Merge changes between r2162 and r2243 from /fsf/trunk.

git-svn-id: svn://svn.eglibc.org/trunk@2244 7b3dc134-2b1b-0410-93df-9e9f96275f8d

1 files changed, 21 insertions, 1 deletions

diff --git a/libc/sysdeps/powerpc/fpu/fesetenv.c b/libc/sysdeps/powerpc/fpu/fesetenv.c
index ff82dfd17..5a0c742ff 100644
--- a/libc/sysdeps/powerpc/fpu/fesetenv.c
+++ b/libc/sysdeps/powerpc/fpu/fesetenv.c
@@ -1,5 +1,5 @@
 /* Install given floating-point environment.
-   Copyright (C) 1997,99,2000,01,02 Free Software Foundation, Inc.
+   Copyright (C) 1997,99,2000,01,02,07 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
@@ -23,6 +23,26 @@
 int
 __fesetenv (const fenv_t *envp)
 {
+  fenv_union_t old, new;
+
+  /* get the currently set exceptions.  */
+  new.fenv = *envp;
+  old.fenv = fegetenv_register ();
+  
+  /* If the old env has no eabled exceptions and the new env has any enabled
+     exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits.  This will put
+     the hardware into "precise mode" and may cause the FPU to run slower on
+     some hardware.  */
+  if ((old.l[1] & 0x000000F8) == 0 && (new.l[1] & 0x000000F8) != 0)
+    (void)__fe_nomask_env ();
+  
+  /* If the old env had any eabled exceptions and the new env has no enabled
+     exceptions, then mask SIGFPE in the MSR FE0/FE1 bits.  This may allow the
+     FPU to run faster because it always takes the default action and can not 
+     generate SIGFPE. */
+  if ((old.l[1] & 0x000000F8) != 0 && (new.l[1] & 0x000000F8) == 0)
+    (void)__fe_mask_env ();
+    
   fesetenv_register (*envp);
 
   /* Success.  */