// 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(GEKKO)

// naked function (no prolog/epilog)
int32_t scale(int32_t a, int32_t d, int32_t c)
{
//	return ((int64_t)a * d) / c;

	__asm__ __volatile__ (
		" mullw   6, 3, 4\n"
		" mulhw   4, 3, 4\n"
		" mr      3, 6\n"

		" srawi.  0, 5, 31\n"
		" cmpwi cr1, 4, 0\n"
		" crxor   7, 0, 4\n"

		" xor     5, 0, 5\n"
		" subf.   5, 0, 5\n"

		" beq     DivByZero\n"
		" bge   cr1, Div64Common\n"

		" subfic  3, 3, 0\n"
		" subfze  4, 4\n"

		"Div64Common:\n"
		" cmplw   4, 5\n"

		" cntlzw  6, 5\n"
		" xor     4, 4, 3\n"
		" slw     5, 5, 6\n"
		" rotlw   4, 4, 6\n"
		" slw     3, 3, 6\n"
		" li      7, 2\n"
		" xor     4, 4, 3\n"

		" bge DivOverflow\n"
		" mtctr   7\n"

		"Div64Compute:\n"
		" srwi    6, 5, 16\n"
		" divwu   7, 4, 6\n"
		" mullw   6, 7, 6\n"
		" subf    4, 6, 4\n"
		" slwi    4, 4, 16\n"
		" inslwi  4, 3, 16, 16\n"
		" slwi    3, 3, 16\n"
		" clrlwi  6, 5, 16\n"
		" mullw   6, 7, 6\n"
		" subfc   4, 6, 4\n"
		" subfe.  6, 6, 6\n"
		" add     3, 3, 7\n"
		" bge Div64Done\n"
		"Div64Correct:\n"
		" addc    4, 4, 5\n"
		" addze.  6, 6\n"
		" subi    3, 3, 1\n"
		" blt     Div64Correct\n"

		"Div64Done:\n"
		" bdnz    Div64Compute\n"

		" cmpwi   3, 0\n"
		" bso   cr1, Div64QuotientNeg\n"

		" blt     DivOverflow\n"
		" blr\n"

		"Div64QuotientNeg:\n"
		" neg.    3, 3\n"
		" blelr\n"

		"DivOverflow:\n"
		" cror    4, 7, 7\n"

		"DivByZero:\n"
		" lis     3, 0x8000\n"
		" bltlr cr1\n"
		" subi    3, 3, 1\n"
		" blr\n"
	);
}

void clearbufbyte(void *d, int32_t c, int32_t a)
{
	if (a==0) {
		uint8_t *dd = (uint8_t*)d;
		int32_t align = (32 - (int32_t)d) & 31;

		if (align && c >= align) {
			uint32_t izero = 0;
			double fzero = 0;
			c -= align;

			if (align&1) {
				*dd = izero;
				dd += 1;
			}
			if (align&2) {
				*(uint16_t*)dd = izero;
				dd += 2;
			}
			if (align&4) {
				*(uint32_t*)dd = izero;
				dd += 4;
			}
			if (align&8) {
				*(double*)dd = fzero;
				dd += 8;
			}
			if (align&16) {
				*(double*)dd = fzero;
				*(double*)(dd+8) = fzero;
				dd += 16;
			}
		}
		align = c >> 5;
		while (align) {
			__asm__ (
				" dcbz  0, %0\n"
				" addi %0, %0, 32\n"
				: "+r"(dd)
				:
				: "memory"
			);
			align--;
		}
		if ((c &= 31)) {
			while (c--) {
				*dd++ = 0;
			}
		}
		return;
	}
	__asm__ __volatile__ (
		" add    %1, %1, %2\n"
		" neg.   %2, %2\n"
		" beq 2f\n"
		"1:\n"
		" stbx   %0, %1, %2\n"
		" addic. %2, %2, 1\n"
		" rotrwi %0, %0, 8\n"
		" bne 1b\n"
		"2:\n"
		: "+r"(a), "+b"(d), "+r"(c)
		:
		: "cc", "xer", "memory"
	);
}

#elif 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 = (int32_t *)d;

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

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

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

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

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

#endif