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c4be334400
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>
53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
/* Get integer exponent of a floating-point value.
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Copyright (C) 1999-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <limits.h>
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#include <math.h>
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#include <stdbit.h>
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#include <libm-alias-double.h>
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#include "math_config.h"
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#ifdef DEF_AS_LLOGB
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# define DECL_NAME __llogb
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# define FUNC_NAME llogb
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# define RET_TYPE long int
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# define RET_LOGB0 FP_LLOGB0
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# define RET_LOGBNAN FP_LLOGBNAN
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# define RET_LOGMAX LONG_MAX
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# define RET_INVALID __math_invalid_li
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#else
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# define DECL_NAME __ilogb
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# define FUNC_NAME ilogb
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# define RET_TYPE int
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# define RET_LOGB0 FP_ILOGB0
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# define RET_LOGBNAN FP_ILOGBNAN
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# define RET_LOGMAX INT_MAX
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# define RET_INVALID __math_invalid_i
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#endif
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#define __IMPL_NAME(x,y) x ## _ ## y
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#define _IMPL_NAME(x,y) __IMPL_NAME(x,y)
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#define IMPL_NAME _IMPL_NAME(FUNC_NAME, impl)
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#include <w_ilogb-impl.h>
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RET_TYPE
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DECL_NAME (double x)
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{
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return IMPL_NAME (x);
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}
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libm_alias_double (DECL_NAME, FUNC_NAME)
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