[PATCH] D57491: [DAGCombine] Avoid CombineZExtLogicopShiftLoad if there is free ZEXT

[Guozhi Wei via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL352792: [DAGCombine] Avoid CombineZExtLogicopShiftLoad if there is free ZEXT (authored by Carrot, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D57491?vs=184519&id=184580#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57491/new/

https://reviews.llvm.org/D57491

Files:
  llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/trunk/test/CodeGen/X86/pr39098.ll


Index: llvm/trunk/test/CodeGen/X86/pr39098.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/pr39098.ll
+++ llvm/trunk/test/CodeGen/X86/pr39098.ll
@@ -0,0 +1,20 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s
+
+define dso_local void @test_cancel2(i40* %p1, i40* %p2) {
+; CHECK:       # %entry
+; CHECK-NEXT:  movl    (%rdi), %eax
+; CHECK-NEXT:  shrl    %eax
+; CHECK-NEXT:  andl    $524287, %eax
+; CHECK-NEXT:  movl    %eax, (%rsi)
+; CHECK-NEXT:  movb    $0, 4(%rsi)
+; CHECK-NEXT:  retq
+entry:
+  %0 = load i40, i40* %p1, align 8
+  %shl414 = shl i40 %0, 19
+  %unsclear415 = and i40 %shl414, 549755813887
+  %shr416 = lshr i40 %unsclear415, 20
+  %unsclear417 = and i40 %shr416, 549755813887
+  store i40 %unsclear417, i40* %p2, align 8
+  ret void
+}
+
Index: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -8402,6 +8402,9 @@
 SDValue DAGCombiner::CombineZExtLogicopShiftLoad(SDNode *N) {
   assert(N->getOpcode() == ISD::ZERO_EXTEND);
   EVT VT = N->getValueType(0);
+  EVT OrigVT = N->getOperand(0).getValueType();
+  if (TLI.isZExtFree(OrigVT, VT))
+    return SDValue();
 
   // and/or/xor
   SDValue N0 = N->getOperand(0);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D57491.184580.patch
Type: text/x-patch
Size: 1397 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190131/356260b0/attachment.bin>