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 #include "llvm/IR/IntrinsicsNVPTX.h" 20 #include "llvm/Support/CommandLine.h" 21 22 using namespace llvm; 23 24 #define DEBUG_TYPE "nvvm-intr-range" 25 26 namespace llvm { void initializeNVVMIntrRangePass(PassRegistry &); } 27 28 // Add !range metadata based on limits of given SM variant. 29 static cl::opt<unsigned> NVVMIntrRangeSM("nvvm-intr-range-sm", cl::init(20), 30 cl::Hidden, cl::desc("SM variant")); 31 32 namespace { 33 class NVVMIntrRange : public FunctionPass { 34 private: 35 struct { 36 unsigned x, y, z; 37 } MaxBlockSize, MaxGridSize; 38 39 public: 40 static char ID; 41 NVVMIntrRange() : NVVMIntrRange(NVVMIntrRangeSM) {} 42 NVVMIntrRange(unsigned int SmVersion) : FunctionPass(ID) { 43 MaxBlockSize.x = 1024; 44 MaxBlockSize.y = 1024; 45 MaxBlockSize.z = 64; 46 47 MaxGridSize.x = SmVersion >= 30 ? 0x7fffffff : 0xffff; 48 MaxGridSize.y = 0xffff; 49 MaxGridSize.z = 0xffff; 50 51 initializeNVVMIntrRangePass(*PassRegistry::getPassRegistry()); 52 } 53 54 bool runOnFunction(Function &) override; 55 }; 56 } 57 58 FunctionPass *llvm::createNVVMIntrRangePass(unsigned int SmVersion) { 59 return new NVVMIntrRange(SmVersion); 60 } 61 62 char NVVMIntrRange::ID = 0; 63 INITIALIZE_PASS(NVVMIntrRange, "nvvm-intr-range", 64 "Add !range metadata to NVVM intrinsics.", false, false) 65 66 // Adds the passed-in [Low,High) range information as metadata to the 67 // passed-in call instruction. 68 static bool addRangeMetadata(uint64_t Low, uint64_t High, CallInst *C) { 69 // This call already has range metadata, nothing to do. 70 if (C->getMetadata(LLVMContext::MD_range)) 71 return false; 72 73 LLVMContext &Context = C->getParent()->getContext(); 74 IntegerType *Int32Ty = Type::getInt32Ty(Context); 75 Metadata *LowAndHigh[] = { 76 ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Low)), 77 ConstantAsMetadata::get(ConstantInt::get(Int32Ty, High))}; 78 C->setMetadata(LLVMContext::MD_range, MDNode::get(Context, LowAndHigh)); 79 return true; 80 } 81 82 bool NVVMIntrRange::runOnFunction(Function &F) { 83 // Go through the calls in this function. 84 bool Changed = false; 85 for (Instruction &I : instructions(F)) { 86 CallInst *Call = dyn_cast<CallInst>(&I); 87 if (!Call) 88 continue; 89 90 if (Function *Callee = Call->getCalledFunction()) { 91 switch (Callee->getIntrinsicID()) { 92 // Index within block 93 case Intrinsic::nvvm_read_ptx_sreg_tid_x: 94 Changed |= addRangeMetadata(0, MaxBlockSize.x, Call); 95 break; 96 case Intrinsic::nvvm_read_ptx_sreg_tid_y: 97 Changed |= addRangeMetadata(0, MaxBlockSize.y, Call); 98 break; 99 case Intrinsic::nvvm_read_ptx_sreg_tid_z: 100 Changed |= addRangeMetadata(0, MaxBlockSize.z, Call); 101 break; 102 103 // Block size 104 case Intrinsic::nvvm_read_ptx_sreg_ntid_x: 105 Changed |= addRangeMetadata(1, MaxBlockSize.x+1, Call); 106 break; 107 case Intrinsic::nvvm_read_ptx_sreg_ntid_y: 108 Changed |= addRangeMetadata(1, MaxBlockSize.y+1, Call); 109 break; 110 case Intrinsic::nvvm_read_ptx_sreg_ntid_z: 111 Changed |= addRangeMetadata(1, MaxBlockSize.z+1, Call); 112 break; 113 114 // Index within grid 115 case Intrinsic::nvvm_read_ptx_sreg_ctaid_x: 116 Changed |= addRangeMetadata(0, MaxGridSize.x, Call); 117 break; 118 case Intrinsic::nvvm_read_ptx_sreg_ctaid_y: 119 Changed |= addRangeMetadata(0, MaxGridSize.y, Call); 120 break; 121 case Intrinsic::nvvm_read_ptx_sreg_ctaid_z: 122 Changed |= addRangeMetadata(0, MaxGridSize.z, Call); 123 break; 124 125 // Grid size 126 case Intrinsic::nvvm_read_ptx_sreg_nctaid_x: 127 Changed |= addRangeMetadata(1, MaxGridSize.x+1, Call); 128 break; 129 case Intrinsic::nvvm_read_ptx_sreg_nctaid_y: 130 Changed |= addRangeMetadata(1, MaxGridSize.y+1, Call); 131 break; 132 case Intrinsic::nvvm_read_ptx_sreg_nctaid_z: 133 Changed |= addRangeMetadata(1, MaxGridSize.z+1, Call); 134 break; 135 136 // warp size is constant 32. 137 case Intrinsic::nvvm_read_ptx_sreg_warpsize: 138 Changed |= addRangeMetadata(32, 32+1, Call); 139 break; 140 141 // Lane ID is [0..warpsize) 142 case Intrinsic::nvvm_read_ptx_sreg_laneid: 143 Changed |= addRangeMetadata(0, 32, Call); 144 break; 145 146 default: 147 break; 148 } 149 } 150 } 151 152 return Changed; 153 } 154