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

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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
This commit is contained in:
Russ Cox 2013-09-10 14:53:41 -04:00
parent 8edf764fa3
commit 80a153dd51
4 changed files with 19 additions and 8 deletions
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2
src/cmd/6l/l.h
View File

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

6
src/cmd/6l/optab.c
View File

@ -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 },

2
src/cmd/8l/l.h
View File

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

17
src/cmd/8l/optab.c
View File

@ -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 },