(VT == MVT::f64) ? MVT::i64 : MVT::i32);
}
+ APFloat APF = CFP->getValueAPF();
EVT OrigVT = VT;
EVT SVT = VT;
- while (SVT != MVT::f32 && SVT != MVT::f16) {
- SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
- if (ConstantFPSDNode::isValueValidForType(SVT, CFP->getValueAPF()) &&
- // Only do this if the target has a native EXTLOAD instruction from
- // smaller type.
- TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
- TLI.ShouldShrinkFPConstant(OrigVT)) {
- Type *SType = SVT.getTypeForEVT(*DAG.getContext());
- LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
- VT = SVT;
- Extend = true;
+
+ // We don't want to shrink SNaNs. Converting the SNaN back to its real type
+ // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
+ if (!APF.isSignaling()) {
+ while (SVT != MVT::f32 && SVT != MVT::f16) {
+ SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
+ if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
+ // Only do this if the target has a native EXTLOAD instruction from
+ // smaller type.
+ TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
+ TLI.ShouldShrinkFPConstant(OrigVT)) {
+ Type *SType = SVT.getTypeForEVT(*DAG.getContext());
+ LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
+ VT = SVT;
+ Extend = true;
+ }
}
}
--- /dev/null
+; Test loads of SNaN.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+; Test that we don't do an FP extending load, as this would result in a
+; converstion to QNaN.
+define double @f1() {
+; CHECK-LABEL: .LCPI0_0
+; CHECK: .quad 9219994337134247936
+; CHECK-LABEL: f1:
+; CHECK: larl %r1, .LCPI0_0
+; CHECK-NOT: ldeb %f0, 0(%r1)
+; CHECK: ld %f0, 0(%r1)
+ ret double 0x7FF4000000000000
+}