| 0,0 → 1,68 |
|---|
| /* examples for interoperability with assembler |
| |
| 1. Calling assembler code from .c : see in libc\math any .asm file |
| 2. Using inline assembler: see \include\kos32sys1.h and libc\math\fmod.c |
| - https://gcc.gnu.org/onlinedocs/gcc-4.8.5/gcc/Extended-Asm.html |
| - not all constraints from gcc are supported, no "f" or "t" for example |
| - not supported clobberring st registers, must manual add "fstp %%st" at end or similar |
| - need full suffixes for opcodes, fstpl but not fstp |
| |
| 3. Calling c functions from .asm: see \libc\start\start.asm:99 |
| Remember: |
| - small ints always passed as int32, floating point params as 64-bit |
| - returned structs passed on stack with additional hidden 1st param |
| - c functions can use EAX, ECX, EDX without warnings |
| - .c default is cdecl calling convention https://en.wikipedia.org/wiki/X86_calling_conventions |
| - dont use fastcall calling convention, tinycc realized it non-conformant way |
| - tinycc supports only ELF object files |
| |
| tcc can be used as a linker |
| */ |
| |
| |
| |
| |
| #include <stdio.h> |
| #include <math.h> |
| |
| |
| main() |
| { |
| int i; |
| for (i = 0; i < 20; i++) |
| { |
| printf("------------------------------------------------------\n"); |
| printf ( "remainder of 5.3 / 2 is %f\n", remainder (5.3,2) ); |
| printf ( "remainder of 18.5 / 4.2 is %f\n", remainder (18.5,4.2) ); |
| //remainder of 5.3 / 2 is -0.700000 |
| //remainder of 18.5 / 4.2 is 1.700000 |
| |
| printf ( "fmod of 5.3 / 2 is %f\n", fmod (5.3,2) ); |
| printf ( "fmod of 18.5 / 4.2 is %f\n", fmod (18.5,4.2) ); |
| // fmod of 5.3 / 2 is 1.300000 |
| // fmod of 18.5 / 4.2 is 1.700000 |
| |
| double param, fractpart, intpart, result; |
| int n; |
| |
| param = 3.14159265; |
| fractpart = modf (param , &intpart); |
| printf ("%f = %f + %f \n", param, intpart, fractpart); |
| //3.141593 = 3.000000 + 0.141593 |
| |
| param = 0.95; |
| n = 4; |
| result = ldexp (param , n); |
| printf ("%f * 2^%d = %f\n", param, n, result); |
| //0.950000 * 2^4 = 15.200000 |
| |
| param = 8.0; |
| result = frexp (param , &n); |
| printf ("%f = %f * 2^%d\n", param, result, n); |
| //8.000000 = 0.500000 * 2^4 |
| param = 50; |
| result = frexp (param , &n); |
| printf ("%f = %f * 2^%d\n", param, result, n); |
| |
| } |
| } |