KVM: x86 emulator: add bsf/bsr instruction emulation

Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Wei Yongjun 2010-08-10 13:48:22 +08:00 committed by Avi Kivity
parent 8c5eee30a9
commit d9574a25af
1 changed files with 26 additions and 2 deletions

View File

@ -2379,8 +2379,8 @@ static struct opcode twobyte_table[256] = {
/* 0xB8 - 0xBF */
N, N,
G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock),
N, N, D(ByteOp | DstReg | SrcMem | ModRM | Mov),
D(DstReg | SrcMem16 | ModRM | Mov),
D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM),
D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xC0 - 0xCF */
N, N, N, D(DstMem | SrcReg | ModRM | Mov),
N, N, N, GD(0, &group9),
@ -3511,6 +3511,30 @@ twobyte_insn:
btc: /* btc */
emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
break;
case 0xbc: { /* bsf */
u8 zf;
__asm__ ("bsf %2, %0; setz %1"
: "=r"(c->dst.val), "=q"(zf)
: "r"(c->src.val));
ctxt->eflags &= ~X86_EFLAGS_ZF;
if (zf) {
ctxt->eflags |= X86_EFLAGS_ZF;
c->dst.type = OP_NONE; /* Disable writeback. */
}
break;
}
case 0xbd: { /* bsr */
u8 zf;
__asm__ ("bsr %2, %0; setz %1"
: "=r"(c->dst.val), "=q"(zf)
: "r"(c->src.val));
ctxt->eflags &= ~X86_EFLAGS_ZF;
if (zf) {
ctxt->eflags |= X86_EFLAGS_ZF;
c->dst.type = OP_NONE; /* Disable writeback. */
}
break;
}
case 0xbe ... 0xbf: /* movsx */
c->dst.bytes = c->op_bytes;
c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :