powerpc: Use generic e_expf

Generic implementation is faster on both power8 and power9:

POWER9:
- sysdeps/ieee754/flt-32/e_expf.c
  "expf": {
   "workload-spec2017.wrf": {
    "duration": 5.1236e+09,
    "iterations": 7.53344e+08,
    "reciprocal-throughput": 5.9436,
    "latency": 7.65869,
    "max-throughput": 1.68248e+08,
    "min-throughput": 1.30571e+08
   }
  }

- sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S
  "expf": {
   "workload-spec2017.wrf": {
    "duration": 5.14429e+09,
    "iterations": 5.29248e+08,
    "reciprocal-throughput": 8.05372,
    "latency": 11.3863,
    "max-throughput": 1.24166e+08,
    "min-throughput": 8.78249e+07
   }
  }

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/powerpc64/fpu/multiarch/Makefile
	(libm-sysdep_routines): Remove e_expf-power8 and expf-ppc64.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S: Remove
	file.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-ppc64.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/w_expf.c: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/w_expf.c: Likewise.

Reviewed-by: Gabriel F. T. Gomes <gabriel@inconstante.eti.br>

8 files changed, 10 insertions, 383 deletions

diff --git a/ChangeLog b/ChangeLog
index 18eb4d205f..ac4aba09ba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
 2019-06-26  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
+	(libm-sysdep_routines): Remove e_expf-power8 and expf-ppc64.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S: Remove
+	file.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-ppc64.c: Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf.c: Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/w_expf.c: Likewise.
+	* sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S: Likewise.
+	* sysdeps/powerpc/powerpc64/power8/fpu/w_expf.c: Likewise.
+
 	* sysdeps/powerpc/powerpc32/fpu/Makefile
 	[$(subdir) == math] (CFLAGS-s_lround.c): New rule.
 	* sysdeps/powerpc/powerpc32/fpu/s_llround.c (__llround): Add power5+
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
index 48cf8dca3b..118865a1a9 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
@@ -10,7 +10,6 @@ libm-sysdep_routines += s_logb-power7 s_logbf-power7 \
 			s_logbl-power7 s_logb-ppc64 s_logbf-ppc64 \
 			s_logbl-ppc64 e_hypot-ppc64 \
 			e_hypot-power7 e_hypotf-ppc64 e_hypotf-power7 \
-			e_expf-power8 e_expf-ppc64 \
 			$(sysdep_calls:s_%=m_%)
 
 CFLAGS-s_logbf-power7.c = -mcpu=power7
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S
deleted file mode 100644
index e0e14c2a47..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S
+++ /dev/null
@@ -1,24 +0,0 @@
-/* __ieee754_expf() POWER8 version.
-   Copyright (C) 2016-2019 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/>.  */
-
-#undef strong_alias
-#define strong_alias(a, b)
-
-#define __ieee754_expf __ieee754_expf_power8
-
-#include <sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S>
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-ppc64.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-ppc64.c
deleted file mode 100644
index 00c2006d41..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-ppc64.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/* __ieee_expf() PowerPC64 version.
-   Copyright (C) 2016-2019 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 __expf __ieee754_expf_ppc64
-
-#include <sysdeps/ieee754/flt-32/e_expf.c>
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf.c
deleted file mode 100644
index dc0023c244..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Multiple versions of ieee754_expf.
-   Copyright (C) 2016-2019 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 <math_private.h>
-#include <math_ldbl_opt.h>
-#include "init-arch.h"
-
-extern __typeof (__ieee754_expf) __ieee754_expf_ppc64 attribute_hidden;
-extern __typeof (__ieee754_expf) __ieee754_expf_power8 attribute_hidden;
-
-libc_ifunc (__ieee754_expf,
-	    (hwcap2 & PPC_FEATURE2_ARCH_2_07)
-	    ? __ieee754_expf_power8
-	    : __ieee754_expf_ppc64);
-
-strong_alias (__ieee754_expf, __expf_finite)
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/w_expf.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/w_expf.c
deleted file mode 100644
index b5fe164520..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/w_expf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/../math/w_expf.c>
diff --git a/sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S b/sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S
deleted file mode 100644
index 7469a72873..0000000000
--- a/sysdeps/powerpc/powerpc64/power8/fpu/e_expf.S
+++ /dev/null
@@ -1,303 +0,0 @@
-/* Optimized expf().  PowerPC64/POWER8 version.
-   Copyright (C) 2016-2019 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>
-
-/* Short algorithm description:
- *
- *  Let K = 64 (table size).
- *       e^x  = 2^(x/log(2)) = 2^n * T[j] * (1 + P(y))
- *  where:
- *       x = m*log(2)/K + y,    y in [0.0..log(2)/K]
- *       m = n*K + j,           m,n,j - signed integer, j in [0..K-1]
- *       values of 2^(j/K) are tabulated as T[j].
- *
- *       P(y) is a minimax polynomial approximation of expf(y)-1
- *       on small interval [0.0..log(2)/K].
- *
- *       P(y) = P3*y*y*y*y + P2*y*y*y + P1*y*y + P0*y, calculated as
- *       z = y*y;    P(y) = (P3*z + P1)*z + (P2*z + P0)*y
- *
- * Special cases:
- *  expf(NaN) = NaN
- *  expf(+INF) = +INF
- *  expf(-INF) = 0
- *  expf(x) = 1 for subnormals
- *  for finite argument, only expf(0)=1 is exact
- *  expf(x) overflows if x>88.7228317260742190
- *  expf(x) underflows if x<-103.972076416015620
- */
-
-#define C1 0x42ad496b		/* Single precision 125*log(2).  */
-#define C2 0x31800000		/* Single precision 2^(-28).  */
-#define SP_INF 0x7f800000	/* Single precision Inf.  */
-#define SP_EXP_BIAS 0x1fc0	/* Single precision exponent bias.  */
-
-#define DATA_OFFSET r9
-
-/* Implements the function
-
-   float [fp1] expf (float [fp1] x)  */
-
-	.machine power8
-ENTRY (__ieee754_expf, 4)
-	addis	DATA_OFFSET,r2,.Lanchor@toc@ha
-	addi	DATA_OFFSET,DATA_OFFSET,.Lanchor@toc@l
-
-	xscvdpspn v0,v1
-	mfvsrd	r8,v0		/* r8 = x  */
-	lfd	fp2,(.KLN2-.Lanchor)(DATA_OFFSET)
-	lfd	fp3,(.P2-.Lanchor)(DATA_OFFSET)
-	rldicl	r3,r8,32,33	/* r3 = |x|  */
-	lis	r4,C1@ha	/* r4 = 125*log(2)  */
-	ori	r4,r4,C1@l
-	cmpw	r3,r4
-	lfd	fp5,(.P3-.Lanchor)(DATA_OFFSET)
-	lfd	fp4,(.RS-.Lanchor)(DATA_OFFSET)
-	fmadd	fp2,fp1,fp2,fp4	/* fp2 = x * K/log(2) + (2^23 + 2^22)  */
-	bge	L(special_paths)	/* |x| >= 125*log(2) ?  */
-
-	lis	r4,C2@ha
-	ori	r4,r4,C2@l
-	cmpw	r3,r4
-	blt	L(small_args)	/* |x| < 2^(-28) ?  */
-
-	/* Main path: here if 2^(-28) <= |x| < 125*log(2) */
-	frsp	fp6,fp2
-	xscvdpsp v2,v2
-	mfvsrd	r8,v2
-	mr	r3,r8			/* r3 = m  */
-	rldicl	r8,r8,32,58		/* r8 = j  */
-	lfs	fp4,(.SP_RS-.Lanchor)(DATA_OFFSET)
-	fsubs	fp2,fp6,fp4		/* fp2 = m = x * K/log(2)  */
-	srdi	r3,r3,32
-	clrrwi	r3,r3,6			/* r3 = n  */
-	lfd	fp6,(.NLN2K-.Lanchor)(DATA_OFFSET)
-	fmadd	fp0,fp2,fp6,fp1		/* fp0 = y = x - m*log(2)/K  */
-	fmul	fp2,fp0,fp0		/* fp2 = z = y^2  */
-	lfd	fp4,(.P1-.Lanchor)(DATA_OFFSET)
-	lfd	fp6,(.P0-.Lanchor)(DATA_OFFSET)
-	lis	r4,SP_EXP_BIAS@ha
-	ori	r4,r4,SP_EXP_BIAS@l
-	add	r3,r3,r4
-	rldic	r3,r3,49,1		/* r3 = 2^n  */
-	fmadd	fp4,fp5,fp2,fp4		/* fp4 = P3 * z + P1  */
-	fmadd	fp6,fp3,fp2,fp6		/* fp6 = P2 * z + P0  */
-	mtvsrd	v1,r3
-	xscvspdp v1,v1
-	fmul	fp4,fp4,fp2		/* fp4 = (P3 * z + P1)*z  */
-	fmadd	fp0,fp0,fp6,fp4		/* fp0 = P(y)  */
-	sldi	r8,r8,3			/* Access doublewords from T[j].  */
-	addi	r6,DATA_OFFSET,(.Ttable-.Lanchor)
-	lfdx	fp3,r6,r8
-	fmadd	fp0,fp0,fp3,fp3		/* fp0 = T[j] * (1 + P(y))  */
-	fmul	fp1,fp1,fp0		/* fp1 = 2^n * T[j] * (1 + P(y))  */
-	frsp	fp1,fp1
-	blr
-
-	.align	4
-/* x is either underflow, overflow, infinite or NaN.  */
-L(special_paths):
-	srdi	r8,r8,32
-	rlwinm	r8,r8,3,29,29		/* r8 = 0, if x positive.
-					   r8 = 4, otherwise.  */
-	addi	r6,DATA_OFFSET,(.SPRANGE-.Lanchor)
-	lwzx	r4,r6,r8		/* r4 = .SPRANGE[signbit(x)]  */
-	cmpw	r3,r4
-	/* |x| <= .SPRANGE[signbit(x)]  */
-	ble	L(near_under_or_overflow)
-
-	lis	r4,SP_INF@ha
-	ori	r4,r4,SP_INF@l
-	cmpw	r3,r4
-	bge	L(arg_inf_or_nan)	/* |x| > Infinite ?  */
-
-	addi	r6,DATA_OFFSET,(.SPLARGE_SMALL-.Lanchor)
-	lfsx	fp1,r6,r8
-	fmuls	fp1,fp1,fp1
-	blr
-
-
-	.align	4
-L(small_args):
-	/* expf(x) = 1.0, where |x| < |2^(-28)|  */
-	lfs	fp2,(.SPone-.Lanchor)(DATA_OFFSET)
-	fadds	fp1,fp1,fp2
-	blr
-
-
-	.align	4
-L(arg_inf_or_nan:)
-	bne	L(arg_nan)
-
-	/* expf(+INF) = +INF
-	   expf(-INF) = 0  */
-	addi	r6,DATA_OFFSET,(.INF_ZERO-.Lanchor)
-	lfsx	fp1,r6,r8
-	blr
-
-
-	.align	4
-L(arg_nan):
-	/* expf(NaN) = NaN  */
-	fadd	fp1,fp1,fp1
-	frsp	fp1,fp1
-	blr
-
-	.align	4
-L(near_under_or_overflow):
-	frsp	fp6,fp2
-	xscvdpsp v2,v2
-	mfvsrd	r8,v2
-	mr	r3,r8			/* r3 = m  */
-	rldicl	r8,r8,32,58		/* r8 = j  */
-	lfs	fp4,(.SP_RS-.Lanchor)(DATA_OFFSET)
-	fsubs	fp2,fp6,fp4		/* fp2 = m = x * K/log(2)  */
-	srdi	r3,r3,32
-	clrrwi	r3,r3,6			/* r3 = n  */
-	lfd	fp6,(.NLN2K-.Lanchor)(DATA_OFFSET)
-	fmadd	fp0,fp2,fp6,fp1		/* fp0 = y = x - m*log(2)/K  */
-	fmul	fp2,fp0,fp0		/* fp2 = z = y^2  */
-	lfd	fp4,(.P1-.Lanchor)(DATA_OFFSET)
-	lfd	fp6,(.P0-.Lanchor)(DATA_OFFSET)
-	ld	r4,(.DP_EXP_BIAS-.Lanchor)(DATA_OFFSET)
-	add	r3,r3,r4
-	rldic	r3,r3,46,1		/* r3 = 2  */
-	fmadd	fp4,fp5,fp2,fp4		/* fp4 = P3 * z + P1  */
-	fmadd	fp6,fp3,fp2,fp6		/* fp6 = P2 * z + P0  */
-	mtvsrd	v1,r3
-	fmul	fp4,fp4,fp2		/* fp4 = (P3*z + P1)*z  */
-	fmadd	fp0,fp0,fp6,fp4		/* fp0 = P(y)  */
-	sldi	r8,r8,3			/* Access doublewords from T[j].  */
-	addi	r6,DATA_OFFSET,(.Ttable-.Lanchor)
-	lfdx	fp3,r6,r8
-	fmadd	fp0,fp0,fp3,fp3		/* fp0 = T[j] * (1 + T[j])  */
-	fmul	fp1,fp1,fp0		/* fp1 = 2^n * T[j] * (1 + T[j])  */
-	frsp	fp1,fp1
-	blr
-END(__ieee754_expf)
-
-	.section .rodata, "a",@progbits
-.Lanchor:
-	.balign	8
-/* Table T[j] = 2^(j/K).  Double precision.  */
-.Ttable:
-	.8byte	0x3ff0000000000000
-	.8byte	0x3ff02c9a3e778061
-	.8byte	0x3ff059b0d3158574
-	.8byte	0x3ff0874518759bc8
-	.8byte	0x3ff0b5586cf9890f
-	.8byte	0x3ff0e3ec32d3d1a2
-	.8byte	0x3ff11301d0125b51
-	.8byte	0x3ff1429aaea92de0
-	.8byte	0x3ff172b83c7d517b
-	.8byte	0x3ff1a35beb6fcb75
-	.8byte	0x3ff1d4873168b9aa
-	.8byte	0x3ff2063b88628cd6
-	.8byte	0x3ff2387a6e756238
-	.8byte	0x3ff26b4565e27cdd
-	.8byte	0x3ff29e9df51fdee1
-	.8byte	0x3ff2d285a6e4030b
-	.8byte	0x3ff306fe0a31b715
-	.8byte	0x3ff33c08b26416ff
-	.8byte	0x3ff371a7373aa9cb
-	.8byte	0x3ff3a7db34e59ff7
-	.8byte	0x3ff3dea64c123422
-	.8byte	0x3ff4160a21f72e2a
-	.8byte	0x3ff44e086061892d
-	.8byte	0x3ff486a2b5c13cd0
-	.8byte	0x3ff4bfdad5362a27
-	.8byte	0x3ff4f9b2769d2ca7
-	.8byte	0x3ff5342b569d4f82
-	.8byte	0x3ff56f4736b527da
-	.8byte	0x3ff5ab07dd485429
-	.8byte	0x3ff5e76f15ad2148
-	.8byte	0x3ff6247eb03a5585
-	.8byte	0x3ff6623882552225
-	.8byte	0x3ff6a09e667f3bcd
-	.8byte	0x3ff6dfb23c651a2f
-	.8byte	0x3ff71f75e8ec5f74
-	.8byte	0x3ff75feb564267c9
-	.8byte	0x3ff7a11473eb0187
-	.8byte	0x3ff7e2f336cf4e62
-	.8byte	0x3ff82589994cce13
-	.8byte	0x3ff868d99b4492ed
-	.8byte	0x3ff8ace5422aa0db
-	.8byte	0x3ff8f1ae99157736
-	.8byte	0x3ff93737b0cdc5e5
-	.8byte	0x3ff97d829fde4e50
-	.8byte	0x3ff9c49182a3f090
-	.8byte	0x3ffa0c667b5de565
-	.8byte	0x3ffa5503b23e255d
-	.8byte	0x3ffa9e6b5579fdbf
-	.8byte	0x3ffae89f995ad3ad
-	.8byte	0x3ffb33a2b84f15fb
-	.8byte	0x3ffb7f76f2fb5e47
-	.8byte	0x3ffbcc1e904bc1d2
-	.8byte	0x3ffc199bdd85529c
-	.8byte	0x3ffc67f12e57d14b
-	.8byte	0x3ffcb720dcef9069
-	.8byte	0x3ffd072d4a07897c
-	.8byte	0x3ffd5818dcfba487
-	.8byte	0x3ffda9e603db3285
-	.8byte	0x3ffdfc97337b9b5f
-	.8byte	0x3ffe502ee78b3ff6
-	.8byte	0x3ffea4afa2a490da
-	.8byte	0x3ffefa1bee615a27
-	.8byte	0x3fff50765b6e4540
-	.8byte	0x3fffa7c1819e90d8
-
-.KLN2:
-	.8byte	0x40571547652b82fe	/* Double precision K/log(2).  */
-
-/* Double precision polynomial coefficients.  */
-.P0:
-	.8byte	0x3fefffffffffe7c6
-.P1:
-	.8byte	0x3fe00000008d6118
-.P2:
-	.8byte	0x3fc55550da752d4f
-.P3:
-	.8byte	0x3fa56420eb78fa85
-
-.RS:
-	.8byte	0x4168000000000000	/* Double precision 2^23 + 2^22.  */
-.NLN2K:
-	.8byte	0xbf862e42fefa39ef	/* Double precision -log(2)/K.  */
-.DP_EXP_BIAS:
-	.8byte	0x000000000000ffc0	/* Double precision exponent bias.  */
-
-	.balign	4
-.SPone:
-	.4byte	0x3f800000	/* Single precision 1.0.  */
-.SP_RS:
-	.4byte	0x4b400000	/* Single precision 2^23 + 2^22.  */
-
-.SPRANGE: /* Single precision overflow/underflow bounds.  */
-	.4byte	0x42b17217	/* if x>this bound, then result overflows.  */
-	.4byte	0x42cff1b4	/* if x<this bound, then result underflows.  */
-
-.SPLARGE_SMALL:
-	.4byte	0x71800000	/* 2^100.  */
-	.4byte	0x0d800000	/* 2^-100.  */
-
-.INF_ZERO:
-	.4byte	0x7f800000	/* Single precision Inf.  */
-	.4byte	0		/* Single precision zero.  */
-
-strong_alias (__ieee754_expf, __expf_finite)
diff --git a/sysdeps/powerpc/powerpc64/power8/fpu/w_expf.c b/sysdeps/powerpc/powerpc64/power8/fpu/w_expf.c
deleted file mode 100644
index b5fe164520..0000000000
--- a/sysdeps/powerpc/powerpc64/power8/fpu/w_expf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/../math/w_expf.c>