[llvm] f7f430c - [InstCombine] Fixed non-determinisctic order of new instructions

[Stanislav Mekhanoshin via llvm-commits]

Author: Stanislav Mekhanoshin
Date: 2021-10-28T12:14:02-07:00
New Revision: f7f430c9136330545637aaddebf013da05c0f370

URL: https://github.com/llvm/llvm-project/commit/f7f430c9136330545637aaddebf013da05c0f370
DIFF: https://github.com/llvm/llvm-project/commit/f7f430c9136330545637aaddebf013da05c0f370.diff

LOG: [InstCombine] Fixed non-determinisctic order of new instructions

Fixes non-determinisctic order of XOR instructions created after
5a7a458306cd. The order of call argument evaluation is not
defined, so create one Value before the call.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 5ef1145e0985..ac79e21507c5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2805,15 +2805,17 @@ Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
                                   m_Value(C))))) {
     if (match(Op1, m_OneUse(m_c_And(
                        m_OneUse(m_Not(m_c_Or(m_Specific(A), m_Specific(C)))),
-                       m_Specific(B)))))
-      return BinaryOperator::CreateAnd(Builder.CreateXor(B, C),
-                                       Builder.CreateNot(A));
+                       m_Specific(B))))) {
+      Value *Xor = Builder.CreateXor(B, C);
+      return BinaryOperator::CreateAnd(Xor, Builder.CreateNot(A));
+    }
 
     if (match(Op1, m_OneUse(m_c_And(
                        m_OneUse(m_Not(m_c_Or(m_Specific(B), m_Specific(C)))),
-                       m_Specific(A)))))
-      return BinaryOperator::CreateAnd(Builder.CreateXor(A, C),
-                                       Builder.CreateNot(B));
+                       m_Specific(A))))) {
+      Value *Xor = Builder.CreateXor(A, C);
+      return BinaryOperator::CreateAnd(Xor, Builder.CreateNot(B));
+    }
   }
 
   if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))