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AMDGPU: Fix cost model for 16-bit operations on gfx8 #141943

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Jun 17, 2025
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AMDGPU: Fix cost model for 16-bit operations on gfx8 #141943

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2 changes: 1 addition & 1 deletion llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
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Expand Up @@ -721,7 +721,7 @@ GCNTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
if (SLT == MVT::f64)
return LT.first * NElts * get64BitInstrCost(CostKind);

if ((ST->has16BitInsts() && (SLT == MVT::f16 || SLT == MVT::i16)) ||
if ((ST->hasVOP3PInsts() && (SLT == MVT::f16 || SLT == MVT::i16)) ||
(ST->hasPackedFP32Ops() && SLT == MVT::f32))
NElts = (NElts + 1) / 2;

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24 changes: 12 additions & 12 deletions llvm/test/Analysis/CostModel/AMDGPU/canonicalize.ll
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Expand Up @@ -22,12 +22,12 @@ define void @canonicalize_f16() {
;
; GFX8-LABEL: 'canonicalize_f16'
; GFX8-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %f16 = call half @llvm.canonicalize.f16(half undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %v2f16 = call <2 x half> @llvm.canonicalize.v2f16(<2 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v3f16 = call <3 x half> @llvm.canonicalize.v3f16(<3 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v4f16 = call <4 x half> @llvm.canonicalize.v4f16(<4 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v5f16 = call <5 x half> @llvm.canonicalize.v5f16(<5 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v16f16 = call <16 x half> @llvm.canonicalize.v16f16(<16 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 48 for instruction: %v17f16 = call <17 x half> @llvm.canonicalize.v17f16(<17 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v2f16 = call <2 x half> @llvm.canonicalize.v2f16(<2 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v3f16 = call <3 x half> @llvm.canonicalize.v3f16(<3 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v4f16 = call <4 x half> @llvm.canonicalize.v4f16(<4 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v5f16 = call <5 x half> @llvm.canonicalize.v5f16(<5 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v16f16 = call <16 x half> @llvm.canonicalize.v16f16(<16 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 96 for instruction: %v17f16 = call <17 x half> @llvm.canonicalize.v17f16(<17 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 10 for instruction: ret void
;
; GFX9-LABEL: 'canonicalize_f16'
Expand Down Expand Up @@ -62,12 +62,12 @@ define void @canonicalize_f16() {
;
; GFX8-SIZE-LABEL: 'canonicalize_f16'
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %f16 = call half @llvm.canonicalize.f16(half undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %v2f16 = call <2 x half> @llvm.canonicalize.v2f16(<2 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v3f16 = call <3 x half> @llvm.canonicalize.v3f16(<3 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v4f16 = call <4 x half> @llvm.canonicalize.v4f16(<4 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v5f16 = call <5 x half> @llvm.canonicalize.v5f16(<5 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v16f16 = call <16 x half> @llvm.canonicalize.v16f16(<16 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 48 for instruction: %v17f16 = call <17 x half> @llvm.canonicalize.v17f16(<17 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v2f16 = call <2 x half> @llvm.canonicalize.v2f16(<2 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v3f16 = call <3 x half> @llvm.canonicalize.v3f16(<3 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v4f16 = call <4 x half> @llvm.canonicalize.v4f16(<4 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v5f16 = call <5 x half> @llvm.canonicalize.v5f16(<5 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v16f16 = call <16 x half> @llvm.canonicalize.v16f16(<16 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 96 for instruction: %v17f16 = call <17 x half> @llvm.canonicalize.v17f16(<17 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: ret void
;
; GFX9-SIZE-LABEL: 'canonicalize_f16'
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28 changes: 14 additions & 14 deletions llvm/test/Analysis/CostModel/AMDGPU/copysign.ll
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Expand Up @@ -23,13 +23,13 @@ define void @copysign_f16() {
;
; GFX8-LABEL: 'copysign_f16'
; GFX8-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %f16 = call half @llvm.copysign.f16(half undef, half undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %v2f16 = call <2 x half> @llvm.copysign.v2f16(<2 x half> undef, <2 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v3f16 = call <3 x half> @llvm.copysign.v3f16(<3 x half> undef, <3 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v4f16 = call <4 x half> @llvm.copysign.v4f16(<4 x half> undef, <4 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v5f16 = call <5 x half> @llvm.copysign.v5f16(<5 x half> undef, <5 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v8f16 = call <8 x half> @llvm.copysign.v8f16(<8 x half> undef, <8 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v9f16 = call <9 x half> @llvm.copysign.v9f16(<9 x half> undef, <9 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v16f16 = call <16 x half> @llvm.copysign.v16f16(<16 x half> undef, <16 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v2f16 = call <2 x half> @llvm.copysign.v2f16(<2 x half> undef, <2 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v3f16 = call <3 x half> @llvm.copysign.v3f16(<3 x half> undef, <3 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v4f16 = call <4 x half> @llvm.copysign.v4f16(<4 x half> undef, <4 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v5f16 = call <5 x half> @llvm.copysign.v5f16(<5 x half> undef, <5 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v8f16 = call <8 x half> @llvm.copysign.v8f16(<8 x half> undef, <8 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v9f16 = call <9 x half> @llvm.copysign.v9f16(<9 x half> undef, <9 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v16f16 = call <16 x half> @llvm.copysign.v16f16(<16 x half> undef, <16 x half> undef)
; GFX8-NEXT: Cost Model: Found an estimated cost of 10 for instruction: ret void
;
; GFX9-LABEL: 'copysign_f16'
Expand Down Expand Up @@ -67,13 +67,13 @@ define void @copysign_f16() {
;
; GFX8-SIZE-LABEL: 'copysign_f16'
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %f16 = call half @llvm.copysign.f16(half undef, half undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %v2f16 = call <2 x half> @llvm.copysign.v2f16(<2 x half> undef, <2 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v3f16 = call <3 x half> @llvm.copysign.v3f16(<3 x half> undef, <3 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v4f16 = call <4 x half> @llvm.copysign.v4f16(<4 x half> undef, <4 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v5f16 = call <5 x half> @llvm.copysign.v5f16(<5 x half> undef, <5 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v8f16 = call <8 x half> @llvm.copysign.v8f16(<8 x half> undef, <8 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v9f16 = call <9 x half> @llvm.copysign.v9f16(<9 x half> undef, <9 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v16f16 = call <16 x half> @llvm.copysign.v16f16(<16 x half> undef, <16 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v2f16 = call <2 x half> @llvm.copysign.v2f16(<2 x half> undef, <2 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v3f16 = call <3 x half> @llvm.copysign.v3f16(<3 x half> undef, <3 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v4f16 = call <4 x half> @llvm.copysign.v4f16(<4 x half> undef, <4 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v5f16 = call <5 x half> @llvm.copysign.v5f16(<5 x half> undef, <5 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %v8f16 = call <8 x half> @llvm.copysign.v8f16(<8 x half> undef, <8 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v9f16 = call <9 x half> @llvm.copysign.v9f16(<9 x half> undef, <9 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %v16f16 = call <16 x half> @llvm.copysign.v16f16(<16 x half> undef, <16 x half> undef)
; GFX8-SIZE-NEXT: Cost Model: Found an estimated cost of 1 for instruction: ret void
;
; GFX9-SIZE-LABEL: 'copysign_f16'
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12 changes: 7 additions & 5 deletions llvm/test/Transforms/SLPVectorizer/AMDGPU/slp-v2f16.ll
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Expand Up @@ -271,7 +271,9 @@ bb:
}

; GCN-LABEL: @copysign_combine_v2f16
; GCN: call <2 x half> @llvm.copysign.v2f16(
; GFX8: call half @llvm.copysign.f16(
; GFX8: call half @llvm.copysign.f16(
; GFX9: call <2 x half> @llvm.copysign.v2f16(
define void @copysign_combine_v2f16(ptr addrspace(1) %arg, half %sign) {
bb:
%tmp = tail call i32 @llvm.amdgcn.workitem.id.x()
Expand All @@ -290,8 +292,6 @@ bb:

; FIXME: Should always vectorize
; GCN-LABEL: @copysign_combine_v4f16
; GCN: call <2 x half> @llvm.copysign.v2f16(

; GFX8: call half @llvm.copysign.f16(
; GFX8: call half @llvm.copysign.f16(

Expand Down Expand Up @@ -327,8 +327,10 @@ bb:
}

; GCN-LABEL: @canonicalize_combine_v4f16
; GCN: call <2 x half> @llvm.canonicalize.v2f16(
; GCN: call <2 x half> @llvm.canonicalize.v2f16(
; GFX8: call half @llvm.canonicalize.f16(
; GFX8: call half @llvm.canonicalize.f16(

; GFX9: call <2 x half> @llvm.canonicalize.v2f16(
define void @canonicalize_combine_v4f16(ptr addrspace(1) %arg) {
bb:
%tmp = tail call i32 @llvm.amdgcn.workitem.id.x()
Expand Down
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