1 //===-- AMDGPUISelLowering.h - AMDGPU Lowering Interface --------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
10 /// Interface definition of the TargetLowering class that is common
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPUISELLOWERING_H
16 #define LLVM_LIB_TARGET_AMDGPU_AMDGPUISELLOWERING_H
19 #include "llvm/CodeGen/CallingConvLower.h"
20 #include "llvm/CodeGen/TargetLowering.h"
24 class AMDGPUMachineFunction
;
25 class AMDGPUSubtarget
;
28 class AMDGPUTargetLowering
: public TargetLowering
{
30 const AMDGPUSubtarget
*Subtarget
;
32 /// \returns AMDGPUISD::FFBH_U32 node if the incoming \p Op may have been
33 /// legalized from a smaller type VT. Need to match pre-legalized type because
34 /// the generic legalization inserts the add/sub between the select and
36 SDValue
getFFBX_U32(SelectionDAG
&DAG
, SDValue Op
, const SDLoc
&DL
, unsigned Opc
) const;
39 static unsigned numBitsUnsigned(SDValue Op
, SelectionDAG
&DAG
);
40 static unsigned numBitsSigned(SDValue Op
, SelectionDAG
&DAG
);
41 static bool hasDefinedInitializer(const GlobalValue
*GV
);
44 SDValue
LowerEXTRACT_SUBVECTOR(SDValue Op
, SelectionDAG
&DAG
) const;
45 SDValue
LowerCONCAT_VECTORS(SDValue Op
, SelectionDAG
&DAG
) const;
46 /// Split a vector store into multiple scalar stores.
47 /// \returns The resulting chain.
49 SDValue
LowerFREM(SDValue Op
, SelectionDAG
&DAG
) const;
50 SDValue
LowerFCEIL(SDValue Op
, SelectionDAG
&DAG
) const;
51 SDValue
LowerFTRUNC(SDValue Op
, SelectionDAG
&DAG
) const;
52 SDValue
LowerFRINT(SDValue Op
, SelectionDAG
&DAG
) const;
53 SDValue
LowerFNEARBYINT(SDValue Op
, SelectionDAG
&DAG
) const;
55 SDValue
LowerFROUND32_16(SDValue Op
, SelectionDAG
&DAG
) const;
56 SDValue
LowerFROUND64(SDValue Op
, SelectionDAG
&DAG
) const;
57 SDValue
LowerFROUND(SDValue Op
, SelectionDAG
&DAG
) const;
58 SDValue
LowerFFLOOR(SDValue Op
, SelectionDAG
&DAG
) const;
59 SDValue
LowerFLOG(SDValue Op
, SelectionDAG
&DAG
,
60 double Log2BaseInverted
) const;
61 SDValue
lowerFEXP(SDValue Op
, SelectionDAG
&DAG
) const;
63 SDValue
LowerCTLZ_CTTZ(SDValue Op
, SelectionDAG
&DAG
) const;
65 SDValue
LowerINT_TO_FP32(SDValue Op
, SelectionDAG
&DAG
, bool Signed
) const;
66 SDValue
LowerINT_TO_FP64(SDValue Op
, SelectionDAG
&DAG
, bool Signed
) const;
67 SDValue
LowerUINT_TO_FP(SDValue Op
, SelectionDAG
&DAG
) const;
68 SDValue
LowerSINT_TO_FP(SDValue Op
, SelectionDAG
&DAG
) const;
70 SDValue
LowerFP64_TO_INT(SDValue Op
, SelectionDAG
&DAG
, bool Signed
) const;
71 SDValue
LowerFP_TO_FP16(SDValue Op
, SelectionDAG
&DAG
) const;
72 SDValue
LowerFP_TO_UINT(SDValue Op
, SelectionDAG
&DAG
) const;
73 SDValue
LowerFP_TO_SINT(SDValue Op
, SelectionDAG
&DAG
) const;
75 SDValue
LowerSIGN_EXTEND_INREG(SDValue Op
, SelectionDAG
&DAG
) const;
78 bool shouldCombineMemoryType(EVT VT
) const;
79 SDValue
performLoadCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
80 SDValue
performStoreCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
81 SDValue
performAssertSZExtCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
82 SDValue
performIntrinsicWOChainCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
84 SDValue
splitBinaryBitConstantOpImpl(DAGCombinerInfo
&DCI
, const SDLoc
&SL
,
85 unsigned Opc
, SDValue LHS
,
86 uint32_t ValLo
, uint32_t ValHi
) const;
87 SDValue
performShlCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
88 SDValue
performSraCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
89 SDValue
performSrlCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
90 SDValue
performTruncateCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
91 SDValue
performMulCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
92 SDValue
performMulhsCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
93 SDValue
performMulhuCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
94 SDValue
performMulLoHi24Combine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
95 SDValue
performCtlz_CttzCombine(const SDLoc
&SL
, SDValue Cond
, SDValue LHS
,
96 SDValue RHS
, DAGCombinerInfo
&DCI
) const;
97 SDValue
performSelectCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
99 bool isConstantCostlierToNegate(SDValue N
) const;
100 SDValue
performFNegCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
101 SDValue
performFAbsCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
102 SDValue
performRcpCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const;
104 static EVT
getEquivalentMemType(LLVMContext
&Context
, EVT VT
);
106 virtual SDValue
LowerGlobalAddress(AMDGPUMachineFunction
*MFI
, SDValue Op
,
107 SelectionDAG
&DAG
) const;
109 /// Return 64-bit value Op as two 32-bit integers.
110 std::pair
<SDValue
, SDValue
> split64BitValue(SDValue Op
,
111 SelectionDAG
&DAG
) const;
112 SDValue
getLoHalf64(SDValue Op
, SelectionDAG
&DAG
) const;
113 SDValue
getHiHalf64(SDValue Op
, SelectionDAG
&DAG
) const;
115 /// Split a vector type into two parts. The first part is a power of two
116 /// vector. The second part is whatever is left over, and is a scalar if it
117 /// would otherwise be a 1-vector.
118 std::pair
<EVT
, EVT
> getSplitDestVTs(const EVT
&VT
, SelectionDAG
&DAG
) const;
120 /// Split a vector value into two parts of types LoVT and HiVT. HiVT could be
122 std::pair
<SDValue
, SDValue
> splitVector(const SDValue
&N
, const SDLoc
&DL
,
123 const EVT
&LoVT
, const EVT
&HighVT
,
124 SelectionDAG
&DAG
) const;
126 /// Split a vector load into 2 loads of half the vector.
127 SDValue
SplitVectorLoad(SDValue Op
, SelectionDAG
&DAG
) const;
129 /// Widen a vector load from vec3 to vec4.
130 SDValue
WidenVectorLoad(SDValue Op
, SelectionDAG
&DAG
) const;
132 /// Split a vector store into 2 stores of half the vector.
133 SDValue
SplitVectorStore(SDValue Op
, SelectionDAG
&DAG
) const;
135 SDValue
LowerSTORE(SDValue Op
, SelectionDAG
&DAG
) const;
136 SDValue
LowerSDIVREM(SDValue Op
, SelectionDAG
&DAG
) const;
137 SDValue
LowerUDIVREM(SDValue Op
, SelectionDAG
&DAG
) const;
138 SDValue
LowerDIVREM24(SDValue Op
, SelectionDAG
&DAG
, bool sign
) const;
139 void LowerUDIVREM64(SDValue Op
, SelectionDAG
&DAG
,
140 SmallVectorImpl
<SDValue
> &Results
) const;
142 void analyzeFormalArgumentsCompute(
144 const SmallVectorImpl
<ISD::InputArg
> &Ins
) const;
147 AMDGPUTargetLowering(const TargetMachine
&TM
, const AMDGPUSubtarget
&STI
);
149 bool mayIgnoreSignedZero(SDValue Op
) const {
150 if (getTargetMachine().Options
.NoSignedZerosFPMath
)
153 const auto Flags
= Op
.getNode()->getFlags();
154 if (Flags
.isDefined())
155 return Flags
.hasNoSignedZeros();
160 static inline SDValue
stripBitcast(SDValue Val
) {
161 return Val
.getOpcode() == ISD::BITCAST
? Val
.getOperand(0) : Val
;
164 static bool allUsesHaveSourceMods(const SDNode
*N
,
165 unsigned CostThreshold
= 4);
166 bool isFAbsFree(EVT VT
) const override
;
167 bool isFNegFree(EVT VT
) const override
;
168 bool isTruncateFree(EVT Src
, EVT Dest
) const override
;
169 bool isTruncateFree(Type
*Src
, Type
*Dest
) const override
;
171 bool isZExtFree(Type
*Src
, Type
*Dest
) const override
;
172 bool isZExtFree(EVT Src
, EVT Dest
) const override
;
173 bool isZExtFree(SDValue Val
, EVT VT2
) const override
;
175 bool isNarrowingProfitable(EVT VT1
, EVT VT2
) const override
;
177 MVT
getVectorIdxTy(const DataLayout
&) const override
;
178 bool isSelectSupported(SelectSupportKind
) const override
;
180 bool isFPImmLegal(const APFloat
&Imm
, EVT VT
,
181 bool ForCodeSize
) const override
;
182 bool ShouldShrinkFPConstant(EVT VT
) const override
;
183 bool shouldReduceLoadWidth(SDNode
*Load
,
184 ISD::LoadExtType ExtType
,
185 EVT ExtVT
) const override
;
187 bool isLoadBitCastBeneficial(EVT
, EVT
, const SelectionDAG
&DAG
,
188 const MachineMemOperand
&MMO
) const final
;
190 bool storeOfVectorConstantIsCheap(EVT MemVT
,
192 unsigned AS
) const override
;
193 bool aggressivelyPreferBuildVectorSources(EVT VecVT
) const override
;
194 bool isCheapToSpeculateCttz() const override
;
195 bool isCheapToSpeculateCtlz() const override
;
197 bool isSDNodeAlwaysUniform(const SDNode
*N
) const override
;
198 static CCAssignFn
*CCAssignFnForCall(CallingConv::ID CC
, bool IsVarArg
);
199 static CCAssignFn
*CCAssignFnForReturn(CallingConv::ID CC
, bool IsVarArg
);
201 SDValue
LowerReturn(SDValue Chain
, CallingConv::ID CallConv
, bool isVarArg
,
202 const SmallVectorImpl
<ISD::OutputArg
> &Outs
,
203 const SmallVectorImpl
<SDValue
> &OutVals
, const SDLoc
&DL
,
204 SelectionDAG
&DAG
) const override
;
206 SDValue
addTokenForArgument(SDValue Chain
,
208 MachineFrameInfo
&MFI
,
209 int ClobberedFI
) const;
211 SDValue
lowerUnhandledCall(CallLoweringInfo
&CLI
,
212 SmallVectorImpl
<SDValue
> &InVals
,
213 StringRef Reason
) const;
214 SDValue
LowerCall(CallLoweringInfo
&CLI
,
215 SmallVectorImpl
<SDValue
> &InVals
) const override
;
217 SDValue
LowerDYNAMIC_STACKALLOC(SDValue Op
,
218 SelectionDAG
&DAG
) const;
220 SDValue
LowerOperation(SDValue Op
, SelectionDAG
&DAG
) const override
;
221 SDValue
PerformDAGCombine(SDNode
*N
, DAGCombinerInfo
&DCI
) const override
;
222 void ReplaceNodeResults(SDNode
* N
,
223 SmallVectorImpl
<SDValue
> &Results
,
224 SelectionDAG
&DAG
) const override
;
226 SDValue
combineFMinMaxLegacy(const SDLoc
&DL
, EVT VT
, SDValue LHS
,
227 SDValue RHS
, SDValue True
, SDValue False
,
228 SDValue CC
, DAGCombinerInfo
&DCI
) const;
230 const char* getTargetNodeName(unsigned Opcode
) const override
;
232 // FIXME: Turn off MergeConsecutiveStores() before Instruction Selection for
233 // AMDGPU. Commit r319036,
234 // (https://github.com/llvm/llvm-project/commit/db77e57ea86d941a4262ef60261692f4cb6893e6)
235 // turned on MergeConsecutiveStores() before Instruction Selection for all
236 // targets. Enough AMDGPU compiles go into an infinite loop (
237 // MergeConsecutiveStores() merges two stores; LegalizeStoreOps() un-merges;
238 // MergeConsecutiveStores() re-merges, etc. ) to warrant turning it off for
240 bool mergeStoresAfterLegalization(EVT
) const override
{ return false; }
242 bool isFsqrtCheap(SDValue Operand
, SelectionDAG
&DAG
) const override
{
245 SDValue
getSqrtEstimate(SDValue Operand
, SelectionDAG
&DAG
, int Enabled
,
246 int &RefinementSteps
, bool &UseOneConstNR
,
247 bool Reciprocal
) const override
;
248 SDValue
getRecipEstimate(SDValue Operand
, SelectionDAG
&DAG
, int Enabled
,
249 int &RefinementSteps
) const override
;
251 virtual SDNode
*PostISelFolding(MachineSDNode
*N
,
252 SelectionDAG
&DAG
) const = 0;
254 /// Determine which of the bits specified in \p Mask are known to be
255 /// either zero or one and return them in the \p KnownZero and \p KnownOne
257 void computeKnownBitsForTargetNode(const SDValue Op
,
259 const APInt
&DemandedElts
,
260 const SelectionDAG
&DAG
,
261 unsigned Depth
= 0) const override
;
263 unsigned ComputeNumSignBitsForTargetNode(SDValue Op
, const APInt
&DemandedElts
,
264 const SelectionDAG
&DAG
,
265 unsigned Depth
= 0) const override
;
267 bool isKnownNeverNaNForTargetNode(SDValue Op
,
268 const SelectionDAG
&DAG
,
270 unsigned Depth
= 0) const override
;
272 /// Helper function that adds Reg to the LiveIn list of the DAG's
275 /// \returns a RegisterSDNode representing Reg if \p RawReg is true, otherwise
276 /// a copy from the register.
277 SDValue
CreateLiveInRegister(SelectionDAG
&DAG
,
278 const TargetRegisterClass
*RC
,
279 unsigned Reg
, EVT VT
,
281 bool RawReg
= false) const;
282 SDValue
CreateLiveInRegister(SelectionDAG
&DAG
,
283 const TargetRegisterClass
*RC
,
284 unsigned Reg
, EVT VT
) const {
285 return CreateLiveInRegister(DAG
, RC
, Reg
, VT
, SDLoc(DAG
.getEntryNode()));
288 // Returns the raw live in register rather than a copy from it.
289 SDValue
CreateLiveInRegisterRaw(SelectionDAG
&DAG
,
290 const TargetRegisterClass
*RC
,
291 unsigned Reg
, EVT VT
) const {
292 return CreateLiveInRegister(DAG
, RC
, Reg
, VT
, SDLoc(DAG
.getEntryNode()), true);
295 /// Similar to CreateLiveInRegister, except value maybe loaded from a stack
296 /// slot rather than passed in a register.
297 SDValue
loadStackInputValue(SelectionDAG
&DAG
,
300 int64_t Offset
) const;
302 SDValue
storeStackInputValue(SelectionDAG
&DAG
,
306 int64_t Offset
) const;
308 SDValue
loadInputValue(SelectionDAG
&DAG
,
309 const TargetRegisterClass
*RC
,
310 EVT VT
, const SDLoc
&SL
,
311 const ArgDescriptor
&Arg
) const;
313 enum ImplicitParameter
{
315 GRID_DIM
= FIRST_IMPLICIT
,
319 /// Helper function that returns the byte offset of the given
320 /// type of implicit parameter.
321 uint32_t getImplicitParameterOffset(const MachineFunction
&MF
,
322 const ImplicitParameter Param
) const;
324 MVT
getFenceOperandTy(const DataLayout
&DL
) const override
{
328 AtomicExpansionKind
shouldExpandAtomicRMWInIR(AtomicRMWInst
*) const override
;
331 namespace AMDGPUISD
{
333 enum NodeType
: unsigned {
335 FIRST_NUMBER
= ISD::BUILTIN_OP_END
,
336 UMUL
, // 32bit unsigned multiplication
338 // End AMDIL ISD Opcodes
345 // Masked control flow nodes.
350 // A uniform kernel return that terminates the wavefront.
353 // Return to a shader part's epilog code.
356 // Return with values from a non-entry function.
362 /// CLAMP value between 0.0 and 1.0. NaN clamped to 0, following clamp output
363 /// modifier behavior with dx10_enable.
366 // This is SETCC with the full mask result which is used for a compare with a
367 // result bit per item in the wavefront.
373 // FP ops with input and output chain.
377 // SIN_HW, COS_HW - f32 for SI, 1 ULP max error, valid from -100 pi to 100 pi.
378 // Denormals handled on some parts.
398 // For emitting ISD::FMAD when f32 denormals are enabled because mac/mad is
399 // treated as an illegal operation.
401 TRIG_PREOP
, // 1 ULP max error for f64
403 // RCP, RSQ - For f32, 1 ULP max error, no denormal handling.
404 // For f64, max error 2^29 ULP, handles denormals.
417 BFE_U32
, // Extract range of bits with zero extension to 32-bits.
418 BFE_I32
, // Extract range of bits with sign extension to 32-bits.
419 BFI
, // (src0 & src1) | (~src0 & src2)
420 BFM
, // Insert a range of bits into a 32-bit word.
421 FFBH_U32
, // ctlz with -1 if input is zero.
423 FFBL_B32
, // cttz with -1 if input is zero.
436 EXPORT
, // exp on SI+
437 EXPORT_DONE
, // exp on SI+ with done bit set
447 // These cvt_f32_ubyte* nodes need to remain consecutive and in order.
453 // Convert two float 32 numbers into a single register holding two packed f16
454 // with round to zero.
461 // Same as the standard node, except the high bits of the resulting integer
465 // Wrapper around fp16 results that are known to zero the high bits.
468 /// This node is for VLIW targets and it is used to represent a vector
469 /// that is stored in consecutive registers with the same channel.
476 BUILD_VERTICAL_VECTOR
,
477 /// Pointer to the start of the shader's constant data.
489 FIRST_MEM_OPCODE_NUMBER
= ISD::FIRST_TARGET_MEMORY_OPCODE
,
499 TBUFFER_STORE_FORMAT
,
500 TBUFFER_STORE_FORMAT_D16
,
502 TBUFFER_LOAD_FORMAT_D16
,
515 BUFFER_LOAD_FORMAT_D16
,
521 BUFFER_STORE_FORMAT_D16
,
534 BUFFER_ATOMIC_CMPSWAP
,
536 BUFFER_ATOMIC_PK_FADD
,
540 LAST_AMDGPU_ISD_NUMBER
544 } // End namespace AMDGPUISD
546 } // End namespace llvm