another shift bug

R=r
OCL=19525
CL=19525

diff --git a/src/cmd/6g/gen.c b/src/cmd/6g/gen.c
index c5159f9d75c42c716a4d86b4644e485d8c88ae7f..f162a67f079cff0aa5beae2940070726642aeed8 100644 (file)
--- a/src/cmd/6g/gen.c
+++ b/src/cmd/6g/gen.c
@@ -6,7 +6,6 @@
 #undef EXTERN
 #define        EXTERN
 #include "gg.h"
-//#include "opt.h"
 
 enum
 {
@@ -93,11 +92,6 @@ if(throwreturn == N) {
        gclean();
        checklabels();
 
-//     if(debug['N']) {
-//             regopt(ptxt);
-//             debug['N'] = 0;
-//     }
-
        if(curfn->type->outtuple != 0) {
                gins(ACALL, N, throwreturn);
        }
@@ -105,6 +99,11 @@ if(throwreturn == N) {
        pc->as = ARET;  // overwrite AEND
        pc->lineno = lineno;
 
+//     if(debug['N']) {
+//             regopt(ptxt);
+//             debug['N'] = 0;
+//     }
+
        // fill in argument size
        ptxt->to.offset = rnd(curfn->type->argwid, maxround);
 
@@ -1212,7 +1211,13 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
        if(nr->op == OLITERAL) {
                regalloc(&n1, nl->type, res);
                cgen(nl, &n1);
-               gins(a, nr, &n1);
+               if(mpgetfix(nr->val.u.xval) >= nl->type->width*8) {
+                       // large shift gets 2 shifts by width
+                       nodconst(&n3, types[TUINT32], nl->type->width*8-1);
+                       gins(a, &n3, &n1);
+                       gins(a, &n3, &n1);
+               } else
+                       gins(a, nr, &n1);
                gmove(&n1, res);
                regfree(&n1);
                goto ret;