Implement and use libc_feholdexcept_setround_53bit and libc_feupdateenv_53bit

so that double arithmetic in s_sin is done in 53 bit (without extend i386 double precision)

diff --git a/sysdeps/generic/math_private.h b/sysdeps/generic/math_private.h
index 777762dd33c1aef29a103fd6c612f6ade4794b18..be1e4d23149175fa8c5513eae80b3119e50531d1 100644 (file)
--- a/sysdeps/generic/math_private.h
+++ b/sysdeps/generic/math_private.h
@@ -370,6 +370,9 @@ extern void __docos (double __x, double __dx, double __v[]);
 #define libc_feholdexcept_setroundl(e, r) \
   do { feholdexcept (e); fesetround (r); } while (0)
 
+#define libc_feholdexcept_setround_53bit(e, r) \
+  libc_feholdexcept_setround (e, r)
+
 #define libc_fetestexcept(e) fetestexcept (e)
 #define libc_fetestexceptf(e) fetestexcept (e)
 #define libc_fetestexceptl(e) fetestexcept (e)
@@ -382,6 +385,8 @@ extern void __docos (double __x, double __dx, double __v[]);
 #define libc_feupdateenvf(e) (void) feupdateenv (e)
 #define libc_feupdateenvl(e) (void) feupdateenv (e)
 
+#define libc_feupdateenv_53bit(e) libc_feupdateenv (e)
+
 #define __nan(str) \
   (__builtin_constant_p (str) && str[0] == '\0' ? NAN : __nan (str))
 #define __nanf(str) \

diff --git a/sysdeps/i386/fpu/math_private.h b/sysdeps/i386/fpu/math_private.h
index 5253998a57039cd7f2fe2efd5a219333cbe2d87e..d96996fadf5ea0936e35fa99da5532003677604e 100644 (file)
--- a/sysdeps/i386/fpu/math_private.h
+++ b/sysdeps/i386/fpu/math_private.h
@@ -16,4 +16,33 @@ do                                                   \
 while (0)
 
 #include_next <math_private.h>
+
+# include <fpu_control.h>
+
+# undef libc_feholdexcept_setround_53bit
+# define libc_feholdexcept_setround_53bit(e, r)        \
+  do                                           \
+    {                                          \
+      fpu_control_t cw;                                \
+      libc_feholdexcept_setround (e, r);       \
+      _FPU_GETCW (cw);                         \
+      cw &= ~(fpu_control_t) _FPU_EXTENDED;    \
+      cw |= _FPU_DOUBLE;                       \
+      _FPU_SETCW (cw);                         \
+    }                                          \
+  while (0)
+
+# undef libc_feupdateenv_53bit
+# define libc_feupdateenv_53bit(e)             \
+  do                                           \
+    {                                          \
+      fpu_control_t cw;                                \
+      libc_feupdateenv (e);                    \
+      _FPU_GETCW (cw);                         \
+      cw &= ~(fpu_control_t) _FPU_EXTENDED;    \
+      cw |= _FPU_EXTENDED;                     \
+      _FPU_SETCW (cw);                         \
+    }                                          \
+  while (0)
+
 #endif

diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index e3e3a2a965b50d12df1d97800530cb4a6f88e53d..4b4b67573d3a38babf904fb602de93b701ab199a 100644 (file)
--- a/sysdeps/ieee754/dbl-64/s_sin.c
+++ b/sysdeps/ieee754/dbl-64/s_sin.c
@@ -1,7 +1,7 @@
 /*
  * IBM Accurate Mathematical Library
  * written by International Business Machines Corp.
- * Copyright (C) 2001, 2009, 2011 Free Software Foundation
+ * Copyright (C) 2001-2012 Free Software Foundation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -111,7 +111,7 @@ __sin(double x){
        fenv_t env;
        double retval = 0;
 
-       libc_feholdexcept_setround (&env, FE_TONEAREST);
+       libc_feholdexcept_setround_53bit (&env, FE_TONEAREST);
 
        u.x = x;
        m = u.i[HIGH_HALF];
@@ -365,7 +365,7 @@ __sin(double x){
        }
 
  ret:
-       libc_feupdateenv (&env);
+       libc_feupdateenv_53bit (&env);
        return retval;
 }
 
@@ -386,7 +386,7 @@ __cos(double x)
   fenv_t env;
   double retval = 0;
 
-  libc_feholdexcept_setround (&env, FE_TONEAREST);
+  libc_feholdexcept_setround_53bit (&env, FE_TONEAREST);
 
   u.x = x;
   m = u.i[HIGH_HALF];
@@ -635,7 +635,7 @@ __cos(double x)
   }
 
  ret:
-  libc_feupdateenv (&env);
+  libc_feupdateenv_53bit (&env);
   return retval;
 }