Convert comparisons like (x == infinity) to (x >= infinity) on targets
where FCMP_OEQ is not legal and FCMP_OGE is, such as x86.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82861 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 7bd85fd..a2baee4 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1922,6 +1922,43 @@
// materialize 0.0.
if (Cond == ISD::SETO || Cond == ISD::SETUO)
return DAG.getSetCC(dl, VT, N0, N0, Cond);
+
+ // If the condition is not legal, see if we can find an equivalent one
+ // which is legal.
+ if (!isCondCodeLegal(Cond, N0.getValueType())) {
+ // If the comparison was an awkward floating-point == or != and one of
+ // the comparison operands is infinity or negative infinity, convert the
+ // condition to a less-awkward <= or >=.
+ if (CFP->getValueAPF().isInfinity()) {
+ if (CFP->getValueAPF().isNegative()) {
+ if (Cond == ISD::SETOEQ &&
+ isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE);
+ if (Cond == ISD::SETUEQ &&
+ isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE);
+ if (Cond == ISD::SETUNE &&
+ isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT);
+ if (Cond == ISD::SETONE &&
+ isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT);
+ } else {
+ if (Cond == ISD::SETOEQ &&
+ isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE);
+ if (Cond == ISD::SETUEQ &&
+ isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE);
+ if (Cond == ISD::SETUNE &&
+ isCondCodeLegal(ISD::SETULT, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT);
+ if (Cond == ISD::SETONE &&
+ isCondCodeLegal(ISD::SETULT, N0.getValueType()))
+ return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT);
+ }
+ }
+ }
}
if (N0 == N1) {