diff options
| author | David Schultz <das@FreeBSD.org> | 2007-01-06 21:46:23 +0000 |
|---|---|---|
| committer | David Schultz <das@FreeBSD.org> | 2007-01-06 21:46:23 +0000 |
| commit | 8185b32b5a8bddbb6cf78f87b848bd042324d6d2 (patch) | |
| tree | 62665f2c7564e85ebe4ba599d4e200d95e83e8fb /lib | |
| parent | 93e0663877691f5e87e6d0e5968d25a73c951f70 (diff) | |
Notes
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/msun/amd64/fenv.h | 13 | ||||
| -rw-r--r-- | lib/msun/i387/fenv.h | 13 |
2 files changed, 24 insertions, 2 deletions
diff --git a/lib/msun/amd64/fenv.h b/lib/msun/amd64/fenv.h index cb213c271c5f..b4d7379e8ff0 100644 --- a/lib/msun/amd64/fenv.h +++ b/lib/msun/amd64/fenv.h @@ -78,6 +78,9 @@ extern const fenv_t __fe_dfl_env; #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw)) #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env)) +#define __fldenvx(__env) __asm __volatile("fldenv %0" : : "m" (__env) \ + : "st", "st(1)", "st(2)", "st(3)", "st(4)", \ + "st(5)", "st(6)", "st(7)") #define __fnclex() __asm __volatile("fnclex") #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env))) #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw))) @@ -171,7 +174,15 @@ static __inline int fesetenv(const fenv_t *__envp) { - __fldenv(__envp->__x87); + /* + * XXX Using fldenvx() instead of fldenv() tells the compiler that this + * instruction clobbers the i387 register stack. This happens because + * we restore the tag word from the saved environment. Normally, this + * would happen anyway and we wouldn't care, because the ABI allows + * function calls to clobber the i387 regs. However, fesetenv() is + * inlined, so we need to be more careful. + */ + __fldenvx(__envp->__x87); __ldmxcsr(__envp->__mxcsr); return (0); } diff --git a/lib/msun/i387/fenv.h b/lib/msun/i387/fenv.h index cbe9a6b6de90..c4eab02d9dfc 100644 --- a/lib/msun/i387/fenv.h +++ b/lib/msun/i387/fenv.h @@ -99,6 +99,9 @@ extern const fenv_t __fe_dfl_env; #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw)) #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env)) +#define __fldenvx(__env) __asm __volatile("fldenv %0" : : "m" (__env) \ + : "st", "st(1)", "st(2)", "st(3)", "st(4)", \ + "st(5)", "st(6)", "st(7)") #define __fnclex() __asm __volatile("fnclex") #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env))) #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw))) @@ -207,7 +210,15 @@ fesetenv(const fenv_t *__envp) __mxcsr = __get_mxcsr(__env); __set_mxcsr(__env, 0xffffffff); - __fldenv(__env); + /* + * XXX Using fldenvx() instead of fldenv() tells the compiler that this + * instruction clobbers the i387 register stack. This happens because + * we restore the tag word from the saved environment. Normally, this + * would happen anyway and we wouldn't care, because the ABI allows + * function calls to clobber the i387 regs. However, fesetenv() is + * inlined, so we need to be more careful. + */ + __fldenvx(__env); if (__HAS_SSE()) __ldmxcsr(__mxcsr); return (0); |