Drop ISD::MEMSET, ISD::MEMMOVE, and ISD::MEMCPY, which are not Legal
on any current target and aren't optimized in DAGCombiner. Instead
of using intermediate nodes, expand the operations, choosing between
simple loads/stores, target-specific code, and library calls,
immediately.
Previously, the code to emit optimized code for these operations
was only used at initial SelectionDAG construction time; now it is
used at all times. This fixes some cases where rep;movs was being
used for small copies where simple loads/stores would be better.
This also cleans up code that checks for alignments less than 4;
let the targets make that decision instead of doing it in
target-independent code. This allows x86 to use rep;movs in
low-alignment cases.
Also, this fixes a bug that resulted in the use of rep;stos for
memsets of 0 with non-constant memory size when the alignment was
at least 4. It's better to use the library in this case, which
can be significantly faster when the size is large.
This also preserves more SourceValue information when memory
intrinsics are lowered into simple loads/stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49572 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index d809950..2abe237 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -441,8 +441,8 @@
SDOperand Ret,
SelectionDAG &DAG) const;
- virtual const TargetSubtarget* getSubtarget() {
- return static_cast<const TargetSubtarget*>(Subtarget);
+ virtual const X86Subtarget* getSubtarget() {
+ return Subtarget;
}
/// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
@@ -512,9 +512,6 @@
SDOperand LowerSELECT(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerBRCOND(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerMEMSET(SDOperand Op, SelectionDAG &DAG);
- SDOperand LowerMEMCPYInline(SDOperand Dest, SDOperand Source,
- SDOperand Chain, unsigned Size, unsigned Align,
- SelectionDAG &DAG);
SDOperand LowerJumpTable(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG);
@@ -535,6 +532,19 @@
SDNode *ExpandFP_TO_SINT(SDNode *N, SelectionDAG &DAG);
SDNode *ExpandREADCYCLECOUNTER(SDNode *N, SelectionDAG &DAG);
SDNode *ExpandATOMIC_LCS(SDNode *N, SelectionDAG &DAG);
+
+ SDOperand EmitTargetCodeForMemset(SelectionDAG &DAG,
+ SDOperand Chain,
+ SDOperand Dst, SDOperand Src,
+ SDOperand Size, unsigned Align,
+ Value *DstSV, uint64_t DstOff);
+ SDOperand EmitTargetCodeForMemcpy(SelectionDAG &DAG,
+ SDOperand Chain,
+ SDOperand Dst, SDOperand Src,
+ SDOperand Size, unsigned Align,
+ bool AlwaysInline,
+ Value *DstSV, uint64_t DstOff,
+ Value *SrcSV, uint64_t SrcOff);
};
}