[ARM] GlobalISel: Support G_ICMP for i32 and pointers
Add support throughout the pipeline:
- mark as legal for s32 and pointers
- map to GPRs
- lower to a sequence of instructions, which moves 0 or 1 into the
result register based on the flags set by a CMPrr
We have copied from FastISel a helper function which maps CmpInst
predicates into ARMCC codes. Ideally, we should be able to move it
somewhere that both FastISel and GlobalISel can use.
llvm-svn: 305672
diff --git a/llvm/lib/Target/ARM/ARMInstructionSelector.cpp b/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
index 2ae3bad..4cb0eca 100644
--- a/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
+++ b/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
@@ -42,6 +42,10 @@
private:
bool selectImpl(MachineInstr &I) const;
+ bool selectICmp(MachineInstrBuilder &MIB, const ARMBaseInstrInfo &TII,
+ MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
+ const RegisterBankInfo &RBI) const;
+
const ARMBaseInstrInfo &TII;
const ARMBaseRegisterInfo &TRI;
const ARMBaseTargetMachine &TM;
@@ -243,6 +247,105 @@
return Opc;
}
+static ARMCC::CondCodes getComparePred(CmpInst::Predicate Pred) {
+ switch (Pred) {
+ // Needs two compares...
+ case CmpInst::FCMP_ONE:
+ case CmpInst::FCMP_UEQ:
+ default:
+ // AL is our "false" for now. The other two need more compares.
+ return ARMCC::AL;
+ case CmpInst::ICMP_EQ:
+ case CmpInst::FCMP_OEQ:
+ return ARMCC::EQ;
+ case CmpInst::ICMP_SGT:
+ case CmpInst::FCMP_OGT:
+ return ARMCC::GT;
+ case CmpInst::ICMP_SGE:
+ case CmpInst::FCMP_OGE:
+ return ARMCC::GE;
+ case CmpInst::ICMP_UGT:
+ case CmpInst::FCMP_UGT:
+ return ARMCC::HI;
+ case CmpInst::FCMP_OLT:
+ return ARMCC::MI;
+ case CmpInst::ICMP_ULE:
+ case CmpInst::FCMP_OLE:
+ return ARMCC::LS;
+ case CmpInst::FCMP_ORD:
+ return ARMCC::VC;
+ case CmpInst::FCMP_UNO:
+ return ARMCC::VS;
+ case CmpInst::FCMP_UGE:
+ return ARMCC::PL;
+ case CmpInst::ICMP_SLT:
+ case CmpInst::FCMP_ULT:
+ return ARMCC::LT;
+ case CmpInst::ICMP_SLE:
+ case CmpInst::FCMP_ULE:
+ return ARMCC::LE;
+ case CmpInst::FCMP_UNE:
+ case CmpInst::ICMP_NE:
+ return ARMCC::NE;
+ case CmpInst::ICMP_UGE:
+ return ARMCC::HS;
+ case CmpInst::ICMP_ULT:
+ return ARMCC::LO;
+ }
+}
+
+bool ARMInstructionSelector::selectICmp(MachineInstrBuilder &MIB,
+ const ARMBaseInstrInfo &TII,
+ MachineRegisterInfo &MRI,
+ const TargetRegisterInfo &TRI,
+ const RegisterBankInfo &RBI) const {
+ auto &MBB = *MIB->getParent();
+ auto InsertBefore = std::next(MIB->getIterator());
+ auto &DebugLoc = MIB->getDebugLoc();
+
+ // Move 0 into the result register.
+ auto Mov0I = BuildMI(MBB, InsertBefore, DebugLoc, TII.get(ARM::MOVi))
+ .addDef(MRI.createVirtualRegister(&ARM::GPRRegClass))
+ .addImm(0)
+ .add(predOps(ARMCC::AL))
+ .add(condCodeOp());
+ if (!constrainSelectedInstRegOperands(*Mov0I, TII, TRI, RBI))
+ return false;
+
+ // Perform the comparison.
+ auto LHSReg = MIB->getOperand(2).getReg();
+ auto RHSReg = MIB->getOperand(3).getReg();
+ assert(MRI.getType(LHSReg) == MRI.getType(RHSReg) &&
+ MRI.getType(LHSReg).getSizeInBits() == 32 &&
+ MRI.getType(RHSReg).getSizeInBits() == 32 &&
+ "Unsupported types for comparison operation");
+ auto CmpI = BuildMI(MBB, InsertBefore, DebugLoc, TII.get(ARM::CMPrr))
+ .addUse(LHSReg)
+ .addUse(RHSReg)
+ .add(predOps(ARMCC::AL));
+ if (!constrainSelectedInstRegOperands(*CmpI, TII, TRI, RBI))
+ return false;
+
+ // Move 1 into the result register if the flags say so.
+ auto ResReg = MIB->getOperand(0).getReg();
+ auto Cond =
+ static_cast<CmpInst::Predicate>(MIB->getOperand(1).getPredicate());
+ auto ARMCond = getComparePred(Cond);
+ if (ARMCond == ARMCC::AL)
+ return false;
+
+ auto Mov1I = BuildMI(MBB, InsertBefore, DebugLoc, TII.get(ARM::MOVCCi))
+ .addDef(ResReg)
+ .addUse(Mov0I->getOperand(0).getReg())
+ .addImm(1)
+ .add(predOps(ARMCond, ARM::CPSR));
+ if (!constrainSelectedInstRegOperands(*Mov1I, TII, TRI, RBI))
+ return false;
+
+ MIB->eraseFromParent();
+ return true;
+}
+
bool ARMInstructionSelector::select(MachineInstr &I) const {
assert(I.getParent() && "Instruction should be in a basic block!");
assert(I.getParent()->getParent() && "Instruction should be in a function!");
@@ -343,6 +446,8 @@
I.setDesc(TII.get(COPY));
return selectCopy(I, TII, MRI, TRI, RBI);
}
+ case G_ICMP:
+ return selectICmp(MIB, TII, MRI, TRI, RBI);
case G_GEP:
I.setDesc(TII.get(ARM::ADDrr));
MIB.add(predOps(ARMCC::AL)).add(condCodeOp());
diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index a706079..2892b72 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -86,6 +86,10 @@
setAction({G_CONSTANT, s32}, Legal);
+ setAction({G_ICMP, s1}, Legal);
+ for (auto Ty : {s32, p0})
+ setAction({G_ICMP, 1, Ty}, Legal);
+
if (!ST.useSoftFloat() && ST.hasVFP2()) {
setAction({G_FADD, s32}, Legal);
setAction({G_FADD, s64}, Legal);
diff --git a/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp b/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
index f59b075..2350d0c 100644
--- a/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
@@ -255,6 +255,16 @@
OperandsMapping =
getOperandsMapping({&ARM::ValueMappings[ARM::GPR3OpsIdx], nullptr});
break;
+ case G_ICMP: {
+ LLT Ty2 = MRI.getType(MI.getOperand(2).getReg());
+ (void)Ty2;
+ assert(Ty2.getSizeInBits() == 32 && "Unsupported size for G_ICMP");
+ OperandsMapping =
+ getOperandsMapping({&ARM::ValueMappings[ARM::GPR3OpsIdx], nullptr,
+ &ARM::ValueMappings[ARM::GPR3OpsIdx],
+ &ARM::ValueMappings[ARM::GPR3OpsIdx]});
+ break;
+ }
case G_MERGE_VALUES: {
// We only support G_MERGE_VALUES for creating a double precision floating
// point value out of two GPRs.