KVM: x86 emulator: simplify sib decoding
Instead of using sparse switches, use simpler if/else sequences.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 3721cfd..ca7ab24 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -748,24 +748,12 @@
base_reg |= sib & 7;
scale = sib >> 6;
- switch (base_reg) {
- case 5:
- case 13:
- if (c->modrm_mod != 0)
- c->modrm_ea += c->regs[base_reg];
- else
- c->modrm_ea +=
- insn_fetch(s32, 4, c->eip);
- break;
- default:
+ if ((base_reg & 7) == 5 && c->modrm_mod == 0)
+ c->modrm_ea += insn_fetch(s32, 4, c->eip);
+ else
c->modrm_ea += c->regs[base_reg];
- }
- switch (index_reg) {
- case 4:
- break;
- default:
+ if (index_reg != 4)
c->modrm_ea += c->regs[index_reg] << scale;
- }
break;
case 5:
case 13: