i386: Replace assembly versions of e_expf with generic e_expf.c

This patch replaces i386 assembly versions of e_expf with generic
e_expf.c.  For workload-spec2017.wrf, on Nehalem, it improves
performance by:

                           Before            After     Improvement
reciprocal-throughput      55.5724          40.2664       38%
latency                    80.0687          60.8517       31%

On Skylake, it improves performance by:

                           Before            After     Improvement
reciprocal-throughput      62.4056          39.4188       58%
latency                    85.5496          59.6377       43%

On IvyBridge with --disable-multi-arch, it improves performance by:

                           Before            After     Improvement
reciprocal-throughput      133.707          40.3778       231%
latency                    149.191          63.2515       135%

	* sysdeps/i386/fpu/e_exp2f_data.c: Removed.
	* sysdeps/i386/fpu/e_expf.S: Likewise.
	* sysdeps/i386/fpu/math_errf.c: Likewise.
	* sysdeps/i386/fpu/w_expf.c: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/e_expf-ia32.S: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/w_expf.c: Likewise.
	* sysdeps/i386/fpu/libm-test-ulps: Updated for generic e_expf.c.
	* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/Makefile (libm-sysdep_routines):
	Remove e_expf-ia32.
	(CFLAGS-e_expf-sse2.c): New.
	* sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.c: New file.
	* sysdeps/i386/i686/fpu/multiarch/e_expf.c: Rewritten.

7 files changed, 29 insertions, 365 deletions

diff --git a/sysdeps/i386/i686/fpu/multiarch/Makefile b/sysdeps/i386/i686/fpu/multiarch/Makefile
index 7d9089232f..c5e8cfd689 100644
--- a/sysdeps/i386/i686/fpu/multiarch/Makefile
+++ b/sysdeps/i386/i686/fpu/multiarch/Makefile
@@ -1,4 +1,6 @@
 ifeq ($(subdir),math)
-libm-sysdep_routines += e_expf-sse2 e_expf-ia32 s_sinf-sse2 s_cosf-sse2 \
+libm-sysdep_routines += e_expf-sse2 s_sinf-sse2 s_cosf-sse2 \
                         s_sincosf-sse2
+
+CFLAGS-e_expf-sse2.c = -msse2 -mfpmath=sse
 endif
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_expf-ia32.S b/sysdeps/i386/i686/fpu/multiarch/e_expf-ia32.S
deleted file mode 100644
index b486b4d1ca..0000000000
--- a/sysdeps/i386/i686/fpu/multiarch/e_expf-ia32.S
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
-   Copyright (C) 2012-2017 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 __ieee754_expf __ieee754_expf_ia32
-#define __expf_finite __expf_finite_ia32
-
-#include <sysdeps/i386/fpu/e_expf.S>
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S b/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S
deleted file mode 100644
index e6bb6fa289..0000000000
--- a/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S
+++ /dev/null
@@ -1,325 +0,0 @@
-/* SSE2 version of __ieee754_expf and __expf_finite
-   Copyright (C) 2012-2017 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(x)-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:
- *  __ieee754_expf_sse2(NaN) = NaN
- *  __ieee754_expf_sse2(+INF) = +INF
- *  __ieee754_expf_sse2(-INF) = 0
- *  __ieee754_expf_sse2(x) = 1 for subnormals
- *  for finite argument, only __ieee754_expf_sse2(0)=1 is exact
- *  __ieee754_expf_sse2(x) overflows if x>700
- *  __ieee754_expf_sse2(x) underflows if x<-700
- *
- * Note:
- *  For |x|<700, __ieee754_expf_sse2 computes result in double precision,
- *  with accuracy a bit more than needed for expf, and does not round it
- *  to single precision.
- */
-
-
-#ifdef	PIC
-# define MO1(symbol)			L(symbol)##@GOTOFF(%edx)
-# define MO2(symbol,reg2,_scale)	L(symbol)##@GOTOFF(%edx,reg2,_scale)
-#else
-# define MO1(symbol)			L(symbol)
-# define MO2(symbol,reg2,_scale)	L(symbol)(,reg2,_scale)
-#endif
-
-	.text
-ENTRY(__ieee754_expf_sse2)
-	/* Input: single precision x on stack at address 4(%esp) */
-
-#ifdef	PIC
-	LOAD_PIC_REG(dx)
-#endif
-
-	cvtss2sd	4(%esp), %xmm1	/* Convert x to double precision */
-	mov	4(%esp), %ecx		/* Copy x */
-	movsd	MO1(DP_KLN2), %xmm2	/* DP K/log(2) */
-	movsd	MO1(DP_P2), %xmm3	/* DP P2 */
-	movl	%ecx, %eax		/* x */
-	mulsd	%xmm1, %xmm2		/* DP x*K/log(2) */
-	andl	$0x7fffffff, %ecx	/* |x| */
-	cmpl	$0x442f0000, %ecx	/* |x|<700 ? */
-	movsd	MO1(DP_P3), %xmm4	/* DP P3 */
-	addsd	MO1(DP_RS), %xmm2	/* DP x*K/log(2)+RS */
-	jae	L(special_paths)
-
-	/* Here if |x|<700 */
-	cmpl	$0x31800000, %ecx	/* |x|<2^(-28) ? */
-	jb	L(small_arg)
-
-	/* Main path: here if 2^(-28)<=|x|<700 */
-	cvtsd2ss	%xmm2, %xmm2	/* SP x*K/log(2)+RS */
-	movd	%xmm2, %eax		/* bits of n*K+j with trash */
-	subss	MO1(SP_RS), %xmm2	/* SP t=round(x*K/log(2)) */
-	movl	%eax, %ecx		/* n*K+j with trash */
-	cvtss2sd	%xmm2, %xmm2	/* DP t */
-	andl	$0x3f, %eax		/* bits of j */
-	mulsd	MO1(DP_NLN2K), %xmm2	/* DP -t*log(2)/K */
-	andl	$0xffffffc0, %ecx	/* bits of n */
-#ifdef __AVX__
-	vaddsd	%xmm1, %xmm2, %xmm0	/* DP y=x-t*log(2)/K */
-	vmulsd	%xmm0, %xmm0, %xmm2	/* DP z=y*y */
-#else
-	addsd	%xmm1, %xmm2		/* DP y=x-t*log(2)/K */
-	movaps	%xmm2, %xmm0		/* DP y */
-	mulsd	%xmm2, %xmm2		/* DP z=y*y */
-#endif
-	mulsd	%xmm2, %xmm4		/* DP P3*z */
-	addl	$0xffc0, %ecx		/* bits of n + DP exponent bias */
-	mulsd	%xmm2, %xmm3		/* DP P2*z */
-	shrl	$2, %ecx		/* High 2 bytes of DP 2^n */
-	pxor	%xmm1, %xmm1		/* clear %xmm1 */
-	addsd	MO1(DP_P1), %xmm4	/* DP P3*z+P1 */
-	addsd	MO1(DP_P0), %xmm3	/* DP P2*z+P0 */
-	pinsrw	$3, %ecx, %xmm1		/* DP 2^n */
-	mulsd	%xmm2, %xmm4		/* DP (P3*z+P1)*z */
-	mulsd	%xmm3, %xmm0		/* DP (P2*z+P0)*y */
-	addsd	%xmm4, %xmm0		/* DP P(y) */
-	mulsd	MO2(DP_T,%eax,8), %xmm0	/* DP P(y)*T[j] */
-	addsd	MO2(DP_T,%eax,8), %xmm0	/* DP T[j]*(P(y)+1) */
-	mulsd	%xmm1, %xmm0		/* DP result=2^n*(T[j]*(P(y)+1)) */
-	cvtsd2ss	%xmm0, %xmm1
-
-	lea	-4(%esp), %esp		/* Borrow 4 bytes of stack frame */
-	movss	%xmm1, 0(%esp)		/* Move result from sse... */
-	flds	0(%esp)			/* ...to FPU. */
-	lea	4(%esp), %esp		/* Return back 4 bytes of stack frame */
-	ret
-
-	.p2align	4
-L(small_arg):
-	/* Here if 0<=|x|<2^(-28) */
-	movss	4(%esp), %xmm0		/* load x */
-	addss	MO1(SP_ONE), %xmm0	/* 1.0 + x */
-	/* Return 1.0 with inexact raised, except for x==0 */
-	jmp	L(epilogue)
-
-	.p2align	4
-L(special_paths):
-	/* Here if x is NaN, or Inf, or finite |x|>=700 */
-	movss	4(%esp), %xmm0		/* load x */
-
-	cmpl	$0x7f800000, %ecx	/* |x| is finite ? */
-	jae	L(arg_inf_or_nan)
-
-	/* Here if finite |x|>=700 */
-	testl	$0x80000000, %eax	/* sign of x nonzero ? */
-	je	L(res_overflow)
-
-	/* Here if finite x<=-700 */
-	movss	MO1(SP_SMALL), %xmm0	/* load small value 2^(-100) */
-	mulss	%xmm0, %xmm0		/* Return underflowed result (zero or subnormal) */
-	jmp	L(epilogue)
-
-	.p2align	4
-L(res_overflow):
-	/* Here if finite x>=700 */
-	movss	MO1(SP_LARGE), %xmm0	/* load large value 2^100 */
-	mulss	%xmm0, %xmm0		/* Return overflowed result (Inf or max normal) */
-	jmp	L(epilogue)
-
-	.p2align	4
-L(arg_inf_or_nan):
-	/* Here if |x| is Inf or NAN */
-	jne	L(arg_nan)	/* |x| is Inf ? */
-
-	/* Here if |x| is Inf */
-	shrl	$31, %eax		/* Get sign bit of x */
-	movss	MO2(SP_INF_0,%eax,4), %xmm0/* return zero or Inf, depending on sign of x */
-	jmp	L(epilogue)
-
-	.p2align	4
-L(arg_nan):
-	/* Here if |x| is NaN */
-	addss	%xmm0, %xmm0		/* Return x+x (raise invalid) */
-
-	.p2align	4
-L(epilogue):
-	lea	-4(%esp), %esp		/* Borrow 4 bytes of stack frame */
-	movss	%xmm0, 0(%esp)		/* Move result from sse... */
-	flds	0(%esp)			/* ...to FPU. */
-	lea	4(%esp), %esp		/* Return back 4 bytes of stack frame */
-	ret
-END(__ieee754_expf_sse2)
-
-	.section .rodata, "a"
-	.p2align 3
-L(DP_T): /* table of double precision values 2^(j/K) for j=[0..K-1] */
-	.long	0x00000000, 0x3ff00000
-	.long	0x3e778061, 0x3ff02c9a
-	.long	0xd3158574, 0x3ff059b0
-	.long	0x18759bc8, 0x3ff08745
-	.long	0x6cf9890f, 0x3ff0b558
-	.long	0x32d3d1a2, 0x3ff0e3ec
-	.long	0xd0125b51, 0x3ff11301
-	.long	0xaea92de0, 0x3ff1429a
-	.long	0x3c7d517b, 0x3ff172b8
-	.long	0xeb6fcb75, 0x3ff1a35b
-	.long	0x3168b9aa, 0x3ff1d487
-	.long	0x88628cd6, 0x3ff2063b
-	.long	0x6e756238, 0x3ff2387a
-	.long	0x65e27cdd, 0x3ff26b45
-	.long	0xf51fdee1, 0x3ff29e9d
-	.long	0xa6e4030b, 0x3ff2d285
-	.long	0x0a31b715, 0x3ff306fe
-	.long	0xb26416ff, 0x3ff33c08
-	.long	0x373aa9cb, 0x3ff371a7
-	.long	0x34e59ff7, 0x3ff3a7db
-	.long	0x4c123422, 0x3ff3dea6
-	.long	0x21f72e2a, 0x3ff4160a
-	.long	0x6061892d, 0x3ff44e08
-	.long	0xb5c13cd0, 0x3ff486a2
-	.long	0xd5362a27, 0x3ff4bfda
-	.long	0x769d2ca7, 0x3ff4f9b2
-	.long	0x569d4f82, 0x3ff5342b
-	.long	0x36b527da, 0x3ff56f47
-	.long	0xdd485429, 0x3ff5ab07
-	.long	0x15ad2148, 0x3ff5e76f
-	.long	0xb03a5585, 0x3ff6247e
-	.long	0x82552225, 0x3ff66238
-	.long	0x667f3bcd, 0x3ff6a09e
-	.long	0x3c651a2f, 0x3ff6dfb2
-	.long	0xe8ec5f74, 0x3ff71f75
-	.long	0x564267c9, 0x3ff75feb
-	.long	0x73eb0187, 0x3ff7a114
-	.long	0x36cf4e62, 0x3ff7e2f3
-	.long	0x994cce13, 0x3ff82589
-	.long	0x9b4492ed, 0x3ff868d9
-	.long	0x422aa0db, 0x3ff8ace5
-	.long	0x99157736, 0x3ff8f1ae
-	.long	0xb0cdc5e5, 0x3ff93737
-	.long	0x9fde4e50, 0x3ff97d82
-	.long	0x82a3f090, 0x3ff9c491
-	.long	0x7b5de565, 0x3ffa0c66
-	.long	0xb23e255d, 0x3ffa5503
-	.long	0x5579fdbf, 0x3ffa9e6b
-	.long	0x995ad3ad, 0x3ffae89f
-	.long	0xb84f15fb, 0x3ffb33a2
-	.long	0xf2fb5e47, 0x3ffb7f76
-	.long	0x904bc1d2, 0x3ffbcc1e
-	.long	0xdd85529c, 0x3ffc199b
-	.long	0x2e57d14b, 0x3ffc67f1
-	.long	0xdcef9069, 0x3ffcb720
-	.long	0x4a07897c, 0x3ffd072d
-	.long	0xdcfba487, 0x3ffd5818
-	.long	0x03db3285, 0x3ffda9e6
-	.long	0x337b9b5f, 0x3ffdfc97
-	.long	0xe78b3ff6, 0x3ffe502e
-	.long	0xa2a490da, 0x3ffea4af
-	.long	0xee615a27, 0x3ffefa1b
-	.long	0x5b6e4540, 0x3fff5076
-	.long	0x819e90d8, 0x3fffa7c1
-	.type L(DP_T), @object
-	ASM_SIZE_DIRECTIVE(L(DP_T))
-
-	.section .rodata.cst8,"aM",@progbits,8
-	.p2align 3
-L(DP_KLN2): /* double precision K/log(2) */
-	.long	0x652b82fe, 0x40571547
-	.type L(DP_KLN2), @object
-	ASM_SIZE_DIRECTIVE(L(DP_KLN2))
-
-	.p2align 3
-L(DP_NLN2K): /* double precision -log(2)/K */
-	.long	0xfefa39ef, 0xbf862e42
-	.type L(DP_NLN2K), @object
-	ASM_SIZE_DIRECTIVE(L(DP_NLN2K))
-
-	.p2align 3
-L(DP_RS): /* double precision 2^23+2^22 */
-	.long	0x00000000, 0x41680000
-	.type L(DP_RS), @object
-	ASM_SIZE_DIRECTIVE(L(DP_RS))
-
-	.p2align 3
-L(DP_P3): /* double precision polynomial coefficient P3 */
-	.long	0xeb78fa85, 0x3fa56420
-	.type L(DP_P3), @object
-	ASM_SIZE_DIRECTIVE(L(DP_P3))
-
-	.p2align 3
-L(DP_P1): /* double precision polynomial coefficient P1 */
-	.long	0x008d6118, 0x3fe00000
-	.type L(DP_P1), @object
-	ASM_SIZE_DIRECTIVE(L(DP_P1))
-
-	.p2align 3
-L(DP_P2): /* double precision polynomial coefficient P2 */
-	.long	0xda752d4f, 0x3fc55550
-	.type L(DP_P2), @object
-	ASM_SIZE_DIRECTIVE(L(DP_P2))
-
-	.p2align 3
-L(DP_P0): /* double precision polynomial coefficient P0 */
-	.long	0xffffe7c6, 0x3fefffff
-	.type L(DP_P0), @object
-	ASM_SIZE_DIRECTIVE(L(DP_P0))
-
-	.p2align 2
-L(SP_INF_0):
-	.long	0x7f800000	/* single precision Inf */
-	.long	0		/* single precision zero */
-	.type L(SP_INF_0), @object
-	ASM_SIZE_DIRECTIVE(L(SP_INF_0))
-
-	.section .rodata.cst4,"aM",@progbits,4
-	.p2align 2
-L(SP_RS): /* single precision 2^23+2^22 */
-	.long	0x4b400000
-	.type L(SP_RS), @object
-	ASM_SIZE_DIRECTIVE(L(SP_RS))
-
-	.p2align 2
-L(SP_SMALL): /* single precision small value 2^(-100) */
-	.long	0x0d800000
-	.type L(SP_SMALL), @object
-	ASM_SIZE_DIRECTIVE(L(SP_SMALL))
-
-	.p2align 2
-L(SP_LARGE): /* single precision large value 2^100 */
-	.long	0x71800000
-	.type L(SP_LARGE), @object
-	ASM_SIZE_DIRECTIVE(L(SP_LARGE))
-
-	.p2align 2
-L(SP_ONE): /* single precision 1.0 */
-	.long	0x3f800000
-	.type L(SP_ONE), @object
-	ASM_SIZE_DIRECTIVE(L(SP_ONE))
-
-strong_alias (__ieee754_expf_sse2, __expf_finite_sse2)
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.c b/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.c
new file mode 100644
index 0000000000..7c758e6556
--- /dev/null
+++ b/sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.c
@@ -0,0 +1,3 @@
+#define __expf __expf_sse2
+
+#include <sysdeps/ieee754/flt-32/e_expf.c>
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_expf.c b/sysdeps/i386/i686/fpu/multiarch/e_expf.c
index 388cf98a39..bd4240e560 100644
--- a/sysdeps/i386/i686/fpu/multiarch/e_expf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/e_expf.c
@@ -1,4 +1,4 @@
-/* Multiple versions of expf
+/* Multiple versions of expf.
    Copyright (C) 2012-2017 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -16,22 +16,25 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <init-arch.h>
+extern float __redirect_expf (float);
 
-extern double __ieee754_expf_sse2 (double);
-extern double __ieee754_expf_ia32 (double);
+#define SYMBOL_NAME expf
+#include "ifunc-sse2.h"
 
-double __ieee754_expf (double);
-libm_ifunc (__ieee754_expf,
-	    HAS_CPU_FEATURE (SSE2)
-	    ? __ieee754_expf_sse2
-	    : __ieee754_expf_ia32);
+libc_ifunc_redirected (__redirect_expf, __expf, IFUNC_SELECTOR ());
 
-extern double __expf_finite_sse2 (double);
-extern double __expf_finite_ia32 (double);
+#ifdef SHARED
+__hidden_ver1 (__expf_ia32, __GI___expf, __redirect_expf)
+  __attribute__ ((visibility ("hidden")));
 
-double __expf_finite (double);
-libm_ifunc (__expf_finite,
-	    HAS_CPU_FEATURE (SSE2)
-	    ? __expf_finite_sse2
-	    : __expf_finite_ia32);
+# include <shlib-compat.h>
+versioned_symbol (libm, __expf, expf, GLIBC_2_27);
+#else
+weak_alias (__expf, expf)
+#endif
+
+strong_alias (__expf, __ieee754_expf)
+strong_alias (__expf, __expf_finite)
+
+#define __expf __expf_ia32
+#include <sysdeps/ieee754/flt-32/e_expf.c>
diff --git a/sysdeps/i386/i686/fpu/multiarch/libm-test-ulps b/sysdeps/i386/i686/fpu/multiarch/libm-test-ulps
index d81c28ba95..5ff641f848 100644
--- a/sysdeps/i386/i686/fpu/multiarch/libm-test-ulps
+++ b/sysdeps/i386/i686/fpu/multiarch/libm-test-ulps
@@ -1928,13 +1928,17 @@ ldouble: 1
 
 Function: "exp_downward":
 double: 1
+float: 1
 idouble: 1
+ifloat: 1
 ildouble: 1
 ldouble: 1
 
 Function: "exp_towardzero":
 double: 1
+float: 1
 idouble: 1
+ifloat: 1
 ildouble: 2
 ldouble: 2
 
diff --git a/sysdeps/i386/i686/fpu/multiarch/w_expf.c b/sysdeps/i386/i686/fpu/multiarch/w_expf.c
deleted file mode 100644
index b5fe164520..0000000000
--- a/sysdeps/i386/i686/fpu/multiarch/w_expf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/../math/w_expf.c>