From 390656affd8993ce6332dca3fa86d57659622fdf Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 8 Aug 2013 16:44:16 -0400
Subject: [PATCH] cmd/gc: fix stkptrsize calculation
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I moved the pointer block from one end of the frame
to the other toward the end of working on the last CL,
and of course that made the optimization no longer work.

Now it works again:

0030 (bug361.go:12) DATA    gclocals·0+0(SB)/4,$4
0030 (bug361.go:12) DATA    gclocals·0+4(SB)/4,$3
0030 (bug361.go:12) GLOBL   gclocals·0+0(SB),8,$8

Fixes arm build (this time for sure!).

TBR=golang-dev
CC=cshapiro, golang-dev, iant
https://golang.org/cl/12627044
---
 src/cmd/gc/pgen.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/src/cmd/gc/pgen.c b/src/cmd/gc/pgen.c
index ad005a8f926..64b03b341f9 100644
--- a/src/cmd/gc/pgen.c
+++ b/src/cmd/gc/pgen.c
@@ -341,7 +341,7 @@ dumpgclocals(Node* fn, Sym *sym)
 		node = ll->n;
 		if(node->class == PAUTO && node->op == ONAME) {
 			if(haspointers(node->type)) {
-				xoffset = node->xoffset + stksize;
+				xoffset = node->xoffset + stkptrsize;
 				walktype1(node->type, &xoffset, bv);
 			}
 		}
@@ -397,7 +397,6 @@ allocauto(Prog* ptxt)
 	NodeList *ll;
 	Node* n;
 	vlong w;
-	vlong ptrlimit;
 
 	if(curfn->dcl == nil) {
 		stksize = 0;
@@ -437,7 +436,7 @@ allocauto(Prog* ptxt)
 
 	// Reassign stack offsets of the locals that are still there.
 	stksize = 0;
-	ptrlimit = -1;
+	stkptrsize = 0;
 	for(ll = curfn->dcl; ll != nil; ll=ll->next) {
 		n = ll->n;
 		if (n->class != PAUTO || n->op != ONAME)
@@ -449,8 +448,8 @@ allocauto(Prog* ptxt)
 			fatal("bad width");
 		stksize += w;
 		stksize = rnd(stksize, n->type->align);
-		if(ptrlimit < 0 && haspointers(n->type))
-			ptrlimit = stksize - w;
+		if(haspointers(n->type))
+			stkptrsize = stksize;
 		if(thechar == '5')
 			stksize = rnd(stksize, widthptr);
 		if(stksize >= (1ULL<<31)) {
@@ -460,11 +459,6 @@ allocauto(Prog* ptxt)
 		n->stkdelta = -stksize - n->xoffset;
 	}
 	stksize = rnd(stksize, widthptr);
-
-	if(ptrlimit < 0)
-		stkptrsize = 0;
-	else
-		stkptrsize = stksize - ptrlimit;
 	stkptrsize = rnd(stkptrsize, widthptr);
 
 	fixautoused(ptxt);