LLV and SCV are 64-bit load-linked and store-conditional. They
were used in runtime as #define WORD. Change them to normal
instruction form.
NOOP is hardware no-op. It was written as WORD $0. Make a name
for it for better disassembly output.
Fixes#12561.
Fixes#18238.
Change-Id: I82c667ce756fa83ef37b034b641e8c4366335e83
Reviewed-on: https://go-review.googlesource.com/40297
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change adds several examples, with emphasis on special or edge
cases such as a directory parameter consisting of an empty string.
Change-Id: Ib4ac3d0f6d503493eeed0c4fda7c12acf782e9e2
Reviewed-on: https://go-review.googlesource.com/43010
Reviewed-by: Steve Francia <spf@golang.org>
Run-TryBot: Jaana Burcu Dogan <jbd@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Noticed while looking at #20356.
Cuts 160k (1%) off of the cmd/compile binary.
Change-Id: If2397bc6971d6be9be6975048adecb0b5efa6d66
Reviewed-on: https://go-review.googlesource.com/43501
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Previous CL (cmd/internal/objabi: shrink SymType down to a uint8) shrinks
SymType down to a uint8 but forgot making according change in goobj.
Fixes#20296
Also add a test to catch such Goobj format inconsistency bug
Change-Id: Ib43dd7122cfcacf611a643814e95f8c5a924941f
Reviewed-on: https://go-review.googlesource.com/42971
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Mark variables as used even when they appear within an expression
context which we can't type-check; e.g., because the expression is
erroneous, or comes from an import "C" declaration.
Fixes#20358.
Change-Id: Ib28cc78d3867c597c7a1ace54de09ada02f5b33a
Reviewed-on: https://go-review.googlesource.com/43500
Reviewed-by: Alan Donovan <adonovan@google.com>
Attaching positions to SB, SP, initial mem can result in
less-good line-numbering when compiled for debugging.
This "fix" also removes source position from a zero-valued
struct (but not from its fields) and from a zero-length
array constant.
This may be a general problem for constants in entry blocks.
Fixes#20367.
Change-Id: I7e9df3341be2e2f60f127d35bb31e43cdcfce9a1
Reviewed-on: https://go-review.googlesource.com/43531
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Enhance the one-live-memory-at-a-time check to run during many
more phases of the SSA backend. Also make it work in an interblock
fashion.
Change types.IsMemory to return true for tuples containing a memory type.
Fix trim pass to build the merged phi correctly. Doesn't affect
code but allows the check to pass after trim runs.
Switch the AddTuple* ops to take the memory-containing tuple argument second.
Update #20335
Change-Id: I5b03ef3606b75a9e4f765276bb8b183cdc172b43
Reviewed-on: https://go-review.googlesource.com/43495
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Documentation of build.Import says:
// If the path is a local import path naming a package that can be imported
// using a standard import path, the returned package will set p.ImportPath
// to that path.
// ...
// If an error occurs, Import returns a non-nil error and a non-nil
// *Package containing partial information.
That behavior was previously untested, and broken by change in CL 33158.
Fix that by avoiding returning early on error for local import paths.
First, gather partial information, and only then check that the p.Dir
directory exists.
Add tests for this behavior.
Fixes#19769.
Fixes#20175 (duplicate of #19769).
Updates #17863.
Change-Id: I169cb35291099d05e02aaa3cb23a7403d1cc3657
Reviewed-on: https://go-review.googlesource.com/42350
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently proto symbolization uses runtime.FuncForPC and assumes each
PC maps to a single frame. This isn't true in the presence of inlining
(even with leaf-only inlining this can get incorrect results).
Change PC symbolization to use runtime.CallersFrames to expand each PC
to all of the frames at that PC.
Change-Id: I8d20dff7495a5de495ae07f569122c225d433ced
Reviewed-on: https://go-review.googlesource.com/41256
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Proto profile conversion is inconsistent about call vs return PCs in
profile locations. The proto defines locations to be call PCs. This is
what we do when proto-izing CPU profiles, but we fail to convert the
return PCs in memory and count profile stacks to call PCs when
converting them to proto locations.
Fix this in the heap and count profile conversion functions.
TestConvertMemProfile also hard-codes this failure to convert from
return PCs to call PCs, so fix up the addresses in the synthesized
profile to be return PCs while checking that we get call PCs out of
the conversion.
Change-Id: If1fc028b86fceac6d71a2d9fa6c41ff442c89296
Reviewed-on: https://go-review.googlesource.com/42951
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Adjust finddebugruntimepath to look for runtime/debug.go file
instead of runtime/runtime.go. This actually finds runtime.GOMAXPROCS
in every Go executable (including windows).
I also included "-Wl,-T,fix_debug_gdb_scripts.ld" parameter to gcc
invocation on windows to work around gcc bug (see #20183 for details).
This CL only fixes windows -buildmode=exe, buildmode=c-archive
is still broken.
Thanks to Egon Elbre and Nick Clifton for investigation.
Fixes#20183Fixes#20218
Change-Id: I5369a4db3913226aef3d9bd6317446856b0a1c34
Reviewed-on: https://go-review.googlesource.com/43331
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #20292. (See discussion in that issue.)
Change-Id: I44cd69394fc47a01776905ec34305ba524c89883
Reviewed-on: https://go-review.googlesource.com/43452
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Make yellow the last highlight color rather than the first.
Yellow is also the color that Chrome uses to highlight
search results, which can be confusing.
Also, when Night Shift is on on macOS,
yellow highlighting is completely invisible.
I suppose should be sleeping instead.
Also, remove a completed TODO.
Change-Id: I0eb4439272fad9ccb5fe8e2cf409fdd5dc15b26e
Reviewed-on: https://go-review.googlesource.com/43463
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When compiling concurrently, we walk all functions before compiling
any of them. Walking functions can cause variables to switch from
being non-addrtaken to addrtaken, e.g. to prepare for a runtime call.
Typechecking propagates addrtaken-ness of closure variables to
their outer variables, so that capturevars can decide whether to
pass the variable's value or a pointer to it.
When all functions are compiled immediately, as long as the containing
function is compiled prior to the closure, this propagation has no effect.
When compilation is deferred, though, in rare cases, this results in
a change in the addrtaken-ness of a variable in the outer function,
which in turn changes the compiler's output.
(This is rare because in a great many cases, a temporary has been
introduced, insulating the outer variable from modification.)
But concurrent compilation must generate identical results.
To fix this, track whether capturevars has run.
If it has, there is no need to update outer variables
when closure variables change.
Capturevars always runs before any functions are walked or compiled.
The remainder of the changes in this CL are to support the test.
In particular, -d=compilelater forces the compiler to walk all
functions before compiling any of them, despite being non-concurrent.
This is useful because -live is fundamentally incompatible with
concurrent compilation, but we want -c=1 to have no behavior changes.
Fixes#20250
Change-Id: I89bcb54268a41e8588af1ac8cc37fbef856a90c2
Reviewed-on: https://go-review.googlesource.com/42853
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
When writing tar files by using the FileInfoHeader
the type bits was set in the mode field of the header
This is not correct according to the standard (GNU/Posix) and
other implementations.
Fixed#20150
Change-Id: I3be7d946a1923ad5827cf45c696546a5e287ebba
Reviewed-on: https://go-review.googlesource.com/42093
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
While at it, unindent source text so column values are easier
to read, remove unnecessary text in output, and simplify the
loop.
Fixes#20346.
Change-Id: I0fde02b9e4242383da427f4cf4c6c13dd0ab3b47
Reviewed-on: https://go-review.googlesource.com/43450
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In some cases it is desirable to customize the way the DNS server is
contacted, for instance to use a specific LocalAddr. While most
operating-system level resolvers do not allow this, we have the
opportunity to do so with the Go resolver. Most of the code was
already in place to allow tests to override the dialer. This exposes
that functionality, and as a side effect eliminates the need for a
testing hook.
Fixes#17404
Change-Id: I1c5e570f8edbcf630090f8ec6feb52e379e3e5c0
Reviewed-on: https://go-review.googlesource.com/37260
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
runtime.gchelper depends on the non-atomic load of work.ndone
happening strictly before the atomic add of work.nwait. Until very
recently (commit 978af9c2db, fixing #20334), the compiler reordered
these operations. This created a race since work.ndone can change as
soon as work.nwait is equal to work.ndone. If that happened, more than
one gchelper could attempt to wake up the work.alldone note, causing a
"double wakeup" panic.
This was fixed in the compiler, but to make this code less subtle,
make the load of work.ndone atomic. This clearly forces the order of
these operations, ensuring the race doesn't happen.
Fixes#19305 (though really 978af9c2db fixed it).
Change-Id: Ieb1a84e1e5044c33ac612c8a5ab6297e7db4c57d
Reviewed-on: https://go-review.googlesource.com/43311
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This adds debugging information when we panic with "heapBitsForSpan:
base out of range".
Updates #20259.
Change-Id: I0dc1a106aa9e9531051c7d08867ace5ef230eb3f
Reviewed-on: https://go-review.googlesource.com/43310
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
On Windows the drive letter is sometime "c:" and sometimes "C:".
Fixes#20336.
Change-Id: I38c86999af9522c51470d60016729d41cfec6b25
Reviewed-on: https://go-review.googlesource.com/43390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
TestCgoContainsSpace builds a small program which mimics $CC.
Usually, $CC attempts to compile a trivial code to detect its own
supported flags (i.e. "-no-pie", which must be passed on some systems),
however the mimic didn't consider these cases.
This CL solve the issue.
Also, use the same name as $CC, it may solve other potential problems.
Fixes#20324
Change-Id: I7a00ac016a5fd0667540f2a715371f8152edc395
Reviewed-on: https://go-review.googlesource.com/43330
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Tuple ops are weird. They are essentially a pair of ops,
one which consumes a mem and one which generates a mem (the Select1).
The schedule pass didn't handle these quite right.
Fix the scheduler to include both parts of the paired op in
the store chain. That makes sure that loads are correctly ordered
with respect to the first of the pair.
Add a check for the ssacheck builder, that there is only one
live store at a time. I thought we already had such a check, but
apparently not...
Fixes#20335
Change-Id: I59eb3446a329100af38d22820b1ca2190ca46a78
Reviewed-on: https://go-review.googlesource.com/43294
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The writebarrier test has to change.
Now that T23 composite literals are passed to the backend,
they get SSA'd, so writes to their fields are treated separately,
so the relevant part of the first write to t23 is now a dead store.
Preserve the intent of the test by splitting it up into two functions.
Reduces code size a bit:
name old object-bytes new object-bytes delta
Template 386k ± 0% 386k ± 0% ~ (all equal)
Unicode 202k ± 0% 202k ± 0% ~ (all equal)
GoTypes 1.16M ± 0% 1.16M ± 0% ~ (all equal)
Compiler 3.92M ± 0% 3.91M ± 0% -0.19% (p=0.008 n=5+5)
SSA 7.91M ± 0% 7.91M ± 0% ~ (all equal)
Flate 228k ± 0% 228k ± 0% -0.05% (p=0.008 n=5+5)
GoParser 283k ± 0% 283k ± 0% ~ (all equal)
Reflect 952k ± 0% 952k ± 0% -0.06% (p=0.008 n=5+5)
Tar 188k ± 0% 188k ± 0% -0.09% (p=0.008 n=5+5)
XML 406k ± 0% 406k ± 0% -0.02% (p=0.008 n=5+5)
[Geo mean] 649k 648k -0.04%
Fixes#18872
Change-Id: Ifeed0f71f13849732999aa731cc2bf40c0f0e32a
Reviewed-on: https://go-review.googlesource.com/43154
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
v is not a pointer receiver, and v.typ isn't used in the lines below.
The assignment is dead. Remove it.
Keep the comment, as it refers to the whole case block and not just the
removed line.
Change-Id: Icb2d20c287d9a41bf620ebe5cdec764cd84178a7
Reviewed-on: https://go-review.googlesource.com/43134
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
They are not exported and not used in the compiler or standard library.
Change-Id: Ie1d210464f826742d282f12258ed1792cbd2d188
Reviewed-on: https://go-review.googlesource.com/43135
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reuse block head or preceding instruction's line number for
register allocator's spill, fill, copy, rematerialization
instructionsl; and also for phi, and for no-src-pos
instructions. Assembler creates same line number tables
for copy-predecessor-line and for no-src-pos,
but copy-predecessor produces better-looking assembly
language output with -S and with GOSSAFUNC, and does not
require changes to tests of existing assembly language.
Split "copyInto" into two cases, one for register allocation,
one for otherwise. This caused the test score line change
count to increase by one, which may reflect legitimately
useful information preserved. Without any special treatment
for copyInto, the change count increases by 21 more, from
51 to 72 (i.e., quite a lot).
There is a test; using two naive "scores" for line number
churn, the old numbering is 2x or 4x worse.
Fixes#18902.
Change-Id: I0a0a69659d30ee4e5d10116a0dd2b8c5df8457b1
Reviewed-on: https://go-review.googlesource.com/36207
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Fixes#7906
Change-Id: Ibcf9cd670593241921ab3c426ff7357f799ebc3e
Reviewed-on: https://go-review.googlesource.com/43072
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Implements detection of x86 cpu features that
are used in the go standard library.
Changes all standard library packages to use the new cpu package
instead of using runtime internal variables to check x86 cpu features.
Updates: #15403
Change-Id: I2999a10cb4d9ec4863ffbed72f4e021a1dbc4bb9
Reviewed-on: https://go-review.googlesource.com/41476
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Eliminates stores of values that have just been loaded from the same
location. Handles the common case where there are up to 3 intermediate
stores to non-overlapping struct fields.
For example the loads and stores of x.a, x.b and x.d in the following
function are now removed:
type T struct {
a, b, c, d int
}
func f(x *T) {
y := *x
y.c += 8
*x = y
}
Before this CL (s390x):
TEXT "".f(SB)
MOVD "".x(R15), R5
MOVD (R5), R1
MOVD 8(R5), R2
MOVD 16(R5), R0
MOVD 24(R5), R4
ADD $8, R0, R3
STMG R1, R4, (R5)
RET
After this CL (s390x):
TEXT "".f(SB)
MOVD "".x(R15), R1
MOVD 16(R1), R0
ADD $8, R0, R0
MOVD R0, 16(R1)
RET
In total these rules are triggered ~5091 times during all.bash,
which is broken down as:
Intermediate stores | Triggered
--------------------+----------
0 | 1434
1 | 2508
2 | 888
3 | 261
--------------------+----------
Change-Id: Ia4721ae40146aceec1fdd3e65b0e9283770bfba5
Reviewed-on: https://go-review.googlesource.com/38793
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The files PPC64.rules and rewritePPC64.go were out of sync due to
conflicts between CL 41630 and CL 42145 (i.e. running 'go run *.go'
in the gen directory resulted in unexpected changes).
Change-Id: I1d409656b66afeab6cb9c6df9b3dcab7859caa75
Reviewed-on: https://go-review.googlesource.com/43091
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
This can make life easier for Delve (and other debuggers),
and can help them with bug reports.
Sample producer field (from objdump):
<48> DW_AT_producer : Go cmd/compile devel +8a59dbf41a Mon May 8 16:02:44 2017 -0400
Change-Id: I0605843c959b53a60a25a3b870aa8755bf5d5b13
Reviewed-on: https://go-review.googlesource.com/33588
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We do a division by the elem type size to check if the array size would
be too large for the virtual address space. This is a silly check if the
size is 0, but the problem is that it means a division by zero and a
panic.
Since arrays of empty structs are valid in a regular program, make them
also work in reflect.
Use a separate, explicit test with struct{}{} to make sure the test for
a zero-sized type is not confused with the rest.
Fixes#20313.
Change-Id: I47b8b87e6541631280b79227bdea6a0f6035c9e0
Reviewed-on: https://go-review.googlesource.com/43131
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This adds math/bits intrinsics for OnesCount, Len, TrailingZeros on
ppc64x.
benchmark old ns/op new ns/op delta
BenchmarkLeadingZeros-16 4.26 1.71 -59.86%
BenchmarkLeadingZeros16-16 3.04 1.83 -39.80%
BenchmarkLeadingZeros32-16 3.31 1.82 -45.02%
BenchmarkLeadingZeros64-16 3.69 1.71 -53.66%
BenchmarkTrailingZeros-16 2.55 1.62 -36.47%
BenchmarkTrailingZeros32-16 2.55 1.77 -30.59%
BenchmarkTrailingZeros64-16 2.78 1.62 -41.73%
BenchmarkOnesCount-16 3.19 0.93 -70.85%
BenchmarkOnesCount32-16 2.55 1.18 -53.73%
BenchmarkOnesCount64-16 3.22 0.93 -71.12%
Update #18616
I also made a change to bits_test.go because when debugging some failures
the output was not quite providing the right argument information.
Change-Id: Ia58d31d1777cf4582a4505f85b11a1202ca07d3e
Reviewed-on: https://go-review.googlesource.com/41630
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Keith Randall <khr@golang.org>
When constructing a new type for an array type in ArrayOf, we don't
reset tflag to 0. All the other methods in the package, such as SliceOf,
do this already. This results in the new array type having weird issues
when being printed, such as having tflagExtraStar set when it shouldn't.
That flag removes the first char to get rid of '*', but when used
incorrectly in this case it eats the '[' character leading to broken
strings like "3]int".
This was fixed in 56752eb2 for issue #16722, but ArrayOf was missed.
Also make the XM test struct have a non-zero size as that leads to a
division by zero panic in ArrayOf.
Fixes#20311.
Change-Id: I18f1027fdbe9f71767201e7424269c3ceeb23eb5
Reviewed-on: https://go-review.googlesource.com/43130
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also change type from map[*types.Type]bool to map[*types.Type]struct{}.
This is basically a clean-up.
Change-Id: I167583eff0fa1070a7522647219476033b52b840
Reviewed-on: https://go-review.googlesource.com/41859
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
OpVarXXX Values don't generate instructions,
so there's no reason not to duplicate them,
and duplicating them generates better code
(fewer branches).
This requires changing the start/end accounting
to correctly handle the case in which we have run
of Values beginning with an OpVarXXX, e.g.
OpVarDef, OpZeroWB, OpMoveWB.
In that case, the sequence of values should begin
at the OpZeroWB, not the OpVarDef.
This also lays the groundwork for experimenting
with allowing duplication of some scalar stores.
Shrinks function text sizes a tiny amount:
name old object-bytes new object-bytes delta
Template 381k ± 0% 381k ± 0% -0.01% (p=0.008 n=5+5)
Unicode 203k ± 0% 203k ± 0% -0.04% (p=0.008 n=5+5)
GoTypes 1.17M ± 0% 1.17M ± 0% -0.01% (p=0.008 n=5+5)
SSA 8.24M ± 0% 8.24M ± 0% -0.00% (p=0.008 n=5+5)
Flate 230k ± 0% 230k ± 0% ~ (all equal)
GoParser 286k ± 0% 286k ± 0% ~ (all equal)
Reflect 1.00M ± 0% 1.00M ± 0% ~ (all equal)
Tar 189k ± 0% 189k ± 0% ~ (all equal)
XML 415k ± 0% 415k ± 0% -0.01% (p=0.008 n=5+5)
Updates #19838
Change-Id: Ic5ef30855919f1468066eba08ae5c4bd9a01db27
Reviewed-on: https://go-review.googlesource.com/42011
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
