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| author | Keith Randall <khr@golang.org> | 2023-03-28 09:41:46 -0700 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2023-03-28 17:31:36 +0000 |
| commit | 4237dea5e36fa4c0900cb6b0850b1871f4e4c404 (patch) | |
| tree | 25e52cb2ba7871efe637b4f2e457712d7efab3b8 /src/cmd/compile/internal/ssa/regalloc.go | |
| parent | 1cfc87e6db5896e84472ca356e6344bc7d61a580 (diff) | |
| download | go-4237dea5e36fa4c0900cb6b0850b1871f4e4c404.tar.xz | |
cmd/compile: lower priority of avoiding registers
We avoid allocating registers when we know they may have a fixed use
later (arg/return value, or the CX shift argument to SHRQ, etc.) But
it isn't worth avoiding that register if it requires moving another
register.
A move we may have to do later is not worth a move we definitely have
to do now.
Fixes #59288
Change-Id: Ibbdcbaea9caee0c5f3e0d6956a1a084ba89757a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/479895
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Diffstat (limited to 'src/cmd/compile/internal/ssa/regalloc.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index 2e121df3cc..c7cdea261d 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -1688,7 +1688,7 @@ func (s *regAllocState) regalloc(f *Func) { } } // Avoid registers we're saving for other values. - if mask&^desired.avoid&^s.nospill != 0 { + if mask&^desired.avoid&^s.nospill&^s.used != 0 { mask &^= desired.avoid } r := s.allocReg(mask, v) |