[PATCH] D82072: [InstCombine] Combine select & Phi by same condition

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev updated this revision to Diff 272613.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82072/new/

https://reviews.llvm.org/D82072

Files:
  llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
  llvm/test/Transforms/InstCombine/select.ll


Index: llvm/test/Transforms/InstCombine/select.ll
===================================================================
--- llvm/test/Transforms/InstCombine/select.ll
+++ llvm/test/Transforms/InstCombine/select.ll
@@ -2000,7 +2000,6 @@
   ret i32 %s
 }
 
-; TODO: Replace with phi[x, z].
 define i32 @select_phi_same_condition(i1 %cond, i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_phi_same_condition(
 ; CHECK-NEXT:  entry:
@@ -2010,8 +2009,7 @@
 ; CHECK:       if.false:
 ; CHECK-NEXT:    br label [[MERGE]]
 ; CHECK:       merge:
-; CHECK-NEXT:    [[PHI:%.*]] = phi i32 [ 0, [[IF_TRUE]] ], [ [[Z:%.*]], [[IF_FALSE]] ]
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[COND]], i32 [[X:%.*]], i32 [[PHI]]
+; CHECK-NEXT:    [[S:%.*]] = phi i32 [ [[Z:%.*]], [[IF_FALSE]] ], [ [[X:%.*]], [[IF_TRUE]] ]
 ; CHECK-NEXT:    ret i32 [[S]]
 ;
 entry:
Index: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2476,9 +2476,9 @@
     // Check implication.
     BasicBlockEdge Incoming(Pred, BB);
     if (DT.dominates(TrueEdge, Incoming))
-      Inputs[Pred] = IfTrue;
+      Inputs[Pred] = IfTrue->DoPHITranslation(BB, Pred);
     else if (DT.dominates(FalseEdge, Incoming))
-      Inputs[Pred] = IfFalse;
+      Inputs[Pred] = IfFalse->DoPHITranslation(BB, Pred);
     else
       return nullptr;
     // Check availability.


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