[release-branch.go1.11] cmd/compile/internal/gc: OMUL should be evaluated when using...

When using soft-float, OMUL might be rewritten to function call
so we should ensure it was evaluated first.

Updates #28688
Fixes #28694

Change-Id: I30b87501782fff62d35151f394a1c22b0d490c6c
Reviewed-on: https://go-review.googlesource.com/c/148837
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
(cherry picked from commit c92e73b70253f5d88c473a7ad6c5b8d61b2debb7)
Reviewed-on: https://go-review.googlesource.com/c/151342
Reviewed-by: Andrew Bonventre <andybons@golang.org>

diff --git a/src/cmd/compile/internal/gc/subr.go b/src/cmd/compile/internal/gc/subr.go
index 0af0ff82c4e934be3e27ab03ef9f7403dd97dfb6..c926b147de525c87088e1935244379ccd5c59336 100644 (file)
--- a/src/cmd/compile/internal/gc/subr.go
+++ b/src/cmd/compile/internal/gc/subr.go
@@ -1116,7 +1116,7 @@ func calcHasCall(n *Node) bool {
 
        // When using soft-float, these ops might be rewritten to function calls
        // so we ensure they are evaluated first.
-       case OADD, OSUB, OMINUS:
+       case OADD, OSUB, OMINUS, OMUL:
                if thearch.SoftFloat && (isFloat[n.Type.Etype] || isComplex[n.Type.Etype]) {
                        return true
                }

diff --git a/test/fixedbugs/issue28688.go b/test/fixedbugs/issue28688.go
new file mode 100644 (file)
index 0000000..0d2000e
--- /dev/null
+++ b/test/fixedbugs/issue28688.go
@@ -0,0 +1,31 @@
+// run -gcflags=-d=softfloat
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+       "fmt"
+)
+
+// When using soft-float, OMUL might be rewritten to function
+// call so we should ensure it was evaluated first. Stack frame
+// setup for "test" function call should happen after call to runtime.fmul32
+
+var x int32 = 1
+
+func main() {
+       var y float32 = 1.0
+       test(x, y*y)
+}
+
+//go:noinline
+func test(id int32, a float32) {
+
+       if id != x {
+               fmt.Printf("got: %d, want: %d\n", id, x)
+               panic("FAIL")
+       }
+}