#include "asm.h"

// unsigned int64 mulu64_m(unsigned a, unsigned b);
	.text
	.global	mulu64_m
mulu64_m:
	movel	d2, -(sp)

	movel	#0x20, macsr	// Put MAC in fraction mode
	movel	#0, d2
	movel	d2, acc 	// Zero acc

	movel	12(sp), d1
	movel	8(sp), d0
	macl	d0, d1		// Form upper half of product
	bplb	1f		// First operand negative?
	movel	d1, d2		// Yep, save unsigned correction
1:	tstl	d1		// Second operand negative?
	bplb	2f		// Nope
	addl	d0, d2		// Yep, save unsigned correction
2:	mulul	d0, d1		// Form lower half
	movel	macsr, ccr	// Overflow?
	bvsb	2f		// Yes
	movel	acc, d0
	asrl	#1, d0		// Correct for binary point position
	addl	d2, d0		// Correct for unsigned

1:	movel	(sp)+, d2
	rts

2:	movel	#0x40000000, d0	// Correct for overflow
	brab	1b