diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 28 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/unpack-fca.ll | 31 |
2 files changed, 59 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 73dd40e4d19..6b0f268c9c8 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -818,6 +818,30 @@ static bool combineStoreToValueType(InstCombiner &IC, StoreInst &SI) { return false; } +static bool unpackStoreToAggregate(InstCombiner &IC, StoreInst &SI) { + // FIXME: We could probably with some care handle both volatile and atomic + // stores here but it isn't clear that this is important. + if (!SI.isSimple()) + return false; + + Value *V = SI.getValueOperand(); + Type *T = V->getType(); + + if (!T->isAggregateType()) + return false; + + if (StructType *ST = dyn_cast<StructType>(T)) { + // If the struct only have one element, we unpack. + if (ST->getNumElements() == 1) { + V = IC.Builder->CreateExtractValue(V, 0); + combineStoreToNewValue(IC, SI, V); + return true; + } + } + + return false; +} + /// equivalentAddressValues - Test if A and B will obviously have the same /// value. This includes recognizing that %t0 and %t1 will have the same /// value in code like this: @@ -867,6 +891,10 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { else if (StoreAlign == 0) SI.setAlignment(EffectiveStoreAlign); + // Try to canonicalize the stored type. + if (unpackStoreToAggregate(*this, SI)) + return EraseInstFromFunction(SI); + // Replace GEP indices if possible. if (Instruction *NewGEPI = replaceGEPIdxWithZero(*this, Ptr, SI)) { Worklist.Add(NewGEPI); diff --git a/llvm/test/Transforms/InstCombine/unpack-fca.ll b/llvm/test/Transforms/InstCombine/unpack-fca.ll new file mode 100644 index 00000000000..5f63330b931 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/unpack-fca.ll @@ -0,0 +1,31 @@ +; RUN: opt -instcombine -S < %s | FileCheck %s + +target datalayout = "e-i64:64-f80:128-n8:16:32:64" +target triple = "x86_64-unknown-linux-gnu" + +%A__vtbl = type { i8*, i32 (%A*)* } +%A = type { %A__vtbl* } + +@A__vtblZ = constant %A__vtbl { i8* null, i32 (%A*)* @A.foo } + +declare i32 @A.foo(%A* nocapture %this) + +declare i8* @allocmemory(i64) + +define void @structA() { +body: + %0 = tail call i8* @allocmemory(i64 32) + %1 = bitcast i8* %0 to %A* +; CHECK: store %A__vtbl* @A__vtblZ + store %A { %A__vtbl* @A__vtblZ }, %A* %1, align 8 + ret void +} + +define void @structOfA() { +body: + %0 = tail call i8* @allocmemory(i64 32) + %1 = bitcast i8* %0 to { %A }* +; CHECK: store %A__vtbl* @A__vtblZ + store { %A } { %A { %A__vtbl* @A__vtblZ } }, { %A }* %1, align 8 + ret void +} |
