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| author | Keith Randall <khr@golang.org> | 2022-06-29 13:22:59 -0700 |
|---|---|---|
| committer | David Chase <drchase@google.com> | 2022-06-30 15:11:19 +0000 |
| commit | 31b8c23c5702f129aca9241bbb2132c90b1929cc (patch) | |
| tree | 8652a9cc34edac13eeedb5d40a5ae383eac066f8 /src/cmd/compile/internal/ssa/loopbce.go | |
| parent | 17083a2fdf4475c3f11a3e6a0ef8cb595a5fc4d6 (diff) | |
| download | go-31b8c23c5702f129aca9241bbb2132c90b1929cc.tar.xz | |
cmd/compile: fix prove pass when upper condition is <= maxint
When the terminating condition is <= X, we need to make sure that
X+step doesn't overflow.
Fixes #53600
Change-Id: I36e5384d05b4d7168e48db6094200fcae409bfe5
Reviewed-on: https://go-review.googlesource.com/c/go/+/415219
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/cmd/compile/internal/ssa/loopbce.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/loopbce.go | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/loopbce.go b/src/cmd/compile/internal/ssa/loopbce.go index 3181edca29..a934cd2c7b 100644 --- a/src/cmd/compile/internal/ssa/loopbce.go +++ b/src/cmd/compile/internal/ssa/loopbce.go @@ -159,6 +159,13 @@ func findIndVar(f *Func) []indVar { step = -step } + if flags&indVarMaxInc != 0 && max.Op == OpConst64 && max.AuxInt+step < max.AuxInt { + // For a <= comparison, we need to make sure that a value equal to + // max can be incremented without overflowing. + // (For a < comparison, the %step check below ensures no overflow.) + continue + } + // Up to now we extracted the induction variable (ind), // the increment delta (inc), the temporary sum (nxt), // the minimum value (min) and the maximum value (max). |