Commit graph

111 commits

Author SHA1 Message Date
Ilya Tocar
4201c2077e cmd/compile: omit racefuncentry/exit when they are not needed
When compiling with -race, we insert calls to racefuncentry,
into every function. Add a rule that removes them in leaf functions,
without instrumented loads/stores.
Shaves ~30kb from "-race" version of go tool:

file difference:
go_old 15626192
go_new 15597520 [-28672 bytes]

section differences:
global text (code) = -24513 bytes (-0.358598%)
read-only data = -5849 bytes (-0.167064%)
Total difference -30362 bytes (-0.097928%)

Fixes #24662

Change-Id: Ia63bf1827f4cf2c25e3e28dcd097c150994ade0a
Reviewed-on: https://go-review.googlesource.com/121235
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-08-20 22:07:22 +00:00
Ilya Tocar
a3593685cf cmd/compile/internal/ssa: remove useless zero extension
We generate MOVBLZX for byte-sized LoadReg, so
(MOVBQZX (LoadReg (Arg))) is the same as
(LoadReg (Arg)). Remove those zero extension where possible.
Triggers several times during all.bash.

Fixes #25378
Updates #15300

Change-Id: If50656e66f217832a13ee8f49c47997f4fcc093a
Reviewed-on: https://go-review.googlesource.com/115617
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-08-20 21:38:20 +00:00
Ilya Tocar
c292b32f33 cmd/compile: enable disjoint memmove inlining on amd64
Memmove can use AVX/prefetches/other optional instructions, so
only do it for small sizes, when call overhead dominates.

Change-Id: Ice5e93deb11462217f7fb5fc350b703109bb4090
Reviewed-on: https://go-review.googlesource.com/112517
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2018-08-20 21:10:12 +00:00
David Chase
0029cd479e cmd/compile: add LocalAddr that takes SP,mem operands
Lack of a well-defined order between VarDef and related
address operations sometimes causes problems with store order
and write barrier transformations; glitches in the order are
made irreparable (by later optimizations) if the two parts of
the glitch straddle a split in the original block caused by
insertion of a write barrier diamond.

Fix this by creating a LocalAddr for addresses of locals
(what VarDef matters for) that takes a memory input to
help make the order explicit.  Addr is modified to only
be legal for SB operand, so there is no overlap between
Addr and LocalAddr uses (there may be some downstream
cleanup from this).

Changes to generic.rules and rewrite.go ensure that codegen
tests continue to pass; CSE of LocalAddr is impaired, not
quite sure of the cost.

Fixes #26105.

Change-Id: Id4192b4440aa4e9d7ba54a465c456df9b530b515
Reviewed-on: https://go-review.googlesource.com/122483
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2018-07-12 18:45:31 +00:00
Michael Munday
5654114d04 cmd/compile: use math/bits functions where possible
Use the math/bits functions to calculate the number of leading/
trailing zeros, bit length and the population count.

The math/bits package is built as part of the bootstrap process
so we do not need to provide an alternative implementation for
Go versions prior to 1.9.

Passes toolstash-check -all.

Change-Id: I393b4cc1c8accd0ca7cb3599d3926fa6319b574f
Reviewed-on: https://go-review.googlesource.com/113336
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-21 09:20:25 +00:00
David Chase
c2c1822b12 cmd/compile: assign and preserve statement boundaries.
A new pass run after ssa building (before any other
optimization) identifies the "first" ssa node for each
statement. Other "noise" nodes are tagged as being never
appropriate for a statement boundary (e.g., VarKill, VarDef,
Phi).

Rewrite, deadcode, cse, and nilcheck are modified to move
the statement boundaries forward whenever possible if a
boundary-tagged ssa value is removed; never-boundary nodes
are ignored in this search (some operations involving
constants are also tagged as never-boundary and also ignored
because they are likely to be moved or removed during
optimization).

Code generation treats all nodes except those explicitly
marked as statement boundaries as "not statement" nodes,
and floats statement boundaries to the beginning of each
same-line run of instructions found within a basic block.

Line number html conversion was modified to make statement
boundary nodes a bit more obvious by prepending a "+".

The code in fuse.go that glued together the value slices
of two blocks produced a result that depended on the
former capacities (not lengths) of the two slices.  This
causes differences in the 386 bootstrap, and also can
sometimes put values into an order that does a worse job
of preserving statement boundaries when values are removed.

Portions of two delve tests that had caught problems were
incorporated into ssa/debug_test.go.  There are some
opportunities to do better with optimized code, but the
next-ing is not lying or overly jumpy.

Over 4 CLs, compilebench geomean measured binary size
increase of 3.5% and compile user time increase of 3.8%
(this is after optimization to reuse a sparse map instead
of creating multiple maps.)

This CL worsens the optimized-debugging experience with
Delve; we need to work with the delve team so that
they can use the is_stmt marks that we're emitting now.

The reference output changes from time to time depending
on other changes in the compiler, sometimes better,
sometimes worse.

This CL now includes a test ensuring that 99+% of the lines
in the Go command itself (a handy optimized binary) include
is_stmt markers.

Change-Id: I359c94e06843f1eb41f9da437bd614885aa9644a
Reviewed-on: https://go-review.googlesource.com/102435
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-05-14 14:09:49 +00:00
Michael Munday
6d00e8c478 cmd/compile: convert memmove call into Move when arguments are disjoint
Move ops can be faster than memmove calls because the number of bytes
to be moved is fixed and they don't incur the overhead of a call.
This change allows memmove to be converted into a Move op when the
arguments are disjoint.

The optimization is only enabled on s390x at the moment, however
other architectures may also benefit from it in the future. The
memmove inlining rule triggers an extra 12 times when compiling the
standard library. It will most likely make more of a difference as the
disjoint function is improved over time (to recognize fresh heap
allocations for example).

Change-Id: I9af570dcfff28257b8e59e0ff584a46d8e248310
Reviewed-on: https://go-review.googlesource.com/110064
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-05-09 11:20:40 +00:00
Keith Randall
f32348669c cmd/compile: rename memory-using operations
Some *mem ops are loads, some are stores, some are modifications.
Replace mem->load for the loads.
Replace mem->store for the stores.
Replace mem->modify for the load-modify-stores.

The only semantic change in this CL is to mark
ADD(Q|L)constmodify (which used to be ADD(Q|L)constmem) as
both a read and a write, instead of just a write. This is arguably
a bug fix, but the bug isn't triggerable at the moment, see CL 112157.

Change-Id: Iccb45aea817b606adb2d712ff99b10ee28e4616a
Reviewed-on: https://go-review.googlesource.com/112159
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-05-08 19:16:50 +00:00
Michael Munday
f31a18ded4 cmd/compile: add some generic composite type optimizations
Propagate values through some wide Zero/Move operations. Among
other things this allows us to optimize some kinds of array
initialization. For example, the following code no longer
requires a temporary be allocated on the stack. Instead it
writes the values directly into the return value.

func f(i uint32) [4]uint32 {
    return [4]uint32{i, i+1, i+2, i+3}
}

The return value is unnecessarily cleared but removing that is
probably a task for dead store analysis (I think it needs to
be able to match multiple Store ops to wide Zero ops).

In order to reliably remove stack variables that are rendered
unnecessary by these new rules I've added a new generic version
of the unread autos elimination pass.

These rules are triggered more than 5000 times when building and
testing the standard library.

Updates #15925 (fixes for arrays of up to 4 elements).
Updates #24386 (fixes for up to 4 kept elements).
Updates #24416.

compilebench results:

name       old time/op       new time/op       delta
Template         353ms ± 5%        359ms ± 3%    ~     (p=0.143 n=10+10)
Unicode          219ms ± 1%        217ms ± 4%    ~     (p=0.740 n=7+10)
GoTypes          1.26s ± 1%        1.26s ± 2%    ~     (p=0.549 n=9+10)
Compiler         6.00s ± 1%        6.08s ± 1%  +1.42%  (p=0.000 n=9+8)
SSA              15.3s ± 2%        15.6s ± 1%  +2.43%  (p=0.000 n=10+10)
Flate            237ms ± 2%        240ms ± 2%  +1.31%  (p=0.015 n=10+10)
GoParser         285ms ± 1%        285ms ± 1%    ~     (p=0.878 n=8+8)
Reflect          797ms ± 3%        807ms ± 2%    ~     (p=0.065 n=9+10)
Tar              334ms ± 0%        335ms ± 4%    ~     (p=0.460 n=8+10)
XML              419ms ± 0%        423ms ± 1%  +0.91%  (p=0.001 n=7+9)
StdCmd           46.0s ± 0%        46.4s ± 0%  +0.85%  (p=0.000 n=9+9)

name       old user-time/op  new user-time/op  delta
Template         337ms ± 3%        346ms ± 5%    ~     (p=0.053 n=9+10)
Unicode          205ms ±10%        205ms ± 8%    ~     (p=1.000 n=10+10)
GoTypes          1.22s ± 2%        1.21s ± 3%    ~     (p=0.436 n=10+10)
Compiler         5.85s ± 1%        5.93s ± 0%  +1.46%  (p=0.000 n=10+8)
SSA              14.9s ± 1%        15.3s ± 1%  +2.62%  (p=0.000 n=10+10)
Flate            229ms ± 4%        228ms ± 6%    ~     (p=0.796 n=10+10)
GoParser         271ms ± 3%        275ms ± 4%    ~     (p=0.165 n=10+10)
Reflect          779ms ± 5%        775ms ± 2%    ~     (p=0.971 n=10+10)
Tar              317ms ± 4%        319ms ± 5%    ~     (p=0.853 n=10+10)
XML              404ms ± 4%        409ms ± 5%    ~     (p=0.436 n=10+10)

name       old alloc/op      new alloc/op      delta
Template        34.9MB ± 0%       35.0MB ± 0%  +0.26%  (p=0.000 n=10+10)
Unicode         29.3MB ± 0%       29.3MB ± 0%  +0.02%  (p=0.000 n=10+10)
GoTypes          115MB ± 0%        115MB ± 0%  +0.30%  (p=0.000 n=10+10)
Compiler         519MB ± 0%        521MB ± 0%  +0.30%  (p=0.000 n=10+10)
SSA             1.55GB ± 0%       1.57GB ± 0%  +1.34%  (p=0.000 n=10+9)
Flate           24.1MB ± 0%       24.2MB ± 0%  +0.10%  (p=0.000 n=10+10)
GoParser        28.1MB ± 0%       28.1MB ± 0%  +0.07%  (p=0.000 n=10+10)
Reflect         78.7MB ± 0%       78.7MB ± 0%  +0.03%  (p=0.000 n=8+10)
Tar             34.4MB ± 0%       34.5MB ± 0%  +0.12%  (p=0.000 n=10+10)
XML             43.2MB ± 0%       43.2MB ± 0%  +0.13%  (p=0.000 n=10+10)

name       old allocs/op     new allocs/op     delta
Template          330k ± 0%         330k ± 0%  -0.01%  (p=0.017 n=10+10)
Unicode           337k ± 0%         337k ± 0%  +0.01%  (p=0.000 n=9+10)
GoTypes          1.15M ± 0%        1.15M ± 0%  +0.03%  (p=0.000 n=10+10)
Compiler         4.77M ± 0%        4.77M ± 0%  +0.03%  (p=0.000 n=9+10)
SSA              12.5M ± 0%        12.6M ± 0%  +1.16%  (p=0.000 n=10+10)
Flate             221k ± 0%         221k ± 0%  +0.05%  (p=0.000 n=9+10)
GoParser          275k ± 0%         275k ± 0%  +0.01%  (p=0.014 n=10+9)
Reflect           944k ± 0%         944k ± 0%  -0.02%  (p=0.000 n=10+10)
Tar               324k ± 0%         323k ± 0%  -0.12%  (p=0.000 n=10+10)
XML               384k ± 0%         384k ± 0%  -0.01%  (p=0.001 n=10+10)

name       old object-bytes  new object-bytes  delta
Template         476kB ± 0%        476kB ± 0%  -0.04%  (p=0.000 n=10+10)
Unicode          218kB ± 0%        218kB ± 0%    ~     (all equal)
GoTypes         1.58MB ± 0%       1.58MB ± 0%  -0.04%  (p=0.000 n=10+10)
Compiler        6.25MB ± 0%       6.24MB ± 0%  -0.09%  (p=0.000 n=10+10)
SSA             15.9MB ± 0%       16.1MB ± 0%  +1.22%  (p=0.000 n=10+10)
Flate            304kB ± 0%        304kB ± 0%  -0.13%  (p=0.000 n=10+10)
GoParser         370kB ± 0%        370kB ± 0%  -0.00%  (p=0.000 n=10+10)
Reflect         1.27MB ± 0%       1.27MB ± 0%  -0.12%  (p=0.000 n=10+10)
Tar              421kB ± 0%        419kB ± 0%  -0.64%  (p=0.000 n=10+10)
XML              518kB ± 0%        517kB ± 0%  -0.12%  (p=0.000 n=10+10)

name       old export-bytes  new export-bytes  delta
Template        16.7kB ± 0%       16.7kB ± 0%    ~     (all equal)
Unicode         6.52kB ± 0%       6.52kB ± 0%    ~     (all equal)
GoTypes         29.2kB ± 0%       29.2kB ± 0%    ~     (all equal)
Compiler        88.0kB ± 0%       88.0kB ± 0%    ~     (all equal)
SSA              109kB ± 0%        109kB ± 0%    ~     (all equal)
Flate           4.49kB ± 0%       4.49kB ± 0%    ~     (all equal)
GoParser        8.10kB ± 0%       8.10kB ± 0%    ~     (all equal)
Reflect         7.71kB ± 0%       7.71kB ± 0%    ~     (all equal)
Tar             9.15kB ± 0%       9.15kB ± 0%    ~     (all equal)
XML             12.3kB ± 0%       12.3kB ± 0%    ~     (all equal)

name       old text-bytes    new text-bytes    delta
HelloSize        676kB ± 0%        672kB ± 0%  -0.59%  (p=0.000 n=10+10)
CmdGoSize       7.26MB ± 0%       7.24MB ± 0%  -0.18%  (p=0.000 n=10+10)

name       old data-bytes    new data-bytes    delta
HelloSize       10.2kB ± 0%       10.2kB ± 0%    ~     (all equal)
CmdGoSize        248kB ± 0%        248kB ± 0%    ~     (all equal)

name       old bss-bytes     new bss-bytes     delta
HelloSize        125kB ± 0%        125kB ± 0%    ~     (all equal)
CmdGoSize        145kB ± 0%        145kB ± 0%    ~     (all equal)

name       old exe-bytes     new exe-bytes     delta
HelloSize       1.46MB ± 0%       1.45MB ± 0%  -0.31%  (p=0.000 n=10+10)
CmdGoSize       14.7MB ± 0%       14.7MB ± 0%  -0.17%  (p=0.000 n=10+10)

Change-Id: Ic72b0c189dd542f391e1c9ab88a76e9148dc4285
Reviewed-on: https://go-review.googlesource.com/106495
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-05-08 10:31:21 +00:00
Josh Bleecher Snyder
743fd9171f cmd/compile: use AuxInt to store shift boundedness
Fixes ssacheck build.

Change-Id: Idf1d2ea9a971a1f17f2fca568099e870bb5d913f
Reviewed-on: https://go-review.googlesource.com/110122
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-04-30 00:59:26 +00:00
Josh Bleecher Snyder
9eb4590ad2 cmd/compile: simplify shifts using bounds from prove pass
The prove pass sometimes has bounds information
that later rewrite passes do not.

Use this information to mark shifts as bounded,
and then use that information to generate better code on amd64.
It may prove to be helpful on other architectures, too.

While here, coalesce the existing shift lowering rules.

This triggers 35 times building std+cmd. The full list is below.

Here's an example from runtime.heapBitsSetType:

			if nb < 8 {
				b |= uintptr(*p) << nb
				p = add1(p)
			} else {
				nb -= 8
			}

We now generate better code on amd64 for that left shift.

Updates #25087

vendor/golang_org/x/crypto/curve25519/mont25519_amd64.go:48:20: Proved Rsh8Ux64 bounded
runtime/mbitmap.go:1252:22: Proved Lsh64x64 bounded
runtime/mbitmap.go:1265:16: Proved Lsh64x64 bounded
runtime/mbitmap.go:1275:28: Proved Lsh64x64 bounded
runtime/mbitmap.go:1645:25: Proved Lsh64x64 bounded
runtime/mbitmap.go:1663:25: Proved Lsh64x64 bounded
runtime/mbitmap.go:1808:41: Proved Lsh64x64 bounded
runtime/mbitmap.go:1831:49: Proved Lsh64x64 bounded
syscall/route_bsd.go:227:23: Proved Lsh32x64 bounded
syscall/route_bsd.go:295:23: Proved Lsh32x64 bounded
syscall/route_darwin.go:40:23: Proved Lsh32x64 bounded
compress/bzip2/bzip2.go:384:26: Proved Lsh64x16 bounded
vendor/golang_org/x/net/route/address.go:370:14: Proved Lsh64x64 bounded
compress/flate/inflate.go:201:54: Proved Lsh64x64 bounded
math/big/prime.go:50:25: Proved Lsh64x64 bounded
vendor/golang_org/x/crypto/cryptobyte/asn1.go:464:43: Proved Lsh8x8 bounded
net/ip.go:87:21: Proved Rsh8Ux64 bounded
cmd/internal/goobj/read.go:267:23: Proved Lsh64x64 bounded
cmd/vendor/golang.org/x/arch/arm64/arm64asm/decode.go:534:27: Proved Lsh32x32 bounded
cmd/vendor/golang.org/x/arch/arm64/arm64asm/decode.go:544:27: Proved Lsh32x32 bounded
cmd/internal/obj/arm/asm5.go:1044:16: Proved Lsh32x64 bounded
cmd/internal/obj/arm/asm5.go:1065:10: Proved Lsh32x32 bounded
cmd/internal/obj/mips/obj0.go:1311:21: Proved Lsh32x64 bounded
cmd/compile/internal/syntax/scanner.go:352:23: Proved Lsh64x64 bounded
go/types/expr.go:222:36: Proved Lsh64x64 bounded
crypto/x509/x509.go:1626:9: Proved Rsh8Ux64 bounded
cmd/link/internal/loadelf/ldelf.go:823:22: Proved Lsh8x64 bounded
net/http/h2_bundle.go:1470:17: Proved Lsh8x8 bounded
net/http/h2_bundle.go:1477:46: Proved Lsh8x8 bounded
net/http/h2_bundle.go:1481:31: Proved Lsh64x8 bounded
cmd/compile/internal/ssa/rewriteARM64.go:18759:17: Proved Lsh64x64 bounded
cmd/compile/internal/ssa/sparsemap.go:70:23: Proved Lsh32x64 bounded
cmd/compile/internal/ssa/sparsemap.go:73:45: Proved Lsh32x64 bounded

Change-Id: I58bb72f3e6f12f6ac69be633ea7222c245438142
Reviewed-on: https://go-review.googlesource.com/109776
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
2018-04-29 15:59:45 +00:00
Geoff Berry
e244a7a7d3 cmd/compile/internal/ssa: add patterns for arm64 bitfield opcodes
Add patterns to match common idioms for EXTR, BFI, BFXIL, SBFIZ, SBFX,
UBFIZ and UBFX opcodes.

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

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

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

instead of

    add x1, x2, x0, lsl #3

Change-Id: I5644a8d70ac7a98e784a377a2b76ab47a3415a4b
Reviewed-on: https://go-review.googlesource.com/88355
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-15 14:10:41 +00:00
Balaram Makam
0e8b7110f6 cmd/compile/internal/ssa: inline small memmove for arm64
This patch enables the optimization for arm64 target.

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

Change-Id: I5714c474e7483d07ca338fbaf49beb4bbcc11c44
Reviewed-on: https://go-review.googlesource.com/98735
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-03-06 18:37:19 +00:00
Ilya Tocar
c2ccc48165 cmd/compile/internal/ssa: refactor zeroUpper32Bits
Explicitly whitelist args of OpSelect{1|2} that zero upper 32 bits.
Use better values in corresponding test.
This should have been a part of  CL 96815, but it was submitted, before
relevant comments.

Change-Id: Ic85d90a4471a17f6d64f8f5c405f21378bf3a30d
Reviewed-on: https://go-review.googlesource.com/97295
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-02-27 20:38:32 +00:00
Giovanni Bajo
68def82008 cmd/compile: fix bit-test rules for highest bit
Bit-test rules failed to match when matching the highest bit
of a word because operands in SSA are signed int64. Fix
them by treating them as unsigned (and correctly handling
32-bit operands as well).

Tests will be added in next CL.

Change-Id: I491c4e88e7e2f87e9bb72bd0d9fa5d4025b90736
Reviewed-on: https://go-review.googlesource.com/94765
Reviewed-by: Keith Randall <khr@golang.org>
2018-02-27 00:51:40 +00:00
Chad Rosier
ecd9e8a2fe cmd/compile/internal/ssa: combine zero stores into larger stores on arm64
This reduces the go tool binary on arm64 by 12k.

go1 results on Amberwing:
name                   old time/op    new time/op    delta
RegexpMatchEasy0_32       249ns ± 0%     249ns ± 0%    ~     (p=0.087 n=10+10)
RegexpMatchEasy0_1K       584ns ± 0%     584ns ± 0%    ~     (all equal)
RegexpMatchEasy1_32       246ns ± 0%     246ns ± 0%    ~     (p=1.000 n=10+10)
RegexpMatchEasy1_1K       806ns ± 0%     806ns ± 0%    ~     (p=0.706 n=10+9)
RegexpMatchMedium_32      314ns ± 0%     314ns ± 0%    ~     (all equal)
RegexpMatchMedium_1K     52.1µs ± 0%    52.1µs ± 0%    ~     (p=0.245 n=10+8)
RegexpMatchHard_32       2.75µs ± 1%    2.75µs ± 1%    ~     (p=0.690 n=10+10)
RegexpMatchHard_1K       78.9µs ± 0%    78.9µs ± 1%    ~     (p=0.295 n=9+9)
FmtFprintfEmpty          58.5ns ± 0%    58.5ns ± 0%    ~     (all equal)
FmtFprintfString          112ns ± 0%     112ns ± 0%    ~     (all equal)
FmtFprintfInt             117ns ± 0%     116ns ± 0%  -0.85%  (p=0.000 n=10+10)
FmtFprintfIntInt          181ns ± 0%     181ns ± 0%    ~     (all equal)
FmtFprintfPrefixedInt     222ns ± 0%     224ns ± 0%  +0.90%  (p=0.000 n=9+10)
FmtFprintfFloat           318ns ± 1%     322ns ± 0%    ~     (p=0.059 n=10+8)
FmtManyArgs               736ns ± 1%     735ns ± 0%    ~     (p=0.206 n=9+9)
Gzip                      437ms ± 0%     436ms ± 0%  -0.25%  (p=0.000 n=10+10)
HTTPClientServer         89.8µs ± 1%    90.2µs ± 2%    ~     (p=0.393 n=10+10)
JSONEncode               20.1ms ± 1%    20.2ms ± 1%    ~     (p=0.065 n=9+10)
JSONDecode               94.2ms ± 1%    93.9ms ± 1%  -0.42%  (p=0.043 n=10+10)
GobDecode                12.7ms ± 1%    12.8ms ± 2%  +0.94%  (p=0.019 n=10+10)
GobEncode                12.1ms ± 0%    12.1ms ± 0%    ~     (p=0.052 n=10+10)
Mandelbrot200            5.06ms ± 0%    5.05ms ± 0%  -0.04%  (p=0.000 n=9+10)
TimeParse                 450ns ± 3%     446ns ± 0%    ~     (p=0.238 n=10+9)
TimeFormat                485ns ± 1%     483ns ± 1%    ~     (p=0.073 n=10+10)
Template                 90.4ms ± 0%    90.7ms ± 0%  +0.29%  (p=0.000 n=8+10)
GoParse                  6.01ms ± 0%    6.03ms ± 0%  +0.35%  (p=0.000 n=10+10)
BinaryTree17              11.7s ± 0%     11.7s ± 0%    ~     (p=0.481 n=10+10)
Revcomp                   669ms ± 0%     669ms ± 0%    ~     (p=0.315 n=10+10)
Fannkuch11                3.40s ± 0%     3.37s ± 0%  -0.92%  (p=0.000 n=10+10)
[Geo mean]               67.9µs         67.9µs       +0.02%

name                   old speed      new speed      delta
RegexpMatchEasy0_32     128MB/s ± 0%   128MB/s ± 0%  -0.08%  (p=0.003 n=8+10)
RegexpMatchEasy0_1K    1.75GB/s ± 0%  1.75GB/s ± 0%    ~     (p=0.642 n=8+10)
RegexpMatchEasy1_32     130MB/s ± 0%   130MB/s ± 0%    ~     (p=0.690 n=10+9)
RegexpMatchEasy1_1K    1.27GB/s ± 0%  1.27GB/s ± 0%    ~     (p=0.661 n=10+9)
RegexpMatchMedium_32   3.18MB/s ± 0%  3.18MB/s ± 0%    ~     (all equal)
RegexpMatchMedium_1K   19.7MB/s ± 0%  19.6MB/s ± 0%    ~     (p=0.190 n=10+9)
RegexpMatchHard_32     11.6MB/s ± 0%  11.6MB/s ± 1%    ~     (p=0.669 n=10+10)
RegexpMatchHard_1K     13.0MB/s ± 0%  13.0MB/s ± 0%    ~     (p=0.718 n=9+9)
Gzip                   44.4MB/s ± 0%  44.5MB/s ± 0%  +0.24%  (p=0.000 n=10+10)
JSONEncode             96.5MB/s ± 1%  96.1MB/s ± 1%    ~     (p=0.065 n=9+10)
JSONDecode             20.6MB/s ± 1%  20.7MB/s ± 1%  +0.42%  (p=0.041 n=10+10)
GobDecode              60.6MB/s ± 1%  60.0MB/s ± 2%  -0.92%  (p=0.016 n=10+10)
GobEncode              63.4MB/s ± 0%  63.6MB/s ± 0%    ~     (p=0.055 n=10+10)
Template               21.5MB/s ± 0%  21.4MB/s ± 0%  -0.30%  (p=0.000 n=9+10)
GoParse                9.64MB/s ± 0%  9.61MB/s ± 0%  -0.36%  (p=0.000 n=10+10)
Revcomp                 380MB/s ± 0%   380MB/s ± 0%    ~     (p=0.323 n=10+10)
[Geo mean]             56.0MB/s       55.9MB/s       -0.07%

Change-Id: Ia732fa57fbcf4767d72382516d9f16705d177736
Reviewed-on: https://go-review.googlesource.com/96435
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-27 00:07:25 +00:00
Ilya Tocar
f4d9c30901 cmd/compile/internal/amd64: use appropriate NEG for div
Currently we generate NEGQ for DIV{Q,L,W}. By generating NEGL and NEGW,
we will reduce code size, because NEGL doesn't require rex prefix.
This also guarantees that upper 32 bits are zeroed, so we can revert CL 85736,
and remove zero-extensions of DIVL results.
Also adds test for redundant zero extend elimination.

Fixes #23310

Change-Id: Ic58c3104c255a71371a06e09d10a975bbe5df587
Reviewed-on: https://go-review.googlesource.com/96815
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2018-02-26 20:09:21 +00:00
philhofer
2d0172c3a7 cmd/compile/internal/ssa: emit csel on arm64
Introduce a new SSA pass to generate CondSelect intstrutions,
and add CondSelect lowering rules for arm64.

In order to make the CSEL instruction easier to optimize,
and to simplify the introduction of CSNEG, CSINC, and CSINV
in the future, modify the CSEL instruction to accept a condition
code in the aux field.

Notably, this change makes the go1 Gzip benchmark
more than 10% faster.

Benchmarks on a Cavium ThunderX:

name                      old time/op    new time/op    delta
BinaryTree17-96              15.9s ± 6%     16.0s ± 4%     ~     (p=0.968 n=10+9)
Fannkuch11-96                7.17s ± 0%     7.00s ± 0%   -2.43%  (p=0.000 n=8+9)
FmtFprintfEmpty-96           208ns ± 1%     207ns ± 0%     ~     (p=0.152 n=10+8)
FmtFprintfString-96          379ns ± 0%     375ns ± 0%   -0.95%  (p=0.000 n=10+9)
FmtFprintfInt-96             385ns ± 0%     383ns ± 0%   -0.52%  (p=0.000 n=9+10)
FmtFprintfIntInt-96          591ns ± 0%     586ns ± 0%   -0.85%  (p=0.006 n=7+9)
FmtFprintfPrefixedInt-96     656ns ± 0%     667ns ± 0%   +1.71%  (p=0.000 n=10+10)
FmtFprintfFloat-96           967ns ± 0%     984ns ± 0%   +1.78%  (p=0.000 n=10+10)
FmtManyArgs-96              2.35µs ± 0%    2.25µs ± 0%   -4.63%  (p=0.000 n=9+8)
GobDecode-96                31.0ms ± 0%    30.8ms ± 0%   -0.36%  (p=0.006 n=9+9)
GobEncode-96                24.4ms ± 0%    24.5ms ± 0%   +0.30%  (p=0.000 n=9+9)
Gzip-96                      1.60s ± 0%     1.43s ± 0%  -10.58%  (p=0.000 n=9+10)
Gunzip-96                    167ms ± 0%     169ms ± 0%   +0.83%  (p=0.000 n=8+9)
HTTPClientServer-96          311µs ± 1%     308µs ± 0%   -0.75%  (p=0.000 n=10+10)
JSONEncode-96               65.0ms ± 0%    64.8ms ± 0%   -0.25%  (p=0.000 n=9+8)
JSONDecode-96                262ms ± 1%     261ms ± 1%     ~     (p=0.579 n=10+10)
Mandelbrot200-96            18.0ms ± 0%    18.1ms ± 0%   +0.17%  (p=0.000 n=8+10)
GoParse-96                  14.0ms ± 0%    14.1ms ± 1%   +0.42%  (p=0.003 n=9+10)
RegexpMatchEasy0_32-96       644ns ± 2%     645ns ± 2%     ~     (p=0.836 n=10+10)
RegexpMatchEasy0_1K-96      3.70µs ± 0%    3.49µs ± 0%   -5.58%  (p=0.000 n=10+10)
RegexpMatchEasy1_32-96       662ns ± 2%     657ns ± 2%     ~     (p=0.137 n=10+10)
RegexpMatchEasy1_1K-96      4.47µs ± 0%    4.31µs ± 0%   -3.48%  (p=0.000 n=10+10)
RegexpMatchMedium_32-96      844ns ± 2%     849ns ± 1%     ~     (p=0.208 n=10+10)
RegexpMatchMedium_1K-96      179µs ± 0%     182µs ± 0%   +1.20%  (p=0.000 n=10+10)
RegexpMatchHard_32-96       10.0µs ± 0%    10.1µs ± 0%   +0.48%  (p=0.000 n=10+9)
RegexpMatchHard_1K-96        297µs ± 0%     297µs ± 0%   -0.14%  (p=0.000 n=10+10)
Revcomp-96                   3.08s ± 0%     3.13s ± 0%   +1.56%  (p=0.000 n=9+9)
Template-96                  276ms ± 2%     275ms ± 1%     ~     (p=0.393 n=10+10)
TimeParse-96                1.37µs ± 0%    1.36µs ± 0%   -0.53%  (p=0.000 n=10+7)
TimeFormat-96               1.40µs ± 0%    1.42µs ± 0%   +0.97%  (p=0.000 n=10+10)
[Geo mean]                   264µs          262µs        -0.77%

Change-Id: Ie54eee4b3092af53e6da3baa6d1755098f57f3a2
Reviewed-on: https://go-review.googlesource.com/55670
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2018-02-20 06:00:54 +00:00
Chad Rosier
51932c326f cmd/compile: improve absorb shifts optimization for arm64
Current absorb shifts optimization can generate dead Value nodes which increase
use count of other live nodes. It will impact other optimizations (such as
combined loads) which are enabled based on specific use count. This patch fixes
the issue by decreasing the use count of nodes referenced by dead Value nodes
generated by absorb shifts optimization.

Performance impacts on go1 benchmarks (data collected on A57@2GHzx8):

name                     old time/op    new time/op    delta
BinaryTree17-8              6.28s ± 2%     6.24s ± 1%     ~     (p=0.065 n=10+9)
Fannkuch11-8                6.32s ± 0%     6.33s ± 0%   +0.17%  (p=0.000 n=10+10)
FmtFprintfEmpty-8          98.9ns ± 0%    99.2ns ± 0%   +0.34%  (p=0.000 n=9+7)
FmtFprintfString-8          183ns ± 1%     182ns ± 1%   -1.01%  (p=0.005 n=9+10)
FmtFprintfInt-8             199ns ± 1%     202ns ± 1%   +1.41%  (p=0.000 n=10+9)
FmtFprintfIntInt-8          272ns ± 1%     276ns ± 3%   +1.36%  (p=0.015 n=10+10)
FmtFprintfPrefixedInt-8     367ns ± 1%     369ns ± 1%   +0.68%  (p=0.042 n=10+10)
FmtFprintfFloat-8           491ns ± 1%     493ns ± 1%     ~     (p=0.064 n=10+10)
FmtManyArgs-8              1.31µs ± 1%    1.32µs ± 1%   +0.39%  (p=0.042 n=8+9)
GobDecode-8                17.0ms ± 2%    16.2ms ± 2%   -4.74%  (p=0.000 n=10+10)
GobEncode-8                13.7ms ± 2%    13.4ms ± 1%   -2.40%  (p=0.000 n=10+9)
Gzip-8                      844ms ± 0%     737ms ± 0%  -12.70%  (p=0.000 n=10+10)
Gunzip-8                   84.4ms ± 1%    83.9ms ± 0%   -0.55%  (p=0.000 n=10+8)
HTTPClientServer-8          122µs ± 1%     124µs ± 1%   +1.75%  (p=0.000 n=10+9)
JSONEncode-8               34.9ms ± 1%    32.4ms ± 0%   -7.11%  (p=0.000 n=10+9)
JSONDecode-8                150ms ± 0%     146ms ± 1%   -2.84%  (p=0.000 n=7+10)
Mandelbrot200-8            10.0ms ± 0%    10.0ms ± 0%     ~     (p=0.529 n=10+10)
GoParse-8                  8.18ms ± 1%    8.03ms ± 0%   -1.93%  (p=0.000 n=10+10)
RegexpMatchEasy0_32-8       209ns ± 0%     209ns ± 0%     ~     (p=0.248 n=10+9)
RegexpMatchEasy0_1K-8       789ns ± 1%     790ns ± 0%     ~     (p=0.361 n=10+10)
RegexpMatchEasy1_32-8       202ns ± 0%     202ns ± 1%     ~     (p=0.137 n=8+10)
RegexpMatchEasy1_1K-8      1.12µs ± 2%    1.12µs ± 1%     ~     (p=0.810 n=10+10)
RegexpMatchMedium_32-8      298ns ± 0%     298ns ± 0%     ~     (p=0.443 n=10+9)
RegexpMatchMedium_1K-8     83.0µs ± 5%    78.6µs ± 0%   -5.37%  (p=0.000 n=10+10)
RegexpMatchHard_32-8       4.32µs ± 0%    4.26µs ± 0%   -1.47%  (p=0.000 n=10+10)
RegexpMatchHard_1K-8        132µs ± 4%     126µs ± 0%   -4.41%  (p=0.000 n=10+9)
Revcomp-8                   1.11s ± 0%     1.11s ± 0%   +0.14%  (p=0.017 n=10+9)
Template-8                  155ms ± 1%     155ms ± 1%     ~     (p=0.796 n=10+10)
TimeParse-8                 774ns ± 1%     785ns ± 1%   +1.41%  (p=0.001 n=10+10)
TimeFormat-8                788ns ± 1%     806ns ± 1%   +2.24%  (p=0.000 n=10+9)

name                     old speed      new speed      delta
GobDecode-8              45.2MB/s ± 2%  47.5MB/s ± 2%   +4.96%  (p=0.000 n=10+10)
GobEncode-8              56.0MB/s ± 2%  57.4MB/s ± 1%   +2.44%  (p=0.000 n=10+9)
Gzip-8                   23.0MB/s ± 0%  26.3MB/s ± 0%  +14.55%  (p=0.000 n=10+10)
Gunzip-8                  230MB/s ± 1%   231MB/s ± 0%   +0.55%  (p=0.000 n=10+8)
JSONEncode-8             55.6MB/s ± 1%  59.9MB/s ± 0%   +7.65%  (p=0.000 n=10+9)
JSONDecode-8             12.9MB/s ± 0%  13.3MB/s ± 1%   +2.94%  (p=0.000 n=7+10)
GoParse-8                7.08MB/s ± 1%  7.22MB/s ± 0%   +1.95%  (p=0.000 n=10+10)
RegexpMatchEasy0_32-8     153MB/s ± 0%   153MB/s ± 0%   -0.16%  (p=0.023 n=10+10)
RegexpMatchEasy0_1K-8    1.30GB/s ± 1%  1.30GB/s ± 0%     ~     (p=0.393 n=10+10)
RegexpMatchEasy1_32-8     158MB/s ± 0%   158MB/s ± 0%     ~     (p=0.684 n=10+10)
RegexpMatchEasy1_1K-8     915MB/s ± 2%   918MB/s ± 1%     ~     (p=0.796 n=10+10)
RegexpMatchMedium_32-8   3.35MB/s ± 0%  3.35MB/s ± 0%     ~     (p=1.000 n=10+9)
RegexpMatchMedium_1K-8   12.3MB/s ± 5%  13.0MB/s ± 0%   +5.56%  (p=0.000 n=10+10)
RegexpMatchHard_32-8     7.40MB/s ± 0%  7.51MB/s ± 0%   +1.50%  (p=0.000 n=10+10)
RegexpMatchHard_1K-8     7.75MB/s ± 4%  8.10MB/s ± 0%   +4.52%  (p=0.000 n=10+8)
Revcomp-8                 229MB/s ± 0%   228MB/s ± 0%   -0.14%  (p=0.017 n=10+9)
Template-8               12.5MB/s ± 1%  12.5MB/s ± 1%     ~     (p=0.780 n=10+10)

Change-Id: I103389f168eac79f6af44e8fef93acc2a7a4ac96
Reviewed-on: https://go-review.googlesource.com/88415
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-02-15 20:54:50 +00:00
Cherry Zhang
7f1c4b3afb cmd/compile: disable "redundant zeroextensions" optimization for Select on AMD64
A Select Op could produce a value with upper 32 bits NOT zeroed,
for example, Div32 is lowered to (Select0 (DIVL x y)).

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

Fixes #23305.

Change-Id: Icf665a2af9ccb0a7ba0ae00c683c9e349638bf85
Reviewed-on: https://go-review.googlesource.com/85736
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-01-02 21:08:35 +00:00
Keith Randall
5419ed3a66 cmd/compile: remove unused code
Found a few functions in cmd/compile that aren't used.

Change-Id: I53957dae6f1a645feb8b95383f0f050964b4f7d4
Reviewed-on: https://go-review.googlesource.com/79975
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-27 16:48:28 +00:00
Ilya Tocar
f3884680fc cmd/compile/internal/ssa: inline memmove with known size
Replace calls to memmove with known (constant) size, with OpMove.
Do it only if it is safe from aliasing point of view.
Helps with code like this:

append(buf,"const str"...)

In strconv this provides nice benefit:
Quote-6                                   731ns ± 2%   647ns ± 3%  -11.41%  (p=0.000 n=10+10)
QuoteRune-6                               117ns ± 5%   111ns ± 1%   -4.54%  (p=0.000 n=10+10)
AppendQuote-6                             475ns ± 0%   396ns ± 0%  -16.59%  (p=0.000 n=9+10)
AppendQuoteRune-6                        32.0ns ± 0%  27.4ns ± 0%  -14.41%  (p=0.000 n=8+9)

Change-Id: I7704f5c51b46aed2d8f033de74c75140fc35036c
Reviewed-on: https://go-review.googlesource.com/54394
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-11-02 20:30:25 +00:00
Keith Randall
1787ced894 cmd/compile: remove Symbol wrappers from Aux fields
We used to have {Arg,Auto,Extern}Symbol structs with which we wrapped
a *gc.Node or *obj.LSym before storing them in the Aux field
of an ssa.Value.  This let the SSA part of the compiler distinguish
between autos and args, for example.  We no longer need the wrappers
as we can query the underlying objects directly.

There was also some sloppy usage, where VarDef had a *gc.Node
directly in its Aux field, whereas the use of that variable had
that *gc.Node wrapped in an AutoSymbol. Thus the Aux fields didn't
match (using ==) when they probably should.
This sloppy usage cleanup is the only thing in the CL that changes the
generated code - we can get rid of some more unused auto variables if
the matching happens reliably.

Removing this wrapper also lets us get rid of the varsyms cache
(which was used to prevent wrapping the same *gc.Node twice).

Change-Id: I0dedf8f82f84bfee413d310342b777316bd1d478
Reviewed-on: https://go-review.googlesource.com/64452
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-09-19 22:03:10 +00:00
Ilya Tocar
782ee23884 cmd/compile/internal/ssa: remove redundant zeroextensions on amd64
Some instructions operating on <= 32 bits also zero out upper 32bits.
Remove zeroextensions of such values. Triggers a few times during
all.bash. Also removes ugly code like:
MOVL CX,CX

Change-Id: I66a46c190dd6929b7e3c52f3fe6b967768d00638
Reviewed-on: https://go-review.googlesource.com/58090
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-08-30 16:22:18 +00:00
philhofer
c59b495963 cmd/compile: add support for arm64 bit-test instructions
Add support for generating TBZ/TBNZ instructions.

The bit-test-and-branch pattern shows up in a number of
important places, including the runtime (gc bitmaps).

Before this change, there were 3 TB[N]?Z instructions in the Go tool,
all of which were in hand-written assembly. After this change, there
are 285. Also, the go1 benchmark binary gets about 4.5kB smaller.

Fixes #21361

Change-Id: I170c138b852754b9b8df149966ca5e62e6dfa771
Reviewed-on: https://go-review.googlesource.com/54470
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-08-15 13:39:11 +00:00
Keith Randall
a027466e4b cmd/compile: check that phis are always first after scheduling
Update #20178

Change-Id: I603f77268ed38afdd84228c775efe006f08f14a7
Reviewed-on: https://go-review.googlesource.com/45018
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-06-07 00:13:20 +00:00
Michael Munday
4fc498d89a cmd/compile: add generic rules to eliminate some unnecessary stores
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>
2017-05-10 15:58:43 +00:00
Josh Bleecher Snyder
46b88c9fbc cmd/compile: change ssa.Type into *types.Type
When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.

In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.

Though this is a big CL, most of the changes are
mechanical and uninteresting.

Interesting bits:

* Add new singleton globals to package types for the special
  SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
  and TTUPLE, for SSA tuple types.
  ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
  to package types.
* We had picked the name "types" in our rules for the handy
  list of types provided by ssa.Config. That conflicted with
  the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
  types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
  and probably also some other duplicated Type methods
  designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
  and they were not particularly careful about types in general.
  Of necessity, this CL switches them to use *types.Type;
  it does not make them more type-accurate.
  Unfortunately, using types.Type means initializing a bit
  of the types universe.
  This is prime for refactoring and improvement.

This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.

name        old alloc/op      new alloc/op      delta
Template         37.9MB ± 0%       37.7MB ± 0%  -0.57%  (p=0.000 n=10+8)
Unicode          28.9MB ± 0%       28.7MB ± 0%  -0.52%  (p=0.000 n=10+10)
GoTypes           110MB ± 0%        109MB ± 0%  -0.88%  (p=0.000 n=10+10)
Flate            24.7MB ± 0%       24.6MB ± 0%  -0.66%  (p=0.000 n=10+10)
GoParser         31.1MB ± 0%       30.9MB ± 0%  -0.61%  (p=0.000 n=10+9)
Reflect          73.9MB ± 0%       73.4MB ± 0%  -0.62%  (p=0.000 n=10+8)
Tar              25.8MB ± 0%       25.6MB ± 0%  -0.77%  (p=0.000 n=9+10)
XML              41.2MB ± 0%       40.9MB ± 0%  -0.80%  (p=0.000 n=10+10)
[Geo mean]       40.5MB            40.3MB       -0.68%

name        old allocs/op     new allocs/op     delta
Template           385k ± 0%         386k ± 0%    ~     (p=0.356 n=10+9)
Unicode            343k ± 1%         344k ± 0%    ~     (p=0.481 n=10+10)
GoTypes           1.16M ± 0%        1.16M ± 0%  -0.16%  (p=0.004 n=10+10)
Flate              238k ± 1%         238k ± 1%    ~     (p=0.853 n=10+10)
GoParser           320k ± 0%         320k ± 0%    ~     (p=0.720 n=10+9)
Reflect            957k ± 0%         957k ± 0%    ~     (p=0.460 n=10+8)
Tar                252k ± 0%         252k ± 0%    ~     (p=0.133 n=9+10)
XML                400k ± 0%         400k ± 0%    ~     (p=0.796 n=10+10)
[Geo mean]         428k              428k       -0.01%


Removing all the interface calls helps non-trivially with CPU, though.

name        old time/op       new time/op       delta
Template          178ms ± 4%        173ms ± 3%  -2.90%  (p=0.000 n=94+96)
Unicode          85.0ms ± 4%       83.9ms ± 4%  -1.23%  (p=0.000 n=96+96)
GoTypes           543ms ± 3%        528ms ± 3%  -2.73%  (p=0.000 n=98+96)
Flate             116ms ± 3%        113ms ± 4%  -2.34%  (p=0.000 n=96+99)
GoParser          144ms ± 3%        140ms ± 4%  -2.80%  (p=0.000 n=99+97)
Reflect           344ms ± 3%        334ms ± 4%  -3.02%  (p=0.000 n=100+99)
Tar               106ms ± 5%        103ms ± 4%  -3.30%  (p=0.000 n=98+94)
XML               198ms ± 5%        192ms ± 4%  -2.88%  (p=0.000 n=92+95)
[Geo mean]        178ms             173ms       -2.65%

name        old user-time/op  new user-time/op  delta
Template          229ms ± 5%        224ms ± 5%  -2.36%  (p=0.000 n=95+99)
Unicode           107ms ± 6%        106ms ± 5%  -1.13%  (p=0.001 n=93+95)
GoTypes           696ms ± 4%        679ms ± 4%  -2.45%  (p=0.000 n=97+99)
Flate             137ms ± 4%        134ms ± 5%  -2.66%  (p=0.000 n=99+96)
GoParser          176ms ± 5%        172ms ± 8%  -2.27%  (p=0.000 n=98+100)
Reflect           430ms ± 6%        411ms ± 5%  -4.46%  (p=0.000 n=100+92)
Tar               128ms ±13%        123ms ±13%  -4.21%  (p=0.000 n=100+100)
XML               239ms ± 6%        233ms ± 6%  -2.50%  (p=0.000 n=95+97)
[Geo mean]        220ms             213ms       -2.76%


Change-Id: I15c7d6268347f8358e75066dfdbd77db24e8d0c1
Reviewed-on: https://go-review.googlesource.com/42145
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-05-09 23:01:51 +00:00
Cherry Zhang
fb0ccc5d0a cmd/internal/obj/arm64, cmd/compile: improve offset folding on ARM64
ARM64 assembler backend only accepts loads and stores with small
or aligned offset. The compiler therefore can only fold small or
aligned offsets into loads and stores. For locals and args, their
offsets to SP are not known until very late, and the compiler
makes conservative decision not folding some of them. However,
in most cases, the offset is indeed small or aligned, and can
be folded into load and store (but actually not).

This CL adds support of loads and stores with large and unaligned
offsets. When the offset doesn't fit into the instruction, it
uses two instructions and (for very large offset) the constant
pool. This way, the compiler doesn't need to be conservative,
and can simply fold the offset.

To make it work, the assembler's optab matching rules need to be
changed. Before, MOVD accepts C_UAUTO32K which matches multiple
of 8 between 0 and 32K, and also C_UAUTO16K, which may not be
multiple of 8 and does not fit into MOVD instruction. The
assembler errors in the latter case. This change makes it only
matches multiple of 8 (or offsets within ±256, which also fits
in instruction), and uses the large-or-unaligned-offset rule
for things doesn't fit (without error). Other sized move rules
are changed similarly.

Class C_UAUTO64K and C_UOREG64K are removed, as they are never
used.

In shared library, load/store of global is rewritten to using
GOT and temp register, which conflicts with the use of temp
register for assembling large offset. So the folding is disabled
for globals in shared library mode.

Reduce cmd/go binary size by 2%.

name                     old time/op    new time/op    delta
BinaryTree17-8              8.67s ± 0%     8.61s ± 0%   -0.60%  (p=0.000 n=9+10)
Fannkuch11-8                6.24s ± 0%     6.19s ± 0%   -0.83%  (p=0.000 n=10+9)
FmtFprintfEmpty-8           116ns ± 0%     116ns ± 0%     ~     (all equal)
FmtFprintfString-8          196ns ± 0%     192ns ± 0%   -1.89%  (p=0.000 n=10+10)
FmtFprintfInt-8             199ns ± 0%     198ns ± 0%   -0.35%  (p=0.001 n=9+10)
FmtFprintfIntInt-8          294ns ± 0%     293ns ± 0%   -0.34%  (p=0.000 n=8+8)
FmtFprintfPrefixedInt-8     318ns ± 1%     318ns ± 1%     ~     (p=1.000 n=10+10)
FmtFprintfFloat-8           537ns ± 0%     531ns ± 0%   -1.17%  (p=0.000 n=9+10)
FmtManyArgs-8              1.19µs ± 1%    1.18µs ± 1%   -1.41%  (p=0.001 n=10+10)
GobDecode-8                17.2ms ± 1%    17.3ms ± 2%     ~     (p=0.165 n=10+10)
GobEncode-8                14.7ms ± 1%    14.7ms ± 2%     ~     (p=0.631 n=10+10)
Gzip-8                      837ms ± 0%     836ms ± 0%   -0.14%  (p=0.006 n=9+10)
Gunzip-8                    141ms ± 0%     139ms ± 0%   -1.24%  (p=0.000 n=9+10)
HTTPClientServer-8          256µs ± 1%     253µs ± 1%   -1.35%  (p=0.000 n=10+10)
JSONEncode-8               40.1ms ± 1%    41.3ms ± 1%   +3.06%  (p=0.000 n=10+9)
JSONDecode-8                157ms ± 1%     156ms ± 1%   -0.83%  (p=0.001 n=9+8)
Mandelbrot200-8            8.94ms ± 0%    8.94ms ± 0%   +0.02%  (p=0.000 n=9+9)
GoParse-8                  8.69ms ± 0%    8.54ms ± 1%   -1.69%  (p=0.000 n=8+10)
RegexpMatchEasy0_32-8       227ns ± 1%     228ns ± 1%   +0.48%  (p=0.016 n=10+9)
RegexpMatchEasy0_1K-8      1.92µs ± 0%    1.63µs ± 0%  -15.08%  (p=0.000 n=10+9)
RegexpMatchEasy1_32-8       256ns ± 0%     251ns ± 0%   -2.19%  (p=0.000 n=10+9)
RegexpMatchEasy1_1K-8      2.38µs ± 0%    2.09µs ± 0%  -12.49%  (p=0.000 n=10+9)
RegexpMatchMedium_32-8      352ns ± 0%     354ns ± 0%   +0.39%  (p=0.002 n=10+9)
RegexpMatchMedium_1K-8      106µs ± 0%     106µs ± 0%   -0.05%  (p=0.005 n=10+9)
RegexpMatchHard_32-8       5.92µs ± 0%    5.89µs ± 0%   -0.40%  (p=0.000 n=9+8)
RegexpMatchHard_1K-8        180µs ± 0%     179µs ± 0%   -0.14%  (p=0.000 n=10+9)
Revcomp-8                   1.20s ± 0%     1.13s ± 0%   -6.29%  (p=0.000 n=9+8)
Template-8                  159ms ± 1%     154ms ± 1%   -3.14%  (p=0.000 n=9+10)
TimeParse-8                 800ns ± 3%     769ns ± 1%   -3.91%  (p=0.000 n=10+10)
TimeFormat-8                826ns ± 2%     817ns ± 2%   -1.04%  (p=0.050 n=10+10)
[Geo mean]                  145µs          143µs        -1.79%

Change-Id: I5fc42087cee9b54ea414f8ef6d6d020b80eb5985
Reviewed-on: https://go-review.googlesource.com/42172
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
2017-05-09 19:41:00 +00:00
Michael Munday
35cf3843a4 cmd/{asm,compile}: avoid zeroAuto clobbering flags on s390x
This CL modifies how MOV[DWHB] instructions that store a constant to
memory are assembled to avoid them clobbering the condition code
(flags). It also modifies zeroAuto to use MOVD instructions instead of
CLEAR (which is assembled as XC).

MOV[DWHB]storeconst ops also no longer clobbers flags.

Note: this CL modifies the assembler so that it can no longer handle
immediates outside the range of an int16 or offsets from SB, which
reflects what the machine instructions support. The compiler doesn't
need this capability any more and I don't think this affects any existing
assembly, but it is easy to workaround if it does.

Fixes #20187.

Change-Id: Ie54947ff38367bd6a19962bf1a6d0296a4accffb
Reviewed-on: https://go-review.googlesource.com/42179
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-02 17:43:31 +00:00
Ben Shi
38fbada557 cmd/compile/internal/ssa: more constant folding rules for ARM
(ADDconst [c] x) && !isARMImmRot(uint32(c)) && isARMImmRot(uint32(-c)) -> (SUBconst [int64(int32(-c))] x)
(SUBconst [c] x) && !isARMImmRot(uint32(c)) && isARMImmRot(uint32(-c)) -> (ADDconst [int64(int32(-c))] x)
Currently
a = a + 0xfffffff1 is compiled to (variable a is in R0)
MVN $14, R11
ADD R11, R0, R0
After applying the above 2 rules, it becomes
SUB $15, R0, R0

(BICconst [c] (BICconst [d] x)) -> (BICconst [int64(int32(c|d))] x)
This rule also optimizes the generated ARM code.

The other rules are added to avoid to generate less optimized ARM code
when substitutions ADD->SUB happen.

Change-Id: I3ead9aae2b446b674e2ab42d37259d38ceb93a4d
Reviewed-on: https://go-review.googlesource.com/41679
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-29 02:53:46 +00:00
Josh Bleecher Snyder
dae5389d3d Revert "cmd/compile: add Type.MustSize and Type.MustAlignment"
This reverts commit 94d540a4b6.

Reason for revert: prefer something along the lines of CL 42018.

Change-Id: I876fe32e98f37d8d725fe55e0fd0ea429c0198e0
Reviewed-on: https://go-review.googlesource.com/42022
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-28 01:24:13 +00:00
Josh Bleecher Snyder
94d540a4b6 cmd/compile: add Type.MustSize and Type.MustAlignment
Type.Size and Type.Alignment are for the front end:
They calculate size and alignment if needed.

Type.MustSize and Type.MustAlignment are for the back end:
They call Fatal if size and alignment are not already calculated.

Most uses are of MustSize and MustAlignment,
but that's because the back end is newer,
and this API was added to support it.

This CL was mostly generated with sed and selective reversion.
The only mildly interesting bit is the change of the ssa.Type interface
and the supporting ssa dummy types.

Follow-up to review feedback on CL 41970.

Passes toolstash-check.

Change-Id: I0d9b9505e57453dae8fb6a236a07a7a02abd459e
Reviewed-on: https://go-review.googlesource.com/42016
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-27 22:57:57 +00:00
Josh Bleecher Snyder
4ee934ad27 cmd/compile: remove references to *os.File from ssa package
This reduces the size of the ssa export data
by 10%, from 76154 to 67886.

It doesn't appear that #20084, which would do this automatically,
is going to be fixed soon. Do it manually for now.

This speeds up compiling cmd/compile/internal/amd64
and presumably its comrades as well:

name          old time/op       new time/op       delta
CompileAMD64       89.6ms ± 6%       86.7ms ± 5%  -3.29%  (p=0.000 n=49+47)

name          old user-time/op  new user-time/op  delta
CompileAMD64        116ms ± 5%        112ms ± 5%  -3.51%  (p=0.000 n=45+42)

name          old alloc/op      new alloc/op      delta
CompileAMD64       26.7MB ± 0%       25.8MB ± 0%  -3.26%  (p=0.008 n=5+5)

name          old allocs/op     new allocs/op     delta
CompileAMD64         223k ± 0%         213k ± 0%  -4.46%  (p=0.008 n=5+5)

Updates #20084

Change-Id: I49e8951c5bfce63ad2b7f4fc3bfa0868c53114f9
Reviewed-on: https://go-review.googlesource.com/41493
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-24 23:58:14 +00:00
Matthew Dempsky
c87520c598 cmd: remove IntSize and Widthint
Use PtrSize and Widthptr instead. CL prepared mostly with sed and
uniq.

Passes toolstash-check -all.

Fixes #19954.

Change-Id: I09371bd7128672885cb8bc4e7f534ad56a88d755
Reviewed-on: https://go-review.googlesource.com/40506
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-22 17:43:43 +00:00
Todd Neal
716219ffd9 cmd/compile: remove dead code
Change-Id: I2d287981d5fcef3aace948c405d618f46200948e
Reviewed-on: https://go-review.googlesource.com/41450
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-22 01:18:40 +00:00
Matthew Dempsky
4eb48a336e cmd/compile/internal/ssa: refactor ARM64 address folding
These patterns are the only uses of isArg and isAuto, and they all
follow a common pattern too. Extract out so that we can more easily
tweak the interface for isArg/isAuto.

Passes toolstash -cmp for linux/arm64.

Change-Id: I9c509dabdc123c93cb1ad2f34fe8c12a9f313f6d
Reviewed-on: https://go-review.googlesource.com/40490
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-04-12 21:21:38 +00:00
Josh Bleecher Snyder
4c1622082e cmd/compile: don't catch panics during rewrite
This is a holdover from the days when we did not
have full SSA coverage and compiled things optimistically,
and catching the panic obscures useful information.

Change-Id: I196790cb6b97419d92b318a2dfa7f1e1097cefb7
Reviewed-on: https://go-review.googlesource.com/39534
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2017-04-04 23:37:17 +00:00
Keith Randall
63a72fd447 cmd/compile: strength-reduce floating point
x*2 -> x+x
x/c, c power of 2 -> x*(1/c)

Fixes #19827

Change-Id: I74c9f0b5b49b2ed26c0990314c7d1d5f9631b6f1
Reviewed-on: https://go-review.googlesource.com/39295
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-04-03 21:27:03 +00:00
Keith Randall
86dc86b4f9 cmd/compile: don't merge load+op if other op arg is still live
We want to merge a load and op into a single instruction

    l = LOAD ptr mem
    y = OP x l

into

    y = OPload x ptr mem

However, all of our OPload instructions require that y uses
the same register as x. If x is needed past this instruction, then
we must copy x somewhere else, losing the whole benefit of merging
the instructions in the first place.

Disable this optimization if x is live past the OP.

Also disable this optimization if the OP is in a deeper loop than the load.

Update #19595

Change-Id: I87f596aad7e91c9127bfb4705cbae47106e1e77a
Reviewed-on: https://go-review.googlesource.com/38337
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2017-03-23 15:53:04 +00:00
Josh Bleecher Snyder
2cdb7f118a cmd/compile: move Frontend field from ssa.Config to ssa.Func
Suggested by mdempsky in CL 38232.
This allows us to use the Frontend field
to associate frontend state and information
with a function.
See the following CL in the series for examples.

This is a giant CL, but it is almost entirely routine refactoring.

The ssa test API is starting to feel a bit unwieldy.
I will clean it up separately, once the dust has settled.

Passes toolstash -cmp.

Updates #15756

Change-Id: I71c573bd96ff7251935fce1391b06b1f133c3caf
Reviewed-on: https://go-review.googlesource.com/38327
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 23:18:57 +00:00
Josh Bleecher Snyder
193510f2f6 cmd/compile: evaluate config as needed in rewrite rules
Prior to this CL, config was an explicit argument
to the SSA rewrite rules, and rules that needed
a Frontend got at it via config.
An upcoming CL moves Frontend from Config to Func,
so rules can no longer reach Frontend via Config.
Passing a Frontend as an argument to the rewrite rules
causes a 2-3% regression in compile times.
This CL takes a different approach:
It treats the variable names "config" and "fe"
as special and calculates them as needed.
The "as needed part" is also important to performance:
If they are calculated eagerly, the nilchecks themselves
cause a regression.

This introduces a little bit of magic into the rewrite
generator. However, from the perspective of the rules,
the config variable was already more or less magic.
And it makes the upcoming changes much clearer.

Passes toolstash -cmp.

Change-Id: I173f2bcc124cba43d53138bfa3775e21316a9107
Reviewed-on: https://go-review.googlesource.com/38326
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-17 22:35:29 +00:00
philhofer
295307ae78 cmd/compile: de-virtualize interface calls
With this change, code like

    h := sha1.New()
    h.Write(buf)
    sum := h.Sum()

gets compiled into static calls rather than
interface calls, because the compiler is able
to prove that 'h' is really a *sha1.digest.

The InterCall re-write rule hits a few dozen times
during make.bash, and hundreds of times during all.bash.

The most common pattern identified by the compiler
is a constructor like

    func New() Interface { return &impl{...} }

where the constructor gets inlined into the caller,
and the result is used immediately. Examples include
{sha1,md5,crc32,crc64,...}.New, base64.NewEncoder,
base64.NewDecoder, errors.New, net.Pipe, and so on.

Some existing benchmarks that change on darwin/amd64:

Crc64/ISO4KB-8        2.67µs ± 1%    2.66µs ± 0%  -0.36%  (p=0.015 n=10+10)
Crc64/ISO1KB-8         694ns ± 0%     690ns ± 1%  -0.59%  (p=0.001 n=10+10)
Adler32KB-8            473ns ± 1%     471ns ± 0%  -0.39%  (p=0.010 n=10+9)

On architectures like amd64, the reduction in code size
appears to contribute more to benchmark improvements than just
removing the indirect call, since that branch gets predicted
accurately when called in a loop.

Updates #19361

Change-Id: I57d4dc21ef40a05ec0fbd55a9bb0eb74cdc67a3d
Reviewed-on: https://go-review.googlesource.com/38139
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-03-14 18:49:23 +00:00
David Chase
b59a405656 Revert "cmd/compile: de-virtualize interface calls"
This reverts commit 4e0c7c3f61.

Reason for revert: The presence-of-optimization test program is fragile, breaks under noopt, and might break if the Go libraries are tweaked.  It needs to be (re)written without reference to other packages.

Change-Id: I3aaf1ab006a1a255f961a978e9c984341740e3c7
Reviewed-on: https://go-review.googlesource.com/38097
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-13 21:15:32 +00:00
Philip Hofer
4e0c7c3f61 cmd/compile: de-virtualize interface calls
With this change, code like

    h := sha1.New()
    h.Write(buf)
    sum := h.Sum()

gets compiled into static calls rather than
interface calls, because the compiler is able
to prove that 'h' is really a *sha1.digest.

The InterCall re-write rule hits a few dozen times
during make.bash, and hundreds of times during all.bash.

The most common pattern identified by the compiler
is a constructor like

    func New() Interface { return &impl{...} }

where the constructor gets inlined into the caller,
and the result is used immediately. Examples include
{sha1,md5,crc32,crc64,...}.New, base64.NewEncoder,
base64.NewDecoder, errors.New, net.Pipe, and so on.

Some existing benchmarks that change on darwin/amd64:

Crc64/ISO4KB-8        2.67µs ± 1%    2.66µs ± 0%  -0.36%  (p=0.015 n=10+10)
Crc64/ISO1KB-8         694ns ± 0%     690ns ± 1%  -0.59%  (p=0.001 n=10+10)
Adler32KB-8            473ns ± 1%     471ns ± 0%  -0.39%  (p=0.010 n=10+9)

On architectures like amd64, the reduction in code size
appears to contribute more to benchmark improvements than just
removing the indirect call, since that branch gets predicted
accurately when called in a loop.

Updates #19361

Change-Id: Ia9d30afdd5f6b4d38d38b14b88f308acae8ce7ed
Reviewed-on: https://go-review.googlesource.com/37751
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-13 18:24:57 +00:00
Philip Hofer
b0e91d836a cmd/compile: clean up ssa.Value memory arg usage
This change adds a method to replace expressions
of the form

   v.Args[len(v.Args)-1]

so that the code's intention to walk memory arguments
is explicit.

Passes toolstash-check.

Change-Id: I0c80d73bc00989dd3cdf72b4f2c8e1075a2515e0
Reviewed-on: https://go-review.googlesource.com/37757
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-09 21:40:47 +00:00
Cherry Zhang
c8eaeb8cba cmd/compile: remove zeroing after newobject
The Zero op right after newobject has been removed. But this rule
does not cover Store of constant zero (for SSA-able types). Add
rules to cover Store op as well.

Updates #19027.

Change-Id: I5d2b62eeca0aa9ce8dc7205b264b779de01c660b
Reviewed-on: https://go-review.googlesource.com/36836
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-03-03 20:36:54 +00:00
Keith Randall
708ba22a0c cmd/compile: move constant divide strength reduction to SSA rules
Currently the conversion from constant divides to multiplies is mostly
done during the walk pass.  This is suboptimal because SSA can
determine that the value being divided by is constant more often
(e.g. after inlining).

Change-Id: If1a9b993edd71be37396b9167f77da271966f85f
Reviewed-on: https://go-review.googlesource.com/37015
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-02-17 06:16:44 +00:00
Keith Randall
01c8719f8b cmd/compile: move rotate instruction generation to SSA
Remove rotate generation from walk.  Remove OLROT and ssa.Lrot* opcodes.
Generate rotates during SSA lowering for architectures that have them.

This CL will allow rotates to be generated in more situations,
like when the shift values are determined to be constant
only after some analysis.

Fixes #18254

Change-Id: I8d6d684ff5ce2511aceaddfda98b908007851079
Reviewed-on: https://go-review.googlesource.com/34232
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-02-02 17:57:15 +00:00
Robert Griesemer
cfd17f51c8 [dev.inline] cmd/compile/internal/ssa: rename various fields from Line to Pos
This is a mostly mechanical rename followed by manual fixes where necessary.

Change-Id: Ie5c670b133db978f15dc03e50dc2da0c80fc8842
Reviewed-on: https://go-review.googlesource.com/34137
Reviewed-by: David Lazar <lazard@golang.org>
2016-12-08 21:36:52 +00:00