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| author |   Wilco <wdijkstr@arm.com> | 2014-06-24 12:04:27 +0000 |
|---|---|---|
| committer | Wilco <wdijkstr@arm.com> | 2014-06-24 12:04:27 +0000 |
| commit | 001f7b773c637560ecfa686452a5e68d60d07db3 (patch) | |
| tree | 08bd670c6b892304a287c56f6cbeb00e92276567 /sysdeps/arm/fedisblxcpt.c | |
| parent | Use libc calls defined by fenv_private.h to implement several fenv functions (diff) | |
| download | glibc-001f7b773c637560ecfa686452a5e68d60d07db3.tar.gz glibc-001f7b773c637560ecfa686452a5e68d60d07db3.tar.bz2 glibc-001f7b773c637560ecfa686452a5e68d60d07db3.zip | |
Speed up the ARM fenv implementation by avoiding unnecessary FPSCR
writes if the FPSCR remains unchanged.
2014-06-24 Wilco <wdijkstr@arm.com>
* sysdeps/arm/fclrexcpt.c (feclearexcept):
Optimize to avoid unnecessary FPSCR writes.
* sysdeps/arm/fedisblxcpt.c (fedisableexcept): Likewise.
* sysdeps/arm/feenablxcpt.c (feenableexcept): Likewise.
* sysdeps/arm/fsetexcptflg.c (fesetexceptflag): Likewise.
* sysdeps/arm/setfpucw.c (__setfpucw): Likewise.
Diffstat (limited to 'sysdeps/arm/fedisblxcpt.c')
| -rw-r--r-- | sysdeps/arm/fedisblxcpt.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sysdeps/arm/fedisblxcpt.c b/sysdeps/arm/fedisblxcpt.c index f2956cd32a..d5e0f0031a 100644 --- a/sysdeps/arm/fedisblxcpt.c +++ b/sysdeps/arm/fedisblxcpt.c @@ -35,7 +35,9 @@ fedisableexcept (int excepts) excepts &= FE_ALL_EXCEPT; new_fpscr = fpscr & ~(excepts << FE_EXCEPT_SHIFT); - _FPU_SETCW (new_fpscr); + /* Write new exceptions if changed. */ + if (new_fpscr != fpscr) + _FPU_SETCW (new_fpscr); return (fpscr >> FE_EXCEPT_SHIFT) & FE_ALL_EXCEPT; } |