[X86][Costmodel] Load/store i16 Stride=6 VF=2 interleaving costs

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/bhscej4WM - for intels `Block RThroughput: =13.0`; for ryzens, `Block RThroughput: <=7.0`
So pick cost of `13`.

For store we have:
https://godbolt.org/z/Yf4Pfnxbq - for intels `Block RThroughput: =10.0`; for ryzens, `Block RThroughput: <=3.5`
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.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D110590

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

@@ -5091,6 +5091,8 @@ InstructionCost X86TTIImpl::getInterleavedMemoryOpCostAVX2(
       {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::v2i16, 13}, // (load 12i16 and) deinterleave into 6 x 2i16
+
       {8, MVT::v8i32, 40} // (load 64i32 and) deinterleave into 8 x 8i32
   };
 
@@ -5120,6 +5122,8 @@ InstructionCost X86TTIImpl::getInterleavedMemoryOpCostAVX2(
       {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::v2i16, 10},  // interleave 6 x 2i16 into 12i16 (and store)
   };
 
   if (Opcode == Instruction::Load) {

llvm/test/Analysis/CostModel/X86/interleaved-load-i16-stride-6.ll

@@ -9,7 +9,7 @@ target triple = "x86_64-unknown-linux-gnu"
 
 ; 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 31 for VF 2 For instruction:   %v0 = load i16, i16* %in0, align 2
+; CHECK: LV: Found an estimated cost of 16 for VF 2 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 58 for VF 4 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 123 for VF 8 For instruction:   %v0 = load i16, i16* %in0, align 2
 ; CHECK: LV: Found an estimated cost of 342 for VF 16 For instruction:   %v0 = load i16, i16* %in0, align 2

llvm/test/Analysis/CostModel/X86/interleaved-store-i16-stride-6.ll

@@ -9,7 +9,7 @@ target triple = "x86_64-unknown-linux-gnu"
 
 ; CHECK: LV: Checking a loop in "test"
 ; CHECK: LV: Found an estimated cost of 1 for VF 1 For instruction:   store i16 %v5, i16* %out5, align 2
-; CHECK: LV: Found an estimated cost of 35 for VF 2 For instruction:   store i16 %v5, i16* %out5, align 2
+; CHECK: LV: Found an estimated cost of 13 for VF 2 For instruction:   store i16 %v5, i16* %out5, align 2
 ; CHECK: LV: Found an estimated cost of 66 for VF 4 For instruction:   store i16 %v5, i16* %out5, align 2
 ; CHECK: LV: Found an estimated cost of 147 for VF 8 For instruction:   store i16 %v5, i16* %out5, align 2
 ; CHECK: LV: Found an estimated cost of 342 for VF 16 For instruction:   store i16 %v5, i16* %out5, align 2