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Juergen Ributzka
5cfc91c9a5
[Constant Hoisting] Fix multiple entries for the same basic block in PHI nodes.
A PHI node usually has only one value/basic block pair per incoming basic block. In the case of a switch statement it is possible that a following PHI node may have more than one such pair per incoming basic block. E.g.: %0 = phi i64 [ 123456, %case2 ], [ 654321, %Entry ], [ 654321, %Entry ] This is valid and the verfier doesn't complain, because both values are the same. Constant hoisting materializes the constant for each operand separately and the value is still the same, but the variable names have changed. As a result the verfier can't recognize anymore that they are the same value and complains. This fix adds special update code for PHI node in constant hoisting to prevent this corner case. This fixes <rdar://problem/16394449> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204537 91177308-0d34-0410-b5e6-96231b3b80d8
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