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tcg/i386: Add tcg_out_vex_modrm

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Prepare for emitting BMI insns which require VEX encoding.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2014-01-27 21:19:40 -08:00
parent a1b29c9ae0
commit ecc7e84327
1 changed files with 38 additions and 3 deletions
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41
tcg/i386/tcg-target.c
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@ -402,9 +402,9 @@ static void tcg_out_opc(TCGContext *s, int opc, int r, int rm, int x)
rex = 0;
rex |= (opc & P_REXW) ? 0x8 : 0x0; /* REX.W */
rex |= (r & 8) >> 1; /* REX.R */
rex |= (x & 8) >> 2; /* REX.X */
rex |= (rm & 8) >> 3; /* REX.B */
rex |= (r & 8) >> 1; /* REX.R */
rex |= (x & 8) >> 2; /* REX.X */
rex |= (rm & 8) >> 3; /* REX.B */
/* P_REXB_{R,RM} indicates that the given register is the low byte.
For %[abcd]l we need no REX prefix, but for %{si,di,bp,sp}l we do,
@ -453,6 +453,41 @@ static void tcg_out_modrm(TCGContext *s, int opc, int r, int rm)
tcg_out8(s, 0xc0 | (LOWREGMASK(r) << 3) | LOWREGMASK(rm));
}
static void tcg_out_vex_modrm(TCGContext *s, int opc, int r, int v, int rm)
{
int tmp;
if ((opc & (P_REXW | P_EXT | P_EXT38)) || (rm & 8)) {
/* Three byte VEX prefix. */
tcg_out8(s, 0xc4);
/* VEX.m-mmmm */
if (opc & P_EXT38) {
tmp = 2;
} else if (opc & P_EXT) {
tmp = 1;
} else {
tcg_abort();
}
tmp |= 0x40; /* VEX.X */
tmp |= (r & 8 ? 0 : 0x80); /* VEX.R */
tmp |= (rm & 8 ? 0 : 0x20); /* VEX.B */
tcg_out8(s, tmp);
tmp = (opc & P_REXW ? 0x80 : 0); /* VEX.W */
} else {
/* Two byte VEX prefix. */
tcg_out8(s, 0xc5);
tmp = (r & 8 ? 0 : 0x80); /* VEX.R */
}
tmp |= (opc & P_DATA16 ? 1 : 0); /* VEX.pp */
tmp |= (~v & 15) << 3; /* VEX.vvvv */
tcg_out8(s, tmp);
tcg_out8(s, opc);
tcg_out8(s, 0xc0 | (LOWREGMASK(r) << 3) | LOWREGMASK(rm));
}
/* Output an opcode with a full "rm + (index<<shift) + offset" address mode.
We handle either RM and INDEX missing with a negative value. In 64-bit
mode for absolute addresses, ~RM is the size of the immediate operand