Avoid using f64 to lower memcpy from constant string. It's cheaper to use i32 store of immediates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100751 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index afb429e..81fc48c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3210,6 +3210,7 @@
unsigned Limit, uint64_t Size,
unsigned DstAlign, unsigned SrcAlign,
bool NonScalarIntSafe,
+ bool MemcpyStrSrc,
SelectionDAG &DAG,
const TargetLowering &TLI) {
assert((SrcAlign == 0 || SrcAlign >= DstAlign) &&
@@ -3218,9 +3219,11 @@
// the value, i.e. memset or memcpy from constant string. Otherwise, it's
// the inferred alignment of the source. 'DstAlign', on the other hand, is the
// specified alignment of the memory operation. If it is zero, that means
- // it's possible to change the alignment of the destination.
+ // it's possible to change the alignment of the destination. 'MemcpyStrSrc'
+ // indicates whether the memcpy source is constant so it does not need to be
+ // loaded.
EVT VT = TLI.getOptimalMemOpType(Size, DstAlign, SrcAlign,
- NonScalarIntSafe, DAG);
+ NonScalarIntSafe, MemcpyStrSrc, DAG);
if (VT == MVT::Other) {
if (DstAlign >= TLI.getTargetData()->getPointerPrefAlignment() ||
@@ -3286,9 +3289,6 @@
// below a certain threshold.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
std::vector<EVT> MemOps;
- uint64_t Limit = -1ULL;
- if (!AlwaysInline)
- Limit = TLI.getMaxStoresPerMemcpy();
bool DstAlignCanChange = false;
MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst);
@@ -3300,9 +3300,13 @@
std::string Str;
bool CopyFromStr = isMemSrcFromString(Src, Str);
bool isZeroStr = CopyFromStr && Str.empty();
+ uint64_t Limit = -1ULL;
+ if (!AlwaysInline)
+ Limit = TLI.getMaxStoresPerMemcpy();
if (!FindOptimalMemOpLowering(MemOps, Limit, Size,
(DstAlignCanChange ? 0 : Align),
- (isZeroStr ? 0 : SrcAlign), true, DAG, TLI))
+ (isZeroStr ? 0 : SrcAlign),
+ true, CopyFromStr, DAG, TLI))
return SDValue();
if (DstAlignCanChange) {
@@ -3390,7 +3394,7 @@
if (!FindOptimalMemOpLowering(MemOps, Limit, Size,
(DstAlignCanChange ? 0 : Align),
- SrcAlign, true, DAG, TLI))
+ SrcAlign, true, false, DAG, TLI))
return SDValue();
if (DstAlignCanChange) {
@@ -3462,7 +3466,7 @@
isa<ConstantSDNode>(Src) && cast<ConstantSDNode>(Src)->isNullValue();
if (!FindOptimalMemOpLowering(MemOps, TLI.getMaxStoresPerMemset(),
Size, (DstAlignCanChange ? 0 : Align), 0,
- NonScalarIntSafe, DAG, TLI))
+ NonScalarIntSafe, false, DAG, TLI))
return SDValue();
if (DstAlignCanChange) {