[dev.power64] liblink: fix g->panicwrap update code generation

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/123400043

diff --git a/src/liblink/obj9.c b/src/liblink/obj9.c
index 3405fce47726f8e9bea3bd94ac58f3066ffa356d..28793676cc6405291d59742027a92f95ef0e5e56 100644 (file)
--- a/src/liblink/obj9.c
+++ b/src/liblink/obj9.c
@@ -512,6 +512,36 @@ addstacksplit(Link *ctxt, LSym *cursym)
                                p->to.type = D_BRANCH;
                                break;
                        }
+                       if(cursym->text->reg & WRAPPER) {
+                               // g->panicwrap -= autosize;
+                               // MOVWZ panicwrap_offset(g), R3
+                               // ADD $-autosize, R3
+                               // MOVWZ R3, panicwrap_offset(g)
+                               p->as = AMOVWZ;
+                               p->from.type = D_OREG;
+                               p->from.reg = REGG;
+                               p->from.offset = 2*ctxt->arch->ptrsize;
+                               p->to.type = D_REG;
+                               p->to.reg = 3;
+                               p = appendp(ctxt, p);
+
+                               p->as = AADD;
+                               p->from.type = D_CONST;
+                               p->from.offset = -autosize;
+                               p->to.type = D_REG;
+                               p->to.reg = 3;
+                               p = appendp(ctxt, p);
+
+                               p->as = AMOVWZ;
+                               p->from.type = D_REG;
+                               p->from.reg = 3;
+                               p->to.type = D_OREG;
+                               p->to.reg = REGG;
+                               p->to.offset = 2*ctxt->arch->ptrsize;
+                               p = appendp(ctxt, p);
+
+                               p->as = ARETURN;
+                       }
                        if(cursym->text->mark & LEAF) {
                                if(!autosize) {
                                        p->as = ABR;