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authorUlrich Drepper <drepper@redhat.com>2004-05-26 04:47:00 +0000
committerUlrich Drepper <drepper@redhat.com>2004-05-26 04:47:00 +0000
commitffdd5e50e18b0cb212acad135e421d932cf3d3a2 (patch)
tree0a2b8dfc93270b99dbbb314cc68152ea2c5b230a /sysdeps/powerpc/fpu/e_sqrtf.c
parenta752d0cc542a891a086d486654a43212f1821360 (diff)
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Update.
2004-05-25  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/fpu/Makefile: Make ld.so a dependency of libm.so.
	* sysdeps/powerpc/fpu/bits/mathinline.h [__LIBC_INERNAL_MATH_INLINES]
	(__ieee754_sqrt): Define as __MATH_INLINE using fsqrt instruction.
	(__ieee754_sqrtf): Define as __MATH_INLINE using fsqrts instruction.
	* sysdeps/powerpc/fpu/e_sqrt.c (__slow_ieee754_sqrt): Moved
	implementation from w_sqrt.c.
	* sysdeps/powerpc/fpu/e_sqrtf.c (__slow_ieee754_sqrtf): Moved
	implementation from w_sqrtf.c.
	* sysdeps/powerpc/fpu/w_sqrt.c (__sqrt): Wrapper implementation
	using inline __ieee754_sqrt().
	* sysdeps/powerpc/fpu/w_sqrtf.c (__sqrtf): Wrapper implementation
	using inline __ieee754_sqrtf().
	* sysdeps/powerpc/powerpc32/sysdep.h [__ASSEMBLER__]: Include
	<sysdeps/powerpc/sysdep.h> independent of __ASSEMBLER__.
	* sysdeps/powerpc/sysdep.h [__ASSEMBLER__] (PPC_FEATURE_*): Define
	PPC_FEATURE_*  independent of __ASSEMBLER__.

2004-05-25  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/pthread/aio_notify.c: Use <> instead of "" for aio_misc.h
	include.
	(aio_start_notify_thread): Define if not defined.
	(notify_func_wrapper): Use it.
	* sysdeps/pthread/aio_misc.c: Use <> instead of "" for aio_misc.h
	include.
	(aio_create_helper_thread): Define if not defined.
	(__aio_create_helper_thread): New function.
	(__aio_enqueue_request): Use aio_create_helper_thread.

	* nis/ypclnt.c (ypall_data, ypall_foreach): Remove.
	(struct ypresp_all_data): New type.
	(__xdr_ypresp_all): Change second argument to
	struct ypresp_all_data *.  Replace ypall_foreach and
	ypall_data with objp->foreach and objp->data.
	(yp_all): Remove status variable, add data.  Replace
	all uses of status with data.status.  Initialize data.foreach
	and data.data instead of ypall_foreach and ypall_data.

2004-05-24  Jakub Jelinek  <jakub@redhat.com>

	* elf/dl-lookup.c (add_dependency): Set DF_1_NODELETE bit
	in l_flags_1, not in l_flags.
Diffstat (limited to 'sysdeps/powerpc/fpu/e_sqrtf.c')
-rw-r--r--sysdeps/powerpc/fpu/e_sqrtf.c163
1 files changed, 162 insertions, 1 deletions
diff --git a/sysdeps/powerpc/fpu/e_sqrtf.c b/sysdeps/powerpc/fpu/e_sqrtf.c
index 01c76d6757..9b701012af 100644
--- a/sysdeps/powerpc/fpu/e_sqrtf.c
+++ b/sysdeps/powerpc/fpu/e_sqrtf.c
@@ -1 +1,162 @@
-/* __ieee754_sqrtf is in w_sqrtf.c  */
+/* Single-precision floating point square root.
+   Copyright (C) 1997, 2003, 2004 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <math.h>
+#include <math_private.h>
+#include <fenv_libc.h>
+#include <inttypes.h>
+
+#include <sysdep.h>
+#include <ldsodefs.h>
+#include <dl-procinfo.h>
+
+static const float almost_half = 0.50000006;	/* 0.5 + 2^-24 */
+static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
+static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
+static const float two48 = 281474976710656.0;
+static const float twom24 = 5.9604644775390625e-8;
+extern const float __t_sqrt[1024];
+
+/* The method is based on a description in
+   Computation of elementary functions on the IBM RISC System/6000 processor,
+   P. W. Markstein, IBM J. Res. Develop, 34(1) 1990.
+   Basically, it consists of two interleaved Newton-Rhapson approximations,
+   one to find the actual square root, and one to find its reciprocal
+   without the expense of a division operation.   The tricky bit here
+   is the use of the POWER/PowerPC multiply-add operation to get the
+   required accuracy with high speed.
+
+   The argument reduction works by a combination of table lookup to
+   obtain the initial guesses, and some careful modification of the
+   generated guesses (which mostly runs on the integer unit, while the
+   Newton-Rhapson is running on the FPU).  */
+
+#ifdef __STDC__
+float
+__slow_ieee754_sqrtf (float x)
+#else
+float
+__slow_ieee754_sqrtf (x)
+     float x;
+#endif
+{
+  const float inf = a_inf.value;
+
+  if (x > 0)
+    {
+      if (x != inf)
+	{
+	  /* Variables named starting with 's' exist in the
+	     argument-reduced space, so that 2 > sx >= 0.5,
+	     1.41... > sg >= 0.70.., 0.70.. >= sy > 0.35... .
+	     Variables named ending with 'i' are integer versions of
+	     floating-point values.  */
+	  float sx;		/* The value of which we're trying to find the square
+				   root.  */
+	  float sg, g;		/* Guess of the square root of x.  */
+	  float sd, d;		/* Difference between the square of the guess and x.  */
+	  float sy;		/* Estimate of 1/2g (overestimated by 1ulp).  */
+	  float sy2;		/* 2*sy */
+	  float e;		/* Difference between y*g and 1/2 (note that e==se).  */
+	  float shx;		/* == sx * fsg */
+	  float fsg;		/* sg*fsg == g.  */
+	  fenv_t fe;		/* Saved floating-point environment (stores rounding
+				   mode and whether the inexact exception is
+				   enabled).  */
+	  uint32_t xi, sxi, fsgi;
+	  const float *t_sqrt;
+
+	  GET_FLOAT_WORD (xi, x);
+	  fe = fegetenv_register ();
+	  relax_fenv_state ();
+	  sxi = (xi & 0x3fffffff) | 0x3f000000;
+	  SET_FLOAT_WORD (sx, sxi);
+	  t_sqrt = __t_sqrt + (xi >> (23 - 8 - 1) & 0x3fe);
+	  sg = t_sqrt[0];
+	  sy = t_sqrt[1];
+
+	  /* Here we have three Newton-Rhapson iterations each of a
+	     division and a square root and the remainder of the
+	     argument reduction, all interleaved.   */
+	  sd = -(sg * sg - sx);
+	  fsgi = (xi + 0x40000000) >> 1 & 0x7f800000;
+	  sy2 = sy + sy;
+	  sg = sy * sd + sg;	/* 16-bit approximation to sqrt(sx). */
+	  e = -(sy * sg - almost_half);
+	  SET_FLOAT_WORD (fsg, fsgi);
+	  sd = -(sg * sg - sx);
+	  sy = sy + e * sy2;
+	  if ((xi & 0x7f800000) == 0)
+	    goto denorm;
+	  shx = sx * fsg;
+	  sg = sg + sy * sd;	/* 32-bit approximation to sqrt(sx),
+				   but perhaps rounded incorrectly.  */
+	  sy2 = sy + sy;
+	  g = sg * fsg;
+	  e = -(sy * sg - almost_half);
+	  d = -(g * sg - shx);
+	  sy = sy + e * sy2;
+	  fesetenv_register (fe);
+	  return g + sy * d;
+	denorm:
+	  /* For denormalised numbers, we normalise, calculate the
+	     square root, and return an adjusted result.  */
+	  fesetenv_register (fe);
+	  return __slow_ieee754_sqrtf (x * two48) * twom24;
+	}
+    }
+  else if (x < 0)
+    {
+      /* For some reason, some PowerPC32 processors don't implement
+         FE_INVALID_SQRT.  */
+#ifdef FE_INVALID_SQRT
+      feraiseexcept (FE_INVALID_SQRT);
+      if (!fetestexcept (FE_INVALID))
+#endif
+	feraiseexcept (FE_INVALID);
+      x = a_nan.value;
+    }
+  return f_washf (x);
+}
+
+
+#ifdef __STDC__
+float
+__ieee754_sqrtf (float x)
+#else
+float
+__ieee754_sqrtf (x)
+     float x;
+#endif
+{
+  double z;
+
+  /* If the CPU is 64-bit we can use the optional FP instructions we.  */
+  if ((GLRO (dl_hwcap) & PPC_FEATURE_64) != 0)
+    {
+      /* Volatile is required to prevent the compiler from moving the 
+         fsqrt instruction above the branch.  */
+      __asm __volatile ("	fsqrts	%0,%1\n"
+				:"=f" (z):"f" (x));
+    }
+  else
+    z = __slow_ieee754_sqrtf (x);
+
+  return z;
+}