Use vmov.f32 to materialize f32 consts on ARM. This relaxes constraints on
register allocation by allowing all 32 D-registers to be used. Patch by Cameron
Zwarich.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152824 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 5fe5a76..2d28280 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -456,6 +456,8 @@
setLoadExtAction(ISD::EXTLOAD, (MVT::SimpleValueType)VT, Expand);
}
+ setOperationAction(ISD::ConstantFP, MVT::f32, Custom);
+
if (Subtarget->hasNEON()) {
addDRTypeForNEON(MVT::v2f32);
addDRTypeForNEON(MVT::v8i8);
@@ -3673,6 +3675,27 @@
return Result;
}
+SDValue ARMTargetLowering::LowerConstantFP(SDValue Op, SelectionDAG &DAG,
+ const ARMSubtarget *ST) const {
+ if (!ST->useNEONForSinglePrecisionFP() || !ST->hasVFP3() || ST->hasD16())
+ return SDValue();
+
+ ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Op);
+ assert(Op.getValueType() == MVT::f32 &&
+ "ConstantFP custom lowering should only occur for f32.");
+
+ APFloat FPVal = CFP->getValueAPF();
+ int ImmVal = ARM_AM::getFP32Imm(FPVal);
+ if (ImmVal == -1)
+ return SDValue();
+
+ DebugLoc DL = Op.getDebugLoc();
+ SDValue NewVal = DAG.getTargetConstant(ImmVal, MVT::i32);
+ SDValue VecConstant = DAG.getNode(ARMISD::VMOVFPIMM, DL, MVT::v2f32, NewVal);
+ return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::f32, VecConstant,
+ DAG.getConstant(0, MVT::i32));
+}
+
/// isNEONModifiedImm - Check if the specified splat value corresponds to a
/// valid vector constant for a NEON instruction with a "modified immediate"
/// operand (e.g., VMOV). If so, return the encoded value.
@@ -5109,6 +5132,7 @@
case ISD::SRA_PARTS: return LowerShiftRightParts(Op, DAG);
case ISD::CTTZ: return LowerCTTZ(Op.getNode(), DAG, Subtarget);
case ISD::SETCC: return LowerVSETCC(Op, DAG);
+ case ISD::ConstantFP: return LowerConstantFP(Op, DAG, Subtarget);
case ISD::BUILD_VECTOR: return LowerBUILD_VECTOR(Op, DAG, Subtarget);
case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);
case ISD::INSERT_VECTOR_ELT: return LowerINSERT_VECTOR_ELT(Op, DAG);