Hello. This is more a question than patch submission: Without the attached changes, the Cygwin cannot be linked for AArch64 failing on: ``` ld: cannot export _fe_nomask_env: symbol not defined ld: cannot export fedisableexcept: symbol not defined ld: cannot export fegetexcept: symbol not defined ld: cannot export fegetprec: symbol not defined ld: cannot export fesetprec: symbol not defined ``` Can anybody share some insights why are those changes needed and whether there is a better way how to overcome this issue?
Note that the `feenableexcept`, `fedisableexcept`, `fegetexcept` implementations are similarly defined in `newlib/libc/machine/mips/machine/fenv-fp.h` for MIPS architecture as well. Thank you, Radek --- >From 17fd8e16061ab199d111b303a44c042ea43c4018 Mon Sep 17 00:00:00 2001 From: Radek Barton <[email protected]> Date: Mon, 9 Jun 2025 08:55:18 +0200 Subject: [PATCH/QUESTION] newlib: fenv: AArch64 Cygwin linking fixes --- newlib/libc/machine/aarch64/machine/fenv-fp.h | 64 +++++++++++++++++++ newlib/libc/machine/aarch64/sys/fenv.h | 40 ------------ newlib/libm/machine/aarch64/fenv.c | 7 ++ winsup/cygwin/fenv.c | 10 +++ 4 files changed, 81 insertions(+), 40 deletions(-) diff --git a/newlib/libc/machine/aarch64/machine/fenv-fp.h b/newlib/libc/machine/aarch64/machine/fenv-fp.h index d8ec3fc76..e42e2d873 100644 --- a/newlib/libc/machine/aarch64/machine/fenv-fp.h +++ b/newlib/libc/machine/aarch64/machine/fenv-fp.h @@ -154,3 +154,67 @@ feupdateenv(const fenv_t *__envp) return (0); } +#if __BSD_VISIBLE + +/* We currently provide no external definitions of the functions below. */ + +__fenv_static inline int +feenableexcept(int __mask) +{ + fenv_t __old_r, __new_r; + + __mrs_fpcr(__old_r); + __new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); + __msr_fpcr(__new_r); + return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); +} + +__fenv_static inline int +fedisableexcept(int __mask) +{ + fenv_t __old_r, __new_r; + + __mrs_fpcr(__old_r); + __new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); + __msr_fpcr(__new_r); + return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); +} + +__fenv_static inline int +fegetexcept(void) +{ + fenv_t __r; + + __mrs_fpcr(__r); + return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT); +} + +#endif /* __BSD_VISIBLE */ + +#if defined(__CYGWIN__) + +/* Returns the currently selected precision, represented by one of the + values of the defined precision macros. */ +__fenv_static inline int +fegetprec (void) +{ + return 0; +} + +/* http://www.open-std.org/jtc1/sc22//WG14/www/docs/n752.htm: + + The fesetprec function establishes the precision represented by its + argument prec. If the argument does not match a precision macro, the + precision is not changed. + + The fesetprec function returns a nonzero value if and only if the + argument matches a precision macro (that is, if and only if the requested + precision can be established). */ +__fenv_static inline int +fesetprec (int prec) +{ + /* Indicate success. */ + return 1; +} + +#endif /* __CYGWIN__ */ diff --git a/newlib/libc/machine/aarch64/sys/fenv.h b/newlib/libc/machine/aarch64/sys/fenv.h index 6b0879269..1cfbeaaf4 100644 --- a/newlib/libc/machine/aarch64/sys/fenv.h +++ b/newlib/libc/machine/aarch64/sys/fenv.h @@ -77,44 +77,4 @@ extern const fenv_t *_fe_dfl_env; #define __mrs_fpsr(__r) __asm __volatile("mrs %0, fpsr" : "=r" (__r)) #define __msr_fpsr(__r) __asm __volatile("msr fpsr, %0" : : "r" (__r)) - -#if __BSD_VISIBLE - -/* We currently provide no external definitions of the functions below. */ - -static inline int -feenableexcept(int __mask) -{ - fenv_t __old_r, __new_r; - - __mrs_fpcr(__old_r); - __new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); - __msr_fpcr(__new_r); - return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); -} - -static inline int -fedisableexcept(int __mask) -{ - fenv_t __old_r, __new_r; - - __mrs_fpcr(__old_r); - __new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT); - __msr_fpcr(__new_r); - return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); -} - -static inline int -fegetexcept(void) -{ - fenv_t __r; - - __mrs_fpcr(__r); - return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT); -} - -#endif /* __BSD_VISIBLE */ - - - #endif /* !_FENV_H_ */ diff --git a/newlib/libm/machine/aarch64/fenv.c b/newlib/libm/machine/aarch64/fenv.c index 3ffe23441..86f8cd5aa 100644 --- a/newlib/libm/machine/aarch64/fenv.c +++ b/newlib/libm/machine/aarch64/fenv.c @@ -55,3 +55,10 @@ extern inline int feupdateenv(const fenv_t *__envp); extern inline int feenableexcept(int __mask); extern inline int fedisableexcept(int __mask); extern inline int fegetexcept(void); + +#if defined(__CYGWIN__) + +extern inline int fegetprec(void); +extern inline int fesetprec(int prec); + +#endif /* CYGWIN */ diff --git a/winsup/cygwin/fenv.c b/winsup/cygwin/fenv.c index 80f7cc52c..1558f76c2 100644 --- a/winsup/cygwin/fenv.c +++ b/winsup/cygwin/fenv.c @@ -3,3 +3,13 @@ being called from mainCRTStartup in crt0.o. */ void _feinitialise (void) {} + +#if defined(__aarch64__) + +#include <fenv.h> +#include <stddef.h> + +/* _fe_nomask_env is exported by cygwin.din but not used at all for AArch64. */ +const fenv_t *_fe_nomask_env = NULL; + +#endif /* __aarch64__ */ -- 2.49.0.vfs.0.3
0001-newlib-fenv-AArch64-Cygwin-linking-fixes.patch
Description: 0001-newlib-fenv-AArch64-Cygwin-linking-fixes.patch
