Conservatively, clear optional flags, such as nsw, when performing
reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124713 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 2d5773a..7208ad0 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -157,6 +157,9 @@
// It simplifies to V. Form "A op V".
I.setOperand(0, A);
I.setOperand(1, V);
+ // Conservatively clear the optional flags, since they may not be
+ // preserved by the reassociation.
+ I.clearSubclassOptionalData();
Changed = true;
++NumReassoc;
continue;
@@ -174,6 +177,9 @@
// It simplifies to V. Form "V op C".
I.setOperand(0, V);
I.setOperand(1, C);
+ // Conservatively clear the optional flags, since they may not be
+ // preserved by the reassociation.
+ I.clearSubclassOptionalData();
Changed = true;
++NumReassoc;
continue;
@@ -193,6 +199,9 @@
// It simplifies to V. Form "V op B".
I.setOperand(0, V);
I.setOperand(1, B);
+ // Conservatively clear the optional flags, since they may not be
+ // preserved by the reassociation.
+ I.clearSubclassOptionalData();
Changed = true;
++NumReassoc;
continue;
@@ -210,6 +219,9 @@
// It simplifies to V. Form "B op V".
I.setOperand(0, B);
I.setOperand(1, V);
+ // Conservatively clear the optional flags, since they may not be
+ // preserved by the reassociation.
+ I.clearSubclassOptionalData();
Changed = true;
++NumReassoc;
continue;
@@ -234,6 +246,9 @@
Worklist.Add(New);
I.setOperand(0, New);
I.setOperand(1, Folded);
+ // Conservatively clear the optional flags, since they may not be
+ // preserved by the reassociation.
+ I.clearSubclassOptionalData();
Changed = true;
continue;
}