powerpc: Remove optimized isnan

The powerpc isnan optimizations are not really a gain:

  - GCC will call libm iff -fsignaling-nans is used. This usage pattern
    is usually not performance oriented and for such calls PLT overhead
    should dominate execution time.

  - The power5, power6, and power6x are just micro-optimization to
    improve the Load-Hit-Store hazards from floating-point to general
    register transfer, and current GCC already has support to minimize
    it by inserting either extra nops or group dispatch instructions.

  - The power7 uses ftdiv to optimize for some input patterns, but at
    cost of others.  Comparing against generic C implementation built
    for powerpc-linux-gnu-power4 (which uses the hp-timing support on
    benchtests):

    - Generic sysdeps/ieee754 implementation:
      "isnan": {
       "": {
        "duration": 4.98415e+09,
        "iterations": 2.34516e+09,
        "max": 45.925,
        "min": 2.052,
        "mean": 2.12529
       },
       "INF": {
        "duration": 4.74057e+09,
        "iterations": 1.69761e+09,
        "max": 91.01,
        "min": 2.052,
        "mean": 2.79249
       },
       "NAN": {
        "duration": 4.74071e+09,
        "iterations": 1.68768e+09,
        "max": 282.343,
        "min": 2.052,
        "mean": 2.809
       }
      }

    - power7 optimized one:
    $ ./testrun.sh benchtests/bench-isnan
      "isnan": {
       "": {
        "duration": 4.96842e+09,
        "iterations": 2.56297e+09,
        "max": 50.048,
        "min": 1.872,
        "mean": 1.93854
       },
       "INF": {
        "duration": 4.76648e+09,
        "iterations": 1.54213e+09,
        "max": 373.408,
        "min": 2.661,
        "mean": 3.09084
       },
       "NAN": {
        "duration": 4.76845e+09,
        "iterations": 1.54515e+09,
        "max": 51.016,
        "min": 2.736,
        "mean": 3.08607
       }
      }

    So it basically optimizes marginally for normal numbers while
    increasing the latency for other kind of FP.

  - The generic implementation requires getting the floating point
    status, disable the invalid operation bit, and restore the
    floating-point status.  Each operation is costly and requires
    flushing the FP pipeline.

    Using the same scenarion for the previous analysis:

      "isnan": {
       "": {
        "duration": 5.08284e+09,
        "iterations": 6.2898e+08,
        "max": 41.844,
        "min": 8.057,
        "mean": 8.08108
       },
       "INF": {
        "duration": 4.97904e+09,
        "iterations": 6.16176e+08,
        "max": 39.661,
        "min": 8.057,
        "mean": 8.08055
       },
       "NAN": {
        "duration": 4.98695e+09,
        "iterations": 5.95866e+08,
        "max": 29.728,
        "min": 8.345,
        "mean": 8.36925
       }
      }

  - The power8 implementation is just the generic implementation using
    ISA 2.07 mfvsrd instruction (which GCC uses for generic implementation).
    So generic implementation is the best option for powerpc64le.

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/fpu/s_isnan.c: Remove file.
	* sysdeps/powerpc/fpu/s_isnanf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile
	(sysdeps_routines, libm-sysdep_routines): Remove s_isnan-* and
	s_isnanf-* objects.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power5.S:
	Remove file
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power6.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power7.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-ppc32.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power5.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power6.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c: Likewise.
	* sysdeps/powerpc/powerpc32/power5/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc32/power5/fpu/s_isnanf.S: Likewise.
	* sysdeps/powerpc/powerpc32/power6/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc32/power6/fpu/s_isnanf.S: Likewise.
	* sysdeps/powerpc/powerpc32/power7/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc32/power7/fpu/s_isnanf.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile (sysdep_calls):
	Remove s_isnan-* and s_isnanf-* objects.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-power5.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-power6.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-power6x.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-power7.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-power8.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan-ppc64.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnanf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power5/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power7/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power7/fpu/s_isnanf.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/s_isnan.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/s_isnanf.S: Likewise.

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

9 files changed, 2 insertions, 287 deletions

diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile
index 7008e775b7..0b39461a1a 100644
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile
@@ -1,6 +1,5 @@
 ifeq ($(subdir),math)
-sysdep_routines += s_isnan-power7 s_isnan-power6 s_isnan-power5 s_isnan-ppc32 \
-		   s_isnanf-power6 s_isnanf-power5 s_isinf-power7 \
+sysdep_routines += s_isinf-power7 \
 		   s_isinf-ppc32 s_isinff-ppc32 s_finite-power7 \
 		   s_finite-ppc32 s_finitef-ppc32 \
 		   s_modf-power5+ s_modf-ppc32 \
@@ -8,9 +7,7 @@ sysdep_routines += s_isnan-power7 s_isnan-power6 s_isnan-power5 s_isnan-ppc32 \
 
 libm-sysdep_routines += s_llrintf-power6 s_llrintf-ppc32 s_llrint-power6 \
 			s_llrint-ppc32 s_llround-power6 s_llround-power5+ \
-			s_llround-ppc32 s_isnan-power7 \
-			s_isnan-power6 s_isnan-power5 s_isnan-ppc32 \
-			s_isnanf-power6 s_isnanf-power5 s_isinf-power7 \
+			s_llround-ppc32 s_isinf-power7 \
 			s_isinf-ppc32 s_isinff-ppc32 s_finite-power7 \
 			s_finite-ppc32 s_finitef-ppc32 s_ceil-power5+ \
 			s_ceil-ppc32 s_ceilf-power5+ s_ceilf-ppc32 \
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power5.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power5.S
deleted file mode 100644
index b4bb2bd4bf..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power5.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/* isnan().  PowerPC32/POWER5 version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-#undef hidden_def
-#define hidden_def(name)
-#undef weak_alias
-#define weak_alias(name, alias)
-#undef strong_alias
-#define strong_alias(name, alias)
-#undef compat_symbol
-#define compat_symbol(lib, name, symbol, ver)
-
-#define __isnan __isnan_power5
-
-#include <sysdeps/powerpc/powerpc32/power5/fpu/s_isnan.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power6.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power6.S
deleted file mode 100644
index c8a429b1e6..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power6.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/* isnan().  PowerPC32/POWER6 version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-#undef hidden_def
-#define hidden_def(name)
-#undef weak_alias
-#define weak_alias(name, alias)
-#undef strong_alias
-#define strong_alias(name, alias)
-#undef compat_symbol
-#define compat_symbol(lib, name, symbol, ver)
-
-#define __isnan __isnan_power6
-
-#include <sysdeps/powerpc/powerpc32/power6/fpu/s_isnan.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power7.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power7.S
deleted file mode 100644
index ae3fc0539b..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-power7.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/* isnan().  PowerPC32/POWER7 version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-#undef hidden_def
-#define hidden_def(name)
-#undef weak_alias
-#define weak_alias(name, alias)
-#undef strong_alias
-#define strong_alias(name, alias)
-#undef compat_symbol
-#define compat_symbol(lib, name, symbol, ver)
-
-#define __isnan __isnan_power7
-
-#include <sysdeps/powerpc/powerpc32/power7/fpu/s_isnan.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-ppc32.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-ppc32.S
deleted file mode 100644
index 4b204ae6cf..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan-ppc32.S
+++ /dev/null
@@ -1,32 +0,0 @@
-/* isnan().  PowerPC32 default version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-#include <math_ldbl_opt.h>
-
-#undef weak_alias
-#define weak_alias(a, b)
-#undef compat_symbol
-#define compat_symbol(a, b, c, d)
-
-#define __isnan __isnan_ppc32
-#undef hidden_def
-#define hidden_def(name)
-  strong_alias (__isnan_ppc32, __GI___isnan)
-
-#include <sysdeps/powerpc/powerpc32/fpu/s_isnan.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c
deleted file mode 100644
index 8a7c31f998..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/* Multiple versions of isnan.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#define __isnan __redirect___isnan
-#define __isnanf __redirect___isnanf
-#define __isnanl __redirect___isnanl
-#include <math.h>
-#include <math_ldbl_opt.h>
-#include <shlib-compat.h>
-#include "init-arch.h"
-
-extern __typeof (__isnan) __isnan_ppc32 attribute_hidden;
-extern __typeof (__isnan) __isnan_power5 attribute_hidden;
-extern __typeof (__isnan) __isnan_power6 attribute_hidden;
-extern __typeof (__isnan) __isnan_power7 attribute_hidden;
-#undef __isnan
-#undef __isnanf
-#undef __isnanl
-
-libc_ifunc_redirected (__redirect___isnan, __isnan,
-		       (hwcap & PPC_FEATURE_ARCH_2_06)
-		       ? __isnan_power7
-		       : (hwcap & PPC_FEATURE_ARCH_2_05)
-			 ? __isnan_power6
-			 : (hwcap & PPC_FEATURE_POWER5)
-			   ? __isnan_power5
-			   : __isnan_ppc32);
-
-weak_alias (__isnan, isnan)
-
-#ifdef NO_LONG_DOUBLE
-strong_alias (__isnan, __isnanl)
-weak_alias (__isnan, isnanl)
-#endif
-
-#if !IS_IN (libm)
-# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
-compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
-compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
-# endif
-#endif
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power5.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power5.S
deleted file mode 100644
index c456d82999..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power5.S
+++ /dev/null
@@ -1,28 +0,0 @@
-/* isnanf().  PowerPC32/POWER5 version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-
-#undef hidden_def
-#define hidden_def(name)
-#undef weak_alias
-#define weak_alias(name, alias)
-
-#define __isnanf __isnanf_power5
-
-#include <sysdeps/powerpc/powerpc32/power5/fpu/s_isnanf.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power6.S b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power6.S
deleted file mode 100644
index 0133cf218f..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf-power6.S
+++ /dev/null
@@ -1,28 +0,0 @@
-/* isnanf().  PowerPC32/POWER6 version.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <sysdep.h>
-
-#undef hidden_def
-#define hidden_def(name)
-#undef weak_alias
-#define weak_alias(name, alias)
-
-#define __isnanf __isnanf_power6
-
-#include <sysdeps/powerpc/powerpc32/power6/fpu/s_isnanf.S>
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c b/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c
deleted file mode 100644
index acb84dbc61..0000000000
--- a/sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c
+++ /dev/null
@@ -1,39 +0,0 @@
-/* Multiple versions of isnanf.
-   Copyright (C) 2013-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   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/>.  */
-
-#include <math.h>
-#include <shlib-compat.h>
-#include "init-arch.h"
-
-/* Both ppc32 and power7 isnan(double) work for float.  */
-extern __typeof (__isnanf) __isnan_ppc32 attribute_hidden;
-extern __typeof (__isnanf) __isnanf_power5 attribute_hidden;
-extern __typeof (__isnanf) __isnanf_power6 attribute_hidden;
-extern __typeof (__isnanf) __isnan_power7 attribute_hidden;
-
-libc_ifunc_hidden (__isnanf, __isnanf,
-		   (hwcap & PPC_FEATURE_ARCH_2_06)
-		   ? __isnan_power7
-		   : (hwcap & PPC_FEATURE_ARCH_2_05)
-		     ? __isnanf_power6
-		     : (hwcap & PPC_FEATURE_POWER5)
-		       ? __isnanf_power5
-		       : __isnan_ppc32);
-
-hidden_def (__isnanf)
-weak_alias (__isnanf, isnanf)