mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-12-27 21:21:50 +03:00
DynamicLoader: Remove math functionality in favor of -lgcc
This links the dynamic linker against libgcc.a instead of having our own copy of the math functions. For now we need to specify -fbuilding-libgcc as a hack to work around a bug with the -nodefaultlibs flag. Once everyone is on the latest toolchain version this can be removed.
This commit is contained in:
Gunnar Beutner
Andreas Kling
parent
224755e6ef
commit
dd39bb7784
Notes:
sideshowbarker
2024-07-18 18:36:26 +09:00
Author: https://github.com/gunnarbeutner Commit: https://github.com/SerenityOS/serenity/commit/dd39bb77845 Pull-request: https://github.com/SerenityOS/serenity/pull/6832
@ -1,6 +1,5 @@
|
||||
set(LOADER_SOURCES
|
||||
main.cpp
|
||||
math.cpp
|
||||
misc.cpp
|
||||
)
|
||||
|
||||
@ -23,11 +22,13 @@ add_definitions(-D_DYNAMIC_LOADER)
|
||||
|
||||
set(SOURCES ${LOADER_SOURCES} ${AK_SOURCES} ${ELF_SOURCES} ${LIBC_SOURCES1} ${LIBC_SOURCES2} ${LIBC_SOURCES3} ${LIBSYSTEM_SOURCES})
|
||||
|
||||
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti -nostdlib -pie -fpic -DNO_TLS")
|
||||
# FIXME: Remove -fbuilding-libgcc after the next toolchain update
|
||||
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fbuilding-libgcc -fno-rtti -nostdlib -pie -fpic -DNO_TLS")
|
||||
|
||||
set_source_files_properties (../Libraries/LibC/ssp.cpp PROPERTIES COMPILE_FLAGS
|
||||
"-fno-stack-protector")
|
||||
|
||||
add_executable(Loader.so ${SOURCES})
|
||||
target_link_libraries(Loader.so gcc)
|
||||
target_link_options(Loader.so PRIVATE LINKER:--no-dynamic-linker)
|
||||
install(TARGETS Loader.so RUNTIME DESTINATION usr/lib/)
|
||||
|
||||
@ -116,4 +116,10 @@ void _start(int argc, char** argv, char** envp)
|
||||
ELF::DynamicLinker::linker_main(move(main_program_name), main_program_fd, is_secure, argc, argv, envp);
|
||||
VERIFY_NOT_REACHED();
|
||||
}
|
||||
|
||||
void _fini();
|
||||
|
||||
void _fini()
|
||||
{
|
||||
}
|
||||
}
|
||||
|
||||
@ -1,170 +0,0 @@
|
||||
/*
|
||||
* Copyright (c) 2020, the SerenityOS developers.
|
||||
*
|
||||
* SPDX-License-Identifier: BSD-2-Clause
|
||||
*/
|
||||
|
||||
// TODO: Is there a compiler flag we can use to still get these math functions? (and compile with -nostdlib)
|
||||
// FIXME: What do we do with this regarding copyright stuff?
|
||||
// code for math functions taken from here:
|
||||
// https://gitlab.incom.co/CM-Shield/u-boot/commit/aa7839b39c2ee77f9ab8c393c56b8d812507dbb7
|
||||
// https://github.com/zayac/qemu-arm/blob/master/qemu/roms/ipxe/src/libgcc/__udivmoddi4.c
|
||||
// https://code.woboq.org/llvm/compiler-rt/lib/builtins/divdi3.c.html
|
||||
|
||||
#include "math.h"
|
||||
|
||||
extern "C" {
|
||||
|
||||
union overlay64 {
|
||||
u64 longw;
|
||||
struct {
|
||||
u32 lower;
|
||||
u32 higher;
|
||||
} words;
|
||||
};
|
||||
|
||||
u64 __ashldi3(u64 num, unsigned int shift)
|
||||
{
|
||||
union overlay64 output;
|
||||
|
||||
output.longw = num;
|
||||
if (shift >= 32) {
|
||||
output.words.higher = output.words.lower << (shift - 32);
|
||||
output.words.lower = 0;
|
||||
} else {
|
||||
if (!shift)
|
||||
return num;
|
||||
output.words.higher = (output.words.higher << shift) | (output.words.lower >> (32 - shift));
|
||||
output.words.lower = output.words.lower << shift;
|
||||
}
|
||||
return output.longw;
|
||||
}
|
||||
|
||||
u64 __lshrdi3(u64 num, unsigned int shift)
|
||||
{
|
||||
union overlay64 output;
|
||||
|
||||
output.longw = num;
|
||||
if (shift >= 32) {
|
||||
output.words.lower = output.words.higher >> (shift - 32);
|
||||
output.words.higher = 0;
|
||||
} else {
|
||||
if (!shift)
|
||||
return num;
|
||||
output.words.lower = output.words.lower >> shift | (output.words.higher << (32 - shift));
|
||||
output.words.higher = output.words.higher >> shift;
|
||||
}
|
||||
return output.longw;
|
||||
}
|
||||
|
||||
#define MAX_32BIT_UINT ((((u64)1) << 32) - 1)
|
||||
|
||||
static u64 _64bit_divide(u64 dividend, u64 divider, u64* rem_p)
|
||||
{
|
||||
u64 result = 0;
|
||||
|
||||
/*
|
||||
* If divider is zero - let the rest of the system care about the
|
||||
* exception.
|
||||
*/
|
||||
if (!divider)
|
||||
return 1 / (u32)divider;
|
||||
|
||||
/* As an optimization, let's not use 64 bit division unless we must. */
|
||||
if (dividend <= MAX_32BIT_UINT) {
|
||||
if (divider > MAX_32BIT_UINT) {
|
||||
result = 0;
|
||||
if (rem_p)
|
||||
*rem_p = divider;
|
||||
} else {
|
||||
result = (u32)dividend / (u32)divider;
|
||||
if (rem_p)
|
||||
*rem_p = (u32)dividend % (u32)divider;
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
while (divider <= dividend) {
|
||||
u64 locald = divider;
|
||||
u64 limit = __lshrdi3(dividend, 1);
|
||||
int shifts = 0;
|
||||
|
||||
while (locald <= limit) {
|
||||
shifts++;
|
||||
locald = locald + locald;
|
||||
}
|
||||
result |= __ashldi3(1, shifts);
|
||||
dividend -= locald;
|
||||
}
|
||||
|
||||
if (rem_p)
|
||||
*rem_p = dividend;
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
u64 __udivdi3(u64 num, u64 den)
|
||||
{
|
||||
return _64bit_divide(num, den, nullptr);
|
||||
}
|
||||
|
||||
u64 __umoddi3(u64 num, u64 den)
|
||||
{
|
||||
u64 v = 0;
|
||||
|
||||
_64bit_divide(num, den, &v);
|
||||
return v;
|
||||
}
|
||||
|
||||
uint64_t __udivmoddi4(uint64_t num, uint64_t den, uint64_t* rem_p)
|
||||
{
|
||||
uint64_t quot = 0, qbit = 1;
|
||||
|
||||
if (den == 0) {
|
||||
return 1 / ((unsigned)den); /* Intentional divide by zero, without
|
||||
triggering a compiler warning which
|
||||
would abort the build */
|
||||
}
|
||||
|
||||
/* Left-justify denominator and count shift */
|
||||
while ((int64_t)den >= 0) {
|
||||
den <<= 1;
|
||||
qbit <<= 1;
|
||||
}
|
||||
|
||||
while (qbit) {
|
||||
if (den <= num) {
|
||||
num -= den;
|
||||
quot += qbit;
|
||||
}
|
||||
den >>= 1;
|
||||
qbit >>= 1;
|
||||
}
|
||||
|
||||
if (rem_p)
|
||||
*rem_p = num;
|
||||
|
||||
return quot;
|
||||
}
|
||||
int64_t __divdi3(int64_t a, int64_t b)
|
||||
{
|
||||
const int bits_in_dword_m1 = (int)(sizeof(int64_t) * 8) - 1;
|
||||
int64_t s_a = a >> bits_in_dword_m1; // s_a = a < 0 ? -1 : 0
|
||||
int64_t s_b = b >> bits_in_dword_m1; // s_b = b < 0 ? -1 : 0
|
||||
a = (a ^ s_a) - s_a; // negate if s_a == -1
|
||||
b = (b ^ s_b) - s_b; // negate if s_b == -1
|
||||
s_a ^= s_b; // sign of quotient
|
||||
return (__udivmoddi4(a, b, (uint64_t*)0) ^ s_a) - s_a; // negate if s_a == -1
|
||||
}
|
||||
int64_t __moddi3(int64_t a, int64_t b)
|
||||
{
|
||||
const int bits_in_dword_m1 = (int)(sizeof(int64_t) * 8) - 1;
|
||||
int64_t s = b >> bits_in_dword_m1; // s = b < 0 ? -1 : 0
|
||||
b = (b ^ s) - s; // negate if s == -1
|
||||
s = a >> bits_in_dword_m1; // s = a < 0 ? -1 : 0
|
||||
a = (a ^ s) - s; // negate if s == -1
|
||||
uint64_t r = 0;
|
||||
__udivmoddi4(a, b, &r);
|
||||
return ((int64_t)r ^ s) - s; // negate if s == -1
|
||||
}
|
||||
}
|
||||
@ -1,26 +0,0 @@
|
||||
/*
|
||||
* Copyright (c) 2020, the SerenityOS developers.
|
||||
*
|
||||
* SPDX-License-Identifier: BSD-2-Clause
|
||||
*/
|
||||
|
||||
#pragma once
|
||||
|
||||
#include <AK/Types.h>
|
||||
|
||||
extern "C" {
|
||||
|
||||
u64 __ashldi3(u64 num, unsigned int shift);
|
||||
|
||||
u64 __lshrdi3(u64 num, unsigned int shift);
|
||||
|
||||
u64 __udivdi3(u64 num, u64 den);
|
||||
|
||||
u64 __umoddi3(u64 num, u64 den);
|
||||
|
||||
uint64_t __udivmoddi4(uint64_t num, uint64_t den, uint64_t* rem_p);
|
||||
|
||||
int64_t __divdi3(int64_t a, int64_t b);
|
||||
|
||||
int64_t __moddi3(int64_t a, int64_t b);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user