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Use double precision instead of scaling for powerpc __ieee754_hypotf

This commit is contained in:
Andreas Schwab 2012-03-15 15:16:31 +01:00
parent e85b09d064
commit 11e0098ef0
3 changed files with 15 additions and 40 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2012-03-15 Andreas Schwab <schwab@linux-m68k.org>
* sysdeps/powerpc/fpu/e_hypotf.c: Use double precision instead of
scaling.
* sysdeps/powerpc/fpu/libm-test-ulps: Update.
2012-03-15 Andreas Jaeger <aj@suse.de> 2012-03-15 Andreas Jaeger <aj@suse.de>
[BZ #13852] [BZ #13852]

44
sysdeps/powerpc/fpu/e_hypotf.c
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@ -1,5 +1,5 @@
/* Pythagorean addition using floats /* Pythagorean addition using floats
Copyright (C) 2011 Free Software Foundation, Inc. Copyright (C) 2011, 2012 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011 Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011
@ -22,21 +22,13 @@
static const float two30 = 1.0737418e09; static const float two30 = 1.0737418e09;
static const float two50 = 1.1259000e15;
static const float two60 = 1.1529221e18;
static const float two126 = 8.5070592e+37;
static const float twoM50 = 8.8817842e-16;
static const float twoM60 = 6.7762644e-21;
static const float pdnum = 1.1754939e-38;
/* __ieee754_hypotf(x,y) /* __ieee754_hypotf(x,y)
*
* This a FP only version without any FP->INT conversion. This a FP only version without any FP->INT conversion.
* It is similar to default C version, making appropriates It is similar to default C version, making appropriates
* overflow and underflows checks as well scaling when it overflow and underflows checks as using double precision
* is needed. instead of scaling. */
*/
#ifdef _ARCH_PWR7 #ifdef _ARCH_PWR7
/* POWER7 isinf and isnan optimizations are fast. */ /* POWER7 isinf and isnan optimizations are fast. */
@ -92,27 +84,7 @@ __ieee754_hypotf (float x, float y)
{ {
return x + y; return x + y;
} }
if (x > two50)
{ return __ieee754_sqrt ((double) x * x + (double) y * y);
x *= twoM60;
y *= twoM60;
return __ieee754_sqrtf (x * x + y * y) / twoM60;
}
if (y < twoM50)
{
if (y <= pdnum)
{
x *= two126;
y *= two126;
return __ieee754_sqrtf (x * x + y * y) / two126;
}
else
{
x *= two60;
y *= two60;
return __ieee754_sqrtf (x * x + y * y) / two60;
}
}
return __ieee754_sqrtf (x * x + y * y);
} }
strong_alias (__ieee754_hypotf, __hypotf_finite) strong_alias (__ieee754_hypotf, __hypotf_finite)

5
sysdeps/powerpc/fpu/libm-test-ulps
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@ -1119,10 +1119,7 @@ ildouble: 1
ldouble: 1 ldouble: 1
Test "hypot (0x1.234566p-126, 0x1.234566p-126) == 1.891441686191081936598531534017449451173e-38": Test "hypot (0x1.234566p-126, 0x1.234566p-126) == 1.891441686191081936598531534017449451173e-38":
double: 1 double: 1
float: 6
idouble: 1 idouble: 1
Test "hypot (0x3p125, 0x4p125) == 0x5p125":
float: 1
Test "hypot (12.4, -0.7) == 12.419742348374220601176836866763271": Test "hypot (12.4, -0.7) == 12.419742348374220601176836866763271":
double: 1 double: 1
float: 1 float: 1
@ -2247,7 +2244,7 @@ ldouble: 1
Function: "hypot": Function: "hypot":
double: 1 double: 1
float: 6 float: 1
idouble: 1 idouble: 1
ifloat: 1 ifloat: 1
ildouble: 1 ildouble: 1