xref: /freebsd/contrib/llvm-project/llvm/lib/Target/SPIRV/SPIRVTargetTransformInfo.h (revision 700637cbb5e582861067a11aaca4d053546871d2)
1 //===- SPIRVTargetTransformInfo.h - SPIR-V specific TTI ---------*- C++ -*-===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 // \file
9 // This file contains a TargetTransformInfoImplBase conforming object specific
10 // to the SPIRV target machine. It uses the target's detailed information to
11 // provide more precise answers to certain TTI queries, while letting the
12 // target independent and default TTI implementations handle the rest.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_LIB_TARGET_SPIRV_SPIRVTARGETTRANSFORMINFO_H
17 #define LLVM_LIB_TARGET_SPIRV_SPIRVTARGETTRANSFORMINFO_H
18 
19 #include "SPIRV.h"
20 #include "SPIRVTargetMachine.h"
21 #include "llvm/Analysis/TargetTransformInfo.h"
22 #include "llvm/CodeGen/BasicTTIImpl.h"
23 
24 namespace llvm {
25 class SPIRVTTIImpl final : public BasicTTIImplBase<SPIRVTTIImpl> {
26   using BaseT = BasicTTIImplBase<SPIRVTTIImpl>;
27   using TTI = TargetTransformInfo;
28 
29   friend BaseT;
30 
31   const SPIRVSubtarget *ST;
32   const SPIRVTargetLowering *TLI;
33 
getST()34   const TargetSubtargetInfo *getST() const { return ST; }
getTLI()35   const SPIRVTargetLowering *getTLI() const { return TLI; }
36 
37 public:
SPIRVTTIImpl(const SPIRVTargetMachine * TM,const Function & F)38   explicit SPIRVTTIImpl(const SPIRVTargetMachine *TM, const Function &F)
39       : BaseT(TM, F.getDataLayout()), ST(TM->getSubtargetImpl(F)),
40         TLI(ST->getTargetLowering()) {}
41 
getPopcntSupport(unsigned TyWidth)42   TTI::PopcntSupportKind getPopcntSupport(unsigned TyWidth) const override {
43     // SPIR-V natively supports OpBitcount, per 3.53.14 in the spec, as such it
44     // is reasonable to assume the Op is fast / preferable to the expanded loop.
45     // Furthermore, this prevents information being lost if transforms are
46     // applied to SPIR-V before lowering to a concrete target.
47     if (!isPowerOf2_32(TyWidth) || TyWidth > 64)
48       return TTI::PSK_Software; // Arbitrary bit-width INT is not core SPIR-V.
49     return TTI::PSK_FastHardware;
50   }
51 
getFlatAddressSpace()52   unsigned getFlatAddressSpace() const override {
53     // Clang has 2 distinct address space maps. One where
54     // default=4=Generic, and one with default=0=Function. This depends on the
55     // environment.
56     return ST->isShader() ? 0 : 4;
57   }
58   bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
59                                   Intrinsic::ID IID) const override;
60   Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II, Value *OldV,
61                                           Value *NewV) const override;
62 };
63 
64 } // namespace llvm
65 
66 #endif // LLVM_LIB_TARGET_SPIRV_SPIRVTARGETTRANSFORMINFO_H
67