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| author | Keith Randall <khr@golang.org> | 2020-11-20 14:02:37 -0800 |
|---|---|---|
| committer | Carlos Amedee <carlos@golang.org> | 2020-12-03 13:58:36 +0000 |
| commit | 679482fc602445b9b2d37739e7b048e2d4913646 (patch) | |
| tree | c56a2148d8cc3067141bea561b21cf17eafcae1d | |
| parent | 9e27a089d644950cba52108f6634badc5880c6e0 (diff) | |
| download | go-679482fc602445b9b2d37739e7b048e2d4913646.tar.gz go-679482fc602445b9b2d37739e7b048e2d4913646.zip | |
[release-branch.go1.14] cmd/compile: sign extend constant folding properly
MOVLconst must have a properly sign-extended auxint constant.
The bit operations in these rules don't enforce that invariant.
Fixes #42755
Change-Id: I729afcad18752d9b7739e49709020e3be7b3653e
Reviewed-on: https://go-review.googlesource.com/c/go/+/272030
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
| -rw-r--r-- | src/cmd/compile/internal/ssa/gen/AMD64.rules | 6 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteAMD64.go | 12 | ||||
| -rw-r--r-- | test/fixedbugs/issue42753.go | 13 |
3 files changed, 22 insertions, 9 deletions
diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules index 2d662d5ae6..f819aefcfd 100644 --- a/src/cmd/compile/internal/ssa/gen/AMD64.rules +++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules @@ -1465,11 +1465,11 @@ (NOTQ (MOVQconst [c])) -> (MOVQconst [^c]) (NOTL (MOVLconst [c])) -> (MOVLconst [^c]) (BTSQconst [c] (MOVQconst [d])) -> (MOVQconst [d|(1<<uint32(c))]) -(BTSLconst [c] (MOVLconst [d])) -> (MOVLconst [d|(1<<uint32(c))]) +(BTSLconst [c] (MOVLconst [d])) -> (MOVLconst [int64(int32(d|(1<<uint32(c))))]) (BTRQconst [c] (MOVQconst [d])) -> (MOVQconst [d&^(1<<uint32(c))]) -(BTRLconst [c] (MOVLconst [d])) -> (MOVLconst [d&^(1<<uint32(c))]) +(BTRLconst [c] (MOVLconst [d])) -> (MOVLconst [int64(int32(d&^(1<<uint32(c))))]) (BTCQconst [c] (MOVQconst [d])) -> (MOVQconst [d^(1<<uint32(c))]) -(BTCLconst [c] (MOVLconst [d])) -> (MOVLconst [d^(1<<uint32(c))]) +(BTCLconst [c] (MOVLconst [d])) -> (MOVLconst [int64(int32(d^(1<<uint32(c))))]) // generic simplifications // TODO: more of this diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go index c104157cec..366eac0706 100644 --- a/src/cmd/compile/internal/ssa/rewriteAMD64.go +++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go @@ -4326,7 +4326,7 @@ func rewriteValueAMD64_OpAMD64BTCLconst_0(v *Value) bool { return true } // match: (BTCLconst [c] (MOVLconst [d])) - // result: (MOVLconst [d^(1<<uint32(c))]) + // result: (MOVLconst [int64(int32(d^(1<<uint32(c))))]) for { c := v.AuxInt v_0 := v.Args[0] @@ -4335,7 +4335,7 @@ func rewriteValueAMD64_OpAMD64BTCLconst_0(v *Value) bool { } d := v_0.AuxInt v.reset(OpAMD64MOVLconst) - v.AuxInt = d ^ (1 << uint32(c)) + v.AuxInt = int64(int32(d ^ (1 << uint32(c)))) return true } return false @@ -4825,7 +4825,7 @@ func rewriteValueAMD64_OpAMD64BTRLconst_0(v *Value) bool { return true } // match: (BTRLconst [c] (MOVLconst [d])) - // result: (MOVLconst [d&^(1<<uint32(c))]) + // result: (MOVLconst [int64(int32(d&^(1<<uint32(c))))]) for { c := v.AuxInt v_0 := v.Args[0] @@ -4834,7 +4834,7 @@ func rewriteValueAMD64_OpAMD64BTRLconst_0(v *Value) bool { } d := v_0.AuxInt v.reset(OpAMD64MOVLconst) - v.AuxInt = d &^ (1 << uint32(c)) + v.AuxInt = int64(int32(d &^ (1 << uint32(c)))) return true } return false @@ -5181,7 +5181,7 @@ func rewriteValueAMD64_OpAMD64BTSLconst_0(v *Value) bool { return true } // match: (BTSLconst [c] (MOVLconst [d])) - // result: (MOVLconst [d|(1<<uint32(c))]) + // result: (MOVLconst [int64(int32(d|(1<<uint32(c))))]) for { c := v.AuxInt v_0 := v.Args[0] @@ -5190,7 +5190,7 @@ func rewriteValueAMD64_OpAMD64BTSLconst_0(v *Value) bool { } d := v_0.AuxInt v.reset(OpAMD64MOVLconst) - v.AuxInt = d | (1 << uint32(c)) + v.AuxInt = int64(int32(d | (1 << uint32(c)))) return true } return false diff --git a/test/fixedbugs/issue42753.go b/test/fixedbugs/issue42753.go new file mode 100644 index 0000000000..a998d1d3b3 --- /dev/null +++ b/test/fixedbugs/issue42753.go @@ -0,0 +1,13 @@ +// compile -d=ssa/check/on + +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +func f() uint32 { + s := "\x01" + x := -int32(s[0]) + return uint32(x) & 0x7fffffff +} |