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authorUlrich Drepper <drepper@redhat.com>2007-05-07 06:22:38 +0000
committerUlrich Drepper <drepper@redhat.com>2007-05-07 06:22:38 +0000
commit4a59e9adcb9e8475a00ea9088b26b74b48998dd0 (patch)
treebd8ca665d3df88463cb4e328510db9625f9df75c /sysdeps/powerpc/fpu/feupdateenv.c
parent15eca72044d2148b4fe7fe5a0f89ea12a87640fe (diff)
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2007-04-30 Steven Munroe <sjmunroe@us.ibm.com>
Peter Bergner <bergner@us.ibm.com> * sysdeps/powerpc/bits/fenv.h: Declare __fe_mask_env extern. Define FE_NOMASK_ENV as FE_EANBLED_ENV. Define FE_MASK_ENV. * sysdeps/powerpc/fpu/Makefile: Add fe_mask to libm-support. * sysdeps/powerpc/fpu/fe_mask.c: New file. * sysdeps/powerpc/fpu/fe_nomask.c: Correct comment. * sysdeps/powerpc/fpu/fedisblxcpt.c (fedisableexcept): Call __fe_mask_env() if all FP exceptions disabled. * sysdeps/powerpc/fpu/feholdexcpt.c (feholdexcept): Copy high 32-bits from old FPSCR to new fenv to propagate DFP rounding modes. Call __fe_mask_env() if FP exceptions previously enabled. * sysdeps/powerpc/fpu/fesetenv.c (fesetenv): Change mask to merge exceptions from env. Use __fe_nomask_env() or __fe_mask_env() when transitioning from all exceptions disabled to any exception enabled or visa versa. * sysdeps/powerpc/fpu/feupdateenv.c (__feupdateenv): Change mask to merge exceptions from env. Call __fe_nomask_env or __fe_mask_env when transitioning from all exceptions disabled to any exception enabled or visa versa. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fe_nomask.c: Moved to... * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/fe_nomask.c: ...here. * sysdeps/unix/sysv/linux/powerpc/powerpc64/fe_nomask.c: Moved to... * sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu/fe_nomask.c: ...here. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/fe_mask.c: New file. * sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu/fe_mask.c: New file.
Diffstat (limited to 'sysdeps/powerpc/fpu/feupdateenv.c')
-rw-r--r--sysdeps/powerpc/fpu/feupdateenv.c22
1 files changed, 19 insertions, 3 deletions
diff --git a/sysdeps/powerpc/fpu/feupdateenv.c b/sysdeps/powerpc/fpu/feupdateenv.c
index 3a60d0f33d..5a4000f599 100644
--- a/sysdeps/powerpc/fpu/feupdateenv.c
+++ b/sysdeps/powerpc/fpu/feupdateenv.c
@@ -1,5 +1,5 @@
/* Install given floating-point environment and raise exceptions.
- Copyright (C) 1997,99,2000,01 Free Software Foundation, Inc.
+ Copyright (C) 1997,99,2000,01,07 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
@@ -30,8 +30,24 @@ __feupdateenv (const fenv_t *envp)
new.fenv = *envp;
old.fenv = fegetenv_register ();
- /* Copy the set exceptions from `old' to `new'. */
- new.l[1] = (new.l[1] & 0xE00000FF) | (old.l[1] & 0x1FFFFF00);
+ /* Restore rounding mode and exception enable from *envp and merge
+ exceptions. Leave fraction rounded/inexact and FP result/CC bits
+ unchanged. */
+ new.l[1] = (old.l[1] & 0x1FFFFF00) | (new.l[1] & 0x1FF80FFF);
+
+ /* 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 ();
/* Atomically enable and raise (if appropriate) exceptions set in `new'. */
fesetenv_register (new.fenv);