libPCM.utility source code

1 /*
2  * libPCM by László Szerémi.
3  * Copyright under Boost License.
4  */
5 
6 module libPCM.utility;
7 
8 @nogc package:
9 	/**
10 	 * Converts a floating point value to integer
11 	 */
12 	int floatToInt(float input){
13 		int result;
14 		asm @nogc{
15 			fld		input;
16 			frndint	;
17 			fist	result;
18 		}
19 		return result;
20 	}
21 	/**
22 	 * Converts a floating point value to integer
23 	 */
24 	int doubleToInt(double input){
25 		int result;
26 		asm @nogc{
27 			fld		input;
28 			frndint	;
29 			fist	result;
30 		}
31 		return result;
32 	}
33 	/**
34 	 * Copies a part of memory.
35 	 */
36 	void memCpy(void* src, void* dest, size_t length){
37 		if(!length) return;
38 		asm @nogc{
39 			mov		ECX, length;
40 			mov		ESI, src;
41 			mov		EDI, dest;
42 
43 			cmp		ECX, 16;
44 			jl		copy1byte;
45 
46 		copy16byte:
47 			movups	XMM0, [ESI];
48 			movups	[EDI], XMM0;
49 			add		ESI, 16;
50 			add		EDI, 16;
51 			sub		ECX, 16;
52 			cmp		ECX, 16;
53 			jge		copy16byte;
54 			cmp		ECX, 0;
55 			jz		endOfAlgorithm;
56 
57 		copy1byte:
58 			mov		AL, [ESI];
59 			mov		[EDI], AL;
60 			inc		ESI;
61 			inc		EDI;
62 			dec		ECX;
63 			cmp		ECX, 0;
64 			jnz		copy1byte;
65 		endOfAlgorithm:
66 			;
67 		}
68 	}
69 	int signExtend(int val, uint bits){
70 		int workPad;
71 		uint shift = int.sizeof - bits;
72 		*cast(uint*)&workPad = cast(uint)(val<<shift);
73 		return workPad;
74 	}