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UserspaceEmulator: Implement the SAR instruction

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Let's try doing this with some inline assembly. We know we're running
on an x86 target anyway. :^)
This commit is contained in:
Andreas Kling 2020-07-10 20:15:53 +02:00
parent 3899effb19
commit 04d58f54b3
2 changed files with 118 additions and 28 deletions
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83
DevTools/UserspaceEmulator/SoftCPU.cpp
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@ -652,15 +652,80 @@ void SoftCPU::ROR_RM8_CL(const X86::Instruction&) { TODO(); }
void SoftCPU::ROR_RM8_imm8(const X86::Instruction&) { TODO(); }
void SoftCPU::SAHF(const X86::Instruction&) { TODO(); }
void SoftCPU::SALC(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM16_1(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM16_CL(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM16_imm8(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM32_1(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM32_CL(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM32_imm8(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM8_1(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM8_CL(const X86::Instruction&) { TODO(); }
void SoftCPU::SAR_RM8_imm8(const X86::Instruction&) { TODO(); }
template<typename T>
T SoftCPU::sar_impl(T data, u8 steps)
{
if (steps == 0)
return data;
u32 result = 0;
u32 new_flags = 0;
asm("sarl %%cl, %%eax\n"
"mov %%eax, %%ebx\n"
"pushf\n"
"pop %%eax\n"
: "=a"(new_flags), "=b"(result)
: "a"(data), "c"(steps));
set_flags_oszapc(new_flags);
return result;
}
void SoftCPU::SAR_RM16_1(const X86::Instruction& insn)
{
auto data = insn.modrm().read16(*this, insn);
insn.modrm().write16(*this, insn, sar_impl(data, 1));
}
void SoftCPU::SAR_RM16_CL(const X86::Instruction& insn)
{
auto data = insn.modrm().read16(*this, insn);
insn.modrm().write16(*this, insn, sar_impl(data, cl()));
}
void SoftCPU::SAR_RM16_imm8(const X86::Instruction& insn)
{
auto data = insn.modrm().read16(*this, insn);
insn.modrm().write16(*this, insn, sar_impl(data, insn.imm8()));
}
void SoftCPU::SAR_RM32_1(const X86::Instruction& insn)
{
auto data = insn.modrm().read32(*this, insn);
insn.modrm().write32(*this, insn, sar_impl(data, 1));
}
void SoftCPU::SAR_RM32_CL(const X86::Instruction& insn)
{
auto data = insn.modrm().read32(*this, insn);
insn.modrm().write32(*this, insn, sar_impl(data, cl()));
}
void SoftCPU::SAR_RM32_imm8(const X86::Instruction& insn)
{
auto data = insn.modrm().read32(*this, insn);
insn.modrm().write32(*this, insn, sar_impl(data, insn.imm8()));
}
void SoftCPU::SAR_RM8_1(const X86::Instruction& insn)
{
auto data = insn.modrm().read8(*this, insn);
insn.modrm().write8(*this, insn, sar_impl(data, 1));
}
void SoftCPU::SAR_RM8_CL(const X86::Instruction& insn)
{
auto data = insn.modrm().read8(*this, insn);
insn.modrm().write8(*this, insn, sar_impl(data, cl()));
}
void SoftCPU::SAR_RM8_imm8(const X86::Instruction& insn)
{
auto data = insn.modrm().read8(*this, insn);
insn.modrm().write8(*this, insn, sar_impl(data, insn.imm8()));
}
void SoftCPU::SBB_AL_imm8(const X86::Instruction&) { TODO(); }
void SoftCPU::SBB_AX_imm16(const X86::Instruction&) { TODO(); }
void SoftCPU::SBB_EAX_imm32(const X86::Instruction&) { TODO(); }