diff mbox series

[3/5] i386: Use generic exp10f

Message ID 20200409195945.10393-3-adhemerval.zanella@linaro.org
State New
Headers show
Series [1/5] benchtests: Add exp10f benchmark | expand

Commit Message

develop--- via Libc-alpha April 9, 2020, 7:59 p.m. UTC 
The generic implementation is twice as fast.  Using the exp10f
benchmark:

 * master:
  "exp10f": {
   "": {
    "duration": 4.25753e+09,
    "iterations": 3.3376e+07,
    "max": 1414.77,
    "min": 103.649,
    "mean": 127.563
   }
  }

 * patched:
  "exp10f": {
   "": {
    "duration": 4.05755e+09,
    "iterations": 6.9136e+07,
    "max": 1489.64,
    "min": 50.95,
    "mean": 58.6894
   }
  }

Checked on i686-linux-gnu.
---
 sysdeps/i386/fpu/e_exp10f.S | 54 -------------------------------------
 1 file changed, 54 deletions(-)
 delete mode 100644 sysdeps/i386/fpu/e_exp10f.S

Comments

Adhemerval Zanella Netto April 29, 2020, 5:11 p.m. UTC | #1 
Ping.

On 09/04/2020 16:59, Adhemerval Zanella wrote:
> The generic implementation is twice as fast.  Using the exp10f
> benchmark:
> 
>  * master:
>   "exp10f": {
>    "": {
>     "duration": 4.25753e+09,
>     "iterations": 3.3376e+07,
>     "max": 1414.77,
>     "min": 103.649,
>     "mean": 127.563
>    }
>   }
> 
>  * patched:
>   "exp10f": {
>    "": {
>     "duration": 4.05755e+09,
>     "iterations": 6.9136e+07,
>     "max": 1489.64,
>     "min": 50.95,
>     "mean": 58.6894
>    }
>   }
> 
> Checked on i686-linux-gnu.
> ---
>  sysdeps/i386/fpu/e_exp10f.S | 54 -------------------------------------
>  1 file changed, 54 deletions(-)
>  delete mode 100644 sysdeps/i386/fpu/e_exp10f.S
> 
> diff --git a/sysdeps/i386/fpu/e_exp10f.S b/sysdeps/i386/fpu/e_exp10f.S
> deleted file mode 100644
> index 196ce8744a..0000000000
> --- a/sysdeps/i386/fpu/e_exp10f.S
> +++ /dev/null
> @@ -1,54 +0,0 @@
> -/*
> - * Written by Ulrich Drepper.
> - */
> -
> -#include <machine/asm.h>
> -#include <i386-math-asm.h>
> -#include <libm-alias-finite.h>
> -
> -DEFINE_FLT_MIN
> -
> -#ifdef PIC
> -# define MO(op) op##@GOTOFF(%ecx)
> -#else
> -# define MO(op) op
> -#endif
> -
> -	.text
> -/* 10^x = 2^(x * log2(10)) */
> -ENTRY(__ieee754_exp10f)
> -#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.  */
> -	fldl2t
> -	fmulp				/* x * log2(10) */
> -	fld	%st
> -	frndint				/* int(x * log2(10)) */
> -	fsubr	%st,%st(1)		/* fract(x * log2(10)) */
> -	fxch
> -	f2xm1				/* 2^(fract(x * log2(10))) - 1 */
> -	fld1
> -	faddp				/* 2^(fract(x * log2(10))) */
> -	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_exp10f)
> -libm_alias_finite (__ieee754_exp10f, __exp10f)
>
Adhemerval Zanella Netto May 20, 2020, 8:19 p.m. UTC | #2 
Ping (x2).

On 29/04/2020 14:11, Adhemerval Zanella wrote:
> Ping.
> 
> On 09/04/2020 16:59, Adhemerval Zanella wrote:
>> The generic implementation is twice as fast.  Using the exp10f
>> benchmark:
>>
>>  * master:
>>   "exp10f": {
>>    "": {
>>     "duration": 4.25753e+09,
>>     "iterations": 3.3376e+07,
>>     "max": 1414.77,
>>     "min": 103.649,
>>     "mean": 127.563
>>    }
>>   }
>>
>>  * patched:
>>   "exp10f": {
>>    "": {
>>     "duration": 4.05755e+09,
>>     "iterations": 6.9136e+07,
>>     "max": 1489.64,
>>     "min": 50.95,
>>     "mean": 58.6894
>>    }
>>   }
>>
>> Checked on i686-linux-gnu.
>> ---
>>  sysdeps/i386/fpu/e_exp10f.S | 54 -------------------------------------
>>  1 file changed, 54 deletions(-)
>>  delete mode 100644 sysdeps/i386/fpu/e_exp10f.S
>>
>> diff --git a/sysdeps/i386/fpu/e_exp10f.S b/sysdeps/i386/fpu/e_exp10f.S
>> deleted file mode 100644
>> index 196ce8744a..0000000000
>> --- a/sysdeps/i386/fpu/e_exp10f.S
>> +++ /dev/null
>> @@ -1,54 +0,0 @@
>> -/*
>> - * Written by Ulrich Drepper.
>> - */
>> -
>> -#include <machine/asm.h>
>> -#include <i386-math-asm.h>
>> -#include <libm-alias-finite.h>
>> -
>> -DEFINE_FLT_MIN
>> -
>> -#ifdef PIC
>> -# define MO(op) op##@GOTOFF(%ecx)
>> -#else
>> -# define MO(op) op
>> -#endif
>> -
>> -	.text
>> -/* 10^x = 2^(x * log2(10)) */
>> -ENTRY(__ieee754_exp10f)
>> -#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.  */
>> -	fldl2t
>> -	fmulp				/* x * log2(10) */
>> -	fld	%st
>> -	frndint				/* int(x * log2(10)) */
>> -	fsubr	%st,%st(1)		/* fract(x * log2(10)) */
>> -	fxch
>> -	f2xm1				/* 2^(fract(x * log2(10))) - 1 */
>> -	fld1
>> -	faddp				/* 2^(fract(x * log2(10))) */
>> -	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_exp10f)
>> -libm_alias_finite (__ieee754_exp10f, __exp10f)
>>
diff mbox series

Patch

diff --git a/sysdeps/i386/fpu/e_exp10f.S b/sysdeps/i386/fpu/e_exp10f.S
deleted file mode 100644
index 196ce8744a..0000000000
--- a/sysdeps/i386/fpu/e_exp10f.S
+++ /dev/null
@@ -1,54 +0,0 @@ 
-/*
- * Written by Ulrich Drepper.
- */
-
-#include <machine/asm.h>
-#include <i386-math-asm.h>
-#include <libm-alias-finite.h>
-
-DEFINE_FLT_MIN
-
-#ifdef PIC
-# define MO(op) op##@GOTOFF(%ecx)
-#else
-# define MO(op) op
-#endif
-
-	.text
-/* 10^x = 2^(x * log2(10)) */
-ENTRY(__ieee754_exp10f)
-#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.  */
-	fldl2t
-	fmulp				/* x * log2(10) */
-	fld	%st
-	frndint				/* int(x * log2(10)) */
-	fsubr	%st,%st(1)		/* fract(x * log2(10)) */
-	fxch
-	f2xm1				/* 2^(fract(x * log2(10))) - 1 */
-	fld1
-	faddp				/* 2^(fract(x * log2(10))) */
-	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_exp10f)
-libm_alias_finite (__ieee754_exp10f, __exp10f)