcodes and use it in zcse. Doesn't affect
speed, but allows better checking in checkFunc and removes the need
to keep a list of zero arg opcodes up to date.
Change-Id: I157c6587154604119720ec6228b767b6e52bb5c7
Reviewed-on: https://go-review.googlesource.com/19994
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
plive doesn't like the fact that we put JMPs right
after CALL ops to select{send,recv}.
Fixes SSA -N build.
Change-Id: I9b3c9e5293196094fd5a6206dd2f99784951f7a9
Reviewed-on: https://go-review.googlesource.com/19982
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Just like we do for integer loads/stores.
Update #14511
Change-Id: Ic6ca6b54301438a5701ea5fb0be755451cb24d45
Reviewed-on: https://go-review.googlesource.com/19923
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
Our stack frame sizes look pretty good now. Lower the stack
guard from 1024 to 720.
Tip is currently using 720.
We could go lower (to 640 at least) except PPC doesn't like that.
Change-Id: Ie5f96c0e822435638223f1e8a2bd1a1eed68e6aa
Reviewed-on: https://go-review.googlesource.com/19922
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The -d compiler flag can also specify ssa phase and flag,
for example -d=ssa/generic_cse/time,ssa/generic_cse/stats
Spaces in the phase names can be specified with an
underscore. Flags currently parsed (not necessarily
recognized by the phases yet) are:
on, off, mem, time, debug, stats, and test
On, off and time are handled in the harness,
debug, stats, and test are interpreted by the phase itself.
The pass is now attached to the Func being compiled, and a
new method logStats(key, ...value) on *Func to encourage a
semi-standardized format for that output. Output fields
are separated by tabs to ease digestion by awk and
spreadsheets. For example,
if f.pass.stats > 0 {
f.logStat("CSE REWRITES", rewrites)
}
Change-Id: I16db2b5af64c50ca9a47efeb51d961147a903abc
Reviewed-on: https://go-review.googlesource.com/19885
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
Found looking at mapaccess1_faststr.
runtime.throw never returns.
Do x+y+c with an LEA.
Change-Id: I27ea6669324242a6302397cbdc73230891d97591
Reviewed-on: https://go-review.googlesource.com/19911
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The @ directive used to read the target block after some value
structure had already changed. I don't think it was ever really
a bug, but it's confusing.
It might fail like this:
(Foo x y) -> @v.Args[0].Block (Bar y (Baz ...))
v.Op = Bar
v.Args[0] = y
v.Args[1] = v.Args[0].Block.NewValue(Baz, ...)
That new value is allocated in the block of y, not the
block of x.
Anyway, read the destination block first so this
potential bug can't happen.
Change-Id: Ie41d2fc349b35cefaa319fa9327808bcb781b4e2
Reviewed-on: https://go-review.googlesource.com/19900
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
In regalloc, make LoadReg instructions use the line number
of their *use*, not their *source*. This reduces the
tendency of debugger stepping to "jump around" the program.
Change-Id: I59e2eeac4dca9168d8af3a93effbc5bdacac2881
Reviewed-on: https://go-review.googlesource.com/19836
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Helps keep line numbers around for debugging, particularly
for break and continue statements (which often compile
down to nothing).
Update #14379
Change-Id: I6ea06aa887b0450d9ba4f11e319e5c263f5a98ba
Reviewed-on: https://go-review.googlesource.com/19848
Reviewed-by: David Chase <drchase@google.com>
Saves about 2k for binaries in pkg/tool/linux_amd64.
Also useful when opt runs after cse (as in 12960) which reorders
arguments for commutative operations such as Add64.
Change-Id: I49ad53afa53db9736bd35c425f4fb35fb511fd63
Reviewed-on: https://go-review.googlesource.com/19827
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
While investigating the differences between 19710 (remove
tautological controls) and 12960 (bounds and nil propagation)
I observed that part of the wins of 19710 come from missed
opportunities for deadcode elimination due to phis.
See for example runtime.stackcacherelease. 19710 happens much
later than 12960 and has more chances to eliminate bounds.
Size of pkg/tool/linux_amd64/* excluding compile:
-this -12960 95882248
+this -12960 95880120
-this +12960 95581512
+this +12960 95555224
This change saves about 25k.
Change-Id: Id2f4e55fc92b71595842ce493c3ed527d424fe0e
Reviewed-on: https://go-review.googlesource.com/19728
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
util.go was originally added in golang.org/cl/4851, and later moved to
its current location in golang.org/cl/10287.
Change-Id: I10b4941d42ae1ff2e78990c497c1347bbbae4e3d
Reviewed-on: https://go-review.googlesource.com/19851
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The upper bits of 8/16/32 bit constants are undefined. We need to
truncate in order to prevent x86.oclass misidentifying the size of the
constant.
Fixes#14389
Change-Id: I3e5ff79cd904376572a93f489ba7e152a5cb6e60
Reviewed-on: https://go-review.googlesource.com/19740
Reviewed-by: Keith Randall <khr@golang.org>
Pass lexer around so state is accessible and dependency is explicit.
In the process remove EOF -> '\n' conversion that has to be corrected
for when reporting errors.
Change-Id: If95564b70e7484dedc1f5348e585cd19acbc1243
Reviewed-on: https://go-review.googlesource.com/19819
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Loads of stores from the same pointer with compatible types
can be replaced with a copy.
Change-Id: I514b3ed8e5b6a9c432946880eac67a51b1607932
Reviewed-on: https://go-review.googlesource.com/19743
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The structure of the code meant that an embedded field was never
checked for export status. We need to check the name of the type,
which is either of type T or type *T, and T might be unexported.
Fixes#14356.
Change-Id: I56f468e9b8ae67e9ed7509ed0b91d860507baed2
Reviewed-on: https://go-review.googlesource.com/19701
Reviewed-by: Robert Griesemer <gri@golang.org>
Cuts 20k off cmd/go and 32k off golang.org/x/tools/cmd/godoc, approx 0.15% each.
For #6853 and #9930
Change-Id: Ic510b76b80a9153b1ede7b3533d2dbc16caa5c63
Reviewed-on: https://go-review.googlesource.com/19768
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
When visiting the AST to add counters, there are special cases in which
the code calls cuts the walking short by returning nil. In some cases
certain nodes are ignored, e.g. Init and Cond inside IfStmt.
The fix is to explicitly walk all the children nodes (not only
Body and Else) when cutting the current walk. Similar approach
was taken with SwitchStmt and TypeSwitchStmt.
While the existing test code doesn't handle different counters in the
same line, the generated HTML report does it correctly (because it takes
column into account).
The previous behavior caused lines in function literals to not be
tracked when those literals were inside Init or Cond of an IfStmt for
example.
Fixes#14039.
Change-Id: Iad591363330843ad833bd79a0388d709c8d0c8aa
Reviewed-on: https://go-review.googlesource.com/19775
Reviewed-by: Rob Pike <r@golang.org>
These files were not added to the repo. They contain conversion
routines and corresponding tests not used by the compiler and
thus are technically not needed.
However, future changes to math/big (and corresponding updates
of this vendored version) may require these files to exist.
Add them to avoid unnecessary confusion.
Change-Id: Ie390fb54f499463b2bba2fdc084967539afbeeb3
Reviewed-on: https://go-review.googlesource.com/19730
Reviewed-by: Alan Donovan <adonovan@google.com>
Replaced comparison based on (*Type).String() with an
allocation-free structural comparison. Roughly doubles
speed of CSE, also reduces allocations.
Checked that roughly the same number of CSEs were detected
during make.bash (about a million) and that "new" CSEs
were caused by the effect described above.
Change-Id: Id205a9f6986efd518043e12d651f0b01206aeb1b
Reviewed-on: https://go-review.googlesource.com/19471
Reviewed-by: Keith Randall <khr@golang.org>
* If a operation is commutative order the parameters
in a canonical way.
Size of pkg/tool/linux_amd64/* excluding compile:
before: 95882288
after: 95868152
change: 14136 ~0.015%
I tried something similar with Leq and Geq, but the results were
not great because it confuses the 'lowered cse' pass too much
which can no longer remove redundant comparisons from IsInBounds.
Change-Id: I2f928663a11320bfc51c7fa47e384b7411c420ba
Reviewed-on: https://go-review.googlesource.com/19727
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Spotted a minor source of excess allocation in the register
allocator. Rearranged the dominator tree code to pull its
scratch memory from a reused buffer attached to Config.
Change-Id: I6da6e7b112f7d3eb1fd00c58faa8214cdea44e38
Reviewed-on: https://go-review.googlesource.com/19450
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add an initial cse pass that only operates on zero argument
values. This removes the need for a special case in cse for removing
OpSB and speeds up arithConst_ssa.go compilation by 9% while slowing
"test -c net/http" by 1.5%.
Change-Id: Id1500482485426f66c6c2eba75eeaf4f19c8a889
Reviewed-on: https://go-review.googlesource.com/19454
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Also eliminates per-maptype hiter and hmap types, since they're not
really needed anyway. Update packages reflect and runtime
accordingly.
Reduces golang.org/x/tools/cmd/godoc's text segment by ~170kB:
text data bss dec hex filename
13085702 140640 151520 13377862 cc2146 godoc.before
12915382 140640 151520 13207542 c987f6 godoc.after
Updates #6853.
Change-Id: I948b2bc1f22d477c1756204996b4e3e1fb568d81
Reviewed-on: https://go-review.googlesource.com/16610
Reviewed-by: Keith Randall <khr@golang.org>
These functions are really simple, the overhead of calling
them (in both time and code size) is larger than the inlined versions.
Reorganize how the nil case in a type switch is handled, as we have
to check for nil explicitly now anyway.
Saves about 0.8% in the binary size of the go tool.
Change-Id: I8501b62d72fde43650b79f52b5f699f1fbd0e7e7
Reviewed-on: https://go-review.googlesource.com/19814
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This adds a test case with aliased pointers to ensure modifications to
dse don't remove valid stores.
Change-Id: I143653250f46a403835218ec685bcd336d5087ef
Reviewed-on: https://go-review.googlesource.com/19795
Reviewed-by: Keith Randall <khr@golang.org>
Previously, given two Nodes n1 and n2 of different non-PAUTO classes
(e.g., PPARAM and PPARAMOUT), cmpstackvarlt(n1, n2) and
cmpstackvarlt(n2, n1) both returned true, which is nonsense.
This doesn't seem to cause any visible miscompilation problems, but
notably fixing it does cause toolstash/buildall to fail.
Change-Id: I33b2c66e902c5eced875d8fbf18b7cfdc81e8aed
Reviewed-on: https://go-review.googlesource.com/19778
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Order's "temp" and "free" fields use NodeLists in a rather
non-idiomatic way. Instead of using the "list" or "concat" functions,
it manipulates them directly and without the normal invariants (e.g.,
it doesn't maintain the "End" field).
Rather than convert it to more typical usage, just replace with a
slice, which ends up much simpler anyway.
Passes toolstash/buildall.
Change-Id: Ibd0f24324bd674c0d5bb1bc40d073b01e7824ad5
Reviewed-on: https://go-review.googlesource.com/19776
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There's no need for 8 different ways to represent that a type is
non-comparable.
While here, move AMEM out of the runtime-known algorithm values since
it's not needed at run-time, and get rid of the unused AUNK constant.
Change-Id: Ie23972b692c6f27fc5f1a908561b3e26ef5a50e9
Reviewed-on: https://go-review.googlesource.com/19779
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This allows the compiler to generate better code
containing fewer jumps and only a single return value.
Cuts 12k off cmd/go and 16k off golang.org/x/tools/cmd/godoc, approx 0.1% each.
For #6853 and #9930
Change-Id: I009616df797760b01e09f06357a2d6fd6ebcf307
Reviewed-on: https://go-review.googlesource.com/19767
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
All [0]T values are equal.
[1]T values are equal iff their sole components are.
This types show up most frequently as a by-product of variadic
function calls, such as fmt.Printf("abc") or fmt.Printf("%v", x).
Cuts 12k off cmd/go and 22k off golang.org/x/tools/cmd/godoc, approx 0.1% each.
For #6853 and #9930
Change-Id: Ic9b7aeb8cc945804246340f6f5e67bbf6008773e
Reviewed-on: https://go-review.googlesource.com/19766
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
You can not use cannot, but you cannot spell cannot can not.
Change-Id: I2f0971481a460804de96fd8c9e46a9cc62a3fc5b
Reviewed-on: https://go-review.googlesource.com/19772
Reviewed-by: Rob Pike <r@golang.org>
The old code used an extra function call and switch to inspect the
current token and determine the new state of curio.nlsemi. However,
the lexer knows the token w/o the need of an extra test and thus
can set curio.nlsemi directly:
- removed need for extra function call in next
- renamed _yylex to next
- set nlsemi at the point a token is identified
- moved nlsemi from curio to lexer - it's really part of the lexer state
This change makes the lexer call sequence less convoluted and should
also speed up the lexing a bit.
Change-Id: Iaf2683081f04231cb62c94e1400d455f98f6f82a
Reviewed-on: https://go-review.googlesource.com/19765
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Lower-case letters are more common in identifiers.
Change-Id: I49c39e3ac810eea57d15c1433608daec212c9792
Reviewed-on: https://go-review.googlesource.com/19760
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Rename yySymType to lexer; should eventually capture all lexer state.
Embed lexer in parser and access lexer token data directly.
Change-Id: I246194705d594f80426f3ba77d8580af9185daf7
Reviewed-on: https://go-review.googlesource.com/19759
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
