1 /*===- InstrProfiling.c - Support library for PGO instrumentation ---------===*\
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 #include "InstrProfiling.h"
11 #include <string.h>
12 
13 uint64_t __llvm_profile_get_magic(void) {
14   /* Magic number to detect file format and endianness.
15    *
16    * Use 255 at one end, since no UTF-8 file can use that character.  Avoid 0,
17    * so that utilities, like strings, don't grab it as a string.  129 is also
18    * invalid UTF-8, and high enough to be interesting.
19    *
20    * Use "lprofr" in the centre to stand for "LLVM Profile Raw", or "lprofR"
21    * for 32-bit platforms.
22    */
23   unsigned char R = sizeof(void *) == sizeof(uint64_t) ? 'r' : 'R';
24   return
25     (uint64_t)255 << 56 |
26     (uint64_t)'l' << 48 |
27     (uint64_t)'p' << 40 |
28     (uint64_t)'r' << 32 |
29     (uint64_t)'o' << 24 |
30     (uint64_t)'f' << 16 |
31     (uint64_t) R  <<  8 |
32     (uint64_t)129;
33 }
34 
35 uint64_t __llvm_profile_get_version(void) {
36   /* This should be bumped any time the output format changes. */
37   return 1;
38 }
39 
40 void __llvm_profile_reset_counters(void) {
41   uint64_t *I = __llvm_profile_counters_begin();
42   uint64_t *E = __llvm_profile_counters_end();
43 
44   memset(I, 0, sizeof(uint64_t)*(E - I));
45 }
46