diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index da96f232b80..59cf824ca7d 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -1034,9 +1034,8 @@ SimpleRegisterCoalescing::isWinToJoinVRWithSrcPhysReg(MachineInstr *CopyMI, unsigned Threshold = allocatableRCRegs_[RC].count() * 2; unsigned Length = li_->getApproximateInstructionCount(DstInt); if (Length > Threshold && - (((float)std::distance(mri_->use_nodbg_begin(DstInt.reg), - mri_->use_nodbg_end()) / Length) < - (1.0 / Threshold))) + std::distance(mri_->use_nodbg_begin(DstInt.reg), + mri_->use_nodbg_end()) * Threshold < Length) return false; // If the virtual register live interval extends into a loop, turn down @@ -1092,9 +1091,8 @@ SimpleRegisterCoalescing::isWinToJoinVRWithDstPhysReg(MachineInstr *CopyMI, unsigned Threshold = allocatableRCRegs_[RC].count() * 2; unsigned Length = li_->getApproximateInstructionCount(SrcInt); if (Length > Threshold && - (((float)std::distance(mri_->use_nodbg_begin(SrcInt.reg), - mri_->use_nodbg_end()) / Length) < - (1.0 / Threshold))) + std::distance(mri_->use_nodbg_begin(SrcInt.reg), + mri_->use_nodbg_end()) * Threshold < Length) return false; if (SrcInt.empty()) @@ -1164,18 +1162,16 @@ SimpleRegisterCoalescing::isWinToJoinCrossClass(unsigned SrcReg, mri_->use_nodbg_end()); unsigned DstUses = std::distance(mri_->use_nodbg_begin(DstReg), mri_->use_nodbg_end()); - float NewDensity = ((float)(SrcUses + DstUses) / (SrcSize + DstSize)) / - NewRCCount; + unsigned NewUses = SrcUses + DstUses; + unsigned NewSize = SrcSize + DstSize; if (SrcRC != NewRC && SrcSize > NewRCCount) { unsigned SrcRCCount = allocatableRCRegs_[SrcRC].count(); - float Density = ((float)SrcUses / SrcSize) / SrcRCCount; - if (NewDensity > Density * 2.0f) + if (NewUses*SrcSize*SrcRCCount > 2*SrcUses*NewSize*NewRCCount) return false; } if (DstRC != NewRC && DstSize > NewRCCount) { unsigned DstRCCount = allocatableRCRegs_[DstRC].count(); - float Density = ((float)DstUses / DstSize) / DstRCCount; - if (NewDensity > Density * 2.0f) + if (NewUses*DstSize*DstRCCount > 2*DstUses*NewSize*NewRCCount) return false; } return true; @@ -1669,10 +1665,9 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg); unsigned Threshold = allocatableRCRegs_[RC].count() * 2; unsigned Length = li_->getApproximateInstructionCount(JoinVInt); - float Ratio = 1.0 / Threshold; if (Length > Threshold && - (((float)std::distance(mri_->use_nodbg_begin(JoinVReg), - mri_->use_nodbg_end()) / Length) < Ratio)) { + std::distance(mri_->use_nodbg_begin(JoinVReg), + mri_->use_nodbg_end()) * Threshold < Length) { // Before giving up coalescing, if definition of source is defined by // trivial computation, try rematerializing it. if (ReMaterializeTrivialDef(SrcInt, DstReg, DstSubIdx, CopyMI))