about summary refs log tree commit diff
path: root/sysdeps/i386
diff options
context:
space:
mode:
authorSzabolcs Nagy <szabolcs.nagy@arm.com>2017-09-04 17:53:47 +0100
committerSzabolcs Nagy <szabolcs.nagy@arm.com>2017-09-29 17:17:41 +0100
commit875c76c7048fe4a8c67c265cdae057cb3ca19f44 (patch)
treeee66c284e87c2a5b62b7d6e39fcdd0295bd058cc /sysdeps/i386
parent90c42e40d06ee35c4a2206fa2e00f49a988ee0c1 (diff)
downloadglibc-875c76c7048fe4a8c67c265cdae057cb3ca19f44.tar.gz
glibc-875c76c7048fe4a8c67c265cdae057cb3ca19f44.tar.xz
glibc-875c76c7048fe4a8c67c265cdae057cb3ca19f44.zip
New generic log2f
Similar to the new logf: double precision arithmetics and a small
lookup table is used. The argument reduction step is the same as in
the new logf.

without wrapper on aarch64:
log2f reciprocal-throughput: 2.3x faster
log2f latency: 2.1x faster
old worst case error: 1.72 ulp
new worst case error: 0.75 ulp
aarch64 .text size: -252 bytes
aarch64 .rodata size: +244 bytes

	* math/Makefile (type-float-routines): Add e_log2f_data.
	* sysdeps/ieee754/flt-32/e_log2f.c: New implementation.
	* sysdeps/ieee754/flt-32/e_log2f_data.c: New file.
	* sysdeps/ieee754/flt-32/math_config.h (__log2f_data): Define.
	(LOG2F_TABLE_BITS, LOG2F_POLY_ORDER): Define.
	* sysdeps/i386/fpu/e_log2f_data.c: New file.
	* sysdeps/ia64/fpu/e_log2f_data.c: New file.
	* sysdeps/m68k/m680x0/fpu/e_log2f_data.c: New file.
Diffstat (limited to 'sysdeps/i386')
-rw-r--r--sysdeps/i386/fpu/e_log2f_data.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/e_log2f_data.c b/sysdeps/i386/fpu/e_log2f_data.c
new file mode 100644
index 0000000000..1cc8931700
--- /dev/null
+++ b/sysdeps/i386/fpu/e_log2f_data.c
@@ -0,0 +1 @@
+/* Not needed.  */