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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2013-02-04 15:19:33 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2013-02-04 15:19:33 +0000 |
| commit | a220aeb58f30a6b3fc991883e8107d5e1198c53b (patch) | |
| tree | c8a3fea7ba6af0b3f32fc4651a64edb3d12d57c7 | |
| parent | 9fa9251bbad191feb52273b0f3d44531a5fd78a0 (diff) | |
| download | llvm-a220aeb58f30a6b3fc991883e8107d5e1198c53b.tar.gz llvm-a220aeb58f30a6b3fc991883e8107d5e1198c53b.tar.bz2 llvm-a220aeb58f30a6b3fc991883e8107d5e1198c53b.tar.xz | |
X86: Open up some opportunities for constant folding by postponing shift lowering.
Fixes PR15141.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174327 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 6 | ||||
| -rw-r--r-- | test/CodeGen/X86/avx-shift.ll | 10 |
2 files changed, 12 insertions, 4 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 5b3f06689f..496202380a 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -11583,8 +11583,7 @@ SDValue X86TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) const { // Lower SHL with variable shift amount. if (VT == MVT::v4i32 && Op->getOpcode() == ISD::SHL) { - Op = DAG.getNode(X86ISD::VSHLI, dl, VT, Op.getOperand(1), - DAG.getConstant(23, MVT::i32)); + Op = DAG.getNode(ISD::SHL, dl, VT, Amt, DAG.getConstant(23, VT)); Op = DAG.getNode(ISD::ADD, dl, VT, Op, DAG.getConstant(0x3f800000U, VT)); Op = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, Op); @@ -11595,8 +11594,7 @@ SDValue X86TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) const { assert(Subtarget->hasSSE2() && "Need SSE2 for pslli/pcmpeq."); // a = a << 5; - Op = DAG.getNode(X86ISD::VSHLI, dl, MVT::v8i16, Op.getOperand(1), - DAG.getConstant(5, MVT::i32)); + Op = DAG.getNode(ISD::SHL, dl, VT, Amt, DAG.getConstant(5, VT)); Op = DAG.getNode(ISD::BITCAST, dl, VT, Op); // Turn 'a' into a mask suitable for VSELECT diff --git a/test/CodeGen/X86/avx-shift.ll b/test/CodeGen/X86/avx-shift.ll index 681747b844..b0bff454c1 100644 --- a/test/CodeGen/X86/avx-shift.ll +++ b/test/CodeGen/X86/avx-shift.ll @@ -112,6 +112,16 @@ define <8 x i32> @vshift08(<8 x i32> %a) nounwind { ret <8 x i32> %bitop } +; PR15141 +; CHECK: _vshift13: +; CHECK-NOT: vpsll +; CHECK: vcvttps2dq +; CHECK-NEXT: vpmulld +define <4 x i32> @vshift13(<4 x i32> %in) { + %T = shl <4 x i32> %in, <i32 0, i32 1, i32 2, i32 4> + ret <4 x i32> %T +} + ;;; Uses shifts for sign extension ; CHECK: _sext_v16i16 ; CHECK: vpsllw |