diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 45 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/2010-08-19-StoreNarrowing.ll | 21 |
2 files changed, 0 insertions, 66 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 2f3d8b2b3e3..b68fbc2db5c 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -14,13 +14,11 @@ #include "InstCombine.h" #include "llvm/IntrinsicInst.h" #include "llvm/Analysis/Loads.h" -#include "llvm/Support/PatternMatch.h" #include "llvm/Target/TargetData.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/Local.h" #include "llvm/ADT/Statistic.h" using namespace llvm; -using namespace PatternMatch; STATISTIC(NumDeadStore, "Number of dead stores eliminated"); @@ -475,49 +473,6 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { if (SI.isVolatile()) return 0; // Don't hack volatile stores. - // Attempt to narrow sequences where we load a wide value, perform bitmasks - // that only affect the low bits of it, and then store it back. This - // typically arises from bitfield initializers in C++. - ConstantInt *CI1 =0, *CI2 = 0; - Value *Ld = 0; - if (getTargetData() && - match(SI.getValueOperand(), - m_And(m_Or(m_Value(Ld), m_ConstantInt(CI1)), m_ConstantInt(CI2))) && - isa<LoadInst>(Ld) && - equivalentAddressValues(cast<LoadInst>(Ld)->getPointerOperand(), Ptr)) { - APInt OrMask = CI1->getValue(); - APInt AndMask = CI2->getValue(); - - // Compute the prefix of the value that is unmodified by the bitmasking. - unsigned LeadingAndOnes = AndMask.countLeadingOnes(); - unsigned LeadingOrZeros = OrMask.countLeadingZeros(); - unsigned Prefix = std::min(LeadingAndOnes, LeadingOrZeros); - uint64_t NewWidth = AndMask.getBitWidth() - Prefix; - if (!isPowerOf2_64(NewWidth)) NewWidth = NextPowerOf2(NewWidth); - - // If we can find a power-of-2 prefix (and if the values we're working with - // are themselves POT widths), then we can narrow the store. We rely on - // later iterations of instcombine to propagate the demanded bits to narrow - // the other computations in the chain. - if (NewWidth < AndMask.getBitWidth() && - isPowerOf2_64(AndMask.getBitWidth())) { - const Type *NewType = IntegerType::get(Ptr->getContext(), NewWidth); - const Type *NewPtrType = PointerType::getUnqual(NewType); - - Value *NewVal = Builder->CreateTrunc(SI.getValueOperand(), NewType); - Value *NewPtr = Builder->CreateBitCast(Ptr, NewPtrType); - - // On big endian targets, we need to offset from the original pointer - // in order to store to the low-bit suffix. - if (getTargetData()->isBigEndian()) { - uint64_t GEPOffset = (AndMask.getBitWidth() - NewWidth) / 8; - NewPtr = Builder->CreateConstGEP1_64(NewPtr, GEPOffset); - } - - return new StoreInst(NewVal, NewPtr); - } - } - // store X, null -> turns into 'unreachable' in SimplifyCFG if (isa<ConstantPointerNull>(Ptr) && SI.getPointerAddressSpace() == 0) { if (!isa<UndefValue>(Val)) { diff --git a/llvm/test/Transforms/InstCombine/2010-08-19-StoreNarrowing.ll b/llvm/test/Transforms/InstCombine/2010-08-19-StoreNarrowing.ll index d4d528943fe..e69de29bb2d 100644 --- a/llvm/test/Transforms/InstCombine/2010-08-19-StoreNarrowing.ll +++ b/llvm/test/Transforms/InstCombine/2010-08-19-StoreNarrowing.ll @@ -1,21 +0,0 @@ -; RUN: opt -S -instcombine %s | not grep and -target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" -target triple = "x86_64-apple-darwin10.0.0" - -%class.A = type { i8, [3 x i8] } - -define void @_ZN1AC2Ev(%class.A* %this) nounwind ssp align 2 { -entry: - %0 = bitcast %class.A* %this to i32* ; <i32*> [#uses=5] - %1 = load i32* %0, align 4 ; <i32> [#uses=1] - %2 = and i32 %1, -8 ; <i32> [#uses=2] - store i32 %2, i32* %0, align 4 - %3 = and i32 %2, -57 ; <i32> [#uses=1] - %4 = or i32 %3, 8 ; <i32> [#uses=2] - store i32 %4, i32* %0, align 4 - %5 = and i32 %4, -65 ; <i32> [#uses=2] - store i32 %5, i32* %0, align 4 - %6 = and i32 %5, -129 ; <i32> [#uses=1] - store i32 %6, i32* %0, align 4 - ret void -} |
