[PATCH] D73791: Fix broken invariant

[Guillaume Chatelet via Phabricator via llvm-commits]

gchatelet created this revision.
gchatelet added a reviewer: courbet.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
gchatelet updated this revision to Diff 241756.
gchatelet added a comment.

- Added asserts


A Copy with a source that is zeros is the same as a Set of zeros.
This fixes the invariant that SrcAlign should always be non-null.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73791

Files:
  llvm/include/llvm/CodeGen/TargetLowering.h
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/test/CodeGen/AArch64/memcpy-f128.ll


Index: llvm/test/CodeGen/AArch64/memcpy-f128.ll
===================================================================
--- llvm/test/CodeGen/AArch64/memcpy-f128.ll
+++ llvm/test/CodeGen/AArch64/memcpy-f128.ll
@@ -7,9 +7,6 @@
 
 define void @test1() {
 ; CHECK-LABEL: @test1
-; CHECK: adrp
-; CHECK: ldr q0
-; CHECK: str q0
 ; CHECK: ret
 entry:
   tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 8 undef, i8* align 8 bitcast (%structA* @stubA to i8*), i64 48, i1 false)
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5908,12 +5908,14 @@
   bool CopyFromConstant = isMemSrcFromConstant(Src, Slice);
   bool isZeroConstant = CopyFromConstant && Slice.Array == nullptr;
   unsigned Limit = AlwaysInline ? ~0U : TLI.getMaxStoresPerMemcpy(OptSize);
+  const MemOp Op = isZeroConstant
+                       ? MemOp::Set(Size, DstAlignCanChange, Alignment,
+                                    /*IsZeroMemset*/ true, isVol)
+                       : MemOp::Copy(Size, DstAlignCanChange, Alignment,
+                                     SrcAlign, isVol, CopyFromConstant);
   if (!TLI.findOptimalMemOpLowering(
-          MemOps, Limit,
-          MemOp::Copy(Size, DstAlignCanChange, Alignment,
-                      isZeroConstant ? 0 : SrcAlign, isVol, CopyFromConstant),
-          DstPtrInfo.getAddrSpace(), SrcPtrInfo.getAddrSpace(),
-          MF.getFunction().getAttributes()))
+          MemOps, Limit, Op, DstPtrInfo.getAddrSpace(),
+          SrcPtrInfo.getAddrSpace(), MF.getFunction().getAttributes()))
     return SDValue();
 
   if (DstAlignCanChange) {
Index: llvm/include/llvm/CodeGen/TargetLowering.h
===================================================================
--- llvm/include/llvm/CodeGen/TargetLowering.h
+++ llvm/include/llvm/CodeGen/TargetLowering.h
@@ -125,6 +125,8 @@
   static MemOp Copy(uint64_t Size, bool DstAlignCanChange, unsigned DstAlign,
                     unsigned SrcAlign, bool IsVolatile,
                     bool MemcpyStrSrc = false) {
+    assert(DstAlign && "Alignment should be set");
+    assert(SrcAlign && "Alignment should be set");
     return {
         /*.Size =*/Size,
         /*.DstAlign =*/DstAlignCanChange ? 0 : DstAlign,
@@ -137,6 +139,7 @@
   }
   static MemOp Set(uint64_t Size, bool DstAlignCanChange, unsigned DstAlign,
                    bool IsZeroMemset, bool IsVolatile) {
+    assert(DstAlign && "Alignment should be set");
     return {
         /*.Size =*/Size,
         /*.DstAlign =*/DstAlignCanChange ? 0 : DstAlign,


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