cmd/6l, cmd/8l: fix MOVL MOVQ optab

The entry for LEAL/LEAQ in these optabs was listed as having
two data bytes in the y array. In fact they had and expect no data
bytes. However, the general loop expects to be able to look at at
least one data byte, to make sure it is not 0x0f. So give them each
a single data byte set to 0 (not 0x0f).

Since the MOV instructions have the largest optab cases, this
requires growing the size of the data array.

Clang found this bug because the general o->op[z] == 0x0f
test was using z == 22, which was out of bounds.

In practice the next byte in memory was probably not 0x0f
so it wasn't truly broken. But might as well be clean.

Update #5764

R=ken2
CC=golang-dev
https://golang.org/cl/13241050

src/cmd/6l/l.h

@@ -193,7 +193,7 @@ struct	Optab
 	short	as;
 	uchar*	ytab;
 	uchar	prefix;
-	uchar	op[22];
+	uchar	op[23];
 };
 struct	Movtab
 {

src/cmd/6l/optab.c

@@ -913,7 +913,7 @@ Optab optab[] =
 	{ AMOVHLPS,	yxr,	Pm, 0x12 },
 	{ AMOVHPD,	yxmov,	Pe, 0x16,0x17 },
 	{ AMOVHPS,	yxmov,	Pm, 0x16,0x17 },
-	{ AMOVL,	ymovl,	Px, 0x89,0x8b,0x31,0xb8,0xc7,(00),0x6e,0x7e,Pe,0x6e,Pe,0x7e },
+	{ AMOVL,	ymovl,	Px, 0x89,0x8b,0x31,0xb8,0xc7,(00),0x6e,0x7e,Pe,0x6e,Pe,0x7e,0 },
 	{ AMOVLHPS,	yxr,	Pm, 0x16 },
 	{ AMOVLPD,	yxmov,	Pe, 0x12,0x13 },
 	{ AMOVLPS,	yxmov,	Pm, 0x12,0x13 },
@@ -925,7 +925,7 @@ Optab optab[] =
 	{ AMOVNTPD,	yxr_ml,	Pe, 0x2b },
 	{ AMOVNTPS,	yxr_ml,	Pm, 0x2b },
 	{ AMOVNTQ,	ymr_ml,	Pm, 0xe7 },
-	{ AMOVQ,	ymovq,	Pw, 0x89, 0x8b, 0x31, 0xc7,(00), 0xb8, 0xc7,(00), 0x6f, 0x7f, 0x6e, 0x7e, Pf2,0xd6, Pf3,0x7e, Pe,0xd6, Pe,0x6e, Pe,0x7e },
+	{ AMOVQ,	ymovq,	Pw, 0x89, 0x8b, 0x31, 0xc7,(00), 0xb8, 0xc7,(00), 0x6f, 0x7f, 0x6e, 0x7e, Pf2,0xd6, Pf3,0x7e, Pe,0xd6, Pe,0x6e, Pe,0x7e,0 },
 	{ AMOVQOZX,	ymrxr,	Pf3, 0xd6,0x7e },
 	{ AMOVSB,	ynone,	Pb, 0xa4 },
 	{ AMOVSD,	yxmov,	Pf2, 0x10,0x11 },
@@ -935,7 +935,7 @@ Optab optab[] =
 	{ AMOVSW,	ynone,	Pe, 0xa5 },
 	{ AMOVUPD,	yxmov,	Pe, 0x10,0x11 },
 	{ AMOVUPS,	yxmov,	Pm, 0x10,0x11 },
-	{ AMOVW,	ymovw,	Pe, 0x89,0x8b,0x31,0xb8,0xc7,(00) },
+	{ AMOVW,	ymovw,	Pe, 0x89,0x8b,0x31,0xb8,0xc7,(00),0 },
 	{ AMOVWLSX,	yml_rl,	Pm, 0xbf },
 	{ AMOVWLZX,	yml_rl,	Pm, 0xb7 },
 	{ AMOVWQSX,	yml_rl,	Pw, 0x0f,0xbf },

src/cmd/8l/l.h

@@ -175,7 +175,7 @@ struct	Optab
 	short	as;
 	uchar*	ytab;
 	uchar	prefix;
-	uchar	op[12];
+	uchar	op[13];
 };
 
 enum

src/cmd/8l/optab.c

@@ -152,6 +152,17 @@ uchar	ymovb[] =
 	Yi32,	Ymb,	Zibo_m,	2,
 	0
 };
+uchar	ymovw[] =
+{
+	Yrl,	Yml,	Zr_m,	1,
+	Yml,	Yrl,	Zm_r,	1,
+	Yi0,	Yrl,	Zclr,	1+2,
+//	Yi0,	Yml,	Zibo_m,	2,	// shorter but slower AND $0,dst
+	Yi32,	Yrl,	Zil_rp,	1,
+	Yi32,	Yml,	Zilo_m,	2,
+	Yiauto,	Yrl,	Zaut_r,	1,
+	0
+};
 uchar	ymovl[] =
 {
 	Yrl,	Yml,	Zr_m,	1,
@@ -162,7 +173,7 @@ uchar	ymovl[] =
 	Yi32,	Yml,	Zilo_m,	2,
 	Yml,	Yxr,	Zm_r_xm,	2,	// XMM MOVD (32 bit)
 	Yxr,	Yml,	Zr_m_xm,	2,	// XMM MOVD (32 bit)
-	Yiauto,	Yrl,	Zaut_r,	2,
+	Yiauto,	Yrl,	Zaut_r,	1,
 	0
 };
 uchar	ymovq[] =
@@ -592,8 +603,8 @@ Optab optab[] =
 	{ ALSLL,	yml_rl,	Pm, 0x03  },
 	{ ALSLW,	yml_rl,	Pq, 0x03  },
 	{ AMOVB,	ymovb,	Pb, 0x88,0x8a,0xb0,0xc6,(00) },
-	{ AMOVL,	ymovl,	Px, 0x89,0x8b,0x31,0x83,(04),0xb8,0xc7,(00),Pe,0x6e,Pe,0x7e },
-	{ AMOVW,	ymovl,	Pe, 0x89,0x8b,0x31,0x83,(04),0xb8,0xc7,(00) },
+	{ AMOVL,	ymovl,	Px, 0x89,0x8b,0x31,0x83,(04),0xb8,0xc7,(00),Pe,0x6e,Pe,0x7e,0 },
+	{ AMOVW,	ymovw,	Pe, 0x89,0x8b,0x31,0x83,(04),0xb8,0xc7,(00),0 },
 	{ AMOVQ,	ymovq,	Pf3, 0x7e },
 	{ AMOVBLSX,	ymb_rl,	Pm, 0xbe },
 	{ AMOVBLZX,	ymb_rl,	Pm, 0xb6 },