[PATCH 2/5] x86: correct decoding of packed-FP-only AVX encodings
Jan Beulich
jbeulich@suse.com
Mon Jun 8 07:45:20 GMT 2020
Various AVX insns utilizing the X macro fail to reject F3/F2 embedded
prefix encodings. As the PREFIX_OPCODE attribute wasn't used by any
non-legacy-encoded insns so far, re-use it to achieve the intended
effect.
gas/
2020-06-XX Jan Beulich <jbeulich@suse.com>
* testsuite/gas/i386/prefix.s: Add bogus REP / EVEX.W prefix
with VEX/EVEX encoding tests.
* testsuite/gas/i386/prefix.d: Adjust expectations.
opcodes/
2020-06-XX Jan Beulich <jbeulich@suse.com>
* i386-dis.c (vex_table): Use PREFIX_OPCODE for vunpcklpX,
vunpckhpX, vmovapX, vandpX, vandnpX, vorpX, vxorpX and vshufpX.
(vex_len_table) : Likewise for vmovlpX, vmovhpX, vmovntpX, and
vmovmskpX.
(print_insn): Drop pointless check against bad_opcode. Split
prefix validation into legacy and VEX-and-alike parts.
(putop): Re-work 'X' macro handling.
---
This could in principle be used to significantly decrease table sizes
by making AVX extensions of originally MMX insns (encoded with an
embedded 66 prefix), by introducing a suitable macro and avoiding the
need for the various respective PREFIX_* enumerators / indirections.
--- a/gas/testsuite/gas/i386/prefix.d
+++ b/gas/testsuite/gas/i386/prefix.d
@@ -72,6 +72,20 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: f2 0f c7 \(bad\)
[ ]*[a-f0-9]+: f0 90 lock nop
+[ ]*[a-f0-9]+: f3 0f 28 repz \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: c5 fa 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: c4 e1 7b 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: 62 f1 fc 08 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: 62 f1 7e 08 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: 62 f1 7d 08 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
+[ ]*[a-f0-9]+: 62 f1 ff 08 28 \(bad\) *
+[ ]*[a-f0-9]+: ff cc dec %esp
[ ]*[a-f0-9]+: c5 fb e6 40 20 vcvtpd2dqx 0x20\(%eax\),%xmm0
[ ]*[a-f0-9]+: 62 f1 ff 18 e6 40 04 vcvtpd2dq 0x20\(%eax\)\{1to2\},%xmm0
[ ]*[a-f0-9]+: c5 fb e6 40 20 vcvtpd2dqx 0x20\(%eax\),%xmm0
--- a/gas/testsuite/gas/i386/prefix.s
+++ b/gas/testsuite/gas/i386/prefix.s
@@ -391,6 +391,66 @@
nop
+ repz; movaps %xmm7, %xmm7
+ int $3
+
+# "repz" vmovaps %xmm7, %xmm7
+ .byte 0xc5
+ .byte 0xfa
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
+# "repnz" {vex3} vmovaps %xmm7, %xmm7
+ .byte 0xc4
+ .byte 0xe1
+ .byte 0x7b
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
+# "EVEX.W1" vmovaps %xmm7, %xmm7
+ .byte 0x62
+ .byte 0xf1
+ .byte 0xfc
+ .byte 0x08
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
+# "repz" vmovaps %xmm7, %xmm7
+ .byte 0x62
+ .byte 0xf1
+ .byte 0x7e
+ .byte 0x08
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
+# "EVEX.W0" vmovapd %xmm7, %xmm7
+ .byte 0x62
+ .byte 0xf1
+ .byte 0x7d
+ .byte 0x08
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
+# "repnz" vmovapd %xmm7, %xmm7
+ .byte 0x62
+ .byte 0xf1
+ .byte 0xff
+ .byte 0x08
+ .byte 0x28
+ .byte 0xff
+
+ int $3
+
vcvtpd2dqx 0x20(%eax),%xmm0
vcvtpd2dq 0x20(%eax){1to2},%xmm0
vcvtpd2dqx 0x20(%eax),%xmm0
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -8485,8 +8485,8 @@ static const struct dis386 vex_table[][2
{ PREFIX_TABLE (PREFIX_VEX_0F11) },
{ PREFIX_TABLE (PREFIX_VEX_0F12) },
{ MOD_TABLE (MOD_VEX_0F13) },
- { "vunpcklpX", { XM, Vex, EXx }, 0 },
- { "vunpckhpX", { XM, Vex, EXx }, 0 },
+ { "vunpcklpX", { XM, Vex, EXx }, PREFIX_OPCODE },
+ { "vunpckhpX", { XM, Vex, EXx }, PREFIX_OPCODE },
{ PREFIX_TABLE (PREFIX_VEX_0F16) },
{ MOD_TABLE (MOD_VEX_0F17) },
/* 18 */
@@ -8508,8 +8508,8 @@ static const struct dis386 vex_table[][2
{ Bad_Opcode },
{ Bad_Opcode },
/* 28 */
- { "vmovapX", { XM, EXx }, 0 },
- { "vmovapX", { EXxS, XM }, 0 },
+ { "vmovapX", { XM, EXx }, PREFIX_OPCODE },
+ { "vmovapX", { EXxS, XM }, PREFIX_OPCODE },
{ PREFIX_TABLE (PREFIX_VEX_0F2A) },
{ MOD_TABLE (MOD_VEX_0F2B) },
{ PREFIX_TABLE (PREFIX_VEX_0F2C) },
@@ -8557,10 +8557,10 @@ static const struct dis386 vex_table[][2
{ PREFIX_TABLE (PREFIX_VEX_0F51) },
{ PREFIX_TABLE (PREFIX_VEX_0F52) },
{ PREFIX_TABLE (PREFIX_VEX_0F53) },
- { "vandpX", { XM, Vex, EXx }, 0 },
- { "vandnpX", { XM, Vex, EXx }, 0 },
- { "vorpX", { XM, Vex, EXx }, 0 },
- { "vxorpX", { XM, Vex, EXx }, 0 },
+ { "vandpX", { XM, Vex, EXx }, PREFIX_OPCODE },
+ { "vandnpX", { XM, Vex, EXx }, PREFIX_OPCODE },
+ { "vorpX", { XM, Vex, EXx }, PREFIX_OPCODE },
+ { "vxorpX", { XM, Vex, EXx }, PREFIX_OPCODE },
/* 58 */
{ PREFIX_TABLE (PREFIX_VEX_0F58) },
{ PREFIX_TABLE (PREFIX_VEX_0F59) },
@@ -8685,7 +8685,7 @@ static const struct dis386 vex_table[][2
{ Bad_Opcode },
{ PREFIX_TABLE (PREFIX_VEX_0FC4) },
{ PREFIX_TABLE (PREFIX_VEX_0FC5) },
- { "vshufpX", { XM, Vex, EXx, Ib }, 0 },
+ { "vshufpX", { XM, Vex, EXx, Ib }, PREFIX_OPCODE },
{ Bad_Opcode },
/* c8 */
{ Bad_Opcode },
@@ -9355,7 +9355,7 @@ static const struct dis386 vex_len_table
/* VEX_LEN_0F13_M_0 */
{
- { "vmovlpX", { EXq, XM }, 0 },
+ { "vmovlpX", { EXq, XM }, PREFIX_OPCODE },
},
/* VEX_LEN_0F16_P_0_M_0 */
@@ -9375,7 +9375,7 @@ static const struct dis386 vex_len_table
/* VEX_LEN_0F17_M_0 */
{
- { "vmovhpX", { EXq, XM }, 0 },
+ { "vmovhpX", { EXq, XM }, PREFIX_OPCODE },
},
/* VEX_LEN_0F41_P_0 */
@@ -10592,7 +10592,7 @@ static const struct dis386 mod_table[][2
},
{
/* MOD_VEX_0F2B */
- { "vmovntpX", { Mx, XM }, 0 },
+ { "vmovntpX", { Mx, XM }, PREFIX_OPCODE },
},
{
/* MOD_VEX_W_0_0F41_P_0_LEN_1 */
@@ -10752,7 +10752,7 @@ static const struct dis386 mod_table[][2
{
/* MOD_VEX_0F50 */
{ Bad_Opcode },
- { "vmovmskpX", { Gdq, XS }, 0 },
+ { "vmovmskpX", { Gdq, XS }, PREFIX_OPCODE },
},
{
/* MOD_VEX_0F71_REG_2 */
@@ -12266,14 +12266,18 @@ print_insn (bfd_vma pc, disassemble_info
PREFIX_REPZ/PREFIX_REPNZ fix, we check the PREFIX_DATA prefix
separately. */
if (dp->prefix_requirement == PREFIX_OPCODE
- && dp != &bad_opcode
- && (((prefixes
- & (PREFIX_REPZ | PREFIX_REPNZ)) != 0
+ && (((need_vex
+ ? vex.prefix == REPE_PREFIX_OPCODE
+ || vex.prefix == REPNE_PREFIX_OPCODE
+ : (prefixes
+ & (PREFIX_REPZ | PREFIX_REPNZ)) != 0)
&& (used_prefixes
& (PREFIX_REPZ | PREFIX_REPNZ)) == 0)
- || ((((prefixes
- & (PREFIX_REPZ | PREFIX_REPNZ | PREFIX_DATA))
- == PREFIX_DATA)
+ || (((need_vex
+ ? vex.prefix == DATA_PREFIX_OPCODE
+ : ((prefixes
+ & (PREFIX_REPZ | PREFIX_REPNZ | PREFIX_DATA))
+ == PREFIX_DATA))
&& (used_prefixes & PREFIX_DATA) == 0))))
{
(*info->fprintf_func) (info->stream, "(bad)");
@@ -13230,21 +13234,15 @@ putop (const char *in_template, int size
SAVE_LAST (*p);
break;
}
- if (need_vex && vex.prefix)
+ if (need_vex
+ ? vex.prefix == DATA_PREFIX_OPCODE
+ : prefixes & PREFIX_DATA)
{
- if (vex.prefix == DATA_PREFIX_OPCODE)
- *obufp++ = 'd';
- else
- *obufp++ = 's';
+ *obufp++ = 'd';
+ used_prefixes |= PREFIX_DATA;
}
else
- {
- if (prefixes & PREFIX_DATA)
- *obufp++ = 'd';
- else
- *obufp++ = 's';
- used_prefixes |= (prefixes & PREFIX_DATA);
- }
+ *obufp++ = 's';
break;
case 'Y':
if (l == 0 && len == 1)
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