6g, 8g: handle slice by sub-word-sized index (uint8, int8, uint16, int16)
R=ken2
CC=golang-dev
https://golang.org/cl/1960042
diff --git a/src/cmd/6g/ggen.c b/src/cmd/6g/ggen.c
index 46ca326..1e045da 100644
--- a/src/cmd/6g/ggen.c
+++ b/src/cmd/6g/ggen.c
@@ -1145,16 +1145,18 @@
n1.op = OXXX;
t = types[TUINT32];
- if(is64(nl->type) || is64(nr->type)) {
- // two 64-bit is just a 64-bit compare,
- // but one 32 and one 64 needs to copy
- // the 32 into a register to get the full comparison.
- t = types[TUINT64];
- if(!is64(nl->type) && nl->op != OLITERAL) {
+ if(nl->type->width != t->width || nr->type->width != t->width) {
+ if((is64(nl->type) && nl->op != OLITERAL) || (is64(nr->type) && nr->op != OLITERAL))
+ t = types[TUINT64];
+
+ // Check if we need to use a temporary.
+ // At least one of the arguments is 32 bits
+ // (the len or cap) so one temporary suffices.
+ if(nl->type->width != t->width && nl->op != OLITERAL) {
regalloc(&n1, t, nl);
gmove(nl, &n1);
nl = &n1;
- } else if(!is64(nr->type) && nr->op != OLITERAL) {
+ } else if(nr->type->width != t->width && nr->op != OLITERAL) {
regalloc(&n1, t, nr);
gmove(nr, &n1);
nr = &n1;
diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index 40f348c..5c51833 100644
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -857,7 +857,8 @@
vlong cl;
Prog *p1;
int op;
- Node *c;
+ Node *c, n1;
+ Type *t;
op = OLE;
if(smallintconst(nl)) {
@@ -872,16 +873,34 @@
nl = nr;
nr = c;
}
-
- gins(optoas(OCMP, types[TUINT32]), nl, nr);
+
+ // Arguments are known not to be 64-bit,
+ // but they might be smaller than 32 bits.
+ // Check if we need to use a temporary.
+ // At least one of the arguments is 32 bits
+ // (the len or cap) so one temporary suffices.
+ n1.op = OXXX;
+ t = types[TUINT32];
+ if(nl->type->width != t->width) {
+ regalloc(&n1, t, nl);
+ gmove(nl, &n1);
+ nl = &n1;
+ } else if(nr->type->width != t->width) {
+ regalloc(&n1, t, nr);
+ gmove(nr, &n1);
+ nr = &n1;
+ }
+ gins(optoas(OCMP, t), nl, nr);
+ if(n1.op != OXXX)
+ regfree(&n1);
if(throwpc == nil) {
- p1 = gbranch(optoas(op, types[TUINT32]), T);
+ p1 = gbranch(optoas(op, t), T);
throwpc = pc;
ginscall(panicslice, 0);
patch(p1, pc);
} else {
op = brcom(op);
- p1 = gbranch(optoas(op, types[TUINT32]), T);
+ p1 = gbranch(optoas(op, t), T);
patch(p1, throwpc);
}
}
@@ -1045,6 +1064,7 @@
// if(lb[1] > old.nel[0]) goto throw;
n2 = nodes[0];
n2.xoffset += Array_nel;
+ n2.type = types[TUINT32];
cmpandthrow(&nodes[1], &n2);
// ret.nel = old.nel[0]-lb[1];
@@ -1064,6 +1084,7 @@
// if(hb[2] > old.cap[0]) goto throw;
n2 = nodes[0];
n2.xoffset += Array_cap;
+ n2.type = types[TUINT32];
cmpandthrow(&nodes[2], &n2);
// if(lb[1] > hb[2]) goto throw;
diff --git a/src/pkg/exp/draw/x11/auth.go b/src/pkg/exp/draw/x11/auth.go
index b4c75a3..896dedf 100644
--- a/src/pkg/exp/draw/x11/auth.go
+++ b/src/pkg/exp/draw/x11/auth.go
@@ -16,10 +16,7 @@
if err != nil {
return 0, err
}
- // TODO(nigeltao): remove the workaround when bug 1011 gets fixed.
- //return uint16(b[0])<<8 + uint16(b[1]), nil
- ret := uint16(b[0])<<8 + uint16(b[1])
- return ret, nil
+ return uint16(b[0])<<8 + uint16(b[1]), nil
}
// readStr reads a length-prefixed string from r, using b as a scratch buffer.
diff --git a/test/fixedbugs/bug303.go b/test/fixedbugs/bug303.go
new file mode 100644
index 0000000..3bd790f
--- /dev/null
+++ b/test/fixedbugs/bug303.go
@@ -0,0 +1,37 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// 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.
+
+// Issue 1011. Removing either #1 or #3 avoided the crash at #2.
+
+package main
+
+import (
+ "io"
+ "strings"
+)
+
+func readU16BE(b []byte) uint16 {
+ b[0] = 0
+ b[1] = 1
+ return uint16(b[0])<<8 + uint16(b[1]) // #1
+ n := uint16(b[0])<<8 + uint16(b[1])
+ return n
+}
+
+func readStr(r io.Reader, b []byte) string {
+ n := readU16BE(b)
+ if int(n) > len(b) {
+ return "err: n>b"
+ }
+ io.ReadFull(r, b[0:n]) // #2
+ return string(b[0:n]) // #3
+ return "ok"
+}
+
+func main() {
+ br := strings.NewReader("abcd")
+ readStr(br, make([]byte, 256))
+}
