[llvm] r232935 - [SDAG] Don't widen VSETCC during type legalization for split operands

[Hal Finkel]

Author: hfinkel
Date: Mon Mar 23 03:22:43 2015
New Revision: 232935

URL: http://llvm.org/viewvc/llvm-project?rev=232935&view=rev
Log:
[SDAG] Don't widen VSETCC during type legalization for split operands

Because the operands of a vector SETCC node can be of a different type from the
result (and often are), it can happen that even if we'd prefer to widen the
result type of the SETCC, the operands have been split instead. In this case,
the SETCC result also must be split. This mirrors what is done in
WidenVecRes_SELECT, and should be NFC elsewhere because if the operands are not
widened the following calls to GetWidenedVector will assert (which is what was
happening in the test case).

Added:
    llvm/trunk/test/CodeGen/PowerPC/qpx-split-vsetcc.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp?rev=232935&r1=232934&r2=232935&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp Mon Mar 23 03:22:43 2015
@@ -2553,6 +2553,16 @@ SDValue DAGTypeLegalizer::WidenVecRes_VS
   assert(InVT.isVector() && "can not widen non-vector type");
   EVT WidenInVT = EVT::getVectorVT(*DAG.getContext(),
                                    InVT.getVectorElementType(), WidenNumElts);
+
+  // The input and output types often differ here, and it could be that while
+  // we'd prefer to widen the result type, the input operands have been split.
+  // In this case, we also need to split the result of this node as well.
+  if (getTypeAction(InVT) == TargetLowering::TypeSplitVector) {
+    SDValue SplitVSetCC = SplitVecOp_VSETCC(N);
+    SDValue Res = ModifyToType(SplitVSetCC, WidenVT);
+    return Res;
+  }
+
   InOp1 = GetWidenedVector(InOp1);
   SDValue InOp2 = GetWidenedVector(N->getOperand(1));
 

Added: llvm/trunk/test/CodeGen/PowerPC/qpx-split-vsetcc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/qpx-split-vsetcc.ll?rev=232935&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/qpx-split-vsetcc.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/qpx-split-vsetcc.ll Mon Mar 23 03:22:43 2015
@@ -0,0 +1,40 @@
+; RUN: llc -mcpu=a2q < %s | FileCheck %s
+target datalayout = "E-m:e-i64:64-n32:64"
+target triple = "powerpc64-bgq-linux"
+
+; Function Attrs: nounwind
+define void @gsl_sf_legendre_Pl_deriv_array() #0 {
+entry:
+  br i1 undef, label %do.body.i, label %if.else.i
+
+do.body.i:                                        ; preds = %entry
+  unreachable
+
+if.else.i:                                        ; preds = %entry
+  br i1 undef, label %return, label %for.body46.lr.ph
+
+for.body46.lr.ph:                                 ; preds = %if.else.i
+  br label %vector.body198
+
+vector.body198:                                   ; preds = %vector.body198, %for.body46.lr.ph
+  %0 = icmp ne <4 x i32> undef, zeroinitializer
+  %1 = select <4 x i1> %0, <4 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <4 x double> <double -5.000000e-01, double -5.000000e-01, double -5.000000e-01, double -5.000000e-01>
+  %2 = fmul <4 x double> undef, %1
+  %3 = fmul <4 x double> undef, %2
+  %4 = fmul <4 x double> %3, undef
+  store <4 x double> %4, <4 x double>* undef, align 8
+  br label %vector.body198
+
+; CHECK-LABEL: @gsl_sf_legendre_Pl_deriv_array
+; CHECK: qvlfiwzx
+; CHECK: qvfcfidu
+; CHECK: qvfcmpeq
+; CHECK: qvfsel
+; CHECK: qvfmul
+
+return:                                           ; preds = %if.else.i
+  ret void
+}
+
+attributes #0 = { nounwind }
+