Commit 022a4c41 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r228969: 

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r228969 | hfinkel | 2015-02-12 14:43:52 -0800 (Thu, 12 Feb 2015) | 7 lines

[SDAG] Don't try to use FP_EXTEND/FP_ROUND for int<->fp promotions

The PowerPC backend has long promoted some floating-point vector operations
(such as select) to integer vector operations. Unfortunately, this behavior was
broken by r216555. When using FP_EXTEND/FP_ROUND for promotions, we must check
that both the old and new types are floating-point types. Otherwise, we must
use BITCAST as we did prior to r216555 for everything.
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llvm-svn: 228986
parent aae610a1

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp

+5 −3
Original line number Diff line number Diff line
@@ -390,7 +390,8 @@ SDValue VectorLegalizer::Promote(SDValue Op) { 
      if (Op.getOperand(j)

              .getValueType()

              .getVectorElementType()

              .isFloatingPoint())

              .isFloatingPoint() &&

          NVT.isVector() && NVT.getVectorElementType().isFloatingPoint())

        Operands[j] = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Op.getOperand(j));

      else

        Operands[j] = DAG.getNode(ISD::BITCAST, dl, NVT, Op.getOperand(j));
@@ -399,8 +400,9 @@ SDValue VectorLegalizer::Promote(SDValue Op) { 
  }



  Op = DAG.getNode(Op.getOpcode(), dl, NVT, Operands);

  if (VT.isFloatingPoint() ||

      (VT.isVector() && VT.getVectorElementType().isFloatingPoint()))

  if ((VT.isFloatingPoint() && NVT.isFloatingPoint()) ||

      (VT.isVector() && VT.getVectorElementType().isFloatingPoint() &&

       NVT.isVector() && NVT.getVectorElementType().isFloatingPoint()))

    return DAG.getNode(ISD::FP_ROUND, dl, VT, Op, DAG.getIntPtrConstant(0));

  else

    return DAG.getNode(ISD::BITCAST, dl, VT, Op);

llvm/test/CodeGen/PowerPC/vsel-prom.ll

0 → 100644
+23 −0
Original line number Diff line number Diff line 
; RUN: llc -mcpu=pwr7 < %s | FileCheck %s

target datalayout = "E-m:e-i64:64-n32:64"

target triple = "powerpc64-unknown-linux-gnu"



; Function Attrs: nounwind

define void @Compute_Lateral() #0 {

entry:

  br i1 undef, label %if.then, label %if.end



if.then:                                          ; preds = %entry

  unreachable



if.end:                                           ; preds = %entry

  %0 = select i1 undef, <2 x double> undef, <2 x double> zeroinitializer

  %1 = extractelement <2 x double> %0, i32 1

  store double %1, double* undef, align 8

  ret void



; CHECK-LABEL: @Compute_Lateral

}



attributes #0 = { nounwind }