The upper 16 bit differ between signed and unsigned multiplication, so while

for 16x16=16, the unsigned routine can be used, regardless of signedness, this
is not true for 16x16=32.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4438 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/runtime/Makefile b/libsrc/runtime/Makefile
index b92863cab8c5073e7f75fcac66729bae2d61bee8..adb35a8f9eb8fe56b7eeac572f762cec629df03e 100644 (file)
--- a/libsrc/runtime/Makefile
+++ b/libsrc/runtime/Makefile
@@ -81,6 +81,7 @@ OBJS =        add.o           \
                ge.o            \
                gt.o            \
                icmp.o          \
+        imul16x16r32.o  \
        incax1.o        \
        incax2.o        \
                incax3.o        \
@@ -152,7 +153,6 @@ OBJS =      add.o           \
                makebool.o      \
                mod.o           \
                mul.o           \
-        mul16x16r32.o   \
         mul8.o          \
         mul8x8r16.o     \
        mulax3.o        \
@@ -219,6 +219,7 @@ OBJS =      add.o           \
                ule.o           \
                ult.o           \
                umod.o          \
+        umul16x16r32.o  \
                xor.o           \
         zeropage.o
 

diff --git a/libsrc/runtime/imul16x16r32.s b/libsrc/runtime/imul16x16r32.s
new file mode 100644 (file)
index 0000000..d105b72
--- /dev/null
+++ b/libsrc/runtime/imul16x16r32.s
@@ -0,0 +1,50 @@
+;
+; Ullrich von Bassewitz, 2010-11-03
+;
+; CC65 runtime: 16x16 => 32 signed multiplication
+;
+
+        .export         imul16x16r32, _cc65_imul16x16r32
+        .import         popax, negax, umul16x16r32m, negeax
+       .importzp       ptr1, ptr3, tmp1
+
+
+;---------------------------------------------------------------------------
+; 16x16 => 32 signed multiplication routine.
+;
+;   lhs         rhs           result          result also in
+; -------------------------------------------------------------
+;   ptr1        ax            ax:sreg
+;
+; There is probably a faster way to do this.
+;
+
+
+_cc65_imul16x16r32:
+        sta     ptr1
+        stx     ptr1+1
+        jsr     popax
+
+imul16x16r32:
+        stx     tmp1
+        cpx     #0
+        bpl     @L1
+        jsr     negax
+@L1:    sta     ptr3
+        stx     ptr3+1
+
+        lda     ptr1+1
+        eor     tmp1
+        sta     tmp1
+        lda     ptr1
+        ldx     ptr1+1
+        bpl     @L2
+        jsr     negax
+        sta     ptr1
+        stx     ptr1+1
+@L2:    jsr     umul16x16r32m
+        ldy     tmp1
+        bpl     @L3
+        jmp     negeax
+@L3:    rts
+

diff --git a/libsrc/runtime/mul16x16r32.s b/libsrc/runtime/mul16x16r32.s
deleted file mode 100644 (file)
index 72d9fe3..0000000
--- a/libsrc/runtime/mul16x16r32.s
+++ /dev/null
@@ -1,56 +0,0 @@
-;
-; Ullrich von Bassewitz, 2010-11-03
-;
-; CC65 runtime: 16x16 => 32 multiplication
-;
-
-        .export         umul16x16r32, _cc65_umul16x16r32
-               .export         mul16x16r32 := umul16x16r32
-        .import         popax
-       .importzp       ptr1, ptr2, ptr3, ptr4, sreg
-
-
-;---------------------------------------------------------------------------
-; 16x16 => 32 multiplication routine.
-;
-;   lhs         rhs           result          result also in
-; -------------------------------------------------------------
-;   ptr1        ax            ax:sreg          ptr1:sreg
-;
-
-_cc65_umul16x16r32:
-        sta     ptr1
-        stx     ptr1+1
-        jsr     popax
-
-umul16x16r32:
-        sta     ptr3
-        stx     ptr3+1
-               lda     #0
-               sta     sreg+1
-               ldy     #16             ; Number of bits
-
-        lsr     ptr1+1
-        ror     ptr1            ; Get first bit into carry
-@L0:    bcc     @L1
-
-       clc
-       adc     ptr3
-       pha
-               txa                     ; hi byte of left op
-       adc     sreg+1
-       sta     sreg+1
-       pla
-
-@L1:    ror     sreg+1
-       ror     a
-       ror     ptr1+1
-       ror     ptr1
-        dey
-        bne     @L0
-
-        sta     sreg            ; Save byte 3
-       lda     ptr1            ; Load the result
-       ldx     ptr1+1
-       rts                     ; Done
-

diff --git a/libsrc/runtime/umul16x16r32.s b/libsrc/runtime/umul16x16r32.s
new file mode 100644 (file)
index 0000000..d86162c
--- /dev/null
+++ b/libsrc/runtime/umul16x16r32.s
@@ -0,0 +1,57 @@
+;
+; Ullrich von Bassewitz, 2010-11-03
+;
+; CC65 runtime: 16x16 => 32 unsigned multiplication
+;
+
+        .export         _cc65_umul16x16r32, umul16x16r32, umul16x16r32m
+        .import         popax
+       .importzp       ptr1, ptr3, sreg
+
+
+;---------------------------------------------------------------------------
+; 16x16 => 32 unsigned multiplication routine.
+;
+;   lhs         rhs           result          result also in
+; -------------------------------------------------------------
+;   ptr1        ax            ax:sreg          ptr1:sreg
+;
+
+_cc65_umul16x16r32:
+        sta     ptr1
+        stx     ptr1+1
+        jsr     popax
+
+umul16x16r32:
+        sta     ptr3
+        stx     ptr3+1
+
+umul16x16r32m:
+               lda     #0
+               sta     sreg+1
+               ldy     #16             ; Number of bits
+
+        lsr     ptr1+1
+        ror     ptr1            ; Get first bit into carry
+@L0:    bcc     @L1
+
+       clc
+       adc     ptr3
+       pha
+               lda     ptr3+1
+       adc     sreg+1
+       sta     sreg+1
+       pla
+
+@L1:    ror     sreg+1
+       ror     a
+       ror     ptr1+1
+       ror     ptr1
+        dey
+        bne     @L0
+
+        sta     sreg            ; Save byte 3
+       lda     ptr1            ; Load the result
+       ldx     ptr1+1
+       rts                     ; Done
+