Revert my previous change -- the subtraction of two constants was a no-op

before. This is taken care of in the selection DAG pass. In my opinion, this
should be in one place or the other. I.e., it should probably be removed from
the DAG combiner (along with the other arithmetic transformations on constants
that are essentially no-ops).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55889 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2008-09-08 01:56:32 +00:00
parent ca460d5a39
commit 9a0d1ba051

View File

@ -1111,7 +1111,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
return DAG.getConstant(0, N->getValueType(0));
// fold (sub c1, c2) -> c1-c2
if (N0C && N1C)
return DAG.getConstant(N0C->getAPIntValue() - N1C->getAPIntValue(), VT);
return DAG.getNode(ISD::SUB, VT, N0, N1);
// fold (sub x, c) -> (add x, -c)
if (N1C)
return DAG.getNode(ISD::ADD, VT, N0,