llvm-project/llvm/test/CodeGen/AMDGPU/fneg.f16.ll

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; RUN: llc -amdgpu-scalarize-global-loads=false -march=amdgcn -mcpu=kaveri -mtriple=amdgcn--amdhsa -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CI,CIVI %s
; RUN: llc -amdgpu-scalarize-global-loads=false -march=amdgcn -mcpu=tonga -mtriple=amdgcn--amdhsa -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,VI,CIVI,GFX89 %s
; RUN: llc -amdgpu-scalarize-global-loads=false -march=amdgcn -mcpu=gfx900 -mtriple=amdgcn--amdhsa -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX89,GFX9 %s
; FIXME: Should be able to do scalar op
; GCN-LABEL: {{^}}s_fneg_f16:
define amdgpu_kernel void @s_fneg_f16(half addrspace(1)* %out, half %in) #0 {
%fneg = fsub half -0.0, %in
store half %fneg, half addrspace(1)* %out
ret void
}
; FIXME: Should be able to use bit operations when illegal type as
; well.
; GCN-LABEL: {{^}}v_fneg_f16:
; GCN: {{flat|global}}_load_ushort [[VAL:v[0-9]+]],
; GCN: v_xor_b32_e32 [[XOR:v[0-9]+]], 0x8000, [[VAL]]
; VI: flat_store_short v{{\[[0-9]+:[0-9]+\]}}, [[XOR]]
; SI: buffer_store_short [[XOR]]
define amdgpu_kernel void @v_fneg_f16(half addrspace(1)* %out, half addrspace(1)* %in) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%gep.in = getelementptr inbounds half, half addrspace(1)* %in, i32 %tid
%gep.out = getelementptr inbounds half, half addrspace(1)* %in, i32 %tid
%val = load half, half addrspace(1)* %gep.in, align 2
%fneg = fsub half -0.0, %val
store half %fneg, half addrspace(1)* %gep.out
ret void
}
AMDGPU: Try a lot harder to emit scalar loads This has two main components. First, widen widen short constant loads in DAG when they have the correct alignment. This is already done a bit in AMDGPUCodeGenPrepare, since that has access to DivergenceAnalysis. This can't help kernarg loads created in the DAG. Start to use DAG divergence analysis to help this case. The second part is to avoid kernel argument lowering breaking the alignment of short vector elements because calling convention lowering wants to split everything into legal register types. When loading a split type, load the nearest 4-byte aligned segment and shift to get the desired bits. This extra load of the earlier argument piece ends up merging, and the bit extract hopefully folds out. There are a number of improvements and regressions with this, but I think as-is this is a better compromise between several of the worst parts of SelectionDAG. Particularly when i16 is legal, this produces worse code for i8 and i16 element vector kernel arguments. This is partially due to the very weak load merging the DAG does. It only looks for fairly specific combines between pairs of loads which no longer appear. In particular this causes v4i16 loads to be split into 2 components when previously the two halves were merged. Worse, because of the newly introduced shifts, there is a lot more unnecessary vector packing and unpacking code emitted. At least some of this is due to reporting false for isTypeDesirableForOp for i16 as a workaround for the lack of divergence information in the DAG. The cases where this happens it doesn't actually matter, but the relevant code in SimplifyDemandedBits doens't have the context to know to ignore this. The use of the scalar cache is probably more important than the mess of mostly scalar instructions doing this packing and unpacking. Future work can fix this, possibly by making better use of the new DAG divergence information for controlling promotion decisions, or adding another version of shift + trunc + shift combines that doesn't only know about the used types. llvm-svn: 334180
2018-06-07 17:54:49 +08:00
; GCN-LABEL: {{^}}s_fneg_free_f16:
; GCN: s_load_dword [[NEG_VALUE:s[0-9]+]],
; GCN: s_xor_b32 [[XOR:s[0-9]+]], [[NEG_VALUE]], 0x8000{{$}}
; GCN: v_mov_b32_e32 [[V_XOR:v[0-9]+]], [[XOR]]
; GCN: {{flat|global}}_store_short v{{\[[0-9]+:[0-9]+\]}}, [[V_XOR]]
AMDGPU: Try a lot harder to emit scalar loads This has two main components. First, widen widen short constant loads in DAG when they have the correct alignment. This is already done a bit in AMDGPUCodeGenPrepare, since that has access to DivergenceAnalysis. This can't help kernarg loads created in the DAG. Start to use DAG divergence analysis to help this case. The second part is to avoid kernel argument lowering breaking the alignment of short vector elements because calling convention lowering wants to split everything into legal register types. When loading a split type, load the nearest 4-byte aligned segment and shift to get the desired bits. This extra load of the earlier argument piece ends up merging, and the bit extract hopefully folds out. There are a number of improvements and regressions with this, but I think as-is this is a better compromise between several of the worst parts of SelectionDAG. Particularly when i16 is legal, this produces worse code for i8 and i16 element vector kernel arguments. This is partially due to the very weak load merging the DAG does. It only looks for fairly specific combines between pairs of loads which no longer appear. In particular this causes v4i16 loads to be split into 2 components when previously the two halves were merged. Worse, because of the newly introduced shifts, there is a lot more unnecessary vector packing and unpacking code emitted. At least some of this is due to reporting false for isTypeDesirableForOp for i16 as a workaround for the lack of divergence information in the DAG. The cases where this happens it doesn't actually matter, but the relevant code in SimplifyDemandedBits doens't have the context to know to ignore this. The use of the scalar cache is probably more important than the mess of mostly scalar instructions doing this packing and unpacking. Future work can fix this, possibly by making better use of the new DAG divergence information for controlling promotion decisions, or adding another version of shift + trunc + shift combines that doesn't only know about the used types. llvm-svn: 334180
2018-06-07 17:54:49 +08:00
define amdgpu_kernel void @s_fneg_free_f16(half addrspace(1)* %out, i16 %in) #0 {
%bc = bitcast i16 %in to half
%fsub = fsub half -0.0, %bc
store half %fsub, half addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}v_fneg_fold_f16:
; GCN: {{flat|global}}_load_ushort [[NEG_VALUE:v[0-9]+]]
; CI-DAG: v_cvt_f32_f16_e32 [[CVT_VAL:v[0-9]+]], [[NEG_VALUE]]
; CI-DAG: v_cvt_f32_f16_e64 [[NEG_CVT0:v[0-9]+]], -[[NEG_VALUE]]
; CI: v_mul_f32_e32 [[MUL:v[0-9]+]], [[NEG_CVT0]], [[CVT_VAL]]
; CI: v_cvt_f16_f32_e32 [[CVT1:v[0-9]+]], [[MUL]]
; CI: flat_store_short v{{\[[0-9]+:[0-9]+\]}}, [[CVT1]]
; VI-NOT: [[NEG_VALUE]]
; VI: v_mul_f16_e64 v{{[0-9]+}}, -[[NEG_VALUE]], [[NEG_VALUE]]
define amdgpu_kernel void @v_fneg_fold_f16(half addrspace(1)* %out, half addrspace(1)* %in) #0 {
%val = load half, half addrspace(1)* %in
%fsub = fsub half -0.0, %val
%fmul = fmul half %fsub, %val
store half %fmul, half addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}s_fneg_v2f16:
; GCN: s_xor_b32 s{{[0-9]+}}, s{{[0-9]+}}, 0x80008000
define amdgpu_kernel void @s_fneg_v2f16(<2 x half> addrspace(1)* %out, <2 x half> %in) #0 {
%fneg = fsub <2 x half> <half -0.0, half -0.0>, %in
store <2 x half> %fneg, <2 x half> addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}s_fneg_v2f16_nonload:
; GCN: s_xor_b32 s{{[0-9]+}}, s{{[0-9]+}}, 0x80008000
define amdgpu_kernel void @s_fneg_v2f16_nonload(<2 x half> addrspace(1)* %out) #0 {
%in = call i32 asm sideeffect "; def $0", "=s"()
%in.bc = bitcast i32 %in to <2 x half>
%fneg = fsub <2 x half> <half -0.0, half -0.0>, %in.bc
store <2 x half> %fneg, <2 x half> addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}v_fneg_v2f16:
; GCN: {{flat|global}}_load_dword [[VAL:v[0-9]+]]
; GCN: v_xor_b32_e32 v{{[0-9]+}}, 0x80008000, [[VAL]]
define amdgpu_kernel void @v_fneg_v2f16(<2 x half> addrspace(1)* %out, <2 x half> addrspace(1)* %in) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%gep.in = getelementptr inbounds <2 x half>, <2 x half> addrspace(1)* %in, i32 %tid
%gep.out = getelementptr inbounds <2 x half>, <2 x half> addrspace(1)* %in, i32 %tid
%val = load <2 x half>, <2 x half> addrspace(1)* %gep.in, align 2
%fneg = fsub <2 x half> <half -0.0, half -0.0>, %val
store <2 x half> %fneg, <2 x half> addrspace(1)* %gep.out
ret void
}
; GCN-LABEL: {{^}}fneg_free_v2f16:
; GCN: s_load_dword [[VAL:s[0-9]+]]
; GCN: s_xor_b32 s{{[0-9]+}}, [[VAL]], 0x80008000
define amdgpu_kernel void @fneg_free_v2f16(<2 x half> addrspace(1)* %out, i32 %in) #0 {
%bc = bitcast i32 %in to <2 x half>
%fsub = fsub <2 x half> <half -0.0, half -0.0>, %bc
store <2 x half> %fsub, <2 x half> addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}v_fneg_fold_v2f16:
; GCN: {{flat|global}}_load_dword [[VAL:v[0-9]+]]
; CI: v_xor_b32_e32 [[FNEG:v[0-9]+]], 0x80008000, [[VAL]]
; CI: v_lshrrev_b32_e32
; CI: v_lshrrev_b32_e32
; CI: v_cvt_f32_f16_e32 v{{[0-9]+}}, v{{[0-9]+}}
; CI: v_cvt_f32_f16_e32 v{{[0-9]+}}, v{{[0-9]+}}
; CI: v_mul_f32_e32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
; CI: v_cvt_f16_f32
; CI: v_mul_f32_e32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
; CI: v_cvt_f16_f32
; VI: v_mul_f16_sdwa v{{[0-9]+}}, -v{{[0-9]+}}, v{{[0-9]+}} dst_sel:WORD_1 dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
; VI: v_mul_f16_e64 v{{[0-9]+}}, -v{{[0-9]+}}, v{{[0-9]+}}
; GFX9: v_pk_mul_f16 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}} neg_lo:[1,0] neg_hi:[1,0]{{$}}
define amdgpu_kernel void @v_fneg_fold_v2f16(<2 x half> addrspace(1)* %out, <2 x half> addrspace(1)* %in) #0 {
%val = load <2 x half>, <2 x half> addrspace(1)* %in
%fsub = fsub <2 x half> <half -0.0, half -0.0>, %val
%fmul = fmul <2 x half> %fsub, %val
store <2 x half> %fmul, <2 x half> addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}v_extract_fneg_fold_v2f16:
; GCN-DAG: {{flat|global}}_load_dword [[VAL:v[0-9]+]]
; CI-DAG: v_mul_f32_e32 v{{[0-9]+}}, -4.0, v{{[0-9]+}}
; CI-DAG: v_sub_f32_e32 v{{[0-9]+}}, 2.0, v{{[0-9]+}}
; GFX89-DAG: v_mul_f16_e32 v{{[0-9]+}}, -4.0, [[VAL]]
; GFX89-DAG: v_mov_b32_e32 [[CONST2:v[0-9]+]], 0x4000
; GFX89-DAG: v_sub_f16_sdwa v{{[0-9]+}}, [[CONST2]], [[VAL]] dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_1
define amdgpu_kernel void @v_extract_fneg_fold_v2f16(<2 x half> addrspace(1)* %in) #0 {
%val = load <2 x half>, <2 x half> addrspace(1)* %in
%fneg = fsub <2 x half> <half -0.0, half -0.0>, %val
%elt0 = extractelement <2 x half> %fneg, i32 0
%elt1 = extractelement <2 x half> %fneg, i32 1
%fmul0 = fmul half %elt0, 4.0
%fadd1 = fadd half %elt1, 2.0
store volatile half %fmul0, half addrspace(1)* undef
store volatile half %fadd1, half addrspace(1)* undef
ret void
}
; GCN-LABEL: {{^}}v_extract_fneg_no_fold_v2f16:
; GCN: {{flat|global}}_load_dword [[VAL:v[0-9]+]]
; GCN: v_xor_b32_e32 [[NEG:v[0-9]+]], 0x80008000, [[VAL]]
; CIVI: v_lshrrev_b32_e32 [[ELT1:v[0-9]+]], 16, [[NEG]]
; GFX9: global_store_short_d16_hi v{{\[[0-9]+:[0-9]+\]}}, [[NEG]], off
define amdgpu_kernel void @v_extract_fneg_no_fold_v2f16(<2 x half> addrspace(1)* %in) #0 {
%val = load <2 x half>, <2 x half> addrspace(1)* %in
%fneg = fsub <2 x half> <half -0.0, half -0.0>, %val
%elt0 = extractelement <2 x half> %fneg, i32 0
%elt1 = extractelement <2 x half> %fneg, i32 1
store volatile half %elt0, half addrspace(1)* undef
store volatile half %elt1, half addrspace(1)* undef
ret void
}
declare i32 @llvm.amdgcn.workitem.id.x() #1
attributes #0 = { nounwind }
attributes #1 = { nounwind readnone }