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ddb5d0db37
The code in #29218 resulted in an If block containing only its control. That block was then converted by fuseIf into a plain block; as a result, that control value was dead. However, the control value was still present in b.Values. This prevented further fusing of that block. This change beefs up the check in fuseIf to allow fusing blocks that contain only dead values (if any). In the case of #29218, this enables enough extra fusing that the control value could be eliminated, allowing all values in turn to be eliminated. This change also fuses 34 new blocks during make.bash. It is not clear that this fixes every variant of #29218, but it is a reasonable standalone change. And code like #29218 is rare and fundamentally buggy, so we can handle new instances if/when they actually occur. Fixes #29218 Negligible toolspeed impact. name old time/op new time/op delta Template 213ms ± 3% 213ms ± 2% ~ (p=0.914 n=97+88) Unicode 89.8ms ± 2% 89.6ms ± 2% -0.22% (p=0.045 n=93+95) GoTypes 712ms ± 3% 709ms ± 2% -0.35% (p=0.023 n=95+95) Compiler 3.24s ± 2% 3.23s ± 2% -0.30% (p=0.020 n=98+97) SSA 10.0s ± 1% 10.0s ± 1% ~ (p=0.382 n=98+99) Flate 135ms ± 3% 135ms ± 2% ~ (p=0.983 n=98+98) GoParser 158ms ± 2% 158ms ± 2% ~ (p=0.170 n=99+99) Reflect 447ms ± 3% 447ms ± 2% ~ (p=0.538 n=98+89) Tar 189ms ± 2% 189ms ± 3% ~ (p=0.874 n=95+96) XML 251ms ± 2% 251ms ± 2% ~ (p=0.434 n=94+96) [Geo mean] 427ms 426ms -0.15% name old user-time/op new user-time/op delta Template 264ms ± 2% 265ms ± 2% ~ (p=0.075 n=96+90) Unicode 119ms ± 6% 119ms ± 7% ~ (p=0.864 n=99+98) GoTypes 926ms ± 2% 924ms ± 2% ~ (p=0.071 n=94+94) Compiler 4.38s ± 2% 4.37s ± 2% -0.34% (p=0.001 n=98+97) SSA 13.4s ± 1% 13.4s ± 1% ~ (p=0.693 n=90+93) Flate 162ms ± 3% 161ms ± 2% ~ (p=0.163 n=99+99) GoParser 186ms ± 2% 186ms ± 3% ~ (p=0.130 n=96+100) Reflect 572ms ± 3% 572ms ± 2% ~ (p=0.608 n=97+97) Tar 239ms ± 2% 239ms ± 3% ~ (p=0.999 n=93+91) XML 302ms ± 2% 302ms ± 2% ~ (p=0.627 n=91+97) [Geo mean] 540ms 540ms -0.08% file before after Δ % asm 4862704 4858608 -4096 -0.084% compile 24001568 24001680 +112 +0.000% total 132520780 132516796 -3984 -0.003% file before after Δ % cmd/compile/internal/gc.a 8887638 8887596 -42 -0.000% cmd/compile/internal/ssa.a 29995056 29998986 +3930 +0.013% cmd/internal/obj/wasm.a 209444 203652 -5792 -2.765% total 129471798 129469894 -1904 -0.001% Change-Id: I2d18f9278e68b9766058ae8ca621e844f9d89dd8 Reviewed-on: https://go-review.googlesource.com/c/go/+/177140 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
25 lines
308 B
Go
25 lines
308 B
Go
// compile
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// Copyright 2019 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package p
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type T struct {
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b bool
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string
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}
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func f() {
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var b bool
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var t T
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for {
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switch &t.b {
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case &b:
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if b {
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}
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}
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}
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}
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