1//===-- NVPTXutil.cpp - Functions exported to CodeGen --*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the functions that can be used in CodeGen.
11//
12//===----------------------------------------------------------------------===//
13
14#include "NVPTXutil.h"
15#include "NVPTX.h"
16
17using namespace llvm;
18
19namespace llvm {
20
21bool isParamLoad(const MachineInstr *MI)
22{
23  if ((MI->getOpcode() != NVPTX::LD_i32_avar) &&
24      (MI->getOpcode() != NVPTX::LD_i64_avar))
25    return false;
26  if (MI->getOperand(2).isImm() == false)
27    return false;
28  if (MI->getOperand(2).getImm() != NVPTX::PTXLdStInstCode::PARAM)
29    return false;
30  return true;
31}
32
33#define DATA_MASK     0x7f
34#define DIGIT_WIDTH   7
35#define MORE_BYTES    0x80
36
37static int encode_leb128(uint64_t val, int *nbytes,
38                         char *space, int splen)
39{
40  char *a;
41  char *end = space + splen;
42
43  a = space;
44  do {
45    unsigned char uc;
46
47    if (a >= end)
48      return 1;
49    uc = val & DATA_MASK;
50    val >>= DIGIT_WIDTH;
51    if (val != 0)
52      uc |= MORE_BYTES;
53    *a = uc;
54    a++;
55  } while (val);
56  *nbytes = a - space;
57  return 0;
58}
59
60#undef DATA_MASK
61#undef DIGIT_WIDTH
62#undef MORE_BYTES
63
64uint64_t encode_leb128(const char *str)
65{
66  union { uint64_t x; char a[8]; } temp64;
67
68  temp64.x = 0;
69
70  for (unsigned i=0,e=strlen(str); i!=e; ++i)
71    temp64.a[i] = str[e-1-i];
72
73  char encoded[16];
74  int nbytes;
75
76  int retval = encode_leb128(temp64.x, &nbytes, encoded, 16);
77
78  (void)retval;
79  assert(retval == 0 &&
80         "Encoding to leb128 failed");
81
82  assert(nbytes <= 8 &&
83         "Cannot support register names with leb128 encoding > 8 bytes");
84
85  temp64.x = 0;
86  for (int i=0; i<nbytes; ++i)
87    temp64.a[i] = encoded[i];
88
89  return temp64.x;
90}
91
92} // end namespace llvm
93