[llvm] r353844 - GlobalISel: Use default rounding mode when extending fconstant

[Matt Arsenault via llvm-commits]

Author: arsenm
Date: Tue Feb 12 06:54:54 2019
New Revision: 353844

URL: http://llvm.org/viewvc/llvm-project?rev=353844&view=rev
Log:
GlobalISel: Use default rounding mode when extending fconstant

I don't think this matters since the values should all be exactly
representable.

Modified:
    llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

Modified: llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp?rev=353844&r1=353843&r2=353844&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp Tue Feb 12 06:54:54 2019
@@ -1148,14 +1148,19 @@ LegalizerHelper::widenScalar(MachineInst
     bool LosesInfo;
     switch (WideTy.getSizeInBits()) {
     case 32:
-      Val.convert(APFloat::IEEEsingle(), APFloat::rmTowardZero, &LosesInfo);
+      Val.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven,
+                  &LosesInfo);
       break;
     case 64:
-      Val.convert(APFloat::IEEEdouble(), APFloat::rmTowardZero, &LosesInfo);
+      Val.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
+                  &LosesInfo);
       break;
     default:
-      llvm_unreachable("Unhandled fp widen type");
+      return UnableToLegalize;
     }
+
+    assert(!LosesInfo && "extend should always be lossless");
+
     Observer.changingInstr(MI);
     SrcMO.setFPImm(ConstantFP::get(Ctx, Val));