cmd/5c, cmd/5g, cmd/5l: introduce MOVBS and MOVHS instructions.

MOVBS and MOVHS are defined as duplicates of MOVB and MOVH,
and perform sign-extension moving.
No change is made to code generation.

Update #1837

R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/12682043

10 files changed, 69 insertions, 26 deletions

diff --git a/src/cmd/5c/peep.c b/src/cmd/5c/peep.c
index 31c1322757..22328c18c3 100644
--- a/src/cmd/5c/peep.c
+++ b/src/cmd/5c/peep.c
@@ -127,8 +127,10 @@ loop1:
 			}
 			continue;
 		case AMOVH:
+		case AMOVHS:
 		case AMOVHU:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 			if(p->to.type != D_REG)
 				continue;
@@ -152,6 +154,7 @@ loop1:
 		switch(p->as) {
 		case AMOVW:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 			if(p->from.type == D_OREG && p->from.offset == 0)
 				xtramodes(r, &p->from);
@@ -824,7 +827,7 @@ xtramodes(Reg *r, Adr *a)
 	Adr v;
 
 	p = r->prog;
-	if(p->as == AMOVB && p->from.type == D_OREG)	/* byte load */
+	if((p->as == AMOVB || p->as == AMOVBS) && p->from.type == D_OREG)	/* byte load */
 		return 0;
 	v = *a;
 	v.type = D_REG;
@@ -836,7 +839,7 @@ xtramodes(Reg *r, Adr *a)
 		case AADD:
 			if(p1->from.type == D_REG ||
 			   (p1->from.type == D_SHIFT && (p1->from.offset&(1<<4)) == 0 &&
-			    (p->as != AMOVB || (a == &p->from && (p1->from.offset&~0xf) == 0))) ||
+			    ((p->as != AMOVB && p->as != AMOVBS) || (a == &p->from && (p1->from.offset&~0xf) == 0))) ||
 			   (p1->from.type == D_CONST &&
 			    p1->from.offset > -4096 && p1->from.offset < 4096))
 			if(nochange(uniqs(r1), r, p1)) {
@@ -961,8 +964,10 @@ copyu(Prog *p, Adr *v, Adr *s)
 	case AMOVF:
 	case AMOVD:
 	case AMOVH:
+	case AMOVHS:
 	case AMOVHU:
 	case AMOVB:
+	case AMOVBS:
 	case AMOVBU:
 	case AMOVDW:
 	case AMOVWD:
diff --git a/src/cmd/5c/reg.c b/src/cmd/5c/reg.c
index 25bfc58222..c12bd4711d 100644
--- a/src/cmd/5c/reg.c
+++ b/src/cmd/5c/reg.c
@@ -175,8 +175,10 @@ regopt(Prog *p)
 		 */
 		case ANOP:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 		case AMOVH:
+		case AMOVHS:
 		case AMOVHU:
 		case AMOVW:
 		case AMOVF:
diff --git a/src/cmd/5c/txt.c b/src/cmd/5c/txt.c
index 81da9fb801..6d9b69d001 100644
--- a/src/cmd/5c/txt.c
+++ b/src/cmd/5c/txt.c
@@ -594,13 +594,13 @@ gmove(Node *f, Node *t)
 			a = AMOVD;
 			break;
 		case TCHAR:
-			a = AMOVB;
+			a = AMOVBS;
 			break;
 		case TUCHAR:
 			a = AMOVBU;
 			break;
 		case TSHORT:
-			a = AMOVH;
+			a = AMOVHS;
 			break;
 		case TUSHORT:
 			a = AMOVHU;
@@ -630,13 +630,13 @@ gmove(Node *f, Node *t)
 			a = AMOVBU;
 			break;
 		case TCHAR:
-			a = AMOVB;
+			a = AMOVBS;
 			break;
 		case TUSHORT:
 			a = AMOVHU;
 			break;
 		case TSHORT:
-			a = AMOVH;
+			a = AMOVHS;
 			break;
 		case TFLOAT:
 			a = AMOVF;
@@ -761,13 +761,13 @@ gmove(Node *f, Node *t)
 		switch(tt) {
 		case TDOUBLE:
 			regalloc(&nod, f, Z);
-			gins(AMOVH, f, &nod);
+			gins(AMOVHS, f, &nod);
 			gins(AMOVWD, &nod, t);
 			regfree(&nod);
 			return;
 		case TFLOAT:
 			regalloc(&nod, f, Z);
-			gins(AMOVH, f, &nod);
+			gins(AMOVHS, f, &nod);
 			gins(AMOVWF, &nod, t);
 			regfree(&nod);
 			return;
@@ -776,7 +776,7 @@ gmove(Node *f, Node *t)
 		case TULONG:
 		case TLONG:
 		case TIND:
-			a = AMOVH;
+			a = AMOVHS;
 			break;
 		case TSHORT:
 		case TUSHORT:
@@ -819,13 +819,13 @@ gmove(Node *f, Node *t)
 		switch(tt) {
 		case TDOUBLE:
 			regalloc(&nod, f, Z);
-			gins(AMOVB, f, &nod);
+			gins(AMOVBS, f, &nod);
 			gins(AMOVWD, &nod, t);
 			regfree(&nod);
 			return;
 		case TFLOAT:
 			regalloc(&nod, f, Z);
-			gins(AMOVB, f, &nod);
+			gins(AMOVBS, f, &nod);
 			gins(AMOVWF, &nod, t);
 			regfree(&nod);
 			return;
@@ -836,7 +836,7 @@ gmove(Node *f, Node *t)
 		case TIND:
 		case TSHORT:
 		case TUSHORT:
-			a = AMOVB;
+			a = AMOVBS;
 			break;
 		case TCHAR:
 		case TUCHAR:
@@ -893,13 +893,13 @@ gmover(Node *f, Node *t)
 	if(typechlp[ft] && typechlp[tt] && ewidth[ft] >= ewidth[tt]){
 		switch(tt){
 		case TSHORT:
-			a = AMOVH;
+			a = AMOVHS;
 			break;
 		case TUSHORT:
 			a = AMOVHU;
 			break;
 		case TCHAR:
-			a = AMOVB;
+			a = AMOVBS;
 			break;
 		case TUCHAR:
 			a = AMOVBU;
diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index be4b7df503..2f0009f36c 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -1877,7 +1877,8 @@ lit:
 	default:
 		return 0;
 	case AADD: case ASUB: case AAND: case AORR: case AEOR:
-	case AMOVB: case AMOVBU: case AMOVH: case AMOVHU:
+	case AMOVB: case AMOVBS: case AMOVBU:
+	case AMOVH: case AMOVHS: case AMOVHU:
 	case AMOVW:
 		break;
 	}
diff --git a/src/cmd/5g/peep.c b/src/cmd/5g/peep.c
index c8e8174d36..78785bfe25 100644
--- a/src/cmd/5g/peep.c
+++ b/src/cmd/5g/peep.c
@@ -153,8 +153,10 @@ loop1:
 			break;
 
 		case AMOVH:
+		case AMOVHS:
 		case AMOVHU:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 			/*
 			 * look for MOVB x,R; MOVB R,R
@@ -181,6 +183,7 @@ loop1:
 		switch(p->as) {
 		case AMOVW:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 			if(p->from.type == D_OREG && p->from.offset == 0)
 				xtramodes(r, &p->from);
@@ -893,7 +896,7 @@ xtramodes(Reg *r, Adr *a)
 				break;
 			if(p1->from.type == D_REG ||
 			   (p1->from.type == D_SHIFT && (p1->from.offset&(1<<4)) == 0 &&
-			    (p->as != AMOVB || (a == &p->from && (p1->from.offset&~0xf) == 0))) ||
+			    ((p->as != AMOVB && p->as != AMOVBS) || (a == &p->from && (p1->from.offset&~0xf) == 0))) ||
 			   (p1->from.type == D_CONST &&
 			    p1->from.offset > -4096 && p1->from.offset < 4096))
 			if(nochange(uniqs(r1), r, p1)) {
@@ -1016,8 +1019,10 @@ copyu(Prog *p, Adr *v, Adr *s)
 	case AMOVF:
 	case AMOVD:
 	case AMOVH:
+	case AMOVHS:
 	case AMOVHU:
 	case AMOVB:
+	case AMOVBS:
 	case AMOVBU:
 	case AMOVFW:
 	case AMOVWF:
diff --git a/src/cmd/5g/reg.c b/src/cmd/5g/reg.c
index 0c2898c4c9..3230ec33c8 100644
--- a/src/cmd/5g/reg.c
+++ b/src/cmd/5g/reg.c
@@ -374,6 +374,7 @@ regopt(Prog *firstp)
 		 */
 		case ANOP:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 		case AMOVD:
 		case AMOVDF:
@@ -381,6 +382,7 @@ regopt(Prog *firstp)
 		case AMOVF:
 		case AMOVFW:
 		case AMOVH:
+		case AMOVHS:
 		case AMOVHU:
 		case AMOVW:
 		case AMOVWD:
diff --git a/src/cmd/5l/5.out.h b/src/cmd/5l/5.out.h
index 85dd17a8e5..b47eee3aa9 100644
--- a/src/cmd/5l/5.out.h
+++ b/src/cmd/5l/5.out.h
@@ -135,8 +135,10 @@ enum	as
 	AMODU,
 
 	AMOVB,
+	AMOVBS,
 	AMOVBU,
 	AMOVH,
+	AMOVHS,
 	AMOVHU,
 	AMOVW,
 	AMOVM,
diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index 20ed5e5ae1..92296b5bc9 100644
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -954,7 +954,7 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		r = p->to.reg;
 		o1 |= (p->from.reg)|(r<<12);
 		o2 |= (r)|(r<<12);
-		if(p->as == AMOVB || p->as == AMOVBU) {
+		if(p->as == AMOVB || p->as == AMOVBS || p->as == AMOVBU) {
 			o1 |= (24<<7);
 			o2 |= (24<<7);
 		} else {
@@ -1035,7 +1035,7 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(r == NREG)
 			r = o->param;
 		o2 = olrr(REGTMP,r, p->to.reg, p->scond);
-		if(p->as == AMOVBU || p->as == AMOVB)
+		if(p->as == AMOVBU || p->as == AMOVBS || p->as == AMOVB)
 			o2 |= 1<<22;
 		break;
 
@@ -1224,7 +1224,7 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(p->to.reg == NREG)
 			diag("MOV to shifter operand");
 		o1 = osrr(p->from.reg, p->to.offset, p->to.reg, p->scond);
-		if(p->as == AMOVB || p->as == AMOVBU)
+		if(p->as == AMOVB || p->as == AMOVBS || p->as == AMOVBU)
 			o1 |= 1<<22;
 		break;
 
@@ -1265,7 +1265,7 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(!o1)
 			break;
 		o2 = olr(0, REGTMP, p->to.reg, p->scond);
-		if(p->as == AMOVBU || p->as == AMOVB)
+		if(p->as == AMOVBU || p->as == AMOVBS || p->as == AMOVB)
 			o2 |= 1<<22;
 		if(o->flag & LPCREL) {
 			o3 = o2;
@@ -1309,9 +1309,9 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(r == NREG)
 			r = o->param;
 		o1 = olhr(instoffset, r, p->to.reg, p->scond);
-		if(p->as == AMOVB)
+		if(p->as == AMOVB || p->as == AMOVBS)
 			o1 ^= (1<<5)|(1<<6);
-		else if(p->as == AMOVH)
+		else if(p->as == AMOVH || p->as == AMOVHS)
 			o1 ^= (1<<6);
 		break;
 	case 72:	/* movh/movhu R,L(R) -> strh */
@@ -1331,9 +1331,9 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(r == NREG)
 			r = o->param;
 		o2 = olhrr(REGTMP, r, p->to.reg, p->scond);
-		if(p->as == AMOVB)
+		if(p->as == AMOVB || p->as == AMOVBS)
 			o2 ^= (1<<5)|(1<<6);
-		else if(p->as == AMOVH)
+		else if(p->as == AMOVH || p->as == AMOVHS)
 			o2 ^= (1<<6);
 		break;
 	case 74:	/* bx $I */
@@ -1485,9 +1485,9 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
 		if(!o1)
 			break;
 		o2 = olhr(0, REGTMP, p->to.reg, p->scond);
-		if(p->as == AMOVB)
+		if(p->as == AMOVB || p->as == AMOVBS)
 			o2 ^= (1<<5)|(1<<6);
-		else if(p->as == AMOVH)
+		else if(p->as == AMOVH || p->as == AMOVHS)
 			o2 ^= (1<<6);
 		if(o->flag & LPCREL) {
 			o3 = o2;
diff --git a/src/cmd/5l/optab.c b/src/cmd/5l/optab.c
index 91cadbdf45..dfd93f31d1 100644
--- a/src/cmd/5l/optab.c
+++ b/src/cmd/5l/optab.c
@@ -95,8 +95,10 @@ Optab	optab[] =
 	{ ACMP,		C_LCON,	C_REG,	C_NONE,		13, 8, 0,	LFROM },
 
 	{ AMOVB,	C_REG,	C_NONE,	C_REG,		14, 8, 0 },
+	{ AMOVBS,	C_REG,	C_NONE,	C_REG,		14, 8, 0 },
 	{ AMOVBU,	C_REG,	C_NONE,	C_REG,		58, 4, 0 },
 	{ AMOVH,	C_REG,	C_NONE,	C_REG,		14, 8, 0 },
+	{ AMOVHS,	C_REG,	C_NONE,	C_REG,		14, 8, 0 },
 	{ AMOVHU,	C_REG,	C_NONE,	C_REG,		14, 8, 0 },
 
 	{ AMUL,		C_REG,	C_REG,	C_REG,		15, 4, 0 },
@@ -112,6 +114,8 @@ Optab	optab[] =
 	{ AMOVW,	C_REG,	C_NONE,	C_SOREG,	20, 4, 0 },
 	{ AMOVB,	C_REG,	C_NONE,	C_SAUTO,	20, 4, REGSP },
 	{ AMOVB,	C_REG,	C_NONE,	C_SOREG,	20, 4, 0 },
+	{ AMOVBS,	C_REG,	C_NONE,	C_SAUTO,	20, 4, REGSP },
+	{ AMOVBS,	C_REG,	C_NONE,	C_SOREG,	20, 4, 0 },
 	{ AMOVBU,	C_REG,	C_NONE,	C_SAUTO,	20, 4, REGSP },
 	{ AMOVBU,	C_REG,	C_NONE,	C_SOREG,	20, 4, 0 },
 
@@ -126,6 +130,9 @@ Optab	optab[] =
 	{ AMOVB,	C_REG,	C_NONE,	C_LAUTO,	30, 8, REGSP,	LTO },
 	{ AMOVB,	C_REG,	C_NONE,	C_LOREG,	30, 8, 0,	LTO },
 	{ AMOVB,	C_REG,	C_NONE,	C_ADDR,		64, 8, 0,	LTO | LPCREL, 4 },
+	{ AMOVBS,	C_REG,	C_NONE,	C_LAUTO,	30, 8, REGSP,	LTO },
+	{ AMOVBS,	C_REG,	C_NONE,	C_LOREG,	30, 8, 0,	LTO },
+	{ AMOVBS,	C_REG,	C_NONE,	C_ADDR,		64, 8, 0,	LTO | LPCREL, 4 },
 	{ AMOVBU,	C_REG,	C_NONE,	C_LAUTO,	30, 8, REGSP,	LTO },
 	{ AMOVBU,	C_REG,	C_NONE,	C_LOREG,	30, 8, 0,	LTO },
 	{ AMOVBU,	C_REG,	C_NONE,	C_ADDR,		64, 8, 0,	LTO | LPCREL, 4 },
@@ -176,9 +183,11 @@ Optab	optab[] =
 	{ AMOVBU,	C_SHIFT,C_NONE,	C_REG,		59, 4, 0 },
 
 	{ AMOVB,	C_SHIFT,C_NONE,	C_REG,		60, 4, 0 },
+	{ AMOVBS,	C_SHIFT,C_NONE,	C_REG,		60, 4, 0 },
 
 	{ AMOVW,	C_REG,	C_NONE,	C_SHIFT,	61, 4, 0 },
 	{ AMOVB,	C_REG,	C_NONE,	C_SHIFT,	61, 4, 0 },
+	{ AMOVBS,	C_REG,	C_NONE,	C_SHIFT,	61, 4, 0 },
 	{ AMOVBU,	C_REG,	C_NONE,	C_SHIFT,	61, 4, 0 },
 
 	{ ACASE,	C_REG,	C_NONE,	C_NONE,		62, 4, 0, LPCREL, 8 },
@@ -186,19 +195,28 @@ Optab	optab[] =
 
 	{ AMOVH,	C_REG,	C_NONE, C_HAUTO,	70, 4, REGSP,	0 },
 	{ AMOVH,	C_REG,	C_NONE,	C_HOREG,	70, 4, 0,	0 },
+	{ AMOVHS,	C_REG,	C_NONE, C_HAUTO,	70, 4, REGSP,	0 },
+	{ AMOVHS,	C_REG,	C_NONE,	C_HOREG,	70, 4, 0,	0 },
 	{ AMOVHU,	C_REG,	C_NONE, C_HAUTO,	70, 4, REGSP,	0 },
 	{ AMOVHU,	C_REG,	C_NONE,	C_HOREG,	70, 4, 0,	0 },
 
 	{ AMOVB,	C_HAUTO,C_NONE,	C_REG,		71, 4, REGSP,	0 },
 	{ AMOVB,	C_HOREG,C_NONE,	C_REG,		71, 4, 0,	0 },
+	{ AMOVBS,	C_HAUTO,C_NONE,	C_REG,		71, 4, REGSP,	0 },
+	{ AMOVBS,	C_HOREG,C_NONE,	C_REG,		71, 4, 0,	0 },
 	{ AMOVH,	C_HAUTO,C_NONE, C_REG,		71, 4, REGSP,	0 },
 	{ AMOVH,	C_HOREG,C_NONE,	C_REG,		71, 4, 0,	0 },
+	{ AMOVHS,	C_HAUTO,C_NONE, C_REG,		71, 4, REGSP,	0 },
+	{ AMOVHS,	C_HOREG,C_NONE,	C_REG,		71, 4, 0,	0 },
 	{ AMOVHU,	C_HAUTO,C_NONE, C_REG,		71, 4, REGSP,	0 },
 	{ AMOVHU,	C_HOREG,C_NONE,	C_REG,		71, 4, 0,	0 },
 
 	{ AMOVH,	C_REG,	C_NONE, C_LAUTO,	72, 8, REGSP,	LTO },
 	{ AMOVH,	C_REG,	C_NONE,	C_LOREG,	72, 8, 0,	LTO },
 	{ AMOVH,	C_REG,	C_NONE,	C_ADDR,	94, 8, 0,	LTO | LPCREL, 4 },
+	{ AMOVHS,	C_REG,	C_NONE, C_LAUTO,	72, 8, REGSP,	LTO },
+	{ AMOVHS,	C_REG,	C_NONE,	C_LOREG,	72, 8, 0,	LTO },
+	{ AMOVHS,	C_REG,	C_NONE,	C_ADDR,	94, 8, 0,	LTO | LPCREL, 4 },
 	{ AMOVHU,	C_REG,	C_NONE, C_LAUTO,	72, 8, REGSP,	LTO },
 	{ AMOVHU,	C_REG,	C_NONE,	C_LOREG,	72, 8, 0,	LTO },
 	{ AMOVHU,	C_REG,	C_NONE,	C_ADDR,	94, 8, 0,	LTO | LPCREL, 4 },
@@ -206,9 +224,15 @@ Optab	optab[] =
 	{ AMOVB,	C_LAUTO,C_NONE,	C_REG,		73, 8, REGSP,	LFROM },
 	{ AMOVB,	C_LOREG,C_NONE,	C_REG,		73, 8, 0,	LFROM },
 	{ AMOVB,	C_ADDR,	C_NONE,	C_REG,		93, 8, 0,	LFROM | LPCREL, 4 },
+	{ AMOVBS,	C_LAUTO,C_NONE,	C_REG,		73, 8, REGSP,	LFROM },
+	{ AMOVBS,	C_LOREG,C_NONE,	C_REG,		73, 8, 0,	LFROM },
+	{ AMOVBS,	C_ADDR,	C_NONE,	C_REG,		93, 8, 0,	LFROM | LPCREL, 4 },
 	{ AMOVH,	C_LAUTO,C_NONE, C_REG,		73, 8, REGSP,	LFROM },
 	{ AMOVH,	C_LOREG,C_NONE,	C_REG,		73, 8, 0,	LFROM },
 	{ AMOVH,	C_ADDR,	C_NONE,	C_REG,		93, 8, 0,	LFROM | LPCREL, 4 },
+	{ AMOVHS,	C_LAUTO,C_NONE, C_REG,		73, 8, REGSP,	LFROM },
+	{ AMOVHS,	C_LOREG,C_NONE,	C_REG,		73, 8, 0,	LFROM },
+	{ AMOVHS,	C_ADDR,	C_NONE,	C_REG,		93, 8, 0,	LFROM | LPCREL, 4 },
 	{ AMOVHU,	C_LAUTO,C_NONE, C_REG,		73, 8, REGSP,	LFROM },
 	{ AMOVHU,	C_LOREG,C_NONE,	C_REG,		73, 8, 0,	LFROM },
 	{ AMOVHU,	C_ADDR,	C_NONE,	C_REG,		93, 8, 0,	LFROM | LPCREL, 4 },
diff --git a/src/cmd/5l/span.c b/src/cmd/5l/span.c
index fe7aface97..7201c006f8 100644
--- a/src/cmd/5l/span.c
+++ b/src/cmd/5l/span.c
@@ -813,8 +813,10 @@ buildop(void)
 			break;
 		case AMOVW:
 		case AMOVB:
+		case AMOVBS:
 		case AMOVBU:
 		case AMOVH:
+		case AMOVHS:
 		case AMOVHU:
 			break;
 		case ASWPW: