* src/diff.1 (Index): Many, many optmisiations. Dhrystone up to 201.

[fw/sdcc] / doc / choices.txt

diff --git a/doc/choices.txt b/doc/choices.txt
index d6fbe90c9b05b3e43273b0616e16ccffae8c351c..1442eca452e5bed8306897b5062f5c87fce84d0b 100644 (file)
--- a/doc/choices.txt
+++ b/doc/choices.txt
@@ -218,4 +218,25 @@ Cleaning up the arguments to a call:
          pop    af              ; 5/byte
 
 
-So for 8 bytes and above use the first form.
\ No newline at end of file
+So for 8 bytes and above use the first form.
+
+Pointer assign:
+        ld      hl,bc           ; 4+4
+        ld      e,(hl)          ; 7
+        inc     hl              ; 6
+        ld      d,(hl)          ; 7
+
+vs:
+        ld      a,(bc)          ; 7
+        ld      e,a             ; 4
+        inc     bc              ; 6
+        ld      a,(bc)          ; 7
+        ld      d,a             ; 4
+
+Same cost.  Not worth it, although is does free up HL.
+
+Shift left signed on HL
+      sla  l
+      rl   h                    ; 8+8 = 16
+
+      add  hl,hl                ; 11