8g: out of register bug fix

Fixes #868.

R=ken2
CC=golang-dev
https://golang.org/cl/1695049

diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index 110446a0d772217ee2d235c5549f51030b533425..8a55ffd5987239f642ed9195549b08c229f4b157 100644 (file)
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -672,8 +672,10 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
        a = optoas(op, nl->type);
 
        if(nr->op == OLITERAL) {
+               tempname(&n2, nl->type);
+               cgen(nl, &n2);
                regalloc(&n1, nl->type, res);
-               cgen(nl, &n1);
+               gmove(&n2, &n1);
                sc = mpgetfix(nr->val.u.xval);
                if(sc >= nl->type->width*8) {
                        // large shift gets 2 shifts by width

diff --git a/test/fixedbugs/bug287.go b/test/fixedbugs/bug287.go
new file mode 100644 (file)
index 0000000..a4a08ee
--- /dev/null
+++ b/test/fixedbugs/bug287.go
@@ -0,0 +1,11 @@
+// errchk $G $D/$F.go
+
+// Copyright 2010 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.
+
+// Used to die dividing by zero; issue 879.
+
+package main
+
+var mult [3][...]byte = [3][5]byte{}   // ERROR "\.\.\."

diff --git a/test/fixedbugs/bug288.go b/test/fixedbugs/bug288.go
new file mode 100644 (file)
index 0000000..0105159
--- /dev/null
+++ b/test/fixedbugs/bug288.go
@@ -0,0 +1,18 @@
+// $G $D/$F.go
+
+// Copyright 2010 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.
+
+// Used to run out of registers on 8g.  Issue 868.
+
+package main
+
+func main() {
+       var r uint32
+       var buf [4]byte
+       a := buf[0:4]
+       r = (((((uint32(a[3]) << 8) | uint32(a[2])) << 8) |
+               uint32(a[1])) << 8) | uint32(a[0])
+       _ = r
+}