[llvm] 2db7b31 - [AArch64] Add BF16 fpext and fptrunc costs. (#119524)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 7 01:39:12 PST 2025
Author: David Green
Date: 2025-01-07T09:39:08Z
New Revision: 2db7b314da367e1a6bf8cf34df16f9ad5ad62f5e
URL: https://github.com/llvm/llvm-project/commit/2db7b314da367e1a6bf8cf34df16f9ad5ad62f5e
DIFF: https://github.com/llvm/llvm-project/commit/2db7b314da367e1a6bf8cf34df16f9ad5ad62f5e.diff
LOG: [AArch64] Add BF16 fpext and fptrunc costs. (#119524)
This expands the recently added fp16 fpext and fpround costs to bf16.
Some of the costs are taken from the rough number of instructions
needed, some are a little aspirational.
https://godbolt.org/z/bGEEd1vsW
Added:
Modified:
llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
llvm/test/Analysis/CostModel/AArch64/cast.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 5abe69ef1c9ccf..0e05bdab435920 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -2761,6 +2761,21 @@ InstructionCost AArch64TTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
return AdjustCost(
BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I));
+ static const TypeConversionCostTblEntry BF16Tbl[] = {
+ {ISD::FP_ROUND, MVT::bf16, MVT::f32, 1}, // bfcvt
+ {ISD::FP_ROUND, MVT::bf16, MVT::f64, 1}, // bfcvt
+ {ISD::FP_ROUND, MVT::v4bf16, MVT::v4f32, 1}, // bfcvtn
+ {ISD::FP_ROUND, MVT::v8bf16, MVT::v8f32, 2}, // bfcvtn+bfcvtn2
+ {ISD::FP_ROUND, MVT::v2bf16, MVT::v2f64, 2}, // bfcvtn+fcvtn
+ {ISD::FP_ROUND, MVT::v4bf16, MVT::v4f64, 3}, // fcvtn+fcvtl2+bfcvtn
+ {ISD::FP_ROUND, MVT::v8bf16, MVT::v8f64, 6}, // 2 * fcvtn+fcvtn2+bfcvtn
+ };
+
+ if (ST->hasBF16())
+ if (const auto *Entry = ConvertCostTableLookup(
+ BF16Tbl, ISD, DstTy.getSimpleVT(), SrcTy.getSimpleVT()))
+ return AdjustCost(Entry->Cost);
+
static const TypeConversionCostTblEntry ConversionTbl[] = {
{ISD::TRUNCATE, MVT::v2i8, MVT::v2i64, 1}, // xtn
{ISD::TRUNCATE, MVT::v2i16, MVT::v2i64, 1}, // xtn
@@ -2848,6 +2863,14 @@ InstructionCost AArch64TTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
{ISD::FP_EXTEND, MVT::v2f64, MVT::v2f16, 2}, // fcvtl+fcvtl
{ISD::FP_EXTEND, MVT::v4f64, MVT::v4f16, 3}, // fcvtl+fcvtl2+fcvtl
{ISD::FP_EXTEND, MVT::v8f64, MVT::v8f16, 6}, // 2 * fcvtl+fcvtl2+fcvtl
+ // BF16 (uses shift)
+ {ISD::FP_EXTEND, MVT::f32, MVT::bf16, 1}, // shl
+ {ISD::FP_EXTEND, MVT::f64, MVT::bf16, 2}, // shl+fcvt
+ {ISD::FP_EXTEND, MVT::v4f32, MVT::v4bf16, 1}, // shll
+ {ISD::FP_EXTEND, MVT::v8f32, MVT::v8bf16, 2}, // shll+shll2
+ {ISD::FP_EXTEND, MVT::v2f64, MVT::v2bf16, 2}, // shll+fcvtl
+ {ISD::FP_EXTEND, MVT::v4f64, MVT::v4bf16, 3}, // shll+fcvtl+fcvtl2
+ {ISD::FP_EXTEND, MVT::v8f64, MVT::v8bf16, 6}, // 2 * shll+fcvtl+fcvtl2
// FP Ext and trunc
{ISD::FP_ROUND, MVT::f32, MVT::f64, 1}, // fcvt
{ISD::FP_ROUND, MVT::v2f32, MVT::v2f64, 1}, // fcvtn
@@ -2860,6 +2883,15 @@ InstructionCost AArch64TTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
{ISD::FP_ROUND, MVT::v2f16, MVT::v2f64, 2}, // fcvtn+fcvtn
{ISD::FP_ROUND, MVT::v4f16, MVT::v4f64, 3}, // fcvtn+fcvtn2+fcvtn
{ISD::FP_ROUND, MVT::v8f16, MVT::v8f64, 6}, // 2 * fcvtn+fcvtn2+fcvtn
+ // BF16 (more complex, with +bf16 is handled above)
+ {ISD::FP_ROUND, MVT::bf16, MVT::f32, 8}, // Expansion is ~8 insns
+ {ISD::FP_ROUND, MVT::bf16, MVT::f64, 9}, // fcvtn + above
+ {ISD::FP_ROUND, MVT::v2bf16, MVT::v2f32, 8},
+ {ISD::FP_ROUND, MVT::v4bf16, MVT::v4f32, 8},
+ {ISD::FP_ROUND, MVT::v8bf16, MVT::v8f32, 15},
+ {ISD::FP_ROUND, MVT::v2bf16, MVT::v2f64, 9},
+ {ISD::FP_ROUND, MVT::v4bf16, MVT::v4f64, 10},
+ {ISD::FP_ROUND, MVT::v8bf16, MVT::v8f64, 19},
// LowerVectorINT_TO_FP:
{ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i32, 1},
diff --git a/llvm/test/Analysis/CostModel/AArch64/cast.ll b/llvm/test/Analysis/CostModel/AArch64/cast.ll
index c363b58d939e8f..b82c2f110d8c8c 100644
--- a/llvm/test/Analysis/CostModel/AArch64/cast.ll
+++ b/llvm/test/Analysis/CostModel/AArch64/cast.ll
@@ -1,6 +1,7 @@
; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
; RUN: opt -passes="print<cost-model>" 2>&1 -disable-output -mtriple=aarch64 %s | FileCheck --check-prefixes=CHECK,CHECK-NOFP16 %s
; RUN: opt -passes="print<cost-model>" 2>&1 -disable-output -mtriple=aarch64 -mattr=+fullfp16 %s | FileCheck --check-prefixes=CHECK,CHECK-FP16 %s
+; RUN: opt -passes="print<cost-model>" 2>&1 -disable-output -mtriple=aarch64 -mattr=+fullfp16,+bf16 %s | FileCheck --check-prefixes=CHECK,CHECK-FP16,CHECK-BF16 %s
target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
@@ -1237,28 +1238,51 @@ define void @fp16cast() {
}
define void @bf16cast() {
-; CHECK-LABEL: 'bf16cast'
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extf16f32 = fpext bfloat undef to float
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv2f16f32 = fpext <2 x bfloat> undef to <2 x float>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv4f16f32 = fpext <4 x bfloat> undef to <4 x float>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 3 for instruction: %extv8f16f32 = fpext <8 x bfloat> undef to <8 x float>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %extv16f16f32 = fpext <16 x bfloat> undef to <16 x float>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extf16f64 = fpext bfloat undef to double
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv2f16f64 = fpext <2 x bfloat> undef to <2 x double>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 3 for instruction: %extv4f16f64 = fpext <4 x bfloat> undef to <4 x double>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 7 for instruction: %extv8f16f64 = fpext <8 x bfloat> undef to <8 x double>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 14 for instruction: %extv16f16f64 = fpext <16 x bfloat> undef to <16 x double>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncf16f32 = fptrunc float undef to bfloat
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncv2f16f32 = fptrunc <2 x float> undef to <2 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %truncv4f16f32 = fptrunc <4 x float> undef to <4 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 33 for instruction: %truncv8f16f32 = fptrunc <8 x float> undef to <8 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 66 for instruction: %truncv16f16f32 = fptrunc <16 x float> undef to <16 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncf16f64 = fptrunc double undef to bfloat
-; CHECK-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %truncv2f16f64 = fptrunc <2 x double> undef to <2 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 13 for instruction: %truncv4f16f64 = fptrunc <4 x double> undef to <4 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 27 for instruction: %truncv8f16f64 = fptrunc <8 x double> undef to <8 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 54 for instruction: %truncv16f16f64 = fptrunc <16 x double> undef to <16 x bfloat>
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
+; CHECK-NOFP16-LABEL: 'bf16cast'
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extf16f32 = fpext bfloat undef to float
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv2f16f32 = fpext <2 x bfloat> undef to <2 x float>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv4f16f32 = fpext <4 x bfloat> undef to <4 x float>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extv8f16f32 = fpext <8 x bfloat> undef to <8 x float>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %extv16f16f32 = fpext <16 x bfloat> undef to <16 x float>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extf16f64 = fpext bfloat undef to double
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extv2f16f64 = fpext <2 x bfloat> undef to <2 x double>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 3 for instruction: %extv4f16f64 = fpext <4 x bfloat> undef to <4 x double>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %extv8f16f64 = fpext <8 x bfloat> undef to <8 x double>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 12 for instruction: %extv16f16f64 = fpext <16 x bfloat> undef to <16 x double>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %truncf16f32 = fptrunc float undef to bfloat
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %truncv2f16f32 = fptrunc <2 x float> undef to <2 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %truncv4f16f32 = fptrunc <4 x float> undef to <4 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 15 for instruction: %truncv8f16f32 = fptrunc <8 x float> undef to <8 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 30 for instruction: %truncv16f16f32 = fptrunc <16 x float> undef to <16 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 9 for instruction: %truncf16f64 = fptrunc double undef to bfloat
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 9 for instruction: %truncv2f16f64 = fptrunc <2 x double> undef to <2 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 10 for instruction: %truncv4f16f64 = fptrunc <4 x double> undef to <4 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 19 for instruction: %truncv8f16f64 = fptrunc <8 x double> undef to <8 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 38 for instruction: %truncv16f16f64 = fptrunc <16 x double> undef to <16 x bfloat>
+; CHECK-NOFP16-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+; CHECK-BF16-LABEL: 'bf16cast'
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extf16f32 = fpext bfloat undef to float
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv2f16f32 = fpext <2 x bfloat> undef to <2 x float>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %extv4f16f32 = fpext <4 x bfloat> undef to <4 x float>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extv8f16f32 = fpext <8 x bfloat> undef to <8 x float>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %extv16f16f32 = fpext <16 x bfloat> undef to <16 x float>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extf16f64 = fpext bfloat undef to double
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %extv2f16f64 = fpext <2 x bfloat> undef to <2 x double>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 3 for instruction: %extv4f16f64 = fpext <4 x bfloat> undef to <4 x double>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %extv8f16f64 = fpext <8 x bfloat> undef to <8 x double>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 12 for instruction: %extv16f16f64 = fpext <16 x bfloat> undef to <16 x double>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncf16f32 = fptrunc float undef to bfloat
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %truncv2f16f32 = fptrunc <2 x float> undef to <2 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncv4f16f32 = fptrunc <4 x float> undef to <4 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %truncv8f16f32 = fptrunc <8 x float> undef to <8 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %truncv16f16f32 = fptrunc <16 x float> undef to <16 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %truncf16f64 = fptrunc double undef to bfloat
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %truncv2f16f64 = fptrunc <2 x double> undef to <2 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 3 for instruction: %truncv4f16f64 = fptrunc <4 x double> undef to <4 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %truncv8f16f64 = fptrunc <8 x double> undef to <8 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 12 for instruction: %truncv16f16f64 = fptrunc <16 x double> undef to <16 x bfloat>
+; CHECK-BF16-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
;
%extf16f32 = fpext bfloat undef to float
%extv2f16f32 = fpext <2 x bfloat> undef to <2 x float>
More information about the llvm-commits
mailing list