diff options
Diffstat (limited to 'libc/sysdeps/linux/csky/fpu_control.h')
| -rw-r--r-- | libc/sysdeps/linux/csky/fpu_control.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/csky/fpu_control.h b/libc/sysdeps/linux/csky/fpu_control.h new file mode 100644 index 000000000..a2d615554 --- /dev/null +++ b/libc/sysdeps/linux/csky/fpu_control.h @@ -0,0 +1,147 @@ +/* FPU control word bits. C-SKY version. + Copyright (C) 2018-2025 Free Software Foundation, Inc. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _FPU_CONTROL_H +#define _FPU_CONTROL_H + +/* C-SKY FPU floating point control register bits. + + 31-28 -> Reserved (read as 0, write with 0). + 27 -> 0: Flush denormalized results to zero. + 1: Flush denormalized results to signed minimal normal number. + 26 -> Reserved (read as 0, write with 0). + 25-24 -> Rounding control. + 23-6 -> Reserved (read as 0, write with 0). + 5 -> Enable exception for input denormalized exception. + 4 -> Enable exception for inexact exception. + 3 -> Enable exception for underflow exception. + 2 -> Enable exception for overflow exception. + 1 -> Enable exception for division by zero exception. + 0 -> Enable exception for invalid operation exception. + + Rounding Control: + 00 - Rounding to nearest (RN). + 01 - Rounding toward zero (RZ). + 10 - Rounding (up) toward plus infinity (RP). + 11 - Rounding (down)toward minus infinity (RM). + + C-SKY FPU floating point exception status register bits. + + 15 -> Accumulate bit for any exception. + 14 -> Reserved (read as 0, write with 0). + 13 -> Cause bit for input denormalized exception. + 12 -> Cause bit for inexact exception. + 11 -> Cause bit for underflow exception. + 10 -> Cause bit for overflow exception. + 9 -> Cause bit for division by zero exception. + 8 -> Cause bit for invalid operation exception. + 7 -> Flag bit for any exception. + 6 -> Reserved (read as 0, write with 0). + 5 -> Flag exception for input denormalized exception. + 4 -> Flag exception for inexact exception. + 3 -> Flag exception for underflow exception. + 2 -> Flag exception for overflow exception. + 1 -> Flag exception for division by zero exception. + 0 -> Flag exception for invalid operation exception. */ + +#include <features.h> + +#ifdef __csky_soft_float__ + +# define _FPU_RESERVED 0xffffffff +# define _FPU_DEFAULT 0x00000000 +typedef unsigned int fpu_control_t; +# define _FPU_GETCW(cw) (cw) = 0 +# define _FPU_SETCW(cw) (void) (cw) +# define _FPU_GETFPSR(cw) (cw) = 0 +# define _FPU_SETFPSR(cw) (void) (cw) +extern fpu_control_t __fpu_control; + +#else /* __csky_soft_float__ */ + +/* Masking of interrupts. */ +# define _FPU_MASK_IDE (1 << 5) /* Input denormalized exception. */ +# define _FPU_MASK_IXE (1 << 4) /* Inexact exception. */ +# define _FPU_MASK_UFE (1 << 3) /* Underflow exception. */ +# define _FPU_MASK_OFE (1 << 2) /* Overflow exception. */ +# define _FPU_MASK_DZE (1 << 1) /* Division by zero exception. */ +# define _FPU_MASK_IOE (1 << 0) /* Invalid operation exception. */ + +# define _FPU_MASK_FEA (1 << 15) /* Case for any exception. */ +# define _FPU_MASK_FEC (1 << 7) /* Flag for any exception. */ + +/* Flush denormalized numbers to zero. */ +# define _FPU_FLUSH_TZ 0x8000000 + +/* Rounding control. */ +# define _FPU_RC_NEAREST (0x0 << 24) /* RECOMMENDED. */ +# define _FPU_RC_ZERO (0x1 << 24) +# define _FPU_RC_UP (0x2 << 24) +# define _FPU_RC_DOWN (0x3 << 24) + +# define _FPU_RESERVED 0xf460ffc0 /* Reserved bits in cw. */ +# define _FPU_FPSR_RESERVED 0xffff4040 + +/* The fdlibm code requires strict IEEE double precision arithmetic, + and no interrupts for exceptions, rounding to nearest. */ + +# define _FPU_DEFAULT 0x00000000 +# define _FPU_FPSR_DEFAULT 0x00000000 + +/* IEEE: same as above, but exceptions. */ +# define _FPU_FPCR_IEEE 0x0000001F +# define _FPU_FPSR_IEEE 0x00000000 + +/* Type of the control word. */ +typedef unsigned int fpu_control_t; + +/* Macros for accessing the hardware control word. */ +# if (__CSKY__ == 2) +# define _FPU_GETCW(cw) __asm__ volatile ("mfcr %0, cr<1, 2>" : "=a" (cw)) +# define _FPU_SETCW(cw) __asm__ volatile ("mtcr %0, cr<1, 2>" : : "a" (cw)) +# define _FPU_GETFPSR(cw) __asm__ volatile ("mfcr %0, cr<2, 2>" : "=a" (cw)) +# define _FPU_SETFPSR(cw) __asm__ volatile ("mtcr %0, cr<2, 2>" : : "a" (cw)) +# else +# define _FPU_GETCW(cw) __asm__ volatile ("1: cprcr %0, cpcr2 \n" \ + " btsti %0, 31 \n" \ + " bt 1b \n" \ + " cprcr %0, cpcr1\n" : "=b" (cw)) + +# define _FPU_SETCW(cw) __asm__ volatile ("1: cprcr r7, cpcr2 \n" \ + " btsti r7, 31 \n" \ + " bt 1b \n" \ + " cpwcr %0, cpcr1 \n" \ + : : "b" (cw) : "r7") + +# define _FPU_GETFPSR(cw) __asm__ volatile ("1: cprcr %0, cpcr2 \n" \ + " btsti %0, 31 \n" \ + " bt 1b \n" \ + " cprcr %0, cpcr4\n" : "=b" (cw)) + +# define _FPU_SETFPSR(cw) __asm__ volatile ("1: cprcr r7, cpcr2 \n" \ + " btsti r7, 31 \n" \ + " bt 1b \n" \ + " cpwcr %0, cpcr4 \n" \ + : : "b" (cw) : "r7") +# endif /* __CSKY__ != 2 */ + +/* Default control word set at startup. */ +extern fpu_control_t __fpu_control; + +#endif /* !__csky_soft_float__ */ + +#endif /* fpu_control.h */ |