From dc71d0f1620790ec8e54101ca37e7b31e31208a8 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 15 Jun 2008 21:23:17 -0700 Subject: [PATCH] KVM: x86 emulator: simplify sib decoding Instead of using sparse switches, use simpler if/else sequences. Signed-off-by: Avi Kivity --- arch/x86/kvm/x86_emulate.c | 20 ++++---------------- 1 file changed, 4 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index 3721cfddc973..ca7ab2469a4a 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -748,24 +748,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, 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: -- 2.34.1