diff options
Diffstat (limited to 'lib/Analysis/InlineCost.cpp')
-rw-r--r-- | lib/Analysis/InlineCost.cpp | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/lib/Analysis/InlineCost.cpp b/lib/Analysis/InlineCost.cpp index a6bf4a86a9..bc1ecd2ea4 100644 --- a/lib/Analysis/InlineCost.cpp +++ b/lib/Analysis/InlineCost.cpp @@ -797,9 +797,33 @@ bool CallAnalyzer::analyzeCall(CallSite CS) { FiftyPercentVectorBonus = Threshold; TenPercentVectorBonus = Threshold / 2; - // Subtract off one instruction per call argument as those will be free after - // inlining. - Cost -= CS.arg_size() * InlineConstants::InstrCost; + // Give out bonuses per argument, as the instructions setting them up will + // be gone after inlining. + for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) { + if (TD && CS.isByValArgument(I)) { + // We approximate the number of loads and stores needed by dividing the + // size of the byval type by the target's pointer size. + PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType()); + unsigned TypeSize = TD->getTypeSizeInBits(PTy->getElementType()); + unsigned PointerSize = TD->getPointerSizeInBits(); + // Ceiling division. + unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize; + + // If it generates more than 8 stores it is likely to be expanded as an + // inline memcpy so we take that as an upper bound. Otherwise we assume + // one load and one store per word copied. + // FIXME: The maxStoresPerMemcpy setting from the target should be used + // here instead of a magic number of 8, but it's not available via + // TargetData. + NumStores = std::min(NumStores, 8U); + + Cost -= 2 * NumStores * InlineConstants::InstrCost; + } else { + // For non-byval arguments subtract off one instruction per call + // argument. + Cost -= InlineConstants::InstrCost; + } + } // If there is only one call of the function, and it has internal linkage, // the cost of inlining it drops dramatically. |