mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-23 02:18:51 +09:00
![Alexey Brodkin](/assets/img/avatar_default.png)
This way we may have very limited set of functions implemented so we save some space. Also it allows us to build U-Boot for any ARC core with the same one toolchain because we don't rely on pre-built libgcc. For example: * we may use little-endian toolchain but build U-Boot for ether endianess * we may use non-multilibbed uClibc toolchain but build U-Boot for whatever ARC CPU flavour that current GCC supports Private libgcc built from generic C implementation contributes only 144 bytes to .text section so we don't see significant degradation of size: --->8--- $ arc-linux-size u-boot.libgcc-prebuilt text data bss dec hex filename 222217 24912 214820 461949 70c7d u-boot.libgcc-prebuilt $ arc-linux-size u-boot.libgcc-private text data bss dec hex filename 222361 24912 214820 462093 70d0d u-boot.libgcc-private --->8--- Also I don't notice visible performance degradation compared to pre-built libgcc (where at least "*div*" functions are had-written in assembly) on typical operations of downloading 10Mb uImage over TFTP and bootm. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
162 lines
2.2 KiB
C
162 lines
2.2 KiB
C
/*
|
|
* Copyright (C) 1989-2013 Free Software Foundation, Inc.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include "libgcc2.h"
|
|
|
|
DWtype
|
|
__ashldi3(DWtype u, shift_count_type b)
|
|
{
|
|
if (b == 0)
|
|
return u;
|
|
|
|
const DWunion uu = {.ll = u};
|
|
const shift_count_type bm = W_TYPE_SIZE - b;
|
|
DWunion w;
|
|
|
|
if (bm <= 0) {
|
|
w.s.low = 0;
|
|
w.s.high = (UWtype)uu.s.low << -bm;
|
|
} else {
|
|
const UWtype carries = (UWtype) uu.s.low >> bm;
|
|
|
|
w.s.low = (UWtype)uu.s.low << b;
|
|
w.s.high = ((UWtype)uu.s.high << b) | carries;
|
|
}
|
|
|
|
return w.ll;
|
|
}
|
|
|
|
DWtype
|
|
__ashrdi3(DWtype u, shift_count_type b)
|
|
{
|
|
if (b == 0)
|
|
return u;
|
|
|
|
const DWunion uu = {.ll = u};
|
|
const shift_count_type bm = W_TYPE_SIZE - b;
|
|
DWunion w;
|
|
|
|
if (bm <= 0) {
|
|
/* w.s.high = 1..1 or 0..0 */
|
|
w.s.high = uu.s.high >> (W_TYPE_SIZE - 1);
|
|
w.s.low = uu.s.high >> -bm;
|
|
} else {
|
|
const UWtype carries = (UWtype) uu.s.high << bm;
|
|
|
|
w.s.high = uu.s.high >> b;
|
|
w.s.low = ((UWtype)uu.s.low >> b) | carries;
|
|
}
|
|
|
|
return w.ll;
|
|
}
|
|
|
|
DWtype
|
|
__lshrdi3(DWtype u, shift_count_type b)
|
|
{
|
|
if (b == 0)
|
|
return u;
|
|
|
|
const DWunion uu = {.ll = u};
|
|
const shift_count_type bm = W_TYPE_SIZE - b;
|
|
DWunion w;
|
|
|
|
if (bm <= 0) {
|
|
w.s.high = 0;
|
|
w.s.low = (UWtype)uu.s.high >> -bm;
|
|
} else {
|
|
const UWtype carries = (UWtype)uu.s.high << bm;
|
|
|
|
w.s.high = (UWtype)uu.s.high >> b;
|
|
w.s.low = ((UWtype)uu.s.low >> b) | carries;
|
|
}
|
|
|
|
return w.ll;
|
|
}
|
|
|
|
unsigned long
|
|
udivmodsi4(unsigned long num, unsigned long den, int modwanted)
|
|
{
|
|
unsigned long bit = 1;
|
|
unsigned long res = 0;
|
|
|
|
while (den < num && bit && !(den & (1L<<31))) {
|
|
den <<= 1;
|
|
bit <<= 1;
|
|
}
|
|
|
|
while (bit) {
|
|
if (num >= den) {
|
|
num -= den;
|
|
res |= bit;
|
|
}
|
|
bit >>= 1;
|
|
den >>= 1;
|
|
}
|
|
|
|
if (modwanted)
|
|
return num;
|
|
|
|
return res;
|
|
}
|
|
|
|
long
|
|
__divsi3(long a, long b)
|
|
{
|
|
int neg = 0;
|
|
long res;
|
|
|
|
if (a < 0) {
|
|
a = -a;
|
|
neg = !neg;
|
|
}
|
|
|
|
if (b < 0) {
|
|
b = -b;
|
|
neg = !neg;
|
|
}
|
|
|
|
res = udivmodsi4(a, b, 0);
|
|
|
|
if (neg)
|
|
res = -res;
|
|
|
|
return res;
|
|
}
|
|
|
|
long
|
|
__modsi3(long a, long b)
|
|
{
|
|
int neg = 0;
|
|
long res;
|
|
|
|
if (a < 0) {
|
|
a = -a;
|
|
neg = 1;
|
|
}
|
|
|
|
if (b < 0)
|
|
b = -b;
|
|
|
|
res = udivmodsi4(a, b, 1);
|
|
|
|
if (neg)
|
|
res = -res;
|
|
|
|
return res;
|
|
}
|
|
|
|
long
|
|
__udivsi3(long a, long b)
|
|
{
|
|
return udivmodsi4(a, b, 0);
|
|
}
|
|
|
|
long
|
|
__umodsi3(long a, long b)
|
|
{
|
|
return udivmodsi4(a, b, 1);
|
|
}
|