peep: fix bug in peep optimizer.

reg: enable peep optimizer.
cgen64: better int64 code.

R=r
CC=golang-dev
https://golang.org/cl/3989065

src/cmd/5g/cgen64.c

@@ -204,14 +204,17 @@ cgen64(Node *n, Node *res)
 				// here and below (verify it optimizes to EOR)
 				gins(AEOR, &al, &al);
 				gins(AEOR, &ah, &ah);
-			} else if(v > 32) {
+			} else
+			if(v > 32) {
 				gins(AEOR, &al, &al);
 				//	MOVW	bl<<(v-32), ah
 				gshift(AMOVW, &bl, SHIFT_LL, (v-32), &ah);
-			} else if(v == 32) {
+			} else
+			if(v == 32) {
 				gins(AEOR, &al, &al);
 				gins(AMOVW, &bl, &ah);
-			} else if(v > 0) {
+			} else
+			if(v > 0) {
 				//	MOVW	bl<<v, al
 				gshift(AMOVW, &bl, SHIFT_LL, v, &al);
 
@@ -341,7 +344,8 @@ olsh_break:
 					gins(AEOR, &al, &al);
 					gins(AEOR, &ah, &ah);
 				}
-			} else if(v > 32) {
+			} else
+			if(v > 32) {
 				if(bh.type->etype == TINT32) {
 					//	MOVW	bh->(v-32), al
 					gshift(AMOVW, &bh, SHIFT_AR, v-32, &al);
@@ -353,7 +357,8 @@ olsh_break:
 					gshift(AMOVW, &bh, SHIFT_LR, v-32, &al);
 					gins(AEOR, &ah, &ah);
 				}
-			} else if(v == 32) {
+			} else
+			if(v == 32) {
 				gins(AMOVW, &bh, &al);
 				if(bh.type->etype == TINT32) {
 					//	MOVW	bh->31, ah
@@ -361,7 +366,8 @@ olsh_break:
 				} else {
 					gins(AEOR, &ah, &ah);
 				}
-			} else if( v > 0) {
+			} else
+			if( v > 0) {
 				//	MOVW	bl>>v, al
 				gshift(AMOVW, &bl, SHIFT_LR, v, &al);
 	
@@ -384,11 +390,16 @@ olsh_break:
 
 		regalloc(&s, types[TUINT32], N);
 		regalloc(&creg, types[TUINT32], N);
-		if (is64(r->type)) {
+		if(is64(r->type)) {
 			// shift is >= 1<<32
 			split64(r, &cl, &ch);
 			gmove(&ch, &s);
-			p1 = gins(ATST, &s, N);
+			gins(ATST, &s, N);
+			if(bh.type->etype == TINT32)
+				p1 = gshift(AMOVW, &bh, SHIFT_AR, 31, &ah);
+			else
+				p1 = gins(AEOR, &ah, &ah);
+			p1->scond = C_SCOND_NE;
 			p6 = gbranch(ABNE, T);
 			gmove(&cl, &s);
 			splitclean();
@@ -441,7 +452,6 @@ olsh_break:
 			p1 = gshift(AMOVW, &bh, SHIFT_AR, 31, &ah);
 		else
 			p1 = gins(AEOR, &ah, &ah);
-		p1->scond = C_SCOND_EQ;
 		p4 = gbranch(ABEQ, T);
 
 		// check if shift is < 64
@@ -461,33 +471,23 @@ olsh_break:
 			//	MOVW	bh->(s-32), al
 			p1 = gregshift(AMOVW, &bh, SHIFT_AR, &s, &al);
 			p1->scond = C_SCOND_LO;
-
-			//	MOVW	bh->31, ah
-			p1 = gshift(AMOVW, &bh, SHIFT_AR, 31, &ah);
-			p1->scond = C_SCOND_LO;
 		} else {
 			//	MOVW	bh>>(v-32), al
 			p1 = gregshift(AMOVW, &bh, SHIFT_LR, &s, &al);
 			p1->scond = C_SCOND_LO;
-
-			p1 = gins(AEOR, &ah, &ah);
-			p1->scond = C_SCOND_LO;
 		}
 
 		//	BLO	end
 		p5 = gbranch(ABLO, T);
 
 		// s >= 64
-		if (p6 != P) patch(p6, pc);
+		if(p6 != P)
+			patch(p6, pc);
 		if(bh.type->etype == TINT32) {
 			//	MOVW	bh->31, al
 			gshift(AMOVW, &bh, SHIFT_AR, 31, &al);
-
-			//	MOVW	bh->31, ah
-			gshift(AMOVW, &bh, SHIFT_AR, 31, &ah);
 		} else {
 			gins(AEOR, &al, &al);
-			gins(AEOR, &ah, &ah);
 		}
 
 		patch(p2, pc);

src/cmd/5g/peep.c

@@ -99,6 +99,8 @@ loop1:
 		case AMOVW:
 		case AMOVF:
 		case AMOVD:
+			if(p->scond)
+				break;
 			if(!regtyp(&p->to))
 				break;
 //			if(isdconst(&p->from)) {
@@ -335,6 +337,7 @@ subprop(Reg *r0)
 
 		case AMULLU:
 		case AMULA:
+		case AMVN:
 
 		case ACMN:
 		case AADD:
@@ -347,7 +350,6 @@ subprop(Reg *r0)
 		case AORR:
 		case AAND:
 		case AEOR:
-		case AMVN:
 		case AMUL:
 		case AMULU:
 		case ADIV:
@@ -1014,6 +1016,7 @@ copyu(Prog *p, Adr *v, Adr *s)
 
 	case AMULLU:	/* read, read, write, write */
 	case AMULA:
+	case AMVN:
 		return 2;
 
 	case AADD:	/* read, read, write */
@@ -1027,7 +1030,6 @@ copyu(Prog *p, Adr *v, Adr *s)
 	case AORR:
 	case AAND:
 	case AEOR:
-	case AMVN:
 	case AMUL:
 	case AMULU:
 	case ADIV:

src/cmd/5g/reg.c

@@ -143,7 +143,7 @@ regopt(Prog *firstp)
 	first++;
 
 	if(debug['K']) {
-		if(first != 13)
+		if(first != 2)
 			return;
 //		debug['R'] = 2;
 //		debug['P'] = 2;
@@ -491,7 +491,7 @@ brk:
 	 * peep-hole on basic block
 	 */
 	if(!debug['R'] || debug['P']) {
-//		peep();
+		peep();
 	}
 
 	/*