Add a roundToIntegral method to APFloat, which can be parameterized over various rounding modes. Use this to implement SelectionDAG constant folding of FFLOOR, FCEIL, and FTRUNC.
llvm-svn: 161807
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index d96f275..f4fe892 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2483,6 +2483,24 @@
case ISD::FABS:
V.clearSign();
return getConstantFP(V, VT);
+ case ISD::FCEIL: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardPositive);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
+ case ISD::FTRUNC: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardZero);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
+ case ISD::FFLOOR: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardNegative);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
case ISD::FP_EXTEND: {
bool ignored;
// This can return overflow, underflow, or inexact; we don't care.