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authorH.J. Lu <hjl.tools@gmail.com>2017-10-22 07:54:38 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-10-22 07:54:50 -0700
commitb2f6137ea570933fb4be286574cc58b794eb5b5f (patch)
treeb95f459a9090aba7854e32c454001a610f400728 /sysdeps/i386/fpu
parente1f59bebd885c442c14df3554da9fe08792ce7ce (diff)
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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.
Diffstat (limited to 'sysdeps/i386/fpu')
-rw-r--r--sysdeps/i386/fpu/e_exp2f_data.c1
-rw-r--r--sysdeps/i386/fpu/e_expf.S74
-rw-r--r--sysdeps/i386/fpu/libm-test-ulps6
-rw-r--r--sysdeps/i386/fpu/math_errf.c1
-rw-r--r--sysdeps/i386/fpu/w_expf.c1
5 files changed, 6 insertions, 77 deletions
diff --git a/sysdeps/i386/fpu/e_exp2f_data.c b/sysdeps/i386/fpu/e_exp2f_data.c
deleted file mode 100644
index 1cc8931700..0000000000
--- a/sysdeps/i386/fpu/e_exp2f_data.c
+++ /dev/null
@@ -1 +0,0 @@
-/* Not needed.  */
diff --git a/sysdeps/i386/fpu/e_expf.S b/sysdeps/i386/fpu/e_expf.S
deleted file mode 100644
index 65cb4ec204..0000000000
--- a/sysdeps/i386/fpu/e_expf.S
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * Written by J.T. Conklin <jtc@netbsd.org>.
- * Public domain.
- * Adapted for float type by Ulrich Drepper <drepper@cygnus.com>.
- */
-
-#include <machine/asm.h>
-#include <i386-math-asm.h>
-
-DEFINE_FLT_MIN
-
-#ifdef PIC
-# define MO(op) op##@GOTOFF(%ecx)
-#else
-# define MO(op) op
-#endif
-
-	.text
-/* e^x = 2^(x * log2(e)) */
-ENTRY(__ieee754_expf)
-#ifdef  PIC
-	LOAD_PIC_REG (cx)
-#endif
-	flds	4(%esp)
-/* I added the following ugly construct because exp(+-Inf) resulted
-   in NaN.  The ugliness results from the bright minds at Intel.
-   For the i686 the code can be written better.
-   -- drepper@cygnus.com.  */
-	fxam				/* Is NaN or +-Inf?  */
-	fstsw	%ax
-	movb	$0x45, %dh
-	andb	%ah, %dh
-	cmpb	$0x05, %dh
-	je	1f			/* Is +-Inf, jump.  */
-	fldl2e
-	fmulp				/* x * log2(e) */
-	fld	%st
-	frndint				/* int(x * log2(e)) */
-	fsubr	%st,%st(1)		/* fract(x * log2(e)) */
-	fxch
-	f2xm1				/* 2^(fract(x * log2(e))) - 1 */
-	fld1
-	faddp				/* 2^(fract(x * log2(e))) */
-	fscale				/* e^x */
-	fstp	%st(1)
-	FLT_NARROW_EVAL_UFLOW_NONNEG_NAN
-	ret
-
-1:	testl	$0x200, %eax		/* Test sign.  */
-	jz	2f			/* If positive, jump.  */
-	fstp	%st
-	fldz				/* Set result to 0.  */
-2:	ret
-END (__ieee754_expf)
-
-
-ENTRY(__expf_finite)
-#ifdef  PIC
-	LOAD_PIC_REG (cx)
-#endif
-	fldl2e
-	fmuls	4(%esp)			/* x * log2(e) */
-	fld	%st
-	frndint				/* int(x * log2(e)) */
-	fsubr	%st,%st(1)		/* fract(x * log2(e)) */
-	fxch
-	f2xm1				/* 2^(fract(x * log2(e))) - 1 */
-	fld1
-	faddp				/* 2^(fract(x * log2(e))) */
-	fscale				/* e^x */
-	fstp	%st(1)
-	FLT_NARROW_EVAL_UFLOW_NONNEG
-	ret
-END(__expf_finite)
diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps
index e9be113c0a..c826b29c2c 100644
--- a/sysdeps/i386/fpu/libm-test-ulps
+++ b/sysdeps/i386/fpu/libm-test-ulps
@@ -1928,19 +1928,25 @@ 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
 
 Function: "exp_upward":
 double: 1
+float: 1
 idouble: 1
+ifloat: 1
 ildouble: 1
 ldouble: 1
 
diff --git a/sysdeps/i386/fpu/math_errf.c b/sysdeps/i386/fpu/math_errf.c
deleted file mode 100644
index 1cc8931700..0000000000
--- a/sysdeps/i386/fpu/math_errf.c
+++ /dev/null
@@ -1 +0,0 @@
-/* Not needed.  */
diff --git a/sysdeps/i386/fpu/w_expf.c b/sysdeps/i386/fpu/w_expf.c
deleted file mode 100644
index b5fe164520..0000000000
--- a/sysdeps/i386/fpu/w_expf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/../math/w_expf.c>