[PATCH] D138744: [InstSimplify] Fold more Select with Or pattern

[Liao Chunyu via Phabricator via llvm-commits]

liaolucy created this revision.
liaolucy added a reviewer: spatel.
Herald added a subscriber: hiraditya.
Herald added a project: All.
liaolucy requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Issue: #59196
https://alive2.llvm.org/ce/z/Li-Eqq


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D138744

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp
  llvm/test/Transforms/InstSimplify/select-or-cmp.ll


Index: llvm/test/Transforms/InstSimplify/select-or-cmp.ll
===================================================================
--- llvm/test/Transforms/InstSimplify/select-or-cmp.ll
+++ llvm/test/Transforms/InstSimplify/select-or-cmp.ll
@@ -337,3 +337,21 @@
   %D = select i1 %C, i32 %x, i32 %k
   ret i32 %D
 }
+
+define i1 @select_or_return_true(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_or_return_true(
+; CHECK-NEXT:    ret i1 [[Y:%.*]]
+;
+  %C = or i1 %x, %y
+  %D = select i1 %C, i1 %y, i1 %x
+  ret i1 %D
+}
+
+define <2 x i1> @select_or_return_true1(<2 x i1> %x, <2 x i1> %y) {
+; CHECK-LABEL: @select_or_return_true1(
+; CHECK-NEXT:    ret <2 x i1> [[Y:%.*]]
+;
+  %C = or <2 x i1> %x, %y
+  %D = select <2 x i1>  %C, <2 x i1>  %y, <2 x i1> %x
+  ret <2 x i1> %D
+}
Index: llvm/lib/Analysis/InstructionSimplify.cpp
===================================================================
--- llvm/lib/Analysis/InstructionSimplify.cpp
+++ llvm/lib/Analysis/InstructionSimplify.cpp
@@ -82,6 +82,14 @@
   else
     return nullptr;
 
+  // %C = or %FV, %TV
+  // %D = select %C, %TV, %FV
+  // -->
+  // %TV
+  if (BinOpCode == BinaryOperator::Or &&
+      match(Cond, m_LogicalOr(m_Specific(FalseVal), m_Specific(TrueVal))))
+    return TrueVal;
+
   CmpInst::Predicate ExpectedPred, Pred1, Pred2;
   if (BinOpCode == BinaryOperator::Or) {
     ExpectedPred = ICmpInst::ICMP_NE;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D138744.478052.patch
Type: text/x-patch
Size: 1378 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20221126/0aeb331f/attachment.bin>