Working on the division and multiplication routines.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4443 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/runtime/Makefile

@@ -81,6 +81,7 @@ OBJS = 	add.o		\
        	ge.o		\
        	gt.o		\
        	icmp.o		\
+        idiv32by16r16.o \
         imul16x16r32.o  \
 	incax1.o	\
 	incax2.o	\

libsrc/runtime/idiv32by16r16.s

@@ -0,0 +1,64 @@
+;
+; Ullrich von Bassewitz, 2009-11-04
+;
+; CC65 runtime: 32by16 => 16 signed division
+;
+
+        .export         idiv32by16r16
+       	.import	       	negax, udiv32by16r16m
+
+        .include        "zeropage.inc"
+
+
+;---------------------------------------------------------------------------
+; 32by16 division. Divide ptr1:ptr2 by ptr3. Result is in ptr1, remainder
+; in sreg.
+;
+;   lhs         rhs           result      result also in    remainder
+; -----------------------------------------------------------------------
+;   ptr1:ptr2   ptr3          ax          ptr1              sreg
+;
+
+
+idiv32by16r16:
+        stx     tmp1
+        cpx     #0
+        bpl     @L1
+        jsr     negax
+@L1:    sta     ptr3
+        stx     ptr3+1
+
+        lda     ptr2+1
+        eor     tmp1
+        sta     tmp1
+        bit     ptr2+1
+        bpl     @L3
+
+; Negate the value in ptr1:ptr2
+
+        ldx     #0
+        ldy     #4
+        sec
+@L2:    lda     ptr1,x
+        eor     #$FF
+        adc     #$00
+        sta     ptr1,x
+        inx
+        dey
+        bne     @L2
+
+; Call the unsigned division routine
+
+@L3:    jsr     udiv32by16r16m
+
+; Check the sign of the result
+
+        bit     tmp1
+        bmi     @L4
+        rts
+
+; Negate the result. We do this here only for the result, not for the
+; remainder!
+
+@L4:    jmp     negax
+

libsrc/runtime/imul16x16r32.s

@@ -6,7 +6,8 @@
 
         .export         imul16x16r32
         .import         negax, umul16x16r32m, negeax
-    	.importzp     	ptr1, ptr3, tmp1
+
+        .include        "zeropage.inc"
 
 
 ;---------------------------------------------------------------------------

libsrc/runtime/udiv32by16r16.s

@@ -5,7 +5,8 @@
 ;
 
        	.export	       	udiv32by16r16, udiv32by16r16m
- 	.importzp   	ptr1, ptr2, ptr3, sreg
+
+        .include        "zeropage.inc"
 
 
 ;---------------------------------------------------------------------------

libsrc/runtime/umul16x16r32.s

@@ -5,7 +5,8 @@
 ;
 
         .export         umul16x16r32, umul16x16r32m
-    	.importzp      	ptr1, ptr3, sreg
+
+        .include        "zeropage.inc"
 
 
 ;---------------------------------------------------------------------------