sortix-mirror/libm/arch/x86_64/fpsetprec.S

40 lines
682 B
ArmAsm

/* $NetBSD: fpsetprec.S,v 1.1 2011/03/26 19:51:42 christos Exp $ */
/*
* Written by Frank van der Linden at Wasabi Systems for NetBSD.
* Public domain.
*/
#include <machine/asm.h>
/*
* XXX set both the x87 control word and the SSE mxcsr register.
* Applications should only set exception and round flags
* via the fp*() interface, otherwise the status words
* will get our of sync.
*/
#ifdef WEAK_ALIAS
WEAK_ALIAS(fpsetprec, _fpsetprec)
ENTRY(_fpsetprec)
#else
ENTRY(fpsetprec)
#endif
fnstcw -4(%rsp)
andl $3,%edi
movl -4(%rsp),%edx
rorl $8,%edx
movl %edx,%eax
andl $3,%eax
andl $~3,%edx
orl %edi,%edx
roll $8,%edx
movl %edx,-4(%rsp)
fldcw -4(%rsp)
ret