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[AMDGPU] Teach CalculateByteProvider about AMDGPUISD::PERM #65547

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Merged
merged 1 commit into from
Sep 7, 2023
Merged

[AMDGPU] Teach CalculateByteProvider about AMDGPUISD::PERM #65547

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18 changes: 18 additions & 0 deletions llvm/lib/Target/AMDGPU/SIISelLowering.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -10762,6 +10762,24 @@ calculateByteProvider(const SDValue &Op, unsigned Index, unsigned Depth,
StartingIndex, Index);
}

case AMDGPUISD::PERM: {
auto PermMask = dyn_cast<ConstantSDNode>(Op->getOperand(2));
if (!PermMask)
return std::nullopt;

auto IdxMask =
(PermMask->getZExtValue() & (0xFF << (Index * 8))) >> (Index * 8);
if (IdxMask > 0x07 && IdxMask != 0x0c)
return std::nullopt;

auto NextOp = Op.getOperand(IdxMask > 0x03 ? 0 : 1);
auto NextIndex = IdxMask > 0x03 ? IdxMask % 4 : IdxMask;

return IdxMask != 0x0c ? calculateSrcByte(NextOp, StartingIndex, NextIndex)
: ByteProvider<SDValue>(
ByteProvider<SDValue>::getConstantZero());
}

default: {
return std::nullopt;
}
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35 changes: 35 additions & 0 deletions llvm/test/CodeGen/AMDGPU/permute_i8.ll
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Expand Up @@ -2794,6 +2794,41 @@ define hidden void @extract3744(ptr addrspace(1) %in0, ptr addrspace(1) %in1, pt
ret void
}

declare i32 @llvm.amdgcn.perm(i32, i32, i32)

define hidden void @extract_perm_3744(ptr addrspace(1) %in0, ptr addrspace(1) %in1, ptr addrspace(1) %out0) {
; GFX10-LABEL: extract_perm_3744:
; GFX10: ; %bb.0:
; GFX10-NEXT: s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
; GFX10-NEXT: global_load_dword v6, v[0:1], off
; GFX10-NEXT: global_load_dword v7, v[2:3], off
; GFX10-NEXT: s_waitcnt vmcnt(0)
; GFX10-NEXT: v_perm_b32 v0, v6, v7, 0x3070404
; GFX10-NEXT: global_store_dword v[4:5], v0, off
; GFX10-NEXT: s_setpc_b64 s[30:31]
;
; GFX9-LABEL: extract_perm_3744:
; GFX9: ; %bb.0:
; GFX9-NEXT: s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
; GFX9-NEXT: global_load_dword v6, v[0:1], off
; GFX9-NEXT: global_load_dword v7, v[2:3], off
; GFX9-NEXT: s_mov_b32 s4, 0x3070404
; GFX9-NEXT: s_waitcnt vmcnt(0)
; GFX9-NEXT: v_perm_b32 v0, v6, v7, s4
; GFX9-NEXT: global_store_dword v[4:5], v0, off
; GFX9-NEXT: s_waitcnt vmcnt(0)
; GFX9-NEXT: s_setpc_b64 s[30:31]
%vec1 = load <4 x i8>, ptr addrspace(1) %in0, align 4
%vec2 = load <4 x i8>, ptr addrspace(1) %in1, align 4
%cast1 = bitcast <4 x i8> %vec1 to i32
%cast2 = bitcast <4 x i8> %vec2 to i32
%lo24 = call i32 @llvm.amdgcn.perm(i32 %cast1, i32 %cast1, i32 201523200)
%hi8 = call i32 @llvm.amdgcn.perm(i32 %cast2, i32 %cast2, i32 51121164)
%res = or i32 %hi8, %lo24
store i32 %res, ptr addrspace(1) %out0, align 4
ret void
}

define hidden void @extract1347_v2i16(ptr addrspace(1) %in0, ptr addrspace(1) %in1, ptr addrspace(1) %out0) {
; GFX10-LABEL: extract1347_v2i16:
; GFX10: ; %bb.0:
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