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| author | Matthew Dempsky <mdempsky@google.com> | 2023-06-27 16:51:24 -0700 |
|---|---|---|
| committer | Carlos Amedee <carlos@golang.org> | 2023-06-28 16:07:47 +0000 |
| commit | 79d4defa75a26dd975c6ba3ac938e0e414dfd3e9 (patch) | |
| tree | b2a88c1dab06df2cef15a7341eb11740756fd8c7 | |
| parent | a3093eca64f9efc830c153c835291d751ea167f9 (diff) | |
| download | go-79d4defa75a26dd975c6ba3ac938e0e414dfd3e9.tar.gz go-79d4defa75a26dd975c6ba3ac938e0e414dfd3e9.zip | |
cmd/compile/internal/ssagen: fix min/max codegen, again
The large-function phi placement algorithm evidently doesn't like the
same pseudo-variable being used to represent expressions of varying
types.
Instead, use the same tactic as used for "valVar" (ssa.go:6585--6587),
which is to just generate a fresh marker node each time.
Maybe we could just use the OMIN/OMAX nodes themselves as the key
(like we do for OANDAND/OOROR), but that just seems needlessly risky
for negligible memory savings. Using fresh marker values each time
seems obviously safe by comparison.
Fixes #61041.
Change-Id: Ie2600c9c37b599c2e26ae01f5f8a433025d7fd08
Reviewed-on: https://go-review.googlesource.com/c/go/+/506679
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
| -rw-r--r-- | src/cmd/compile/internal/ssagen/ssa.go | 5 | ||||
| -rw-r--r-- | test/fixedbugs/issue60982.go | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go index 4aedf9cd35..678e1ebc11 100644 --- a/src/cmd/compile/internal/ssagen/ssa.go +++ b/src/cmd/compile/internal/ssagen/ssa.go @@ -949,7 +949,6 @@ var ( typVar = ssaMarker("typ") okVar = ssaMarker("ok") deferBitsVar = ssaMarker("deferBits") - ternaryVar = ssaMarker("ternary") ) // startBlock sets the current block we're generating code in to b. @@ -3621,6 +3620,10 @@ func (s *state) minMax(n *ir.CallExpr) *ssa.Value { // ternary emits code to evaluate cond ? x : y. func (s *state) ternary(cond, x, y *ssa.Value) *ssa.Value { + // Note that we need a new ternaryVar each time (unlike okVar where we can + // reuse the variable) because it might have a different type every time. + ternaryVar := ssaMarker("ternary") + bThen := s.f.NewBlock(ssa.BlockPlain) bElse := s.f.NewBlock(ssa.BlockPlain) bEnd := s.f.NewBlock(ssa.BlockPlain) diff --git a/test/fixedbugs/issue60982.go b/test/fixedbugs/issue60982.go index 11c3af214f..4e5fc34646 100644 --- a/test/fixedbugs/issue60982.go +++ b/test/fixedbugs/issue60982.go @@ -6,8 +6,13 @@ package main -func f(x int) int { +func f(x int, b bool) int { if x >= 1000 { + if b { // from #61041 + var a struct{ f int64 } + _ = max(0, a.f) + } + return max(x, 2000) } // generate 1000 basic blocks to put this function |