target/i386: implement CMPccXADD

The main difficulty here is that a page fault when writing to the destination
must not overwrite the flags.  Therefore, the flags computation must be
inlined instead of using gen_jcc1*.

For simplicity, I am using an unconditional cmpxchg operation, that becomes
a NOP if the comparison fails.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2023-10-10 10:31:39 +02:00
parent e7bbb7cb71
commit 405c7c0708
5 changed files with 133 additions and 1 deletions

View file

@ -538,6 +538,28 @@ static const X86OpEntry opcodes_0F38_00toEF[240] = {
[0xdd] = X86_OP_ENTRY3(VAESENCLAST, V,x, H,x, W,x, vex4 cpuid(AES) p_66),
[0xde] = X86_OP_ENTRY3(VAESDEC, V,x, H,x, W,x, vex4 cpuid(AES) p_66),
[0xdf] = X86_OP_ENTRY3(VAESDECLAST, V,x, H,x, W,x, vex4 cpuid(AES) p_66),
/*
* REG selects srcdest2 operand, VEX.vvvv selects src3. VEX class not found
* in manual, assumed to be 13 from the VEX.L0 constraint.
*/
[0xe0] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe1] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe2] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe3] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe4] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe5] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe6] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe7] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe8] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xe9] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xea] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xeb] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xec] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xed] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xee] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
[0xef] = X86_OP_ENTRY3(CMPccXADD, M,y, G,y, B,y, vex13 xchg chk(o64) cpuid(CMPCCXADD) p_66),
};
/* five rows for no prefix, 66, F3, F2, 66+F2 */
@ -1503,6 +1525,9 @@ static bool has_cpuid_feature(DisasContext *s, X86CPUIDFeature cpuid)
return (s->cpuid_7_0_ebx_features & CPUID_7_0_EBX_AVX2);
case X86_FEAT_SHA_NI:
return (s->cpuid_7_0_ebx_features & CPUID_7_0_EBX_SHA_NI);
case X86_FEAT_CMPCCXADD:
return (s->cpuid_7_1_eax_features & CPUID_7_1_EAX_CMPCCXADD);
}
g_assert_not_reached();
}