It removes the wrapper by moving the error/EDOM handling to an
out-of-line implementation (__math_invalid_i/__math_invalid_li).
Also, __glibc_unlikely is used on errors case since it helps
code generation on recent gcc.
The code now builds to with gcc-14 on aarch64:
0000000000000000 <__ilogb>:
0:
9e660000 fmov x0, d0
4:
d374f801 ubfx x1, x0, #52, #11
8:
340000e1 cbz w1, 24 <__ilogb+0x24>
c:
510ffc20 sub w0, w1, #0x3ff
10:
711ffc3f cmp w1, #0x7ff
14:
54000040 b.eq 1c <__ilogb+0x1c> // b.none
18:
d65f03c0 ret
1c:
12b00000 mov w0, #0x7fffffff // #
2147483647
20:
14000000 b 0 <__math_invalid_i>
24:
d374cc00 lsl x0, x0, #12
28:
b40000a0 cbz x0, 3c <__ilogb+0x3c>
2c:
dac01000 clz x0, x0
30:
12807fc1 mov w1, #0xfffffc01 // #-1023
34:
4b000020 sub w0, w1, w0
38:
d65f03c0 ret
3c:
320107e0 mov w0, #0x80000001 // #-
2147483647
40:
14000000 b 0 <__math_invalid_i>
Some ABI requires additional adjustments:
* i386 and m68k requires to use the template version, since
both provide __ieee754_ilogb implementatations.
* loongarch uses a custom implementation as well.
* powerpc64le also has a custom implementation for POWER9, which
is also used for float and float128 version. The generic
e_ilogb.c implementation is moved on powerpc to keep the
current code as-is.
Checked on aarch64-linux-gnu and x86_64-linux-gnu.
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
+++ /dev/null
-/* Not needed. */
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_llogb_template.c>
-/* Get integer exponent of a floating-point value.
- Copyright (C) 1999-2025 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- 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/>. */
-
-#include <limits.h>
-#include <math.h>
-#include <stdbit.h>
-#include "math_config.h"
-
-int
-__ieee754_ilogb (double x)
-{
- uint64_t ux = asuint64 (x);
- int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
- if (ex == 0) /* zero or subnormal */
- {
- /* Clear sign and exponent */
- ux <<= 12;
- if (ux == 0)
- return FP_ILOGB0;
- /* subnormal */
- return -1023 - stdc_leading_zeros (ux);
- }
- if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */
- return ux << 12 ? FP_ILOGBNAN : INT_MAX;
- return ex - 1023;
-}
+/* ilogb is implemented at w_ilogb.c */
/* Invalid input unless it is a quiet NaN. */
attribute_hidden double __math_invalid (double);
+attribute_hidden int __math_invalid_i (int);
+attribute_hidden long int __math_invalid_li (long int);
/* Error handling using output checking, only for errno setting. */
errno = e;
return y;
}
+
+NOINLINE static int
+with_errno_i (int y, int e)
+{
+ errno = e;
+ return y;
+}
+
+NOINLINE static long int
+with_errno_li (long int y, int e)
+{
+ errno = e;
+ return y;
+}
#else
#define with_errno(x, e) (x)
+#define with_errno_i(x, e) (x)
+#define with_errno_li(x, e) (x)
#endif
attribute_hidden double
return isnan (x) ? y : with_errno (y, EDOM);
}
+attribute_hidden int
+__math_invalid_i (int r)
+{
+ double y = 0.0 / 0.0;
+ math_force_eval (y);
+ return with_errno_i (r, EDOM);
+}
+
+attribute_hidden long int
+__math_invalid_li (long int r)
+{
+ double y = 0.0 / 0.0;
+ math_force_eval (y);
+ return with_errno_li (r, EDOM);
+}
+
/* Check result and set errno if necessary. */
attribute_hidden double
--- /dev/null
+/* Get integer exponent of a floating-point value.
+ Copyright (C) 1999-2025 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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/>. */
+
+static inline RET_TYPE
+IMPL_NAME (double x)
+{
+ uint64_t ux = asuint64 (x);
+ int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
+ if (__glibc_unlikely (ex == 0)) /* zero or subnormal */
+ {
+ /* Clear sign and exponent */
+ ux <<= 12;
+ if (ux == 0)
+ return RET_INVALID (RET_LOGB0);
+ /* subnormal */
+ return (RET_TYPE)-1023 - stdc_leading_zeros (ux);
+ }
+ if (__glibc_unlikely (ex == EXPONENT_MASK >> MANTISSA_WIDTH))
+ /* NaN or Inf */
+ return RET_INVALID (ux << 12 ? RET_LOGBNAN : RET_LOGMAX);
+ return ex - 1023;
+}
--- /dev/null
+/* Get integer exponent of a floating-point value.
+ Copyright (C) 1999-2025 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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/>. */
+
+#include <limits.h>
+#include <math.h>
+#include <stdbit.h>
+#include <libm-alias-double.h>
+#include "math_config.h"
+
+#ifdef DEF_AS_LLOGB
+# define DECL_NAME __llogb
+# define FUNC_NAME llogb
+# define RET_TYPE long int
+# define RET_LOGB0 FP_LLOGB0
+# define RET_LOGBNAN FP_LLOGBNAN
+# define RET_LOGMAX LONG_MAX
+# define RET_INVALID __math_invalid_li
+#else
+# define DECL_NAME __ilogb
+# define FUNC_NAME ilogb
+# define RET_TYPE int
+# define RET_LOGB0 FP_ILOGB0
+# define RET_LOGBNAN FP_ILOGBNAN
+# define RET_LOGMAX INT_MAX
+# define RET_INVALID __math_invalid_i
+#endif
+#define __IMPL_NAME(x,y) x ## _ ## y
+#define _IMPL_NAME(x,y) __IMPL_NAME(x,y)
+#define IMPL_NAME _IMPL_NAME(FUNC_NAME, impl)
+#include <w_ilogb-impl.h>
+
+RET_TYPE
+DECL_NAME (double x)
+{
+ return IMPL_NAME (x);
+}
+libm_alias_double (DECL_NAME, FUNC_NAME)
--- /dev/null
+#define DEF_AS_LLOGB
+#include "w_ilogb.c"
-/* __ieee754_ilogb(). LoongArch version.
+/* Get integer exponent of a floating-point value. LoongArch version.
Copyright (C) 2022-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#define NO_MATH_REDIRECT
-#include <math.h>
#include <fpu_control.h>
-int
-__ieee754_ilogb (double x)
+static inline RET_TYPE
+IMPL_NAME (double x)
{
int x_cond;
asm volatile ("fclass.d \t%0, %1" : "=f" (x_cond) : "f" (x));
if (__glibc_unlikely (x_cond & _FCLASS_ZERO))
- return FP_ILOGB0;
+ return RET_INVALID (RET_LOGB0);
else if (__glibc_unlikely (x_cond & ( _FCLASS_NAN | _FCLASS_INF)))
- return FP_ILOGBNAN;
+ return RET_INVALID (RET_LOGBNAN);
else
{
asm volatile ("fabs.d \t%0, %1" : "=f" (x) : "f" (x));
+++ /dev/null
-/* Not needed. */
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_llogb_template.c>
--- /dev/null
+/* Get integer exponent of a floating-point value.
+ Copyright (C) 1999-2025 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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/>. */
+
+#include <limits.h>
+#include <math.h>
+#include <stdbit.h>
+#include "math_config.h"
+
+int
+__ieee754_ilogb (double x)
+{
+ uint64_t ux = asuint64 (x);
+ int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
+ if (ex == 0) /* zero or subnormal */
+ {
+ /* Clear sign and exponent */
+ ux <<= 12;
+ if (ux == 0)
+ return FP_ILOGB0;
+ /* subnormal */
+ return -1023 - stdc_leading_zeros (ux);
+ }
+ if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */
+ return ux << 12 ? FP_ILOGBNAN : INT_MAX;
+ return ex - 1023;
+}
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-double.h>
+#include <w_llogb_template.c>
projects / thirdparty / glibc.git / commitdiff
