diff options
Diffstat (limited to 'REORG.TODO/sysdeps/x86/init-arch.h')
-rw-r--r-- | REORG.TODO/sysdeps/x86/init-arch.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/x86/init-arch.h b/REORG.TODO/sysdeps/x86/init-arch.h new file mode 100644 index 0000000000..15d3f0975d --- /dev/null +++ b/REORG.TODO/sysdeps/x86/init-arch.h @@ -0,0 +1,75 @@ +/* This file is part of the GNU C Library. + Copyright (C) 2008-2017 Free Software Foundation, Inc. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifdef __ASSEMBLER__ +# include <cpu-features.h> +#else +# include <ldsodefs.h> +#endif + +/* These macros are used to implement ifunc selection in C. To implement + an ifunc function, foo, which returns the address of __foo_sse2 or + __foo_avx2: + + #define foo __redirect_foo + #define __foo __redirect___foo + #include <foo.h> + #undef foo + #undef __foo + #define SYMBOL_NAME foo + #include <init-arch.h> + + extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden; + extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden; + + static inline void * + foo_selector (void) + { + if (use AVX2) + return OPTIMIZE (avx2); + + return OPTIMIZE (sse2); + } + + libc_ifunc_redirected (__redirect_foo, foo, foo_selector ()); + +*/ + +#define PASTER1(x,y) x##_##y +#define EVALUATOR1(x,y) PASTER1 (x,y) +#define PASTER2(x,y) __##x##_##y +#define EVALUATOR2(x,y) PASTER2 (x,y) + +/* Basically set '__redirect_<symbol>' to use as type definition, + '__<symbol>_<variant>' as the optimized implementation and + '<symbol>_ifunc_selector' as the IFUNC selector. */ +#define REDIRECT_NAME EVALUATOR1 (__redirect, SYMBOL_NAME) +#define OPTIMIZE(name) EVALUATOR2 (SYMBOL_NAME, name) +#define IFUNC_SELECTOR EVALUATOR1 (SYMBOL_NAME, ifunc_selector) + +#ifndef __x86_64__ +/* Due to the reordering and the other nifty extensions in i686, it is + not really good to use heavily i586 optimized code on an i686. It's + better to use i486 code if it isn't an i586. */ +# if MINIMUM_ISA == 686 +# define USE_I586 0 +# define USE_I686 1 +# else +# define USE_I586 (HAS_ARCH_FEATURE (I586) && !HAS_ARCH_FEATURE (I686)) +# define USE_I686 HAS_ARCH_FEATURE (I686) +# endif +#endif |