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 __attribute__((visibility("hidden"))) __llvm_profile_get_magic(void)14uint64_t __llvm_profile_get_magic(void) { 15 /* Magic number to detect file format and endianness. 16 * 17 * Use 255 at one end, since no UTF-8 file can use that character. Avoid 0, 18 * so that utilities, like strings, don't grab it as a string. 129 is also 19 * invalid UTF-8, and high enough to be interesting. 20 * 21 * Use "lprofr" in the centre to stand for "LLVM Profile Raw", or "lprofR" 22 * for 32-bit platforms. 23 */ 24 unsigned char R = sizeof(void *) == sizeof(uint64_t) ? 'r' : 'R'; 25 return 26 (uint64_t)255 << 56 | 27 (uint64_t)'l' << 48 | 28 (uint64_t)'p' << 40 | 29 (uint64_t)'r' << 32 | 30 (uint64_t)'o' << 24 | 31 (uint64_t)'f' << 16 | 32 (uint64_t) R << 8 | 33 (uint64_t)129; 34 } 35 36 __attribute__((visibility("hidden"))) __llvm_profile_get_version(void)37uint64_t __llvm_profile_get_version(void) { 38 /* This should be bumped any time the output format changes. */ 39 return 1; 40 } 41 42 __attribute__((visibility("hidden"))) __llvm_profile_reset_counters(void)43void __llvm_profile_reset_counters(void) { 44 uint64_t *I = __llvm_profile_counters_begin(); 45 uint64_t *E = __llvm_profile_counters_end(); 46 47 memset(I, 0, sizeof(uint64_t)*(E - I)); 48 } 49