mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-07-06 03:06:16 +09:00
a67ef280f4
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
/*
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* Copyright (C) 1989-2013 Free Software Foundation, Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include "libgcc2.h"
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DWtype
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__ashldi3(DWtype u, shift_count_type b)
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{
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if (b == 0)
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return u;
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const DWunion uu = {.ll = u};
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const shift_count_type bm = W_TYPE_SIZE - b;
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DWunion w;
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if (bm <= 0) {
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w.s.low = 0;
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w.s.high = (UWtype)uu.s.low << -bm;
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} else {
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const UWtype carries = (UWtype) uu.s.low >> bm;
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w.s.low = (UWtype)uu.s.low << b;
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w.s.high = ((UWtype)uu.s.high << b) | carries;
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}
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return w.ll;
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}
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DWtype
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__ashrdi3(DWtype u, shift_count_type b)
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{
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if (b == 0)
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return u;
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const DWunion uu = {.ll = u};
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const shift_count_type bm = W_TYPE_SIZE - b;
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DWunion w;
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if (bm <= 0) {
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/* w.s.high = 1..1 or 0..0 */
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w.s.high = uu.s.high >> (W_TYPE_SIZE - 1);
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w.s.low = uu.s.high >> -bm;
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} else {
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const UWtype carries = (UWtype) uu.s.high << bm;
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w.s.high = uu.s.high >> b;
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w.s.low = ((UWtype)uu.s.low >> b) | carries;
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}
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return w.ll;
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}
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DWtype
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__lshrdi3(DWtype u, shift_count_type b)
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{
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if (b == 0)
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return u;
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const DWunion uu = {.ll = u};
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const shift_count_type bm = W_TYPE_SIZE - b;
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DWunion w;
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if (bm <= 0) {
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w.s.high = 0;
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w.s.low = (UWtype)uu.s.high >> -bm;
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} else {
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const UWtype carries = (UWtype)uu.s.high << bm;
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w.s.high = (UWtype)uu.s.high >> b;
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w.s.low = ((UWtype)uu.s.low >> b) | carries;
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}
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return w.ll;
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}
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unsigned long
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udivmodsi4(unsigned long num, unsigned long den, int modwanted)
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{
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unsigned long bit = 1;
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unsigned long res = 0;
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while (den < num && bit && !(den & (1L<<31))) {
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den <<= 1;
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bit <<= 1;
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}
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while (bit) {
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if (num >= den) {
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num -= den;
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res |= bit;
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}
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bit >>= 1;
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den >>= 1;
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}
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if (modwanted)
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return num;
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return res;
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}
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long
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__divsi3(long a, long b)
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{
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int neg = 0;
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long res;
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if (a < 0) {
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a = -a;
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neg = !neg;
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}
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if (b < 0) {
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b = -b;
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neg = !neg;
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}
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res = udivmodsi4(a, b, 0);
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if (neg)
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res = -res;
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return res;
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}
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long
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__modsi3(long a, long b)
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{
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int neg = 0;
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long res;
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if (a < 0) {
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a = -a;
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neg = 1;
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}
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if (b < 0)
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b = -b;
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res = udivmodsi4(a, b, 1);
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if (neg)
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res = -res;
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return res;
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}
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long
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__udivsi3(long a, long b)
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{
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return udivmodsi4(a, b, 0);
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}
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long
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__umodsi3(long a, long b)
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{
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return udivmodsi4(a, b, 1);
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}
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