Minor Z80 multiplication improvement

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@5422 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/ChangeLog b/ChangeLog
index 1cbf384eeeee07c14cb1ecdff61483b7a51878e0..9805da8f485cd603854b66e2cf55d86597bff632 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-01 Philipp Klaus Krause <pkk AT spth.de>
+
+       * device/lib/z80/mul.s: 
+         Minor improvement in Z80 16x16 bit multiplication.
+
 2009-03-23 Borut Razem <borut.razem AT siol.net>
 
        * src/SDCCval.c, src/SDCCmain.c, device/include/limits.h,

diff --git a/device/lib/z80/mul.s b/device/lib/z80/mul.s
index b54fd9d73962dbad55f1c08b3dc0d4c1abf0e575..cba10dfe93ce6edd1fadc4b591e91c68f99ac60e 100644 (file)
--- a/device/lib/z80/mul.s
+++ b/device/lib/z80/mul.s
@@ -33,15 +33,14 @@ __mulint_rrx_hds::
        ;;
        ;; Register used: AF,BC,DE,HL
 __mul16::
-        ld      hl,#0
+        ld      l,#0
         ld      a,b
-        ; ld c,c
         ld      b,#16
 
         ;; Optimise for the case when this side has 8 bits of data or
         ;; less.  This is often the case with support address calls.
         or      a
-        jr      NZ,1$
+        jr      NZ,2$
 
         ld      b,#8
         ld      a,c
@@ -49,11 +48,12 @@ __mul16::
         ;; Taken from z88dk, which originally borrowed from the
         ;; Spectrum rom.
         add     hl,hl
+2$:
         rl      c
         rla                     ;DLE 27/11/98
-        jr      NC,2$
+        jr      NC,3$
         add     hl,de
-2$:
+3$:
         djnz    1$
         ret