arm: bugfixes (stack clobbering, indices)

also changed zerodivide to output "BUG"

R=rsc
CC=golang-dev
http://codereview.appspot.com/1871055

6 files changed, 97 insertions, 86 deletions

diff --git a/src/cmd/5g/cgen.c b/src/cmd/5g/cgen.c
index 8072c3ceb..c3042b182 100644
--- a/src/cmd/5g/cgen.c
+++ b/src/cmd/5g/cgen.c
@@ -4,33 +4,6 @@
 
 #include "gg.h"
 
-void
-mgen(Node *n, Node *n1, Node *rg)
-{
-	n1->ostk = 0;
-	n1->op = OEMPTY;
-
-	if(n->addable) {
-		*n1 = *n;
-		n1->ostk = 0;
-		if(n1->op == OREGISTER || n1->op == OINDREG)
-			reg[n->val.u.reg]++;
-		return;
-	}
-	if(n->type->width > widthptr)
-		tempname(n1, n->type);
-	else
-		regalloc(n1, n->type, rg);
-	cgen(n, n1);
-}
-
-void
-mfree(Node *n)
-{
-	if(n->op == OREGISTER)
-		regfree(n);
-}
-
 /*
  * generate:
  *	res = n;
@@ -269,10 +242,26 @@ cgen(Node *n, Node *res)
 			cgen(nl, res);
 			break;
 		}
-
-		mgen(nl, &n1, res);
-		gmove(&n1, res);
-		mfree(&n1);
+		if(nl->addable && !is64(nl->type)) {
+			regalloc(&n1, nl->type, res);
+			gmove(nl, &n1);
+		} else {
+			if(n->type->width > widthptr || is64(nl->type) || isfloat[nl->type->etype])
+				tempname(&n1, nl->type);
+			else
+				regalloc(&n1, nl->type, res);
+			cgen(nl, &n1);
+		}
+		if(n->type->width > widthptr || is64(n->type) || isfloat[n->type->etype])
+			tempname(&n2, n->type);
+		else
+			regalloc(&n2, n->type, N);
+		gmove(&n1, &n2);
+		gmove(&n2, res);
+		if(n1.op == OREGISTER)
+			regfree(&n1);
+		if(n2.op == OREGISTER)
+			regfree(&n2);
 		break;
 
 	case ODOT:
@@ -461,6 +450,41 @@ ret:
 }
 
 /*
+ * generate array index into res.
+ * n might be any size; res is 32-bit.
+ * returns Prog* to patch to panic call.
+ */
+Prog*
+cgenindex(Node *n, Node *res)
+{
+	Node tmp, lo, hi, zero, n1, n2;
+
+	if(!is64(n->type)) {
+		cgen(n, res);
+		return nil;
+	}
+
+	tempname(&tmp, types[TINT64]);
+	cgen(n, &tmp);
+	split64(&tmp, &lo, &hi);
+	gmove(&lo, res);
+	if(debug['B']) {
+		splitclean();
+		return nil;
+	}
+	regalloc(&n1, types[TINT32], N);
+	regalloc(&n2, types[TINT32], N);
+	nodconst(&zero, types[TINT32], 0);
+	gmove(&hi, &n1);
+	gmove(&zero, &n2);
+	gcmp(ACMP, &n1, &n2);
+	regfree(&n2);
+	regfree(&n1);
+	splitclean();
+	return gbranch(ABNE, T);
+}
+
+/*
  * generate:
  *	res = &n;
  */
@@ -469,10 +493,9 @@ agen(Node *n, Node *res)
 {
 	Node *nl, *nr;
 	Node n1, n2, n3, n4, n5, tmp;
-	Prog *p1;
+	Prog *p1, *p2;
 	uint32 w;
 	uint64 v;
-	Type *t;
 
 	if(debug['g']) {
 		dump("\nagen-res", res);
@@ -519,20 +542,20 @@ agen(Node *n, Node *res)
 		break;
 
 	case OINDEX:
-		// TODO(rsc): uint64 indices
+		p2 = nil;  // to be patched to panicindex.
 		w = n->type->width;
 		if(nr->addable) {
 			agenr(nl, &n3, res);
 			if(!isconst(nr, CTINT)) {
 				tempname(&tmp, types[TINT32]);
-				cgen(nr, &tmp);
+				p2 = cgenindex(nr, &tmp);
 				regalloc(&n1, tmp.type, N);
 				gmove(&tmp, &n1);
 			}
 		} else if(nl->addable) {
 			if(!isconst(nr, CTINT)) {
 				tempname(&tmp, types[TINT32]);
-				cgen(nr, &tmp);
+				p2 = cgenindex(nr, &tmp);
 				regalloc(&n1, tmp.type, N);
 				gmove(&tmp, &n1);
 			}
@@ -540,7 +563,7 @@ agen(Node *n, Node *res)
 			agen(nl, &n3);
 		} else {
 			tempname(&tmp, types[TINT32]);
-			cgen(nr, &tmp);
+			p2 = cgenindex(nr, &tmp);
 			nr = &tmp;
 			agenr(nl, &n3, res);
 			regalloc(&n1, tmp.type, N);
@@ -602,12 +625,7 @@ agen(Node *n, Node *res)
 			break;
 		}
 
-		// type of the index
-		t = types[TUINT32];
-		if(issigned[n1.type->etype])
-			t = types[TINT32];
-
-		regalloc(&n2, t, &n1);			// i
+		regalloc(&n2, types[TINT32], &n1);			// i
 		gmove(&n1, &n2);
 		regfree(&n1);
 
@@ -627,6 +645,8 @@ agen(Node *n, Node *res)
 			gcmp(optoas(OCMP, types[TUINT32]), &n2, &n4);
 			regfree(&n4);
 			p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+			if(p2)
+				patch(p2, pc);
 			ginscall(panicindex, 0);
 			patch(p1, pc);
 		}
@@ -653,10 +673,10 @@ agen(Node *n, Node *res)
 			else if(w == 8)
 				gshift(AADD, &n2, SHIFT_LL, 3, &n3);	
 		} else {
-			regalloc(&n4, t, N);
-			nodconst(&n1, t, w);
+			regalloc(&n4, types[TUINT32], N);
+			nodconst(&n1, types[TUINT32], w);
 			gmove(&n1, &n4);
-			gins(optoas(OMUL, t), &n4, &n2);
+			gins(optoas(OMUL, types[TUINT32]), &n4, &n2);
 			gins(optoas(OADD, types[tptr]), &n2, &n3);
 			regfree(&n4);
 			gmove(&n3, res);
@@ -1088,7 +1108,7 @@ stkof(Node *n)
 
 		t = structfirst(&flist, getoutarg(t));
 		if(t != T)
-			return t->width;
+			return t->width + 4;	// correct for LR
 		break;
 	}
 
diff --git a/src/cmd/5g/gg.h b/src/cmd/5g/gg.h
index c62efeb6c..4801e4721 100644
--- a/src/cmd/5g/gg.h
+++ b/src/cmd/5g/gg.h
@@ -90,6 +90,7 @@ void	ginscall(Node*, int);
  * cgen
  */
 void	agen(Node*, Node*);
+Prog* cgenindex(Node *, Node *);
 void	igen(Node*, Node*, Node*);
 void agenr(Node *n, Node *a, Node *res);
 vlong	fieldoffset(Type*, Node*);
diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index 8c5ddbb09..741dbe595 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -991,7 +991,7 @@ gshift(int as, Node *lhs, int32 stype, int32 sval, Node *rhs)
 {
 	Prog *p;
 
-	if (sval <= 0 || sval > 32)
+	if(sval <= 0 || sval > 32)
 		fatal("bad shift value: %d", sval);
 
 	sval = sval&0x1f;
@@ -1054,7 +1054,7 @@ naddr(Node *n, Addr *a, int canemitcode)
 		break;
 
 	case OREGISTER:
-		if (n->val.u.reg <= REGALLOC_RMAX) {
+		if(n->val.u.reg <= REGALLOC_RMAX) {
 			a->type = D_REG;
 			a->reg = n->val.u.reg;
 		} else {
@@ -1594,7 +1594,7 @@ sudoaddable(int as, Node *n, Addr *a, int *w)
 	int64 v;
 	Node n1, n2, n3, n4, *nn, *l, *r;
 	Node *reg, *reg1;
-	Prog *p1;
+	Prog *p1, *p2;
 	Type *t;
 
 	if(n->type == T)
@@ -1732,8 +1732,8 @@ oindex:
 	if(issigned[r->type->etype])
 		t = types[TINT32];
 	regalloc(reg1, t, N);
-	regalloc(&n3, r->type, reg1);
-	cgen(r, &n3);
+	regalloc(&n3, types[TINT32], reg1);
+	p2 = cgenindex(r, &n3);
 	gmove(&n3, reg1);
 	regfree(&n3);
 
@@ -1774,6 +1774,8 @@ oindex:
 		gcmp(optoas(OCMP, types[TUINT32]), reg1, &n3);
 		regfree(&n3);
 		p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+		if(p2)
+			patch(p2, pc);
 		ginscall(panicindex, 0);
 		patch(p1, pc);
 	}
@@ -1786,7 +1788,7 @@ oindex:
 		gmove(&n2, reg);
 	}
 
-	if (*w == 1)
+	if(*w == 1)
 		gins(AADD, reg1, reg);
 	else if(*w == 2)
 		gshift(AADD, reg1, SHIFT_LL, 1, reg);
diff --git a/test/arm-pass.txt b/test/arm-pass.txt
index 476c3bddc..ffc4ee2ab 100644
--- a/test/arm-pass.txt
+++ b/test/arm-pass.txt
@@ -1,5 +1,5 @@
 ./235.go
-# ./64bit.go	# flaky
+# ./64bit.go	# fail, flaky
 ./args.go
 ./assign.go
 ./assign1.go
@@ -65,7 +65,7 @@
 ./indirect.go
 ./indirect1.go
 ./initcomma.go
-# ./initialize.go	# fail, BUG
+./initialize.go
 ./initializerr.go
 ./initsyscall.go
 ./int_lit.go
@@ -116,7 +116,7 @@
 ./varerr.go
 ./varinit.go
 ./vectors.go
-./zerodivide.go
+# ./zerodivide.go	# fail, BUG
 ken/array.go
 ken/chan.go
 ken/chan1.go
@@ -179,7 +179,7 @@ interface/embed0.go
 interface/embed1.go
 interface/explicit.go
 interface/fail.go
-# interface/fake.go	# fail
+interface/fake.go
 interface/pointer.go
 interface/receiver.go
 interface/receiver1.go
@@ -408,7 +408,7 @@ fixedbugs/bug217.go
 fixedbugs/bug218.go
 fixedbugs/bug219.go
 fixedbugs/bug220.go
-# fixedbugs/bug221.go	# fail
+fixedbugs/bug221.go
 fixedbugs/bug222.go
 fixedbugs/bug223.go
 fixedbugs/bug224.go
@@ -423,14 +423,14 @@ fixedbugs/bug232.go
 fixedbugs/bug233.go
 fixedbugs/bug234.go
 fixedbugs/bug235.go
-# fixedbugs/bug236.go	# fail
+fixedbugs/bug236.go
 fixedbugs/bug237.go
 fixedbugs/bug238.go
 fixedbugs/bug239.go
 fixedbugs/bug240.go
 fixedbugs/bug241.go
 fixedbugs/bug242.go
-# fixedbugs/bug243.go	# fail
+fixedbugs/bug243.go
 fixedbugs/bug244.go
 fixedbugs/bug245.go
 fixedbugs/bug246.go
@@ -458,7 +458,7 @@ fixedbugs/bug268.go
 fixedbugs/bug269.go
 fixedbugs/bug270.go
 fixedbugs/bug271.go
-# fixedbugs/bug272.go	# fail
+fixedbugs/bug272.go
 fixedbugs/bug273.go
 fixedbugs/bug274.go
 fixedbugs/bug275.go
@@ -467,7 +467,7 @@ fixedbugs/bug277.go
 fixedbugs/bug278.go
 fixedbugs/bug279.go
 fixedbugs/bug280.go
-# fixedbugs/bug281.go	# fail, BUG
+fixedbugs/bug281.go
 fixedbugs/bug282.go
 fixedbugs/bug283.go
 fixedbugs/bug284.go
diff --git a/test/golden-arm.out b/test/golden-arm.out
index 83f199e94..41829fb03 100644
--- a/test/golden-arm.out
+++ b/test/golden-arm.out
@@ -51,30 +51,6 @@ FAIL
 =========== ./turing.go
 Hello World!
 
-=========== ./zerodivide.go
-int 0/0: expected "divide"; got no error
-int8 0/0: expected "divide"; got no error
-int16 0/0: expected "divide"; got no error
-int32 0/0: expected "divide"; got no error
-int64 0/0: expected "divide"; got no error
-int 1/0: expected "divide"; got no error
-int8 1/0: expected "divide"; got no error
-int16 1/0: expected "divide"; got no error
-int32 1/0: expected "divide"; got no error
-int64 1/0: expected "divide"; got no error
-uint 0/0: expected "divide"; got no error
-uint8 0/0: expected "divide"; got no error
-uint16 0/0: expected "divide"; got no error
-uint32 0/0: expected "divide"; got no error
-uint64 0/0: expected "divide"; got no error
-uintptr 0/0: expected "divide"; got no error
-uint 1/0: expected "divide"; got no error
-uint8 1/0: expected "divide"; got no error
-uint16 1/0: expected "divide"; got no error
-uint32 1/0: expected "divide"; got no error
-uint64 1/0: expected "divide"; got no error
-uintptr 1/0: expected "divide"; got no error
-
 =========== ken/intervar.go
  print 1 bio 2 file 3 -- abc
 
diff --git a/test/zerodivide.go b/test/zerodivide.go
index e0407df7c..e016d0dfe 100644
--- a/test/zerodivide.go
+++ b/test/zerodivide.go
@@ -147,10 +147,22 @@ func main() {
 		case t.err == "" && err == "":
 			// fine
 		case t.err != "" && err == "":
+			if !bad {
+				bad = true
+				fmt.Printf("BUG\n")
+			}
 			fmt.Printf("%s: expected %q; got no error\n", t.name, t.err)
 		case t.err == "" && err != "":
+			if !bad {
+				bad = true
+				fmt.Printf("BUG\n")
+			}
 			fmt.Printf("%s: expected no error; got %q\n", t.name, err)
 		case t.err != "" && err != "":
+			if !bad {
+				bad = true
+				fmt.Printf("BUG\n")
+			}
 			if strings.Index(err, t.err) < 0 {
 				fmt.Printf("%s: expected %q; got %q\n", t.name, t.err, err)
 				continue