From: Cherry Zhang <cherryyz@google.com>
Date: Tue, 20 Apr 2021 17:09:54 +0000 (-0400)
Subject: cmd/compile: guard partially live arg spilling with number of registers
X-Git-Tag: go1.17beta1~551
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=77860ad280;p=gostls13.git

cmd/compile: guard partially live arg spilling with number of registers

The code that does partially live in-register arg spilling is
currently guarded with GOEXPERIMENT=regabiargs. But on platforms
where GOEXPERIMENT=regabiargs is not enabled there are still tests
that use register args. Guard it with actual number of registers
used, so it covers both.

Should fix the freeBSD builder.

Change-Id: I0d3c49d7a2389096cb6b17ca35b9b4ce567bc91e
Reviewed-on: https://go-review.googlesource.com/c/go/+/311830
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
---

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index e7d4865375..c5b1ae2e4a 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -6898,7 +6898,7 @@ func defframe(s *State, e *ssafn, f *ssa.Func) {
 	// and not address-taken (for non-SSA-able or address-taken arguments we always
 	// spill upfront).
 	// TODO(register args) Make liveness more fine-grained to that partial spilling is okay.
-	if buildcfg.Experiment.RegabiArgs {
+	if f.OwnAux.ABIInfo().InRegistersUsed() != 0 {
 		// First, see if it is already spilled before it may be live. Look for a spill
 		// in the entry block up to the first safepoint.
 		type nameOff struct {