MC/X86: Implement custom lowering to make sure we match things like
X86::ADC32ri $0, %eax
to
X86::ADC32i32 $0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104030 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
index ae262ab..ad93083 100644
--- a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
+++ b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
@@ -224,6 +224,26 @@
OutMI.addOperand(OutMI.getOperand(0));
}
+/// \brief Simplify FOO $imm, %{al,ax,eax,rax} to FOO $imm, for instruction with
+/// a short fixed-register form.
+static void SimplifyShortImmForm(MCInst &Inst, unsigned Opcode) {
+ unsigned ImmOp = Inst.getNumOperands() - 1;
+ assert(Inst.getOperand(0).isReg() && Inst.getOperand(ImmOp).isImm() &&
+ ((Inst.getNumOperands() == 3 && Inst.getOperand(1).isReg() &&
+ Inst.getOperand(0).getReg() == Inst.getOperand(1).getReg()) ||
+ Inst.getNumOperands() == 2) && "Unexpected instruction!");
+
+ // Check whether the destination register can be fixed.
+ unsigned Reg = Inst.getOperand(0).getReg();
+ if (Reg != X86::AL && Reg != X86::AX && Reg != X86::EAX && Reg != X86::RAX)
+ return;
+
+ // If so, rewrite the instruction.
+ MCInst New;
+ New.setOpcode(Opcode);
+ New.addOperand(Inst.getOperand(ImmOp));
+ Inst = New;
+}
void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
OutMI.setOpcode(MI->getOpcode());
@@ -332,6 +352,54 @@
case X86::JGE_4: OutMI.setOpcode(X86::JGE_1); break;
case X86::JLE_4: OutMI.setOpcode(X86::JLE_1); break;
case X86::JG_4: OutMI.setOpcode(X86::JG_1); break;
+
+ // We don't currently select the correct instruction form for instructions
+ // which have a short %eax, etc. form. Handle this by custom lowering, for
+ // now.
+ //
+ // Note, we are currently not handling the following instructions:
+ // MOV8ao8, MOV8o8a
+ // MOV16ao16, MOV16o16a
+ // MOV32ao32, MOV32o32a
+ // MOV64ao64, MOV64ao8
+ // MOV64o64a, MOV64o8a
+ // XCHG16ar, XCHG32ar, XCHG64ar
+ case X86::ADC8ri: SimplifyShortImmForm(OutMI, X86::ADC8i8); break;
+ case X86::ADC16ri: SimplifyShortImmForm(OutMI, X86::ADC16i16); break;
+ case X86::ADC32ri: SimplifyShortImmForm(OutMI, X86::ADC32i32); break;
+ case X86::ADC64ri32: SimplifyShortImmForm(OutMI, X86::ADC64i32); break;
+ case X86::ADD8ri: SimplifyShortImmForm(OutMI, X86::ADD8i8); break;
+ case X86::ADD16ri: SimplifyShortImmForm(OutMI, X86::ADD16i16); break;
+ case X86::ADD32ri: SimplifyShortImmForm(OutMI, X86::ADD32i32); break;
+ case X86::ADD64ri32: SimplifyShortImmForm(OutMI, X86::ADD64i32); break;
+ case X86::AND8ri: SimplifyShortImmForm(OutMI, X86::AND8i8); break;
+ case X86::AND16ri: SimplifyShortImmForm(OutMI, X86::AND16i16); break;
+ case X86::AND32ri: SimplifyShortImmForm(OutMI, X86::AND32i32); break;
+ case X86::AND64ri32: SimplifyShortImmForm(OutMI, X86::AND64i32); break;
+ case X86::CMP8ri: SimplifyShortImmForm(OutMI, X86::CMP8i8); break;
+ case X86::CMP16ri: SimplifyShortImmForm(OutMI, X86::CMP16i16); break;
+ case X86::CMP32ri: SimplifyShortImmForm(OutMI, X86::CMP32i32); break;
+ case X86::CMP64ri32: SimplifyShortImmForm(OutMI, X86::CMP64i32); break;
+ case X86::OR8ri: SimplifyShortImmForm(OutMI, X86::OR8i8); break;
+ case X86::OR16ri: SimplifyShortImmForm(OutMI, X86::OR16i16); break;
+ case X86::OR32ri: SimplifyShortImmForm(OutMI, X86::OR32i32); break;
+ case X86::OR64ri32: SimplifyShortImmForm(OutMI, X86::OR64i32); break;
+ case X86::SBB8ri: SimplifyShortImmForm(OutMI, X86::SBB8i8); break;
+ case X86::SBB16ri: SimplifyShortImmForm(OutMI, X86::SBB16i16); break;
+ case X86::SBB32ri: SimplifyShortImmForm(OutMI, X86::SBB32i32); break;
+ case X86::SBB64ri32: SimplifyShortImmForm(OutMI, X86::SBB64i32); break;
+ case X86::SUB8ri: SimplifyShortImmForm(OutMI, X86::SUB8i8); break;
+ case X86::SUB16ri: SimplifyShortImmForm(OutMI, X86::SUB16i16); break;
+ case X86::SUB32ri: SimplifyShortImmForm(OutMI, X86::SUB32i32); break;
+ case X86::SUB64ri32: SimplifyShortImmForm(OutMI, X86::SUB64i32); break;
+ case X86::TEST8ri: SimplifyShortImmForm(OutMI, X86::TEST8i8); break;
+ case X86::TEST16ri: SimplifyShortImmForm(OutMI, X86::TEST16i16); break;
+ case X86::TEST32ri: SimplifyShortImmForm(OutMI, X86::TEST32i32); break;
+ case X86::TEST64ri32: SimplifyShortImmForm(OutMI, X86::TEST64i32); break;
+ case X86::XOR8ri: SimplifyShortImmForm(OutMI, X86::XOR8i8); break;
+ case X86::XOR16ri: SimplifyShortImmForm(OutMI, X86::XOR16i16); break;
+ case X86::XOR32ri: SimplifyShortImmForm(OutMI, X86::XOR32i32); break;
+ case X86::XOR64ri32: SimplifyShortImmForm(OutMI, X86::XOR64i32); break;
}
}