path: root/meta/recipes-core/eglibc/eglibc-2.15/ppc-sqrt.patch

Upstream-Status: Pending

2011-03-22  Joseph Myers  <joseph@codesourcery.com>

        Merge from SG++ 2.11:

        2010-10-05  Nathan Froyd  <froydnj@codesourcery.com>

        Issue #9382

        * sysdeps/powerpc/powerpc32/603e/: New directory.
        * sysdeps/unix/sysv/linux/powerpc/powerpc32/e500mc/: New directory.
        * sysdeps/unix/sysv/linux/powerpc/powerpc32/603e/: New directory.
        * sysdeps/unix/sysv/linux/powerpc/powerpc32/7400/: New directory.
        * sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrtf.c: Update.
        * sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrt.c: Update.
        * sysdeps/powerpc/powerpc64/e5500/fpu/Implies: New file.

Index: libc/sysdeps/powerpc/powerpc32/603e/fpu/e_sqrt.c
===================================================================
--- /dev/null
+++ libc/sysdeps/powerpc/powerpc32/603e/fpu/e_sqrt.c
@@ -0,0 +1,134 @@
+/* Double-precision floating point square root.
+   Copyright (C) 2010 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>
+
+static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
+static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
+static const float two108 = 3.245185536584267269e+32;
+static const float twom54 = 5.551115123125782702e-17;
+static const float half = 0.5;
+
+/* The method is based on the descriptions in:
+
+   _The Handbook of Floating-Pointer Arithmetic_ by Muller et al., chapter 5;
+   _IA-64 and Elementary Functions: Speed and Precision_ by Markstein, chapter 9
+
+   We find the actual square root and half of its reciprocal
+   simultaneously.  */
+
+#ifdef __STDC__
+double
+__ieee754_sqrt (double b)
+#else
+double
+__ieee754_sqrt (b)
+     double b;
+#endif
+{
+  if (__builtin_expect (b > 0, 1))
+    {
+      double y, g, h, d, r;
+      ieee_double_shape_type u;
+
+      if (__builtin_expect (b != a_inf.value, 1))
+        {
+          fenv_t fe;
+
+          fe = fegetenv_register ();
+
+          u.value = b;
+
+          relax_fenv_state ();
+
+          __asm__ ("frsqrte %[estimate], %[x]\n"
+                   : [estimate] "=f" (y) : [x] "f" (b));
+
+          /* Following Muller et al, page 168, equation 5.20.
+
+             h goes to 1/(2*sqrt(b))
+             g goes to sqrt(b).
+
+             We need three iterations to get within 1ulp.  */
+
+          /* Indicate that these can be performed prior to the branch.  GCC
+             insists on sinking them below the branch, however; it seems like
+             they'd be better before the branch so that we can cover any latency
+             from storing the argument and loading its high word.  Oh well.  */
+
+          g = b * y;
+          h = 0.5 * y;
+  
+          /* Handle small numbers by scaling.  */
+          if (__builtin_expect ((u.parts.msw & 0x7ff00000) <= 0x02000000, 0))
+            return __ieee754_sqrt (b * two108) * twom54;
+
+#define FMADD(a_, c_, b_)                                               \
+          ({ double __r;                                                \
+          __asm__ ("fmadd %[r], %[a], %[c], %[b]\n"                     \
+                   : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+          __r;})
+#define FNMSUB(a_, c_, b_)                                          \
+          ({ double __r;                                                \
+          __asm__ ("fnmsub %[r], %[a], %[c], %[b]\n"                     \
+                   : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+          __r;})
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          /* g is now +/- 1ulp, or exactly equal to, the square root of b.  */
+
+          /* Final refinement.  */
+          d = FNMSUB (g, g, b);
+
+          fesetenv_register (fe);
+          return FMADD (d, h, g);
+        }
+    }
+  else if (b < 0)
+    {
+      /* For some reason, some PowerPC32 processors don't implement
+         FE_INVALID_SQRT.  */
+#ifdef FE_INVALID_SQRT
+      feraiseexcept (FE_INVALID_SQRT);
+
+      fenv_union_t u = { .fenv = fegetenv_register () };
+      if ((u.l[1] & FE_INVALID) == 0)
+#endif
+	feraiseexcept (FE_INVALID);
+      b = a_nan.value;
+    }
+  return f_wash (b);
+}
Index: libc/sysdeps/powerpc/powerpc32/603e/fpu/e_sqrtf.c
===================================================================
--- /dev/null
+++ libc/sysdeps/powerpc/powerpc32/603e/fpu/e_sqrtf.c
@@ -0,0 +1,101 @@
+/* Single-precision floating point square root.
+   Copyright (C) 2010 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>
+
+static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
+static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
+static const float threehalf = 1.5;
+
+/* The method is based on the descriptions in:
+
+   _The Handbook of Floating-Pointer Arithmetic_ by Muller et al., chapter 5;
+   _IA-64 and Elementary Functions: Speed and Precision_ by Markstein, chapter 9
+
+   We find the reciprocal square root and use that to compute the actual
+   square root.  */
+
+#ifdef __STDC__
+float
+__ieee754_sqrtf (float b)
+#else
+float
+__ieee754_sqrtf (b)
+     float b;
+#endif
+{
+  if (__builtin_expect (b > 0, 1))
+    {
+#define FMSUB(a_, c_, b_)                                               \
+      ({ double __r;                                                    \
+        __asm__ ("fmsub %[r], %[a], %[c], %[b]\n"                       \
+                 : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+        __r;})
+#define FNMSUB(a_, c_, b_)                                              \
+      ({ double __r;                                                    \
+        __asm__ ("fnmsub %[r], %[a], %[c], %[b]\n"                      \
+                 : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+        __r;})
+
+      if (__builtin_expect (b != a_inf.value, 1))
+        {
+          double y, x;
+          fenv_t fe;
+
+          fe = fegetenv_register ();
+
+          relax_fenv_state ();
+
+          /* Compute y = 1.5 * b - b.  Uses fewer constants than y = 0.5 * b.  */
+          y = FMSUB (threehalf, b, b);
+
+          /* Initial estimate.  */
+          __asm__ ("frsqrte %[x], %[b]\n" : [x] "=f" (x) : [b] "f" (b));
+
+          /* Iterate.  x_{n+1} = x_n * (1.5 - y * (x_n * x_n)).  */
+          x = x * FNMSUB (y, x * x, threehalf);
+          x = x * FNMSUB (y, x * x, threehalf);
+          x = x * FNMSUB (y, x * x, threehalf);
+
+          /* All done.  */
+          fesetenv_register (fe);
+          return x * b;
+        }
+    }
+  else if (b < 0)
+    {
+      /* For some reason, some PowerPC32 processors don't implement
+         FE_INVALID_SQRT.  */
+#ifdef FE_INVALID_SQRT
+      feraiseexcept (FE_INVALID_SQRT);
+
+      fenv_union_t u = { .fenv = fegetenv_register () };
+      if ((u.l[1] & FE_INVALID) == 0)
+#endif
+	feraiseexcept (FE_INVALID);
+      b = a_nan.value;
+    }
+  return f_washf (b);
+}
Index: libc/sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrt.c
===================================================================
--- /dev/null
+++ libc/sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrt.c
@@ -0,0 +1,134 @@
+/* Double-precision floating point square root.
+   Copyright (C) 2010 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>
+
+static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
+static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
+static const float two108 = 3.245185536584267269e+32;
+static const float twom54 = 5.551115123125782702e-17;
+static const float half = 0.5;
+
+/* The method is based on the descriptions in:
+
+   _The Handbook of Floating-Pointer Arithmetic_ by Muller et al., chapter 5;
+   _IA-64 and Elementary Functions: Speed and Precision_ by Markstein, chapter 9
+
+   We find the actual square root and half of its reciprocal
+   simultaneously.  */
+
+#ifdef __STDC__
+double
+__ieee754_sqrt (double b)
+#else
+double
+__ieee754_sqrt (b)
+     double b;
+#endif
+{
+  if (__builtin_expect (b > 0, 1))
+    {
+      double y, g, h, d, r;
+      ieee_double_shape_type u;
+
+      if (__builtin_expect (b != a_inf.value, 1))
+        {
+          fenv_t fe;
+
+          fe = fegetenv_register ();
+
+          u.value = b;
+
+          relax_fenv_state ();
+
+          __asm__ ("frsqrte %[estimate], %[x]\n"
+                   : [estimate] "=f" (y) : [x] "f" (b));
+
+          /* Following Muller et al, page 168, equation 5.20.
+
+             h goes to 1/(2*sqrt(b))
+             g goes to sqrt(b).
+
+             We need three iterations to get within 1ulp.  */
+
+          /* Indicate that these can be performed prior to the branch.  GCC
+             insists on sinking them below the branch, however; it seems like
+             they'd be better before the branch so that we can cover any latency
+             from storing the argument and loading its high word.  Oh well.  */
+
+          g = b * y;
+          h = 0.5 * y;
+  
+          /* Handle small numbers by scaling.  */
+          if (__builtin_expect ((u.parts.msw & 0x7ff00000) <= 0x02000000, 0))
+            return __ieee754_sqrt (b * two108) * twom54;
+
+#define FMADD(a_, c_, b_)                                               \
+          ({ double __r;                                                \
+          __asm__ ("fmadd %[r], %[a], %[c], %[b]\n"                     \
+                   : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+          __r;})
+#define FNMSUB(a_, c_, b_)                                          \
+          ({ double __r;                                                \
+          __asm__ ("fnmsub %[r], %[a], %[c], %[b]\n"                     \
+                   : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+          __r;})
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          r = FNMSUB (g, h, half);
+          g = FMADD (g, r, g);
+          h = FMADD (h, r, h);
+
+          /* g is now +/- 1ulp, or exactly equal to, the square root of b.  */
+
+          /* Final refinement.  */
+          d = FNMSUB (g, g, b);
+
+          fesetenv_register (fe);
+          return FMADD (d, h, g);
+        }
+    }
+  else if (b < 0)
+    {
+      /* For some reason, some PowerPC32 processors don't implement
+         FE_INVALID_SQRT.  */
+#ifdef FE_INVALID_SQRT
+      feraiseexcept (FE_INVALID_SQRT);
+
+      fenv_union_t u = { .fenv = fegetenv_register () };
+      if ((u.l[1] & FE_INVALID) == 0)
+#endif
+	feraiseexcept (FE_INVALID);
+      b = a_nan.value;
+    }
+  return f_wash (b);
+}
Index: libc/sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrtf.c
===================================================================
--- /dev/null
+++ libc/sysdeps/powerpc/powerpc64/e5500/fpu/e_sqrtf.c
@@ -0,0 +1,101 @@
+/* Single-precision floating point square root.
+   Copyright (C) 2010 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>
+
+static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
+static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
+static const float threehalf = 1.5;
+
+/* The method is based on the descriptions in:
+
+   _The Handbook of Floating-Pointer Arithmetic_ by Muller et al., chapter 5;
+   _IA-64 and Elementary Functions: Speed and Precision_ by Markstein, chapter 9
+
+   We find the reciprocal square root and use that to compute the actual
+   square root.  */
+
+#ifdef __STDC__
+float
+__ieee754_sqrtf (float b)
+#else
+float
+__ieee754_sqrtf (b)
+     float b;
+#endif
+{
+  if (__builtin_expect (b > 0, 1))
+    {
+#define FMSUB(a_, c_, b_)                                               \
+      ({ double __r;                                                    \
+        __asm__ ("fmsub %[r], %[a], %[c], %[b]\n"                       \
+                 : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+        __r;})
+#define FNMSUB(a_, c_, b_)                                              \
+      ({ double __r;                                                    \
+        __asm__ ("fnmsub %[r], %[a], %[c], %[b]\n"                      \
+                 : [r] "=f" (__r) : [a] "f" (a_), [c] "f" (c_), [b] "f" (b_)); \
+        __r;})
+
+      if (__builtin_expect (b != a_inf.value, 1))
+        {
+          double y, x;
+          fenv_t fe;
+
+          fe = fegetenv_register ();
+
+          relax_fenv_state ();
+
+          /* Compute y = 1.5 * b - b.  Uses fewer constants than y = 0.5 * b.  */
+          y = FMSUB (threehalf, b, b);
+
+          /* Initial estimate.  */
+          __asm__ ("frsqrte %[x], %[b]\n" : [x] "=f" (x) : [b] "f" (b));
+
+          /* Iterate.  x_{n+1} = x_n * (1.5 - y * (x_n * x_n)).  */
+          x = x * FNMSUB (y, x * x, threehalf);
+          x = x * FNMSUB (y, x * x, threehalf);
+          x = x * FNMSUB (y, x * x, threehalf);
+
+          /* All done.  */
+          fesetenv_register (fe);
+          return x * b;
+        }
+    }
+  else if (b < 0)
+    {
+      /* For some reason, some PowerPC32 processors don't implement
+         FE_INVALID_SQRT.  */
+#ifdef FE_INVALID_SQRT
+      feraiseexcept (FE_INVALID_SQRT);
+
+      fenv_union_t u = { .fenv = fegetenv_register () };
+      if ((u.l[1] & FE_INVALID) == 0)
+#endif
+	feraiseexcept (FE_INVALID);
+      b = a_nan.value;
+    }
+  return f_washf (b);
+}
Index: libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/603e/fpu/Implies
===================================================================
--- /dev/null
+++ libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/603e/fpu/Implies
@@ -0,0 +1 @@
+powerpc/powerpc32/603e/fpu
Index: libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/7400/fpu/Implies
===================================================================
--- /dev/null
+++ libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/7400/fpu/Implies
@@ -0,0 +1 @@
+powerpc/powerpc32/603e/fpu
Index: libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/e500mc/fpu/Implies
===================================================================
--- /dev/null
+++ libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/e500mc/fpu/Implies
@@ -0,0 +1 @@
+powerpc/powerpc32/603e/fpu
Index: libc/sysdeps/unix/sysv/linux/powerpc/powerpc64/e5500/fpu/Implies
===================================================================
--- /dev/null
+++ libc/sysdeps/unix/sysv/linux/powerpc/powerpc64/e5500/fpu/Implies
@@ -0,0 +1 @@
+powerpc/powerpc64/e5500/fpu
Index: libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/e5500/fpu/Implies
===================================================================
--- /dev/null
+++ libc/sysdeps/unix/sysv/linux/powerpc/powerpc32/e5500/fpu/Implies
@@ -0,0 +1 @@
+powerpc/powerpc32/603e/fpu