diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 3 | ||||
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.h | 10 |
2 files changed, 12 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index c1bf2188b1..24dd2fd3bd 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -504,7 +504,8 @@ static SDOperand ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP, if (CFP->isValueValidForType(SVT, CFP->getValueAPF()) && // Only do this if the target has a native EXTLOAD instruction from // smaller type. - TLI.isLoadXLegal(ISD::EXTLOAD, SVT)) { + TLI.isLoadXLegal(ISD::EXTLOAD, SVT) && + TLI.ShouldShrinkFPConstant(VT)) { const Type *SType = MVT::getTypeForValueType(SVT); LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType)); VT = SVT; diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h index d9593a4ef6..e0ddf63bf0 100644 --- a/lib/Target/X86/X86ISelLowering.h +++ b/lib/Target/X86/X86ISelLowering.h @@ -434,6 +434,16 @@ namespace llvm { virtual bool isVectorClearMaskLegal(std::vector<SDOperand> &BVOps, MVT::ValueType EVT, SelectionDAG &DAG) const; + + /// ShouldShrinkFPConstant - If true, then instruction selection should + /// seek to shrink the FP constant of the specified type to a smaller type + /// in order to save space and / or reduce runtime. + virtual bool ShouldShrinkFPConstant(MVT::ValueType VT) const { + // Don't shrink FP constpool if SSE2 is available since cvtss2sd is more + // expensive than a straight movsd. On the other hand, it's important to + // shrink long double fp constant since fldt is very slow. + return !X86ScalarSSEf64 || VT == MVT::f80; + } /// IsEligibleForTailCallOptimization - Check whether the call is eligible /// for tail call optimization. Target which want to do tail call |