[X86][Costmodel] Load/store i16 Stride=4 VF=8 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/dd8T5P471 - for intels Block RThroughput: =33.0; for ryzens, Block RThroughput: <=14.5
So pick cost of 33.

For store we have:
https://godbolt.org/z/zPxcKWhn4 - for intels Block RThroughput: =10.0; for ryzens, Block RThroughput: <=6.0
So pick cost of 10.

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::v2i8, 12},  // (load 8i8 and) deinterleave into 4 x 2i8
       {4, MVT::v4i8, 4},   // (load 16i8 and) deinterleave into 4 x 4i8
       {4, MVT::v8i8, 20},  // (load 32i8 and) deinterleave into 4 x 8i8
       {4, MVT::v16i8, 39}, // (load 64i8 and) deinterleave into 4 x 16i8
       {4, MVT::v32i8, 80}, // (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
 
       {8, MVT::v8i32, 40} // (load 64i32 and) deinterleave into 8 x 8i32
   };
 
   static const CostTblEntry AVX2InterleavedStoreTbl[] = {
       {2, MVT::v2i16, 1}, // interleave 2 x 2i16 into 4i16 (and store)
       {2, MVT::v4i16, 1}, // interleave 2 x 4i16 into 8i16 (and store)
       {2, MVT::v8i16, 3}, // interleave 2 x 8i16 into 16i16 (and store)
static const CostTblEntry AVX2InterleavedStoreTbl[] = {
       {4, MVT::v2i8, 12},  // interleave 4 x 2i8 into 8i8 (and store)
       {4, MVT::v4i8, 9},   // interleave 4 x 4i8 into 16i8 (and store)
       {4, MVT::v8i8, 10},  // interleave 4 x 8i8 into 32i8 (and store)
       {4, MVT::v16i8, 10}, // interleave 4 x 16i8 into 64i8 (and store)
       {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)
   };
 
   if (Opcode == Instruction::Load) {
     if (const auto *Entry =
             CostTableLookup(AVX2InterleavedLoadTbl, Factor, ETy.getSimpleVT()))
       return MemOpCosts + Entry->Cost;
   } else {
     assert(Opcode == Instruction::Store &&

llvm/test/Analysis/CostModel/X86/interleaved-load-i16-stride-4.ll

 ; RUN: opt -loop-vectorize -vectorizer-maximize-bandwidth -S -mattr=+avx2 --debug-only=loop-vectorize < %s 2>&1 | FileCheck %s
 ; REQUIRES: asserts
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @A = global [1024 x i16] zeroinitializer, align 128
 @B = global [1024 x i8] zeroinitializer, align 128
 
 ; CHECK: LV: Checking a loop in "test"
 ; CHECK: LV: Found an estimated cost of 1 for VF 1 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 7 for VF 2 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 18 for VF 4 For instruction:   %v0 = load i16, i16* %in0, align 2
-; CHECK: LV: Found an estimated cost of 82 for VF 8 For instruction:   %v0 = load i16, i16* %in0, align 2
+; CHECK: LV: Found an estimated cost of 35 for VF 8 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 228 for VF 16 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 456 for VF 32 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK-NOT: LV: Found an estimated cost of {{[0-9]+}} for VF {{[0-9]+}} For instruction:   %v0 = load i16, i16* %in0, align 2
 
 define void @test() {
 entry:
   br label %for.body
 

llvm/test/Analysis/CostModel/X86/interleaved-store-i16-stride-4.ll

 ; RUN: opt -loop-vectorize -vectorizer-maximize-bandwidth -S -mattr=+avx2 --debug-only=loop-vectorize < %s 2>&1 | FileCheck %s
 ; REQUIRES: asserts
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @A = global [1024 x i8] zeroinitializer, align 128
 @B = global [1024 x i16] zeroinitializer, align 128
 
 ; CHECK: LV: Checking a loop in "test"
 ; CHECK: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i16 %v3, i16* %out3, align 2
 ; CHECK: LV: Found an estimated cost of 3 for VF 2 For instruction:   store i16 %v3, i16* %out3, align 2
 ; CHECK: LV: Found an estimated cost of 7 for VF 4 For instruction:   store i16 %v3, i16* %out3, align 2
-; CHECK: LV: Found an estimated cost of 98 for VF 8 For instruction:   store i16 %v3, i16* %out3, align 2
+; CHECK: LV: Found an estimated cost of 12 for VF 8 For instruction:   store i16 %v3, i16* %out3, align 2
 ; CHECK: LV: Found an estimated cost of 228 for VF 16 For instruction:   store i16 %v3, i16* %out3, align 2
 ; CHECK: LV: Found an estimated cost of 456 for VF 32 For instruction:   store i16 %v3, i16* %out3, align 2
 ; CHECK-NOT: LV: Found an estimated cost of {{[0-9]+}} for VF {{[0-9]+}} For instruction:   store i16 %v3, i16* %out3, align 2
 
 define void @test() {
 entry:
   br label %for.body