ubuntu-buildroot/output/build/glibc-2.36-81-g4f4d7a13edfd.../sysdeps/powerpc/hwcapinfo.c

83 lines
2.9 KiB
C

/* powerpc HWCAP/HWCAP2 and AT_PLATFORM data pre-processing.
Copyright (C) 2015-2022 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 <unistd.h>
#include <shlib-compat.h>
#include <dl-procinfo.h>
tcbhead_t __tcb __attribute__ ((visibility ("hidden")));
/* This function parses the HWCAP/HWCAP2 fields, adding the previous supported
ISA bits, as well as converting the AT_PLATFORM string to a number. This
data is stored in two global variables that can be used later by the
powerpc-specific code to store it into the TCB. */
void
__tcb_parse_hwcap_and_convert_at_platform (void)
{
uint64_t h1, h2;
/* Read AT_PLATFORM string from auxv and convert it to a number. */
__tcb.at_platform = _dl_string_platform (GLRO (dl_platform));
/* Read HWCAP and HWCAP2 from auxv. */
h1 = GLRO (dl_hwcap);
h2 = GLRO (dl_hwcap2);
/* hwcap contains only the latest supported ISA, the code checks which is
and fills the previous supported ones. */
if (h2 & PPC_FEATURE2_ARCH_2_07)
h1 |= PPC_FEATURE_ARCH_2_06
| PPC_FEATURE_ARCH_2_05
| PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_ARCH_2_06)
h1 |= PPC_FEATURE_ARCH_2_05
| PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_ARCH_2_05)
h1 |= PPC_FEATURE_POWER5_PLUS
| PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_POWER5_PLUS)
h1 |= PPC_FEATURE_POWER5
| PPC_FEATURE_POWER4;
else if (h1 & PPC_FEATURE_POWER5)
h1 |= PPC_FEATURE_POWER4;
/* Consolidate both HWCAP and HWCAP2 into a single doubleword so that
we can read both in a single load later. */
__tcb.hwcap = (h1 << 32) | (h2 & 0xffffffff);
}
#if IS_IN (rtld)
versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \
__parse_hwcap_and_convert_at_platform, GLIBC_2_23);
#endif
/* Export __parse_hwcap_and_convert_at_platform in libc.a. This is used by
GCC to make sure that the HWCAP/Platform bits are stored in the TCB when
using __builtin_cpu_is()/__builtin_cpu_supports() in the static case. */
#ifndef SHARED
weak_alias (__tcb_parse_hwcap_and_convert_at_platform, \
__parse_hwcap_and_convert_at_platform);
#endif