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| author | David Chase <drchase@google.com> | 2022-01-27 11:26:59 -0500 |
|---|---|---|
| committer | Cherry Mui <cherryyz@google.com> | 2022-02-07 18:41:46 +0000 |
| commit | 4d284ea05230c37a653053c163f0eb8b1f9b6138 (patch) | |
| tree | 1cceb89c055ca5219a245f0c16e266916b773e91 /src/cmd/compile/internal/ssa/gen/ARM.rules | |
| parent | fcd482a2d014137d8c20bf02bcc8fe37b107eb8c (diff) | |
| download | go-4d284ea05230c37a653053c163f0eb8b1f9b6138.tar.gz go-4d284ea05230c37a653053c163f0eb8b1f9b6138.zip | |
[release-branch.go1.16] cmd/compile: remove incorrect arm,arm64 CMP->CMN transformations
These can go wrong when one of the operands is the minimum integer value.
Fixes #50866.
Change-Id: I238fe284f60c7ee5aeb9dc9a18e8b1578cdb77d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/381318
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
(cherry picked from commit b7b44b3173f151a2313da7072afd25de80511605)
Reviewed-on: https://go-review.googlesource.com/c/go/+/381475
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Diffstat (limited to 'src/cmd/compile/internal/ssa/gen/ARM.rules')
| -rw-r--r-- | src/cmd/compile/internal/ssa/gen/ARM.rules | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/cmd/compile/internal/ssa/gen/ARM.rules b/src/cmd/compile/internal/ssa/gen/ARM.rules index 69989b0c45..2a30f9c342 100644 --- a/src/cmd/compile/internal/ssa/gen/ARM.rules +++ b/src/cmd/compile/internal/ssa/gen/ARM.rules @@ -1263,8 +1263,8 @@ (SRLconst (SLLconst x [c]) [d]) && objabi.GOARM==7 && uint64(d)>=uint64(c) && uint64(d)<=31 => (BFXU [(d-c)|(32-d)<<8] x) // comparison simplification -((LT|LE|EQ|NE|GE|GT) (CMP x (RSBconst [0] y))) => ((LT|LE|EQ|NE|GE|GT) (CMN x y)) // sense of carry bit not preserved -((LT|LE|EQ|NE|GE|GT) (CMN x (RSBconst [0] y))) => ((LT|LE|EQ|NE|GE|GT) (CMP x y)) // sense of carry bit not preserved +((EQ|NE) (CMP x (RSBconst [0] y))) => ((EQ|NE) (CMN x y)) // sense of carry bit not preserved; see also #50854 +((EQ|NE) (CMN x (RSBconst [0] y))) => ((EQ|NE) (CMP x y)) // sense of carry bit not preserved; see also #50864 (EQ (CMPconst [0] l:(SUB x y)) yes no) && l.Uses==1 => (EQ (CMP x y) yes no) (EQ (CMPconst [0] l:(MULS x y a)) yes no) && l.Uses==1 => (EQ (CMP a (MUL <x.Type> x y)) yes no) (EQ (CMPconst [0] l:(SUBconst [c] x)) yes no) && l.Uses==1 => (EQ (CMPconst [c] x) yes no) |