glibc/sysdeps/i386
Szabolcs Nagy f41b0a43e4 Add new log implementation
Optimized log using carefully generated lookup table with 1/c and log(c)
values for small intervalls around 1.  The log(c) is very near a double
precision value, it has about 62 bits precision.  The algorithm is
log(2^k x) = k log(2) + log(c) + log(x/c), where the last term is
approximated by a polynomial of x/c - 1.  Near 1 a single polynomial of
x - 1 is used.

There is separate code path when fma instruction is not available for
computing x/c - 1 precisely, in which case the table size is doubled.
The code uses __builtin_fma under __FP_FAST_FMA to ensure it is inlined
as an instruction.

With the default configuration settings the worst case error is 0.519 ULP
(and 0.520 without fma), the rodata size is 2192 bytes (4240 without fma).
The non-nearest rounding error is less than 1 ULP.

Improvements on Cortex-A72 compared to current glibc master:
log thruput: 3.28x in [0.01 11.1]
log latency: 2.23x in [0.01 11.1]
log thruput: 1.56x in [0.999 1.001]
log latency: 1.57x in [0.999 1.001]

Tested on
aarch64-linux-gnu (defined __FP_FAST_FMA)
arm-linux-gnueabihf (!defined __FP_FAST_FMA)
x86_64-linux-gnu (!defined __FP_FAST_FMA)
powerpc64le-linux-gnu (defined __FP_FAST_FMA)
targets.

	* NEWS: Mention log improvement.
	* math/Makefile (type-double-routines): Add e_log_data.
	* sysdeps/i386/fpu/e_log_data.c: New file.
	* sysdeps/ia64/fpu/e_log_data.c: New file.
	* sysdeps/ieee754/dbl-64/e_log.c: Rewrite.
	* sysdeps/ieee754/dbl-64/e_log_data.c: New file.
	* sysdeps/ieee754/dbl-64/math_config.h (__log_data): Add.
	* sysdeps/ieee754/dbl-64/ulog.h: Remove.
	* sysdeps/ieee754/dbl-64/ulog.tbl: Remove.
	* sysdeps/m68k/m680x0/fpu/e_log_data.c: New file.
2018-09-12 17:33:30 +01:00
..
fpu Add new log implementation 2018-09-12 17:33:30 +01:00
htl hurd: Bump remaining LGPL2+ htl licences to LGPL 2.1+ 2018-04-02 16:37:36 +02:00
i586 Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
i686 x86: Don't include <init-arch.h> in assembly codes 2018-08-03 08:05:00 -07:00
i786
nptl x86: Rename __glibc_reserved2 to ssp_base in tcbhead_t 2018-07-25 04:39:39 -07:00
sys Drop fpregset unused symbol exposition 2018-04-20 01:27:13 +02:00
____longjmp_chk.S Add sigstack handling to Linux ____longjmp_chk on i386. 2009-07-30 21:50:14 -07:00
__longjmp.S x86: Support shadow stack pointer in setjmp/longjmp 2018-07-14 05:59:53 -07:00
abort-instr.h
add_n.S i386: Add _CET_ENDBR to indirect jump targets in add_n.S/sub_n.S 2018-07-17 16:11:44 -07:00
addmul_1.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
asm-syntax.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
atomic-machine.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
backtrace.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bcopy.S Add i386 memset and memcpy assembly functions 2015-08-27 09:04:54 -07:00
bsd-_setjmp.S x86: Support shadow stack pointer in setjmp/longjmp 2018-07-14 05:59:53 -07:00
bsd-setjmp.S x86: Support shadow stack pointer in setjmp/longjmp 2018-07-14 05:59:53 -07:00
bzero.S Add i386 memset and memcpy assembly functions 2015-08-27 09:04:54 -07:00
cacheinfo.c Move sysdeps/x86_64/cacheinfo.c to sysdeps/x86 2016-05-08 08:49:18 -07:00
configure Add --enable-static-pie configure option to build static PIE [BZ #19574] 2017-12-15 17:12:14 -08:00
configure.ac Add --enable-static-pie configure option to build static PIE [BZ #19574] 2017-12-15 17:12:14 -08:00
crti.S x86: Add _CET_ENDBR to functions in crti.S 2018-07-17 16:05:18 -07:00
crtn.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
dl-cet.c x86: Support IBT and SHSTK in Intel CET [BZ #21598] 2018-07-16 14:08:27 -07:00
dl-irel.h [BZ #20271] Add newlines in __libc_fatal calls. 2018-08-31 18:04:32 -07:00
dl-lookupcfg.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
dl-machine.h elf: Unify symbol address run-time calculation [BZ #19818] 2018-04-04 23:09:37 +01:00
dl-procinfo.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
dl-tls.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
dl-tlsdesc.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
dl-tlsdesc.S x86: Add _CET_ENDBR to functions in dl-tlsdesc.S 2018-07-17 16:07:17 -07:00
dl-trampoline.S x86: Support IBT and SHSTK in Intel CET [BZ #21598] 2018-07-16 14:08:27 -07:00
ffs.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
gccframe.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
gmp-mparam.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
htonl.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
htons.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
i386-mcount.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Implies Add float128 support for x86_64, x86. 2017-06-26 22:02:24 +00:00
init-arch.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
jmpbuf-offsets.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
jmpbuf-unwind.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
ldbl2mpn.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
link-defines.sym Preserve bound registers for pointer pass/return 2015-07-09 06:50:12 -07:00
lshift.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
machine-gmon.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Makefile math: Set 387 and SSE2 rounding mode for tgamma on i386 [BZ #23253] 2018-06-21 08:04:29 +02:00
malloc-alignment.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memchr.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcmp.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcopy.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcpy_chk.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcpy.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memmove_chk.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memmove.S Add i386 memset and memcpy assembly functions 2015-08-27 09:04:54 -07:00
mempcpy_chk.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
mempcpy.S Add i386 memset and memcpy assembly functions 2015-08-27 09:04:54 -07:00
memset_chk.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memset.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memusage.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
mp_clz_tab.c
mul_1.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
preconfigure Move base_machine and machine settings from configure.ac to sysdeps preconfigure fragments. 2014-06-25 17:52:56 +00:00
pthread_spin_trylock.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
rawmemchr.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
rshift.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
setfpucw.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
setjmp.S x86: Support shadow stack pointer in setjmp/longjmp 2018-07-14 05:59:53 -07:00
stackguard-macros.h BZ #15754: CVE-2013-4788 2013-09-23 00:52:09 -04:00
stackinfo.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
start.S i386: Use ENTRY and END in start.S [BZ #23606] 2018-09-12 08:41:26 -07:00
stpcpy.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stpncpy.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcat.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strchr.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strchrnul.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcspn.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
string-inlines.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strlen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strlen.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strpbrk.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strrchr.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strspn.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sub_n.S i386: Add _CET_ENDBR to indirect jump targets in add_n.S/sub_n.S 2018-07-17 16:11:44 -07:00
submul_1.S Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
symbol-hacks.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sysdep.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tls-macros.h i386: Fix build by GCC 5.0 2014-12-30 11:37:41 -08:00
tlsdesc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tlsdesc.sym Introduce TLS descriptors for i386 and x86_64. 2008-05-13 05:41:30 +00:00
tst-audit3.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-audit3.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-audit.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-auditmod3a.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-auditmod3b.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-ld-sse-use.sh Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-stack-align.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Versions Move __fentry__ version definition to sysdeps/{i386,x86_64} 2018-08-10 09:07:44 +02:00