1 //===- NVVMIntrRange.cpp - Set !range metadata for NVVM intrinsics --------===// 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 // 9 // This pass adds appropriate !range metadata for calls to NVVM 10 // intrinsics that return a limited range of values. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "NVPTX.h" 15 #include "llvm/IR/Constants.h" 16 #include "llvm/IR/InstIterator.h" 17 #include "llvm/IR/Instructions.h" 18 #include "llvm/IR/Intrinsics.h" 19 20 using namespace llvm; 21 22 #define DEBUG_TYPE "nvvm-intr-range" 23 24 namespace llvm { void initializeNVVMIntrRangePass(PassRegistry &); } 25 26 // Add !range metadata based on limits of given SM variant. 27 static cl::opt<unsigned> NVVMIntrRangeSM("nvvm-intr-range-sm", cl::init(20), 28 cl::Hidden, cl::desc("SM variant")); 29 30 namespace { 31 class NVVMIntrRange : public FunctionPass { 32 private: 33 struct { 34 unsigned x, y, z; 35 } MaxBlockSize, MaxGridSize; 36 37 public: 38 static char ID; 39 NVVMIntrRange() : NVVMIntrRange(NVVMIntrRangeSM) {} 40 NVVMIntrRange(unsigned int SmVersion) : FunctionPass(ID) { 41 MaxBlockSize.x = 1024; 42 MaxBlockSize.y = 1024; 43 MaxBlockSize.z = 64; 44 45 MaxGridSize.x = SmVersion >= 30 ? 0x7fffffff : 0xffff; 46 MaxGridSize.y = 0xffff; 47 MaxGridSize.z = 0xffff; 48 49 initializeNVVMIntrRangePass(*PassRegistry::getPassRegistry()); 50 } 51 52 bool runOnFunction(Function &) override; 53 }; 54 } 55 56 FunctionPass *llvm::createNVVMIntrRangePass(unsigned int SmVersion) { 57 return new NVVMIntrRange(SmVersion); 58 } 59 60 char NVVMIntrRange::ID = 0; 61 INITIALIZE_PASS(NVVMIntrRange, "nvvm-intr-range", 62 "Add !range metadata to NVVM intrinsics.", false, false) 63 64 // Adds the passed-in [Low,High) range information as metadata to the 65 // passed-in call instruction. 66 static bool addRangeMetadata(uint64_t Low, uint64_t High, CallInst *C) { 67 // This call already has range metadata, nothing to do. 68 if (C->getMetadata(LLVMContext::MD_range)) 69 return false; 70 71 LLVMContext &Context = C->getParent()->getContext(); 72 IntegerType *Int32Ty = Type::getInt32Ty(Context); 73 Metadata *LowAndHigh[] = { 74 ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Low)), 75 ConstantAsMetadata::get(ConstantInt::get(Int32Ty, High))}; 76 C->setMetadata(LLVMContext::MD_range, MDNode::get(Context, LowAndHigh)); 77 return true; 78 } 79 80 bool NVVMIntrRange::runOnFunction(Function &F) { 81 // Go through the calls in this function. 82 bool Changed = false; 83 for (Instruction &I : instructions(F)) { 84 CallInst *Call = dyn_cast<CallInst>(&I); 85 if (!Call) 86 continue; 87 88 if (Function *Callee = Call->getCalledFunction()) { 89 switch (Callee->getIntrinsicID()) { 90 // Index within block 91 case Intrinsic::nvvm_read_ptx_sreg_tid_x: 92 Changed |= addRangeMetadata(0, MaxBlockSize.x, Call); 93 break; 94 case Intrinsic::nvvm_read_ptx_sreg_tid_y: 95 Changed |= addRangeMetadata(0, MaxBlockSize.y, Call); 96 break; 97 case Intrinsic::nvvm_read_ptx_sreg_tid_z: 98 Changed |= addRangeMetadata(0, MaxBlockSize.z, Call); 99 break; 100 101 // Block size 102 case Intrinsic::nvvm_read_ptx_sreg_ntid_x: 103 Changed |= addRangeMetadata(1, MaxBlockSize.x+1, Call); 104 break; 105 case Intrinsic::nvvm_read_ptx_sreg_ntid_y: 106 Changed |= addRangeMetadata(1, MaxBlockSize.y+1, Call); 107 break; 108 case Intrinsic::nvvm_read_ptx_sreg_ntid_z: 109 Changed |= addRangeMetadata(1, MaxBlockSize.z+1, Call); 110 break; 111 112 // Index within grid 113 case Intrinsic::nvvm_read_ptx_sreg_ctaid_x: 114 Changed |= addRangeMetadata(0, MaxGridSize.x, Call); 115 break; 116 case Intrinsic::nvvm_read_ptx_sreg_ctaid_y: 117 Changed |= addRangeMetadata(0, MaxGridSize.y, Call); 118 break; 119 case Intrinsic::nvvm_read_ptx_sreg_ctaid_z: 120 Changed |= addRangeMetadata(0, MaxGridSize.z, Call); 121 break; 122 123 // Grid size 124 case Intrinsic::nvvm_read_ptx_sreg_nctaid_x: 125 Changed |= addRangeMetadata(1, MaxGridSize.x+1, Call); 126 break; 127 case Intrinsic::nvvm_read_ptx_sreg_nctaid_y: 128 Changed |= addRangeMetadata(1, MaxGridSize.y+1, Call); 129 break; 130 case Intrinsic::nvvm_read_ptx_sreg_nctaid_z: 131 Changed |= addRangeMetadata(1, MaxGridSize.z+1, Call); 132 break; 133 134 // warp size is constant 32. 135 case Intrinsic::nvvm_read_ptx_sreg_warpsize: 136 Changed |= addRangeMetadata(32, 32+1, Call); 137 break; 138 139 // Lane ID is [0..warpsize) 140 case Intrinsic::nvvm_read_ptx_sreg_laneid: 141 Changed |= addRangeMetadata(0, 32, Call); 142 break; 143 144 default: 145 break; 146 } 147 } 148 } 149 150 return Changed; 151 } 152