powerpc: refactor logb{f,l}

The power7 logb implementation does not show a performance gain on
ISA 2.07+ chips with faster floating-point to GRP instructions
(currently POWER8 and POWER9).

This patch moves the POWER7 implementation to generic one and enables
it for POWER7.  It also add some cleanup to use inline floating-point
number instead of define them using static const.

The performance difference is for POWER9:

  - Without patch:
  "logb": {
   "subnormal": {
    "duration": 4.99202e+09,
    "iterations": 8.83662e+08,
    "max": 75.194,
    "min": 5.501,
    "mean": 5.64925
   },
   "normal": {
    "duration": 4.97063e+09,
    "iterations": 9.97094e+08,
    "max": 46.489,
    "min": 4.956,
    "mean": 4.98512
   }
  }

  - With patch:
  "logb": {
   "subnormal": {
    "duration": 4.97226e+09,
    "iterations": 9.92036e+08,
    "max": 77.209,
    "min": 4.892,
    "mean": 5.01218
   },
   "normal": {
    "duration": 4.96192e+09,
    "iterations": 1.07545e+09,
    "max": 12.361,
    "min": 4.593,
    "mean": 4.61382
   }
  }

The ifunc implementation is also enabled only for powerpc64.

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/powerpc/power7/fpu/s_logb.c: Move to ...
	* sysdeps/powerpc/fpu/s_logb.c: ... here.  Use inline FP constants.
	* sysdeps/powerpc/power7/fpu/s_logbf.c: Move to ...
	* sysdeps/powerpc/fpu/s_logbf.c: ... here.  Use inline FP constants.
	* sysdeps/powerpc/power7/fpu/s_logbl.c: Move to ...
	* sysdeps/powerpc/fpu/s_logbl.c: ... here.  Use inline FP constants.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logb-power7.c:
	Adjust implementation path.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logbf-power7.c:
	Adjust implementation path.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logbl-power7.c:
	Adjust implementation path.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile
	(libm-sysdep_routines): Add s_log* objects.
	(CFLAGS-s_logbf-power7.c, CFLAGS-s_logbl-power7.c,
	CFLAGS-s_logb-power7.c): New fule.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-power7.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-power7.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-ppc64.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-ppc64.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-power7.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-power7.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-ppc64.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-ppc64.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-power7.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-power7.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-ppc64.c: Move
	to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-ppc64.c:
	... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile: Remove file.
	* sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c: Remove file.
	* sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c: Likewise.
	* sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c: Likewise.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>

14 files changed, 16 insertions, 17 deletions

diff --git a/sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile
index f5fa357d57..b27bad3ba4 100644
--- a/sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile
@@ -32,6 +32,12 @@ libm-sysdep_routines += s_ceil-power5+ \
 			s_llround-power5+ \
 			s_llround-ppc64 \
 			s_llroundf-ppc64 \
+			s_logb-power7 \
+			s_logbf-power7 \
+			s_logbl-power7 \
+			s_logb-ppc64 \
+			s_logbf-ppc64 \
+			s_logbl-ppc64 \
 			$(sysdep_calls:s_%=m_%)
 
 CFLAGS-s_ceil-power5+.c = -mcpu=power5+
@@ -50,6 +56,10 @@ CFLAGS-s_llround-power5+.c += -mcpu=power5+
 
 CFLAGS-s_modf-power5+.c += -mcpu=power5+
 CFLAGS-s_modff-power5+.c += -mcpu=power5+
+CFLAGS-s_logbf-power7.c = -mcpu=power7
+CFLAGS-s_logbl-power7.c = -mcpu=power7
+CFLAGS-s_logb-power7.c = -mcpu=power7
+
 # These files quiet sNaNs in a way that is optimized away without
 # -fsignaling-nans.
 CFLAGS-s_modf-ppc64.c += -fsignaling-nans
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-power7.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-power7.c
index 507862b2bf..807bf58eeb 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-power7.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-power7.c
@@ -16,4 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logb-power7.c>
+#define __logb __logb_power7
+#include <sysdeps/powerpc/fpu/s_logb.c>
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-ppc64.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-ppc64.c
index 8aae1e8f12..8aae1e8f12 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb-ppc64.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb-ppc64.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb.c
index b6d7225112..b6d7225112 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logb.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logb.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-power7.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-power7.c
index 3535ea78cd..4fee11dd84 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-power7.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-power7.c
@@ -16,4 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logbf-power7.c>
+#define __logbf __logbf_power7
+#include <sysdeps/powerpc/fpu/s_logbf.c>
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-ppc64.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-ppc64.c
index 727fabc03c..727fabc03c 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf-ppc64.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf-ppc64.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf.c
index 46875dcde2..46875dcde2 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbf.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbf.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-power7.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-power7.c
index 915636176d..c413d6e50d 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-power7.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-power7.c
@@ -16,4 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_logbl-power7.c>
+#define __logbl __logbl_power7
+#include <sysdeps/powerpc/fpu/s_logbl.c>
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-ppc64.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-ppc64.c
index ffe6e17d5e..ffe6e17d5e 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl-ppc64.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl-ppc64.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl.c b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl.c
index d44122a12b..d44122a12b 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_logbl.c
+++ b/sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_logbl.c
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
deleted file mode 100644
index d7ad1e2724..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
+++ /dev/null
@@ -1,11 +0,0 @@
-ifeq ($(subdir),math)
-sysdep_routines += $(sysdep_calls)
-libm-sysdep_routines += s_logb-power7 s_logbf-power7 \
-			s_logbl-power7 s_logb-ppc64 s_logbf-ppc64 \
-			s_logbl-ppc64 \
-			$(sysdep_calls:s_%=m_%)
-
-CFLAGS-s_logbf-power7.c = -mcpu=power7
-CFLAGS-s_logbl-power7.c = -mcpu=power7
-CFLAGS-s_logb-power7.c = -mcpu=power7
-endif
diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c
deleted file mode 100644
index 2599c771d9..0000000000
--- a/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/powerpc/power7/fpu/s_logb.c>
diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c
deleted file mode 100644
index 7a5a8032e0..0000000000
--- a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/powerpc/power7/fpu/s_logbf.c>
diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c
deleted file mode 100644
index 524ae2c78d..0000000000
--- a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/powerpc/power7/fpu/s_logbl.c>