5g, 6g, 8g: shift, opt fixes

Fixes #1808.

R=ken2
CC=golang-dev
https://golang.org/cl/4813052

src/cmd/5g/cgen64.c

@@ -158,7 +158,7 @@ cgen64(Node *n, Node *res)
 		gins(AMOVW, &hi2, &ch);
 		gins(AMOVW, &lo2, &cl);
 
-		// bl * cl
+		// bl * cl -> ah al
 		p1 = gins(AMULLU, N, N);
 		p1->from.type = D_REG;
 		p1->from.reg = bl.val.u.reg;
@@ -168,7 +168,7 @@ cgen64(Node *n, Node *res)
 		p1->to.offset = al.val.u.reg;
 //print("%P\n", p1);
 
-		// bl * ch
+		// bl * ch + ah -> ah
 		p1 = gins(AMULA, N, N);
 		p1->from.type = D_REG;
 		p1->from.reg = bl.val.u.reg;
@@ -178,7 +178,7 @@ cgen64(Node *n, Node *res)
 		p1->to.offset = ah.val.u.reg;
 //print("%P\n", p1);
 
-		// bh * cl
+		// bh * cl + ah -> ah
 		p1 = gins(AMULA, N, N);
 		p1->from.type = D_REG;
 		p1->from.reg = bh.val.u.reg;

src/cmd/5g/ggen.c

@@ -470,9 +470,10 @@ samereg(Node *a, Node *b)
 void
 cgen_shift(int op, Node *nl, Node *nr, Node *res)
 {
-	Node n1, n2, n3, t;
+	Node n1, n2, n3, nt, t, lo, hi;
 	int w;
-	Prog *p1, *p2, *p3;
+	Prog *p1, *p2, *p3, *pbig;
+	Type *tr;
 	uvlong sc;
 
 	if(nl->type->width > 4)
@@ -504,6 +505,32 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
 		return;
 	}
 
+	pbig = P;
+	tr = nr->type;
+	if(tr->width > 4) {
+		tempname(&nt, nr->type);
+		if(nl->ullman >= nr->ullman) {
+			regalloc(&n2, nl->type, res);
+			cgen(nl, &n2);
+			cgen(nr, &nt);
+			n1 = nt;
+		} else {
+			cgen(nr, &nt);
+			regalloc(&n2, nl->type, res);
+			cgen(nl, &n2);
+		}
+		split64(&nt, &lo, &hi);
+		regalloc(&n1, types[TUINT32], N);
+		regalloc(&n3, types[TUINT32], N);
+		gmove(&lo, &n1);
+		gmove(&hi, &n3);
+		gins(ATST, &n3, N);
+		nodconst(&t, types[TUINT32], w);
+		p1 = gins(AMOVW, &t, &n1);
+		p1->scond = C_SCOND_NE;
+		tr = types[TUINT32];
+		regfree(&n3);
+	} else {
 		if(nl->ullman >= nr->ullman) {
 			regalloc(&n2, nl->type, res);
 			cgen(nl, &n2);
@@ -515,13 +542,14 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
 			regalloc(&n2, nl->type, res);
 			cgen(nl, &n2);
 		}
+	}
 
 	// test for shift being 0
 	p1 = gins(ATST, &n1, N);
 	p3 = gbranch(ABEQ, T);
 
 	// test and fix up large shifts
-	regalloc(&n3, nr->type, N);
+	regalloc(&n3, tr, N);
 	nodconst(&t, types[TUINT32], w);
 	gmove(&t, &n3);
 	gcmp(ACMP, &n1, &n3);

src/cmd/5g/gsubr.c

@@ -497,6 +497,7 @@ fp:
 		n->class = PPARAM;
 		break;
 	}
+	n->typecheck = 1;
 	return n;
 }
 
@@ -1173,6 +1174,7 @@ naddr(Node *n, Addr *a, int canemitcode)
 	a->name = D_NONE;
 	a->reg = NREG;
 	a->node = N;
+	a->etype = 0;
 	if(n == N)
 		return;
 
@@ -1308,6 +1310,7 @@ naddr(Node *n, Addr *a, int canemitcode)
 	case OLEN:
 		// len of string or slice
 		naddr(n->left, a, canemitcode);
+		a->etype = TINT32;
 		if(a->type == D_CONST && a->offset == 0)
 			break;	// len(nil)
 		a->offset += Array_nel;
@@ -1318,6 +1321,7 @@ naddr(Node *n, Addr *a, int canemitcode)
 	case OCAP:
 		// cap of string or slice
 		naddr(n->left, a, canemitcode);
+		a->etype = TINT32;
 		if(a->type == D_CONST && a->offset == 0)
 			break;	// cap(nil)
 		a->offset += Array_cap;
@@ -1327,6 +1331,7 @@ naddr(Node *n, Addr *a, int canemitcode)
 
 	case OADDR:
 		naddr(n->left, a, canemitcode);
+		a->etype = tptr;
 		switch(a->type) {
 		case D_OREG:
 			a->type = D_CONST;
@@ -1819,6 +1824,7 @@ odot:
 
 	a->type = D_NONE;
 	a->name = D_NONE;
+	n1.type = n->type;
 	naddr(&n1, a, 1);
 	goto yes;
 
@@ -1946,7 +1952,6 @@ oindex:
 	a->type = D_OREG;
 	a->reg = reg->val.u.reg;
 	a->offset = 0;
-
 	goto yes;
 
 oindex_const:

src/cmd/5g/peep.c

@@ -933,7 +933,6 @@ xtramodes(Reg *r, Adr *a)
 int
 copyu(Prog *p, Adr *v, Adr *s)
 {
-
 	switch(p->as) {
 
 	default:
@@ -1011,6 +1010,8 @@ copyu(Prog *p, Adr *v, Adr *s)
 			return 0;
 		}
 		if(copyas(&p->to, v)) {
+			if(p->scond != C_SCOND_NONE)
+				return 2;
 			if(copyau(&p->from, v))
 				return 4;
 			return 3;
@@ -1069,6 +1070,8 @@ copyu(Prog *p, Adr *v, Adr *s)
 			return 0;
 		}
 		if(copyas(&p->to, v)) {
+			if(p->scond != C_SCOND_NONE)
+				return 2;
 			if(p->reg == NREG)
 				p->reg = p->to.reg;
 			if(copyau(&p->from, v))

src/cmd/5g/reg.c

@@ -336,6 +336,7 @@ regopt(Prog *firstp)
 		case AMULD:
 		case ADIVF:
 		case ADIVD:
+		case AMULA:
 		case AMULAL:
 		case AMULALU:
 			for(z=0; z<BITS; z++) {
@@ -770,6 +771,7 @@ addmove(Reg *r, int bn, int rn, int f)
 		break;
 	case TBOOL:
 	case TUINT8:
+//print("movbu %E %d %S\n", v->etype, bn, v->sym);
 		p1->as = AMOVBU;
 		break;
 	case TINT16:
@@ -843,9 +845,6 @@ mkvar(Reg *r, Adr *a)
 	n = D_NONE;
 
 	flag = 0;
-	if(a->pun)
-		flag = 1;
-
 	switch(t) {
 	default:
 		print("type %d %d %D\n", t, a->name, a);
@@ -928,7 +927,7 @@ mkvar(Reg *r, Adr *a)
 				if(!flag)
 					return blsh(i);
 
-			// if they overlaps, disable both
+			// if they overlap, disable both
 			if(overlap(v->offset, v->width, o, w)) {
 				v->addr = 1;
 				flag = 1;
@@ -952,6 +951,7 @@ mkvar(Reg *r, Adr *a)
 
 	i = nvar;
 	nvar++;
+//print("var %d %E %D %S\n", i, et, a, s);
 	v = var+i;
 	v->sym = s;
 	v->offset = o;
@@ -963,7 +963,7 @@ mkvar(Reg *r, Adr *a)
 	v->node = a->node;
 	
 	if(debug['R'])
-		print("bit=%2d et=%E pun=%d %D\n", i, et, flag, a);
+		print("bit=%2d et=%2d w=%d+%d %S %D flag=%d\n", i, et, o, w, s, a, v->addr);
 
 	bit = blsh(i);
 	if(n == D_EXTERN || n == D_STATIC)
@@ -1453,10 +1453,6 @@ paint3(Reg *r, int bn, int32 rb, int rn)
 void
 addreg(Adr *a, int rn)
 {
-
-	if(a->type == D_CONST)
-		fatal("addreg: cant do this %D %d\n", a, rn);
-
 	a->sym = 0;
 	a->name = D_NONE;
 	a->type = D_REG;
@@ -1477,8 +1473,7 @@ addreg(Adr *a, int rn)
 int32
 RtoB(int r)
 {
-
+	if(r >= REGTMP-2)	// excluded R9 and R10 for m and g
-	if(r < 2 || r >= REGTMP-2)	// excluded R9 and R10 for m and g
 		return 0;
 	return 1L << r;
 }

src/cmd/6g/gsubr.c

@@ -473,6 +473,7 @@ fatal("shouldnt be used");
 		n->xoffset += types[tptr]->width;
 		break;
 	}
+	n->typecheck = 1;
 	return n;
 }
 
@@ -987,7 +988,6 @@ gins(int as, Node *f, Node *t)
 	if(debug['g'])
 		print("%P\n", p);
 
-
 	w = 0;
 	switch(as) {
 	case AMOVB:

src/cmd/8g/ggen.c

@@ -620,9 +620,9 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 void
 cgen_shift(int op, Node *nl, Node *nr, Node *res)
 {
-	Node n1, n2, cx, oldcx;
+	Node n1, n2, nt, cx, oldcx, hi, lo;
 	int a, w;
-	Prog *p1;
+	Prog *p1, *p2;
 	uvlong sc;
 
 	if(nl->type->width > 4)
@@ -656,8 +656,13 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
 		gmove(&cx, &oldcx);
 	}
 
+	if(nr->type->width > 4) {
+		tempname(&nt, nr->type);
+		n1 = nt;
+	} else {
 		nodreg(&n1, types[TUINT32], D_CX);
 		regalloc(&n1, nr->type, &n1);		// to hold the shift type in CX
+	}
 
 	if(samereg(&cx, res))
 		regalloc(&n2, nl->type, N);
@@ -672,8 +677,21 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
 	}
 
 	// test and fix up large shifts
+	if(nr->type->width > 4) {
+		// delayed reg alloc
+		nodreg(&n1, types[TUINT32], D_CX);
+		regalloc(&n1, types[TUINT32], &n1);		// to hold the shift type in CX
+		split64(&nt, &lo, &hi);
+		gmove(&lo, &n1);
+		gins(optoas(OCMP, types[TUINT32]), &hi, ncon(0));
+		p2 = gbranch(optoas(ONE, types[TUINT32]), T);
+		gins(optoas(OCMP, types[TUINT32]), &n1, ncon(w));
+		p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+		patch(p2, pc);
+	} else {
 		gins(optoas(OCMP, nr->type), &n1, ncon(w));
 		p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+	}
 	if(op == ORSH && issigned[nl->type->etype]) {
 		gins(a, ncon(w-1), &n2);
 	} else {

src/cmd/8g/reg.c

@@ -865,7 +865,7 @@ mkvar(Reg *r, Adr *a)
 			if(v->width == w)
 				return blsh(i);
 
-			// if they overlaps, disable both
+			// if they overlap, disable both
 			if(overlap(v->offset, v->width, o, w)) {
 				if(debug['R'])
 					print("disable %s\n", v->sym->name);
@@ -874,8 +874,6 @@ mkvar(Reg *r, Adr *a)
 			}
 		}
 	}
-	if(a->pun)
-		flag = 1;
 
 	switch(et) {
 	case 0:
@@ -902,7 +900,7 @@ mkvar(Reg *r, Adr *a)
 	v->node = a->node;
 
 	if(debug['R'])
-		print("bit=%2d et=%2d w=%d %S %D flag=%d\n", i, et, w, s, a, v->addr);
+		print("bit=%2d et=%2d w=%d+%d %S %D flag=%d\n", i, et, o, w, s, a, v->addr);
 	ostats.nvar++;
 
 	bit = blsh(i);

src/cmd/gc/bits.c

@@ -150,8 +150,11 @@ Qconv(Fmt *fp)
 			fmtprint(fp, " ");
 		if(var[i].sym == S)
 			fmtprint(fp, "$%lld", var[i].offset);
-		else
+		else {
 			fmtprint(fp, var[i].sym->name);
+			if(var[i].offset != 0)
+				fmtprint(fp, "%+d", var[i].offset);
+		}
 		bits.b[i/32] &= ~(1L << (i%32));
 	}
 	return 0;

test/fixedbugs/bug356.go

@@ -0,0 +1,41 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG: bug344
+
+// Copyright 2011 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 1808
+
+package main
+
+func main() {
+	var i uint64
+	var x int = 12345
+
+	if y := x << (i&5); y != 12345<<0 {
+		println("BUG bug344", y)
+		return
+	}
+	
+	i++
+	if y := x << (i&5); y != 12345<<1 {
+		println("BUG bug344a", y)
+	}
+	
+	i = 70
+	if y := x << i; y != 0 {
+		println("BUG bug344b", y)
+	}
+	
+	i = 1<<32
+	if y := x << i; y != 0 {
+		println("BUG bug344c", y)
+	}
+}
+	
+
+/*
+typecheck [1008592b0]
+.   INDREG a(1) l(15) x(24) tc(2) runtime.ret G0 string
+bug343.go:15: internal compiler error: typecheck INDREG
+*/