summaryrefslogtreecommitdiff
path: root/Source/Library/Common/cppsupport.wtf.cpp
blob: 59a78fc7b6fc6f423d0ee043b92f1eb6f3ae0ba1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
//This file just contains a few methods required for some C++ things to work
#include <types.h>

namespace CMem {
	u8int* memcpy(u8int*, const u8int*, u32int);
};

using namespace CMem;

extern "C" void __cxa_pure_virtual() {}	//Required when using abstract classes

void *__dso_handle;		//Required when using global objects
extern "C" int __cxa_atexit(void (*f)(void*), void *p, void *d) { return 0; }

extern "C" void * memmove(void* dst, const void* src, size_t len) {
	memcpy((u8int*)dst, (const u8int*)src, len);
	return dst;
}

//Functions for quad divisions/modulo. Taken and arranged from klibc include/asm/div64.h
//These only work with 32-bit divisors and only return 32-bit remainder.
//TODO : think of some correct quad div/mod algorithms
inline u64int doDiv(u64int dividend, u32int divisor, u32int *remainder) {
	union {
		u64int v64;
		u32int v32[2];
	} d = { dividend };
	u32int upper;

	upper = d.v32[1];
	d.v32[1] = 0;
	if (upper >= divisor) {
		d.v32[1] = upper / divisor;
		upper %= divisor;
	}
	asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
			"rm" (divisor), "0" (d.v32[0]), "1" (upper));
	return d.v64;
}

extern "C" {
u64int __udivdi3(u64int dividend, u64int b) {
	u32int divisor, remainder;
	divisor = b;
	return doDiv(dividend, divisor, &remainder);
}

u64int __umoddi3(u64int dividend, u64int b) {
	u32int divisor, remainder;
	divisor = b;
	doDiv(dividend, divisor, &remainder);
	return remainder;
}
}