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-rw-r--r--libc/sysdeps/linux/csky/bits/fenv.h123
-rw-r--r--libc/sysdeps/linux/csky/fpu_control.h147
2 files changed, 230 insertions, 40 deletions
diff --git a/libc/sysdeps/linux/csky/bits/fenv.h b/libc/sysdeps/linux/csky/bits/fenv.h
index 3359e1f8e..1428f385a 100644
--- a/libc/sysdeps/linux/csky/bits/fenv.h
+++ b/libc/sysdeps/linux/csky/bits/fenv.h
@@ -1,65 +1,108 @@
-/*
- * Copyright (C) 2017 Hangzhou C-SKY Microsystems co.,ltd.
- *
- * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB
- * in this tarball.
- */
+/* Floating point environment. 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 _FENV_H
# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
#endif
-/* Define bits representing the exception. We use the bit positions of
- the appropriate bits in the FPSR Accrued Exception Byte. */
+#ifdef __csky_hard_float__
+/* Define bits representing the exception. We use the bit positions
+ of the appropriate bits in the FPU control word. */
enum
{
- FE_INEXACT = 1 << 3,
-#define FE_INEXACT FE_INEXACT
- FE_DIVBYZERO = 1 << 4,
-#define FE_DIVBYZERO FE_DIVBYZERO
- FE_UNDERFLOW = 1 << 5,
-#define FE_UNDERFLOW FE_UNDERFLOW
- FE_OVERFLOW = 1 << 6,
-#define FE_OVERFLOW FE_OVERFLOW
- FE_INVALID = 1 << 7
-#define FE_INVALID FE_INVALID
+ FE_INVALID =
+#define FE_INVALID 0x01
+ FE_INVALID,
+ FE_DIVBYZERO =
+#define FE_DIVBYZERO 0x02
+ FE_DIVBYZERO,
+ FE_OVERFLOW =
+#define FE_OVERFLOW 0x04
+ FE_OVERFLOW,
+ FE_UNDERFLOW =
+#define FE_UNDERFLOW 0x08
+ FE_UNDERFLOW,
+ FE_INEXACT =
+#define FE_INEXACT 0x10
+ FE_INEXACT,
+ __FE_DENORMAL = 0x20
};
#define FE_ALL_EXCEPT \
(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
-/* The csky FPU supports all of the four defined rounding modes. We use
- the bit positions in the FPCR Mode Control Byte as the values for the
- appropriate macros. */
+/* The C-SKY FPU supports all of the four defined rounding modes. We
+ use again the bit positions in the FPU control word as the values
+ for the appropriate macros. */
+enum
+ {
+ FE_TONEAREST =
+#define FE_TONEAREST (0x0 << 24)
+ FE_TONEAREST,
+ FE_TOWARDZERO =
+#define FE_TOWARDZERO (0x1 << 24)
+ FE_TOWARDZERO,
+ FE_UPWARD =
+#define FE_UPWARD (0x2 << 24)
+ FE_UPWARD,
+ FE_DOWNWARD =
+#define FE_DOWNWARD (0x3 << 24)
+ FE_DOWNWARD,
+ __FE_ROUND_MASK = (0x3 << 24)
+ };
+
+#else
+
+/* In the soft-float case, only rounding to nearest is supported, with
+ no exceptions. */
+
enum
{
- FE_TONEAREST = 0,
-#define FE_TONEAREST FE_TONEAREST
- FE_TOWARDZERO = 1 << 4,
-#define FE_TOWARDZERO FE_TOWARDZERO
- FE_DOWNWARD = 2 << 4,
-#define FE_DOWNWARD FE_DOWNWARD
- FE_UPWARD = 3 << 4
-#define FE_UPWARD FE_UPWARD
+ __FE_UNDEFINED = -1,
+
+ FE_TONEAREST =
+# define FE_TONEAREST 0x0
+ FE_TONEAREST
};
+# define FE_ALL_EXCEPT 0
+
+#endif
+
/* Type representing exception flags. */
typedef unsigned int fexcept_t;
-/* Type representing floating-point environment. This structure
- corresponds to the layout of the block written by `fmovem'. */
+/* Type representing floating-point environment. */
typedef struct
- {
- unsigned int __control_register;
- unsigned int __status_register;
- unsigned int __instruction_address;
- }
-fenv_t;
+{
+ unsigned int __fpcr;
+ unsigned int __fpsr;
+} fenv_t;
/* If the default argument is used we use this value. */
-#define FE_DFL_ENV ((__const fenv_t *) -1)
+#define FE_DFL_ENV ((const fenv_t *) -1)
-#ifdef __USE_GNU
+#if defined __USE_GNU && defined __csky_hard_float__
/* Floating-point environment where none of the exceptions are masked. */
-# define FE_NOMASK_ENV ((__const fenv_t *) -2)
+# define FE_NOMASK_ENV ((const fenv_t *) -2)
#endif
+
+/* Type representing floating-point control modes. */
+typedef unsigned int femode_t;
+
+/* Default floating-point control modes. */
+# define FE_DFL_MODE ((const femode_t *) -1L)
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 */