From f65692ea562bf24c21ae46854e98584dd4bcc201 Mon Sep 17 00:00:00 2001 From: "khr@golang.org" Date: Sat, 14 Feb 2026 10:04:13 -0800 Subject: cmd/compile: don't drop same register twice For instructions that clobber both of their input registers, make sure we don't clobber the same register twice when both input registers are the same. This is rare, but it can happen. Fixes #77604 Change-Id: I794249cf43a8cc4ab3262055daef9193e2442f73 Reviewed-on: https://go-review.googlesource.com/c/go/+/745621 Reviewed-by: Keith Randall LUCI-TryBot-Result: Go LUCI Reviewed-by: Jorropo Reviewed-by: Dmitri Shuralyov --- src/cmd/compile/internal/ssa/regalloc.go | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src') diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index dbcc93a7dd..c1cef741fa 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -1810,7 +1810,7 @@ func (s *regAllocState) regalloc(f *Func) { if regspec.clobbersArg0 { s.freeReg(register(s.f.getHome(args[0].ID).(*Register).num)) } - if regspec.clobbersArg1 { + if regspec.clobbersArg1 && !(regspec.clobbersArg0 && s.f.getHome(args[0].ID) == s.f.getHome(args[1].ID)) { s.freeReg(register(s.f.getHome(args[1].ID).(*Register).num)) } -- cgit v1.3-5-g9baa