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Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
-rw-r--r--llvm/lib/Target/X86/X86ISelLowering.cpp47
1 files changed, 29 insertions, 18 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 161cf17bfd1..d50cce752cf 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -13776,24 +13776,36 @@ X86TargetLowering::LowerEXTRACT_VECTOR_ELT(SDValue Op,
return ExtractBitFromMaskVector(Op, DAG);
if (!isa<ConstantSDNode>(Idx)) {
- if (VecVT.is512BitVector() ||
- (VecVT.is256BitVector() && Subtarget.hasInt256() &&
- VecVT.getScalarSizeInBits() == 32)) {
-
- MVT MaskEltVT =
- MVT::getIntegerVT(VecVT.getScalarSizeInBits());
- MVT MaskVT = MVT::getVectorVT(MaskEltVT, VecVT.getSizeInBits() /
- MaskEltVT.getSizeInBits());
+ // Its more profitable to go through memory (1 cycles throughput)
+ // than using VMOVD + VPERMV/PSHUFB sequence ( 2/3 cycles throughput)
+ // IACA tool was used to get performace estimation
+ // (https://software.intel.com/en-us/articles/intel-architecture-code-analyzer)
+ //
+ // exmample : extractelement <16 x i8> %a, i32 %i
+ //
+ // Block Throughput: 3.00 Cycles
+ // Throughput Bottleneck: Port5
+ //
+ // | Num Of | Ports pressure in cycles | |
+ // | Uops | 0 - DV | 5 | 6 | 7 | |
+ // ---------------------------------------------
+ // | 1 | | 1.0 | | | CP | vmovd xmm1, edi
+ // | 1 | | 1.0 | | | CP | vpshufb xmm0, xmm0, xmm1
+ // | 2 | 1.0 | 1.0 | | | CP | vpextrb eax, xmm0, 0x0
+ // Total Num Of Uops: 4
+ //
+ //
+ // Block Throughput: 1.00 Cycles
+ // Throughput Bottleneck: PORT2_AGU, PORT3_AGU, Port4
+ //
+ // | | Ports pressure in cycles | |
+ // |Uops| 1 | 2 - D |3 - D | 4 | 5 | |
+ // ---------------------------------------------------------
+ // |2^ | | 0.5 | 0.5 |1.0| |CP| vmovaps xmmword ptr [rsp-0x18], xmm0
+ // |1 |0.5| | | |0.5| | lea rax, ptr [rsp-0x18]
+ // |1 | |0.5, 0.5|0.5, 0.5| | |CP| mov al, byte ptr [rdi+rax*1]
+ // Total Num Of Uops: 4
- Idx = DAG.getZExtOrTrunc(Idx, dl, MaskEltVT);
- auto PtrVT = getPointerTy(DAG.getDataLayout());
- SDValue Mask = DAG.getNode(X86ISD::VINSERT, dl, MaskVT,
- getZeroVector(MaskVT, Subtarget, DAG, dl), Idx,
- DAG.getConstant(0, dl, PtrVT));
- SDValue Perm = DAG.getNode(X86ISD::VPERMV, dl, VecVT, Mask, Vec);
- return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, Op.getValueType(), Perm,
- DAG.getConstant(0, dl, PtrVT));
- }
return SDValue();
}
@@ -23937,7 +23949,6 @@ const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const {
case X86ISD::VTRUNCSTOREUS: return "X86ISD::VTRUNCSTOREUS";
case X86ISD::VMTRUNCSTORES: return "X86ISD::VMTRUNCSTORES";
case X86ISD::VMTRUNCSTOREUS: return "X86ISD::VMTRUNCSTOREUS";
- case X86ISD::VINSERT: return "X86ISD::VINSERT";
case X86ISD::VFPEXT: return "X86ISD::VFPEXT";
case X86ISD::VFPEXT_RND: return "X86ISD::VFPEXT_RND";
case X86ISD::VFPEXTS_RND: return "X86ISD::VFPEXTS_RND";
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