summaryrefslogtreecommitdiffstats
path: root/llvm/lib/Target/NVPTX/NVVMIntrRange.cpp
blob: 5cf7b6691e6381aa1fdb406040fe6d3435e669cd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
//===- NVVMIntrRange.cpp - Set !range metadata for NVVM intrinsics --------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This pass adds appropriate !range metadata for calls to NVVM
// intrinsics that return a limited range of values.
//
//===----------------------------------------------------------------------===//

#include "NVPTX.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"

using namespace llvm;

#define DEBUG_TYPE "nvvm-intr-range"

namespace llvm { void initializeNVVMIntrRangePass(PassRegistry &); }

// Add !range metadata based on limits of given SM variant.
static cl::opt<unsigned> NVVMIntrRangeSM("nvvm-intr-range-sm", cl::init(20),
                                         cl::Hidden, cl::desc("SM variant"));

namespace {
class NVVMIntrRange : public FunctionPass {
 private:
   struct {
     unsigned x, y, z;
   } MaxBlockSize, MaxGridSize;

 public:
   static char ID;
   NVVMIntrRange() : NVVMIntrRange(NVVMIntrRangeSM) {}
   NVVMIntrRange(unsigned int SmVersion) : FunctionPass(ID) {
     MaxBlockSize.x = 1024;
     MaxBlockSize.y = 1024;
     MaxBlockSize.z = 64;

     MaxGridSize.x = SmVersion >= 30 ? 0x7fffffff : 0xffff;
     MaxGridSize.y = 0xffff;
     MaxGridSize.z = 0xffff;

     initializeNVVMIntrRangePass(*PassRegistry::getPassRegistry());
   }

   bool runOnFunction(Function &) override;
};
}

FunctionPass *llvm::createNVVMIntrRangePass(unsigned int SmVersion) {
  return new NVVMIntrRange(SmVersion);
}

char NVVMIntrRange::ID = 0;
INITIALIZE_PASS(NVVMIntrRange, "nvvm-intr-range",
                "Add !range metadata to NVVM intrinsics.", false, false)

// Adds the passed-in [Low,High) range information as metadata to the
// passed-in call instruction.
static bool addRangeMetadata(uint64_t Low, uint64_t High, CallInst *C) {
  // This call already has range metadata, nothing to do.
  if (C->getMetadata(LLVMContext::MD_range))
    return false;

  LLVMContext &Context = C->getParent()->getContext();
  IntegerType *Int32Ty = Type::getInt32Ty(Context);
  Metadata *LowAndHigh[] = {
      ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Low)),
      ConstantAsMetadata::get(ConstantInt::get(Int32Ty, High))};
  C->setMetadata(LLVMContext::MD_range, MDNode::get(Context, LowAndHigh));
  return true;
}

bool NVVMIntrRange::runOnFunction(Function &F) {
  // Go through the calls in this function.
  bool Changed = false;
  for (Instruction &I : instructions(F)) {
    CallInst *Call = dyn_cast<CallInst>(&I);
    if (!Call)
      continue;

    if (Function *Callee = Call->getCalledFunction()) {
      switch (Callee->getIntrinsicID()) {
      // Index within block
      case Intrinsic::nvvm_read_ptx_sreg_tid_x:
        Changed |= addRangeMetadata(0, MaxBlockSize.x, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_tid_y:
        Changed |= addRangeMetadata(0, MaxBlockSize.y, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_tid_z:
        Changed |= addRangeMetadata(0, MaxBlockSize.z, Call);
        break;

      // Block size
      case Intrinsic::nvvm_read_ptx_sreg_ntid_x:
        Changed |= addRangeMetadata(1, MaxBlockSize.x+1, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_ntid_y:
        Changed |= addRangeMetadata(1, MaxBlockSize.y+1, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_ntid_z:
        Changed |= addRangeMetadata(1, MaxBlockSize.z+1, Call);
        break;

      // Index within grid
      case Intrinsic::nvvm_read_ptx_sreg_ctaid_x:
        Changed |= addRangeMetadata(0, MaxGridSize.x, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_ctaid_y:
        Changed |= addRangeMetadata(0, MaxGridSize.y, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_ctaid_z:
        Changed |= addRangeMetadata(0, MaxGridSize.z, Call);
        break;

      // Grid size
      case Intrinsic::nvvm_read_ptx_sreg_nctaid_x:
        Changed |= addRangeMetadata(1, MaxGridSize.x+1, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_nctaid_y:
        Changed |= addRangeMetadata(1, MaxGridSize.y+1, Call);
        break;
      case Intrinsic::nvvm_read_ptx_sreg_nctaid_z:
        Changed |= addRangeMetadata(1, MaxGridSize.z+1, Call);
        break;

      // warp size is constant 32.
      case Intrinsic::nvvm_read_ptx_sreg_warpsize:
        Changed |= addRangeMetadata(32, 32+1, Call);
        break;

      // Lane ID is [0..warpsize)
      case Intrinsic::nvvm_read_ptx_sreg_laneid:
        Changed |= addRangeMetadata(0, 32, Call);
        break;

      default:
        break;
      }
    }
  }

  return Changed;
}
OpenPOWER on IntegriCloud