// Function-wrapped Watcom pragmas
// by Jonathon Fowler (jf@jonof.id.au)
//
// These functions represent some of the more longer-winded pragmas
// from the original pragmas.h wrapped into functions for easier
// use since many jumps and whatnot make it harder to write macro-
// inline versions. I'll eventually convert these to macro-inline
// equivalents.		--Jonathon

//#include "pragmas.h"
#include "compat.h"

int32_t dmval;

#if defined(__GNUC__) && defined(__i386__) && !defined(NOASM)	// NOASM

//
// GCC Inline Assembler version
//

#define ASM __asm__ __volatile__


int32_t boundmulscale(int32_t a, int32_t b, int32_t c)
{
    ASM(
        "imull %%ebx\n\t"
        "movl %%edx, %%ebx\n\t"		// mov ebx, edx
        "shrdl %%cl, %%edx, %%eax\n\t"	// mov eax, edx, cl
        "sarl %%cl, %%edx\n\t"		// sar edx, cl
        "xorl %%eax, %%edx\n\t"		// xor edx, eax
        "js 0f\n\t"			// js checkit
        "xorl %%eax, %%edx\n\t"		// xor edx, eax
        "jz 1f\n\t"			// js skipboundit
        "cmpl $0xffffffff, %%edx\n\t"	// cmp edx, 0xffffffff
        "je 1f\n\t"			// je skipboundit
        "0:\n\t"			// checkit:
        "movl %%ebx, %%eax\n\t"		// mov eax, ebx
        "sarl $31, %%eax\n\t"		// sar eax, 31
        "xorl $0x7fffffff, %%eax\n\t"	// xor eax, 0x7fffffff
        "1:"				// skipboundit:
    : "+a"(a), "+b"(b), "+c"(c)	// input eax ebx ecx
            :
            : "edx", "cc"
        );
    return a;
}


void clearbufbyte(void *D, int32_t c, int32_t a)
{
    ASM(
        "cmpl $4, %%ecx\n\t"
        "jae 1f\n\t"
        "testb $1, %%cl\n\t"
        "jz 0f\n\t"			// jz preskip
        "stosb\n\t"
        "0:\n\t"			// preskip:
        "shrl $1, %%ecx\n\t"
        "rep\n\t"
        "stosw\n\t"
        "jmp 5f\n\t"			// jmp endit
        "1:\n\t"			// intcopy:
        "testl $1, %%edi\n\t"
        "jz 2f\n\t"			// jz skip1
        "stosb\n\t"
        "decl %%ecx\n\t"
        "2:\n\t"			// skip1:
        "testl $2, %%edi\n\t"
        "jz 3f\n\t"			// jz skip2
        "stosw\n\t"
        "subl $2, %%ecx\n\t"
        "3:\n\t"			// skip2:
        "movl %%ecx, %%ebx\n\t"
        "shrl $2, %%ecx\n\t"
        "rep\n\t"
        "stosl\n\t"
        "testb $2, %%bl\n\t"
        "jz 4f\n\t"			// jz skip3
        "stosw\n\t"
        "4:\n\t"			// skip3:
        "testb $1, %%bl\n\t"
        "jz 5f\n\t"			// jz endit
        "stosb\n\t"
        "5:"				// endit
    : "+D"(D), "+c"(c), "+a"(a) :
            : "ebx", "memory", "cc"
        );
}

void copybufbyte(const void *S, void *D, int32_t c)
{
    ASM(
        "cmpl $4, %%ecx\n\t"		// cmp ecx, 4
        "jae 1f\n\t"
        "testb $1, %%cl\n\t"		// test cl, 1
        "jz 0f\n\t"
        "movsb\n\t"
        "0:\n\t"			// preskip:
        "shrl $1, %%ecx\n\t"		// shr ecx, 1
        "rep\n\t"
        "movsw\n\t"
        "jmp 5f\n\t"
        "1:\n\t"			// intcopy:
        "testl $1, %%edi\n\t"		// test edi, 1
        "jz 2f\n\t"
        "movsb\n\t"
        "decl %%ecx\n\t"
        "2:\n\t"			// skip1:
        "testl $2, %%edi\n\t"		// test edi, 2
        "jz 3f\n\t"
        "movsw\n\t"
        "subl $2, %%ecx\n\t"		// sub ecx, 2
        "3:\n\t"			// skip2:
        "movl %%ecx, %%ebx\n\t"		// mov ebx, ecx
        "shrl $2, %%ecx\n\t"		// shr ecx ,2
        "rep\n\t"
        "movsl\n\t"
        "testb $2, %%bl\n\t"		// test bl, 2
        "jz 4f\n\t"
        "movsw\n\t"
        "4:\n\t"			// skip3:
        "testb $1, %%bl\n\t"		// test bl, 1
        "jz 5f\n\t"
        "movsb\n\t"
        "5:"				// endit:
    : "+c"(c), "+S"(S), "+D"(D) :
            : "ebx", "memory", "cc"
        );
}

void copybufreverse(const void *S, void *D, int32_t c)
{
    ASM(
        "shrl $1, %%ecx\n\t"
        "jnc 0f\n\t"		// jnc skipit1
        "movb (%%esi), %%al\n\t"
        "decl %%esi\n\t"
        "movb %%al, (%%edi)\n\t"
        "incl %%edi\n\t"
        "0:\n\t"		// skipit1:
        "shrl $1, %%ecx\n\t"
        "jnc 1f\n\t"		// jnc skipit2
        "movw -1(%%esi), %%ax\n\t"
        "subl $2, %%esi\n\t"
        "rorw $8, %%ax\n\t"
        "movw %%ax, (%%edi)\n\t"
        "addl $2, %%edi\n\t"
        "1:\n\t"		// skipit2
        "testl %%ecx, %%ecx\n\t"
        "jz 3f\n\t"		// jz endloop
        "2:\n\t"		// begloop
        "movl -3(%%esi), %%eax\n\t"
        "subl $4, %%esi\n\t"
        "bswapl %%eax\n\t"
        "movl %%eax, (%%edi)\n\t"
        "addl $4, %%edi\n\t"
        "decl %%ecx\n\t"
        "jnz 2b\n\t"		// jnz begloop
        "3:"
    : "+S"(S), "+D"(D), "+c"(c) :
            : "eax", "memory", "cc"
        );
}

#elif defined(_MSC_VER) && !defined(NOASM)		// __GNUC__ && __i386__

//
// Microsoft C Inline Assembler version
//

#else				// _MSC_VER

//
// Generic C version
//

void qinterpolatedown16(intptr_t bufptr, int32_t num, int32_t val, int32_t add)
{
    // gee, I wonder who could have provided this...
    int32_t i, *lptr = (int32_t *)bufptr;
    for (i=0; i<num; i++) { lptr[i] = (val>>16); val += add; }
}

void qinterpolatedown16short(intptr_t bufptr, int32_t num, int32_t val, int32_t add)
{
    // ...maybe the same person who provided this too?
    int32_t i; int16_t *sptr = (int16_t *)bufptr;
    for (i=0; i<num; i++) { sptr[i] = (int16_t)(val>>16); val += add; }
}

void clearbuf(void *d, int32_t c, int32_t a)
{
    int32_t *p = d;

    while ((c--) > 0) *(p++) = a;
}

void copybuf(const void *s, void *d, int32_t c)
{
    const int32_t *p = s;
    int32_t *q = (int32_t *)d;

    while ((c--) > 0) *(q++) = *(p++);
}

void swapbuf4(void *a, void *b, int32_t c)
{
    int32_t *p = (int32_t *)a, *q = (int32_t *)b;
    int32_t x, y;
    while ((c--) > 0)
    {
        x = *q;
        y = *p;
        *(q++) = y;
        *(p++) = x;
    }
}

void clearbufbyte(void *D, int32_t c, int32_t a)
{
    // Cringe City
    char *p = (char *)D;
    int32_t m[4] = { 0xffl,0xff00l,0xff0000l,0xff000000l };
    int32_t n[4] = { 0,8,16,24 };
    int32_t z=0;
    while ((c--) > 0)
    {
        *(p++) = (uint8_t)((a & m[z])>>n[z]);
        z=(z+1)&3;
    }
}

void copybufbyte(const void *S, void *D, int32_t c)
{
    const char *p = S;
    char *q = D;

    while ((c--) > 0) *(q++) = *(p++);
}

void copybufreverse(const void *S, void *D, int32_t c)
{
    const char *p = S;
    char *q = D;

    while ((c--) > 0) *(q++) = *(p--);
}

#endif