| Message ID | 20170602194258.GA21335@lucon.org |
|---|---|
| State | New |
| Headers | show |
On Fri, Jun 2, 2017 at 12:42 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: > Should they go into include/libc-symbols.h so that they are available > everywhere? > > H.J. > --- > 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: > > __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 ()); > > 2017-06-02 Adhemerval Zanella <adhemerval.zanella@linaro.org> > H.J. Lu <hongjiu.lu@intel.com> > > * sysdeps/x86/init-arch.h (PASTER1): New. > (EVALUATOR1): Likewise. > (PASTER2): Likewise. > (EVALUATOR2): Likewise. > (REDIRECT_NAME): Likewise. > (OPTIMIZE): Likewise. > (IFUNC_SELECTOR): Likewise. > --- > sysdeps/x86/init-arch.h | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > diff --git a/sysdeps/x86/init-arch.h b/sysdeps/x86/init-arch.h > index 6cbc16b..15d3f09 100644 > --- a/sysdeps/x86/init-arch.h > +++ b/sysdeps/x86/init-arch.h > @@ -21,6 +21,46 @@ > # 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 > -- > 2.9.4 > I will check it in today to unblock my AVX2 patches.
diff --git a/sysdeps/x86/init-arch.h b/sysdeps/x86/init-arch.h index 6cbc16b..15d3f09 100644 --- a/sysdeps/x86/init-arch.h +++ b/sysdeps/x86/init-arch.h @@ -21,6 +21,46 @@ # 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
Should they go into include/libc-symbols.h so that they are available everywhere? H.J. --- 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: __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 ()); 2017-06-02 Adhemerval Zanella <adhemerval.zanella@linaro.org> H.J. Lu <hongjiu.lu@intel.com> * sysdeps/x86/init-arch.h (PASTER1): New. (EVALUATOR1): Likewise. (PASTER2): Likewise. (EVALUATOR2): Likewise. (REDIRECT_NAME): Likewise. (OPTIMIZE): Likewise. (IFUNC_SELECTOR): Likewise. --- sysdeps/x86/init-arch.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)