diff options
Diffstat (limited to 'llvm/lib/Target/RISCV/RISCVISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/RISCV/RISCVISelLowering.cpp | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp index 52c027ba314..d3d0d0370b9 100644 --- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp @@ -293,17 +293,22 @@ SDValue RISCVTargetLowering::lowerGlobalAddress(SDValue Op, GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op); const GlobalValue *GV = N->getGlobal(); int64_t Offset = N->getOffset(); + MVT XLenVT = Subtarget.getXLenVT(); if (isPositionIndependent() || Subtarget.is64Bit()) report_fatal_error("Unable to lowerGlobalAddress"); - - SDValue GAHi = - DAG.getTargetGlobalAddress(GV, DL, Ty, Offset, RISCVII::MO_HI); - SDValue GALo = - DAG.getTargetGlobalAddress(GV, DL, Ty, Offset, RISCVII::MO_LO); + // In order to maximise the opportunity for common subexpression elimination, + // emit a separate ADD node for the global address offset instead of folding + // it in the global address node. Later peephole optimisations may choose to + // fold it back in when profitable. + SDValue GAHi = DAG.getTargetGlobalAddress(GV, DL, Ty, 0, RISCVII::MO_HI); + SDValue GALo = DAG.getTargetGlobalAddress(GV, DL, Ty, 0, RISCVII::MO_LO); SDValue MNHi = SDValue(DAG.getMachineNode(RISCV::LUI, DL, Ty, GAHi), 0); SDValue MNLo = SDValue(DAG.getMachineNode(RISCV::ADDI, DL, Ty, MNHi, GALo), 0); + if (Offset != 0) + return DAG.getNode(ISD::ADD, DL, Ty, MNLo, + DAG.getConstant(Offset, DL, XLenVT)); return MNLo; } |
