From 0c617e6026c9b1521aab100662f5c3664dda1768 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Mon, 26 Nov 2012 23:04:53 +0000 Subject: Get rid of the getPointeeAlignment helper function from InstCombineLoadStoreAlloca.cpp, which had many issues. (At least two bugs were noted on llvm-commits, and it was overly conservative.) Instead, use getOrEnforceKnownAlignment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168629 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../InstCombine/InstCombineLoadStoreAlloca.cpp | 26 ++++------------------ 1 file changed, 4 insertions(+), 22 deletions(-) (limited to 'lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp') diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 4d106fc188..fd684200fc 100644 --- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -150,26 +150,6 @@ isOnlyCopiedFromConstantGlobal(AllocaInst *AI, return 0; } -/// getPointeeAlignment - Compute the minimum alignment of the value pointed -/// to by the given pointer. -static unsigned getPointeeAlignment(Value *V, const DataLayout &TD) { - if (ConstantExpr *CE = dyn_cast(V)) - if (CE->getOpcode() == Instruction::BitCast || - (CE->getOpcode() == Instruction::GetElementPtr && - cast(CE)->hasAllZeroIndices())) - return getPointeeAlignment(CE->getOperand(0), TD); - - if (GlobalVariable *GV = dyn_cast(V)) - if (!GV->isDeclaration()) - return TD.getPreferredAlignment(GV); - - if (PointerType *PT = dyn_cast(V->getType())) - if (PT->getElementType()->isSized()) - return TD.getABITypeAlignment(PT->getElementType()); - - return 0; -} - Instruction *InstCombiner::visitAllocaInst(AllocaInst &AI) { // Ensure that the alloca array size argument has type intptr_t, so that // any casting is exposed early. @@ -265,7 +245,7 @@ Instruction *InstCombiner::visitAllocaInst(AllocaInst &AI) { } } - if (TD) { + if (AI.getAlignment()) { // Check to see if this allocation is only modified by a memcpy/memmove from // a constant global whose alignment is equal to or exceeds that of the // allocation. If this is the case, we can change all users to use @@ -274,7 +254,9 @@ Instruction *InstCombiner::visitAllocaInst(AllocaInst &AI) { // is only subsequently read. SmallVector ToDelete; if (MemTransferInst *Copy = isOnlyCopiedFromConstantGlobal(&AI, ToDelete)) { - if (AI.getAlignment() <= getPointeeAlignment(Copy->getSource(), *TD)) { + unsigned SourceAlign = getOrEnforceKnownAlignment(Copy->getSource(), + AI.getAlignment(), TD); + if (AI.getAlignment() <= SourceAlign) { DEBUG(dbgs() << "Found alloca equal to global: " << AI << '\n'); DEBUG(dbgs() << " memcpy = " << *Copy << '\n'); for (unsigned i = 0, e = ToDelete.size(); i != e; ++i) -- cgit v1.2.3