6 // glibc lies about the contents of the fpstate the kernel provides, hiding the FXSR
9 /* Regular FPU environment */
15 unsigned long dataoff;
16 unsigned long datasel;
18 unsigned short status;
19 unsigned short magic; /* 0xffff = regular FPU data only */
21 /* FXSR FPU environment */
22 unsigned long _fxsr_env[6]; /* FXSR FPU env is ignored */
24 unsigned long reserved;
25 struct _fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
26 struct _xmmreg _xmm[8];
27 unsigned long padding[56];
30 #define X86_FXSR_MAGIC 0x0000
32 inline static unsigned int uap_fpu_status(void *uap)
34 ucontext_t *ucontext = (ucontext_t *)uap;
35 struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
36 if (fpregs->magic == X86_FXSR_MAGIC)
37 return fpregs->sw | fpregs->mxcsr;
42 inline static void uap_clear_fpu_status(void *uap)
44 ucontext_t *ucontext = (ucontext_t *)uap;
45 struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
47 if (fpregs->magic == X86_FXSR_MAGIC)
48 fpregs->mxcsr &= 0xffffffc0;
52 #define UAP_STACK_POINTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[7])
53 #define UAP_PROGRAM_COUNTER(ucontext) (((ucontext_t *)ucontext)->uc_mcontext.gregs[14])