diff options
| author | Chris Robinson <[email protected]> | 2017-09-19 03:42:00 -0700 |
|---|---|---|
| committer | Chris Robinson <[email protected]> | 2017-09-19 03:42:00 -0700 |
| commit | bc386af5c5607f0d7a7ed911d5975fc9758c7110 (patch) | |
| tree | 104b28a7705d1a0c0ebebdff549bc10210c66f2a /Alc | |
| parent | 4ca8b4080a2a0a434a35179a869e23c288bb7451 (diff) | |
Manually save and restore the FPU rounding mode on Windows
Apparently there is a bug with at least MinGW-W64 where fegetenv and fesetenv
do not properly save and restore the FPU rounding mode, resulting in the
rounding mode remaining as round-to-zero after certain function calls. I do not
know if this also affects MSVC, but better safe than sorry for now.
Diffstat (limited to 'Alc')
| -rw-r--r-- | Alc/helpers.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Alc/helpers.c b/Alc/helpers.c index 8e6306ae..e9eb5faf 100644 --- a/Alc/helpers.c +++ b/Alc/helpers.c @@ -295,6 +295,13 @@ void SetMixerFPUMode(FPUCtl *ctl) { #ifdef HAVE_FENV_H fegetenv(STATIC_CAST(fenv_t, ctl)); +#ifdef _WIN32 + /* HACK: A nasty bug in MinGW-W64 causes fegetenv and fesetenv to not save + * and restore the FPU rounding mode, so we have to do it manually. Don't + * know if this also applies to MSVC. + */ + ctl->round_mode = fegetround(); +#endif #if defined(__GNUC__) && defined(HAVE_SSE) /* FIXME: Some fegetenv implementations can get the SSE environment too? * How to tell when it does? */ @@ -341,6 +348,9 @@ void RestoreFPUMode(const FPUCtl *ctl) { #ifdef HAVE_FENV_H fesetenv(STATIC_CAST(fenv_t, ctl)); +#ifdef _WIN32 + fesetround(ctl->round_mode); +#endif #if defined(__GNUC__) && defined(HAVE_SSE) if((CPUCapFlags&CPU_CAP_SSE)) __asm__ __volatile__("ldmxcsr %0" : : "m" (*&ctl->sse_state)); |