Basic FastISel support for floating-point constants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55401 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index a956f01..ac35c43 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -56,6 +56,20 @@
return true;
}
+ // Check if the second operand is a constant float.
+ if (ConstantFP *CF = dyn_cast<ConstantFP>(I->getOperand(1))) {
+ unsigned ResultReg = FastEmit_rf_(VT.getSimpleVT(), ISDOpcode, Op0,
+ CF, VT.getSimpleVT());
+ if (ResultReg == 0)
+ // Target-specific code wasn't able to find a machine opcode for
+ // the given ISD opcode and type. Halt "fast" selection and bail.
+ return false;
+
+ // We successfully emitted code for the given LLVM Instruction.
+ ValueMap[I] = ResultReg;
+ return true;
+ }
+
unsigned Op1 = ValueMap[I->getOperand(1)];
if (Op1 == 0)
// Unhandled operand. Halt "fast" selection and bail.
@@ -451,12 +465,23 @@
return 0;
}
+unsigned FastISel::FastEmit_f(MVT::SimpleValueType, MVT::SimpleValueType,
+ ISD::NodeType, ConstantFP * /*FPImm*/) {
+ return 0;
+}
+
unsigned FastISel::FastEmit_ri(MVT::SimpleValueType, MVT::SimpleValueType,
ISD::NodeType, unsigned /*Op0*/,
uint64_t /*Imm*/) {
return 0;
}
+unsigned FastISel::FastEmit_rf(MVT::SimpleValueType, MVT::SimpleValueType,
+ ISD::NodeType, unsigned /*Op0*/,
+ ConstantFP * /*FPImm*/) {
+ return 0;
+}
+
unsigned FastISel::FastEmit_rri(MVT::SimpleValueType, MVT::SimpleValueType,
ISD::NodeType,
unsigned /*Op0*/, unsigned /*Op1*/,
@@ -483,6 +508,45 @@
return FastEmit_rr(VT, VT, Opcode, Op0, MaterialReg);
}
+/// FastEmit_rf_ - This method is a wrapper of FastEmit_ri. It first tries
+/// to emit an instruction with a floating-point immediate operand using
+/// FastEmit_rf. If that fails, it materializes the immediate into a register
+/// and try FastEmit_rr instead.
+unsigned FastISel::FastEmit_rf_(MVT::SimpleValueType VT, ISD::NodeType Opcode,
+ unsigned Op0, ConstantFP *FPImm,
+ MVT::SimpleValueType ImmType) {
+ unsigned ResultReg = 0;
+ // First check if immediate type is legal. If not, we can't use the rf form.
+ if (TLI.getOperationAction(ISD::Constant, ImmType) == TargetLowering::Legal)
+ ResultReg = FastEmit_rf(VT, VT, Opcode, Op0, FPImm);
+ if (ResultReg != 0)
+ return ResultReg;
+
+ // Materialize the constant in a register.
+ unsigned MaterialReg = FastEmit_f(ImmType, ImmType, ISD::ConstantFP, FPImm);
+ if (MaterialReg == 0) {
+ const APFloat &Flt = FPImm->getValueAPF();
+ MVT IntVT = TLI.getPointerTy();
+
+ uint64_t x[2];
+ uint32_t IntBitWidth = IntVT.getSizeInBits();
+ if (Flt.convertToInteger(x, IntBitWidth, /*isSigned=*/true,
+ APFloat::rmTowardZero) != APFloat::opOK)
+ return 0;
+ APInt IntVal(IntBitWidth, 2, x);
+
+ unsigned IntegerReg = FastEmit_i(IntVT.getSimpleVT(), IntVT.getSimpleVT(),
+ ISD::Constant, IntVal.getZExtValue());
+ if (IntegerReg == 0)
+ return 0;
+ MaterialReg = FastEmit_r(IntVT.getSimpleVT(), VT,
+ ISD::SINT_TO_FP, IntegerReg);
+ if (MaterialReg == 0)
+ return 0;
+ }
+ return FastEmit_rr(VT, VT, Opcode, Op0, MaterialReg);
+}
+
unsigned FastISel::createResultReg(const TargetRegisterClass* RC) {
return MRI.createVirtualRegister(RC);
}
@@ -526,6 +590,16 @@
return ResultReg;
}
+unsigned FastISel::FastEmitInst_rf(unsigned MachineInstOpcode,
+ const TargetRegisterClass *RC,
+ unsigned Op0, ConstantFP *FPImm) {
+ unsigned ResultReg = createResultReg(RC);
+ const TargetInstrDesc &II = TII.get(MachineInstOpcode);
+
+ BuildMI(MBB, II, ResultReg).addReg(Op0).addFPImm(FPImm);
+ return ResultReg;
+}
+
unsigned FastISel::FastEmitInst_rri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, unsigned Op1, uint64_t Imm) {