[ARM] Align global variables passed to memory intrinsics
Fill in the TODO in CodeGenPrepare::OptimizeCallInst so that global
variables that are passed to memory intrinsics are aligned in the same
way that allocas are.
Differential Revision: http://reviews.llvm.org/D8421
llvm-svn: 234735
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 91bd565..35376e1 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1288,13 +1288,25 @@
cast<PointerType>(Arg->getType())->getAddressSpace()), 0);
Value *Val = Arg->stripAndAccumulateInBoundsConstantOffsets(*TD, Offset);
uint64_t Offset2 = Offset.getLimitedValue();
+ if ((Offset2 & (PrefAlign-1)) != 0)
+ continue;
AllocaInst *AI;
- if ((Offset2 & (PrefAlign-1)) == 0 &&
- (AI = dyn_cast<AllocaInst>(Val)) &&
+ if ((AI = dyn_cast<AllocaInst>(Val)) &&
AI->getAlignment() < PrefAlign &&
TD->getTypeAllocSize(AI->getAllocatedType()) >= MinSize + Offset2)
AI->setAlignment(PrefAlign);
- // TODO: Also align GlobalVariables
+ // Global variables can only be aligned if they are defined in this
+ // object (i.e. they are uniquely initialized in this object), and
+ // over-aligning global variables that have an explicit section is
+ // forbidden.
+ GlobalVariable *GV;
+ if ((GV = dyn_cast<GlobalVariable>(Val)) &&
+ GV->hasUniqueInitializer() &&
+ !GV->hasSection() &&
+ GV->getAlignment() < PrefAlign &&
+ TD->getTypeAllocSize(
+ GV->getType()->getElementType()) >= MinSize + Offset2)
+ GV->setAlignment(PrefAlign);
}
// If this is a memcpy (or similar) then we may be able to improve the
// alignment