#1018 Z80 optimize assigning same value to multipe variables

[Arjan Bakker]

When assigning a variable to multiple variables I get this result (as expected):

;./test.c:31: dest1 = dest2 = src;
    ld  a, (_src)
    ld  (#_dest2), a
    ld  (#_dest1), a

But when assigning a literal value instead I get this result:

;./test.c:31: dest1 = dest2 = 5;
    ld  hl, #_dest2
    ld  (hl), #0x05
    ld  hl, #_dest1
    ld  (hl), #0x05

SDCC should use a similar approach as in the first example (load A with literal, store at address) (assuming register usage is no problem). That would save 7 t-states and 2 bytes for every additional assignment.

[Ragozini Arturo]

And it would save also a register, as it would use onl A instead of HL