diff options
| author | Keith Randall <khr@golang.org> | 2025-08-01 07:38:55 -0700 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2025-08-01 08:57:29 -0700 |
| commit | eef5f8d93016147718afba8a05282d2ba7332c51 (patch) | |
| tree | 758ad8a47cfbdeac24716e7408ac9a35c2c8642a /src/cmd/compile | |
| parent | e071617222e373f59db8995ce171bae708e0dcef (diff) | |
| download | go-eef5f8d93016147718afba8a05282d2ba7332c51.tar.xz | |
cmd/compile: enforce that locals are always accessed with SP base register
After CL 678937, we could have a situation where the value of the
stack pointer is in both SP and another register. We need to make sure
that regalloc picks SP when issuing a reference to local variables;
the assembler expects that.
Fixes #74836
Change-Id: I2ac73ece6eb44b4a78c1369f8a69e51ab9748754
Reviewed-on: https://go-review.googlesource.com/c/go/+/692395
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Mark Freeman <mark@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/cmd/compile')
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index de49bb40c5..fb9642cfed 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -1583,6 +1583,12 @@ func (s *regAllocState) regalloc(f *Func) { mask &^= desired.avoid } } + if mask&s.values[v.Args[i.idx].ID].regs&(1<<s.SPReg) != 0 { + // Prefer SP register. This ensures that local variables + // use SP as their base register (instead of a copy of the + // stack pointer living in another register). See issue 74836. + mask = 1 << s.SPReg + } args[i.idx] = s.allocValToReg(v.Args[i.idx], mask, true, v.Pos) } |