It removes the wrapper by moving the error/EDOM handling to an
out-of-line implementation (__math_invalidf_i/__math_invalidf_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 <__ilogbf>:
0:
1e260000 fmov w0, s0
4:
d3577801 ubfx x1, x0, #23, #8
8:
340000e1 cbz w1, 24 <__ilogbf+0x24>
c:
5101fc20 sub w0, w1, #0x7f
10:
7103fc3f cmp w1, #0xff
14:
54000040 b.eq 1c <__ilogbf+0x1c> // b.none
18:
d65f03c0 ret
1c:
12b00000 mov w0, #0x7fffffff // #
2147483647
20:
14000000 b 0 <__math_invalidf_i>
24:
53175800 lsl w0, w0, #9
28:
340000a0 cbz w0, 3c <__ilogbf+0x3c>
2c:
5ac01000 clz w0, w0
30:
12800fc1 mov w1, #0xffffff81 // #-127
34:
4b000020 sub w0, w1, w0
38:
d65f03c0 ret
3c:
320107e0 mov w0, #0x80000001 // #-
2147483647
40:
14000000 b 0 <__math_invalidf_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
+#include <math-type-macros-float.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-float.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_ilogbf (float x)
-{
- uint32_t ux = asuint (x);
- int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
- if (ex == 0) /* zero or subnormal */
- {
- /* Clear sign and exponent. */
- ux <<= 1 + EXPONENT_WIDTH;
- if (ux == 0)
- return FP_ILOGB0;
- /* subnormal */
- return -127 - stdc_leading_zeros (ux);
- }
- if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */
- return ux << (1 + EXPONENT_WIDTH) ? FP_ILOGBNAN : INT_MAX;
- return ex - 127;
-}
+/* ilogbf is implemented at w_ilogbf.c */
attribute_hidden float __math_may_uflowf (uint32_t);
attribute_hidden float __math_divzerof (uint32_t);
attribute_hidden float __math_invalidf (float);
+attribute_hidden int __math_invalidf_i (int);
+attribute_hidden long int __math_invalidf_li (long int);
attribute_hidden float __math_edomf (float x);
/* Shared between expf, exp2f, exp10f, and powf. */
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <math-barriers.h>
#include "math_config.h"
#if WANT_ERRNO
errno = e;
return y;
}
+
+NOINLINE static int
+with_errnof_i (int y, int e)
+{
+ errno = e;
+ return y;
+}
+
+NOINLINE static long int
+with_errnof_li (long int y, int e)
+{
+ errno = e;
+ return y;
+}
#else
# define with_errnof(x, e) (x)
+# define with_errnof_i(x, x) (x)
+# define with_errnof_li(x, x) (x)
#endif
attribute_hidden float
float y = (x - x) / (x - x);
return isnan (x) ? y : with_errnof (y, EDOM);
}
+
+attribute_hidden int
+__math_invalidf_i (int x)
+{
+ float y = 0.0f / 0.0f;
+ math_force_eval (y);
+ return with_errnof_i (x, EDOM);
+}
+
+attribute_hidden long int
+__math_invalidf_li (long int x)
+{
+ float y = 0.0f / 0.0f;
+ math_force_eval (y);
+ return with_errnof_li (x, EDOM);
+}
--- /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 (float x)
+{
+ uint32_t ux = asuint (x);
+ int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
+ if (__glibc_unlikely (ex == 0))
+ {
+ /* Zero or subnormal.
+ Clear sign and exponent. */
+ ux <<= 1 + EXPONENT_WIDTH;
+ if (ux == 0)
+ return RET_INVALID (RET_LOGB0);
+ /* subnormal */
+ return (RET_TYPE)-127 - stdc_leading_zeros (ux);
+ }
+ if (__glibc_unlikely (ex == EXPONENT_MASK >> MANTISSA_WIDTH))
+ /* NaN or Inf */
+ return RET_INVALID (ux << (1 + EXPONENT_WIDTH) ? RET_LOGBNAN : RET_LOGMAX);
+ return ex - 127;
+}
--- /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-float.h>
+#include <math-type-macros-float.h>
+#include "math_config.h"
+
+#ifdef DEF_AS_LLOGBF
+# 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_invalidf_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_invalidf_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_ilogbf-impl.h>
+
+RET_TYPE
+M_DECL_FUNC (DECL_NAME) (float x)
+{
+ return IMPL_NAME (x);
+}
+libm_alias_float (DECL_NAME, FUNC_NAME);
--- /dev/null
+#define DEF_AS_LLOGBF
+#include "w_ilogbf.c"
-/* __ieee754_ilogbf(). LoongArch version.
- Copyright (C) 2022-2025 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/>. */
-
-#define NO_MATH_REDIRECT
-#include <math.h>
-#include <fpu_control.h>
-
-int
-__ieee754_ilogbf (float x)
-{
- int x_cond;
- asm volatile ("fclass.s \t%0, %1" : "=f" (x_cond) : "f" (x));
-
- if (__glibc_unlikely (x_cond & _FCLASS_ZERO))
- return FP_ILOGB0;
- else if (__glibc_unlikely (x_cond & ( _FCLASS_NAN | _FCLASS_INF)))
- return FP_ILOGBNAN;
- else
- {
- asm volatile ("fabs.s \t%0, %1" : "=f" (x) : "f" (x));
- asm volatile ("flogb.s \t%0, %1" : "=f" (x) : "f" (x));
- return x;
- }
-}
+/* ilogbf is implemented at w_ilogbf.c */
--- /dev/null
+/* 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.
+
+ 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 <fpu_control.h>
+
+static inline RET_TYPE
+IMPL_NAME (float x)
+{
+ int x_cond;
+ asm volatile ("fclass.s \t%0, %1" : "=f" (x_cond) : "f" (x));
+
+ if (__glibc_unlikely (x_cond & _FCLASS_ZERO))
+ return RET_INVALID (RET_LOGB0);
+ else if (__glibc_unlikely (x_cond & ( _FCLASS_NAN | _FCLASS_INF)))
+ return RET_INVALID (RET_LOGBNAN);
+ else
+ {
+ asm volatile ("fabs.s \t%0, %1" : "=f" (x) : "f" (x));
+ asm volatile ("flogb.s \t%0, %1" : "=f" (x) : "f" (x));
+ return x;
+ }
+}
--- /dev/null
+#include <math-type-macros-float.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-float.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 "sysdeps/ieee754/flt-32/math_config.h"
+
+int
+__ieee754_ilogbf (float x)
+{
+ uint32_t ux = asuint (x);
+ int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
+ if (ex == 0) /* zero or subnormal */
+ {
+ /* Clear sign and exponent. */
+ ux <<= 1 + EXPONENT_WIDTH;
+ if (ux == 0)
+ return FP_ILOGB0;
+ /* sbunormal */
+ return -127 - stdc_leading_zeros (ux);
+ }
+ if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */
+ return ux << (1 + EXPONENT_WIDTH) ? FP_ILOGBNAN : INT_MAX;
+ return ex - 127;
+}
--- /dev/null
+#include <math-type-macros-float.h>
+#include <w_ilogb_template.c>
--- /dev/null
+#include <math-type-macros-float.h>
+#include <w_llogb_template.c>
projects / thirdparty / glibc.git / commitdiff
