Use getStoreSize() in various places instead of 'BitSize >> 3'.

This is needed for cases when the memory access is not as big as the width of
the data type. For instance, storing i1 (1 bit) would be done in a byte (8
bits).

Using 'BitSize >> 3' (or '/ 8') would e.g. give the memory access of an i1 a
size of 0, which for instance makes alias analysis return NoAlias even when
it shouldn't.

There are no tests as this was done as a follow-up to the bugfix for the case
where this was discovered (r318824). This handles more similar cases.

Review: Björn Petterson
https://reviews.llvm.org/D40339

llvm-svn: 319173

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index f49e22b8288..288afad3387 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4140,7 +4140,7 @@ void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) {
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
 
-  if (I.getAlignment() < VT.getSizeInBits() / 8)
+  if (I.getAlignment() < VT.getStoreSize())
     report_fatal_error("Cannot generate unaligned atomic load");
 
   MachineMemOperand *MMO =
@@ -4176,7 +4176,7 @@ void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) {
   EVT VT =
       TLI.getValueType(DAG.getDataLayout(), I.getValueOperand()->getType());
 
-  if (I.getAlignment() < VT.getSizeInBits() / 8)
+  if (I.getAlignment() < VT.getStoreSize())
     report_fatal_error("Cannot generate unaligned atomic store");
 
   SDValue OutChain =