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
This commit is contained in:
Dan Gohman 2011-02-02 02:05:46 +00:00
parent 46985a1440
commit 5195b71941

View File

@ -157,6 +157,9 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) {
// 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 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) {
// 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 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) {
// 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 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) {
// 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 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) {
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;
}