[X86][Costmodel] Load/store i8 Stride=6 VF=2 interleaving costs

[lebedev.ri]

Summary

The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3

For load we have:
https://godbolt.org/z/jvj6jzns5 - for intels Block RThroughput: =6.0; for ryzens, Block RThroughput: <=3.0
So pick cost of 6.

For store we have:
https://godbolt.org/z/ros7eebMP - for intels Block RThroughput: =7.0; for ryzens, Block RThroughput: <=3.0
So pick cost of 7.

I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.

[RKSimon]

LGTM

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

static const CostTblEntry AVX2InterleavedLoadTbl[] = {
       {4, MVT::v32i8, 56}, // (load 128i8 and) deinterleave into 4 x 32i8
 
       {4, MVT::v2i16, 6}, // (load 8i16 and) deinterleave into 4 x 2i16
       {4, MVT::v4i16, 17}, // (load 16i16 and) deinterleave into 4 x 4i16
       {4, MVT::v8i16, 33}, // (load 32i16 and) deinterleave into 4 x 8i16
       {4, MVT::v16i16, 75}, // (load 64i16 and) deinterleave into 4 x 16i16
       {4, MVT::v32i16, 150}, // (load 128i16 and) deinterleave into 4 x 32i16
 
+      {6, MVT::v2i8, 6}, // (load 12i8 and) deinterleave into 6 x 2i8
+
       {6, MVT::v2i16, 13}, // (load 12i16 and) deinterleave into 6 x 2i16
       {6, MVT::v4i16, 9}, // (load 24i16 and) deinterleave into 6 x 4i16
       {6, MVT::v8i16, 39}, // (load 48i16 and) deinterleave into 6 x 8i16
       {6, MVT::v16i16, 106}, // (load 96i16 and) deinterleave into 6 x 16i16
 
       {8, MVT::v8i32, 40} // (load 64i32 and) deinterleave into 8 x 8i32
   };
 
static const CostTblEntry AVX2InterleavedStoreTbl[] = {
       {4, MVT::v32i8, 12}, // interleave 4 x 32i8 into 128i8 (and store)
 
       {4, MVT::v2i16, 2},  // interleave 4 x 2i16 into 8i16 (and store)
       {4, MVT::v4i16, 6},  // interleave 4 x 4i16 into 16i16 (and store)
       {4, MVT::v8i16, 10},  // interleave 4 x 8i16 into 32i16 (and store)
       {4, MVT::v16i16, 32},  // interleave 4 x 16i16 into 64i16 (and store)
       {4, MVT::v32i16, 64},  // interleave 4 x 32i16 into 128i16 (and store)
 
+      {6, MVT::v2i8, 7},  // interleave 6 x 2i8 into 12i8 (and store)
+
       {6, MVT::v2i16, 10},  // interleave 6 x 2i16 into 12i16 (and store)
       {6, MVT::v4i16, 15},  // interleave 6 x 4i16 into 24i16 (and store)
       {6, MVT::v8i16, 21},  // interleave 6 x 8i16 into 48i16 (and store)
       {6, MVT::v16i16, 58},  // interleave 6 x 16i16 into 96i16 (and store)
   };
 
   if (Opcode == Instruction::Load) {
     if (const auto *Entry =

llvm/test/Analysis/CostModel/X86/interleaved-load-i8-stride-6.ll

 ; AVX1: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX1: LV: Found an estimated cost of 27 for VF 2 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX1: LV: Found an estimated cost of 59 for VF 4 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX1: LV: Found an estimated cost of 114 for VF 8 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX1: LV: Found an estimated cost of 243 for VF 16 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX1: LV: Found an estimated cost of 498 for VF 32 For instruction:   %v0 = load i8, i8* %in0, align 1
 ;
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i8, i8* %in0, align 1
-; AVX2: LV: Found an estimated cost of 27 for VF 2 For instruction:   %v0 = load i8, i8* %in0, align 1
+; AVX2: LV: Found an estimated cost of 9 for VF 2 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX2: LV: Found an estimated cost of 59 for VF 4 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX2: LV: Found an estimated cost of 114 for VF 8 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX2: LV: Found an estimated cost of 243 for VF 16 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX2: LV: Found an estimated cost of 498 for VF 32 For instruction:   %v0 = load i8, i8* %in0, align 1
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX512: LV: Found an estimated cost of 7 for VF 2 For instruction:   %v0 = load i8, i8* %in0, align 1
 ; AVX512: LV: Found an estimated cost of 25 for VF 4 For instruction:   %v0 = load i8, i8* %in0, align 1

llvm/test/Analysis/CostModel/X86/interleaved-store-i8-stride-6.ll

 ; AVX1: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX1: LV: Found an estimated cost of 27 for VF 2 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX1: LV: Found an estimated cost of 54 for VF 4 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX1: LV: Found an estimated cost of 101 for VF 8 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX1: LV: Found an estimated cost of 201 for VF 16 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX1: LV: Found an estimated cost of 498 for VF 32 For instruction:   store i8 %v5, i8* %out5, align 1
 ;
 ; AVX2: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i8 %v5, i8* %out5, align 1
-; AVX2: LV: Found an estimated cost of 27 for VF 2 For instruction:   store i8 %v5, i8* %out5, align 1
+; AVX2: LV: Found an estimated cost of 10 for VF 2 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX2: LV: Found an estimated cost of 54 for VF 4 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX2: LV: Found an estimated cost of 101 for VF 8 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX2: LV: Found an estimated cost of 201 for VF 16 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX2: LV: Found an estimated cost of 498 for VF 32 For instruction:   store i8 %v5, i8* %out5, align 1
 ;
 ; AVX512: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX512: LV: Found an estimated cost of 18 for VF 2 For instruction:   store i8 %v5, i8* %out5, align 1
 ; AVX512: LV: Found an estimated cost of 38 for VF 4 For instruction:   store i8 %v5, i8* %out5, align 1