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| author | erifan01 <eric.fang@arm.com> | 2023-03-07 08:44:08 +0800 |
|---|---|---|
| committer | Eric Fang <eric.fang@arm.com> | 2023-03-22 08:32:53 +0000 |
| commit | 91a2e921dd0bdb4d6437091f82b4b22527cafa94 (patch) | |
| tree | 3392b7f11bfb65b0e32d5a9798ce5d53b700e178 /test/codegen | |
| parent | ed2442a0e1d1871f3210f26a1e3adb722ea2467d (diff) | |
| download | go-91a2e921dd0bdb4d6437091f82b4b22527cafa94.tar.xz | |
cmd/compile: fix incorrect truncating when converting CMP to TST on arm64
CL 420434 optimized CMP into TST in some situations, but it has a bug,
these four rules are not correct:
(LessThan (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (LessThan (TSTconst [c] y))
(LessEqual (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (LessEqual (TSTconst [c] y))
(GreaterThan (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (GreaterThan (TSTconst [c] y))
(GreaterEqual (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (GreaterEqual (TSTconst [c] y))
But due to the existence of this rule
(LessThan (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 =>
(LessThan (TSTWconst [int32(c)] y)), the above rules have never been
fired. This CL corrects them as:
(LessThan (CMPconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (LessThan (TSTconst [c] y))
(LessEqual (CMPconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (LessEqual (TSTconst [c] y))
(GreaterThan (CMPconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (GreaterThan (TSTconst [c] y))
(GreaterEqual (CMPconst [0] x:(ANDconst [c] y))) && x.Uses == 1 => (GreaterEqual (TSTconst [c] y))
Change-Id: I7d60bcc9a266ee58388baeaab9f493b57cf1ad55
Reviewed-on: https://go-review.googlesource.com/c/go/+/473617
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Diffstat (limited to 'test/codegen')
| -rw-r--r-- | test/codegen/comparisons.go | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/test/codegen/comparisons.go b/test/codegen/comparisons.go index c613e13ced..ee732e06d9 100644 --- a/test/codegen/comparisons.go +++ b/test/codegen/comparisons.go @@ -234,6 +234,8 @@ func CmpToZero(a, b, d int32, e, f int64, deOptC0, deOptC1 bool) int32 { c7 := e&(f<<3) < 0 // arm64:`CMN\sR[0-9]+<<3,\sR[0-9]+` c8 := e+(f<<3) < 0 + // arm64:`TST\sR[0-9],\sR[0-9]+` + c9 := e&17 < 0 if c0 { return 1 } else if c1 { @@ -252,6 +254,8 @@ func CmpToZero(a, b, d int32, e, f int64, deOptC0, deOptC1 bool) int32 { return 9 } else if c8 { return 10 + } else if c9 { + return 11 } else if deOptC0 { return b + d } else if deOptC1 { |