; ======================================================
; Macros for 16 bit operations
; The suffix "16" is added to common opcodes, eg "add16"
; Only the A register is used (except ld16 (indirect))
; ======================================================

; Summary
;   add16, adc16
;   sub16, sbc16
;   inc16, dec16
;   ld16
;   cmp16
;   shr16, shl16
;   push16, pop16

macro add16 mem, const
    lda {1}
    clc
    adc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    #if {2} < 256
       if carry then inc {1}+1
    #else
       adc #(({2})/256)
       sta {1}+1
    #endif    
end macro

macro add16 mem, mem
    lda {1}
    clc
    adc {2}
    sta {1}
    lda {1}+1
    adc {2}+1
    sta {1}+1                    
end macro

macro add16 mem, const, "1"
    lda {1}
    sec
    adc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    adc #({2}/256)
    sta {1}+1                    
end macro

macro add16 mem, mem, "1"
    lda {1}
    sec
    adc {2}
    sta {1}
    lda {1}+1
    adc {2}+1
    sta {1}+1                    
end macro
    
macro adc16 mem, const
    lda {1}
    adc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    #if {2} < 256
       bcc .local_out
       inc {1}+1
    #else
       adc #(({2})/256)
       sta {1}+1
    #endif
    .local_out:    
end macro

macro adc16 mem, mem
    lda {1}
    adc {2}
    sta {1}
    lda {1}+1
    adc {2}+1
    sta {1}+1                    
end macro

macro sub16 mem, const
    lda {1}
    sec
    sbc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    sbc #(({2})/256)
    sta {1}+1                    
end macro

macro sub16 mem, mem
    lda {1}
    sec
    sbc {2}
    sta {1}
    lda {1}+1
    sbc {2}+1
    sta {1}+1                    
end macro

macro sub16 mem, const, "1"
    lda {1}
    clc
    sbc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    sbc #(({2})/256)
    sta {1}+1                    
end macro

macro sub16 mem, mem, "1"
    lda {1}
    clc
    sbc {2}
    sta {1}
    lda {1}+1
    sbc {2}+1
    sta {1}+1                    
end macro
    
macro sbc16 mem, const
    lda {1}
    sbc #(({2}) MOD 256)
    sta {1}
    lda {1}+1
    sbc #(({2})/256)
    sta {1}+1                    
end macro

macro sbc16 mem, mem
    lda {1}
    sbc {2}
    sta {1}
    lda {1}+1
    sbc {2}+1
    sta {1}+1                    
end macro

macro inc16 mem
    inc {1}
    if zero then inc {1}+1
end macro

macro dec16 mem
    dec {1}
    if negative then dec {1}+1
end macro

macro ld16 "ay", const
    lda #(({2}) MOD 256)
    ldy #(({2})/256)
end macro

macro ld16 "ay", mem
    lda {2}
    ldy {2}+1
end macro

macro ld16 "ax", const
    lda #(({2}) MOD 256)
    ldx #(({2})/256)
end macro

macro ld16 "ax", mem
    lda {2}
    ldx {2}+1
end macro

macro ld16 mem, "ay"
    sta {1}
    sty {1}+1
end macro

macro ld16 mem, "ax"
    sta {1}
    stx {1}+1
end macro

macro ld16 mem, const
   lda #(({2}) MOD 256)
   sta {1}
   #if (({2}) MOD 256) != (({2})/256)
      lda #(({2})/256)
   #endif   
   sta {1}+1   
end macro

macro ld16 mem, mem
    lda {2}
    sta {1}
    lda {2}+1
    sta {1}+1
end macro

macro ld16 indirect, mem
    ldy #0
    lda {2}
    sta ({1}),y
    lda {2}+1
    iny
    sta ({1}),y
end macro

macro ld16 indirect, const
    ldy #0
    lda #({2} MOD 256)    
    sta ({1}),y
    lda #({2}/256)
    iny
    sta ({1}),y
end macro

macro cmp16 mem, const
   lda {1}+1
   cmp #(({2})/256)
   if zero then 
      lda {1}
      cmp #(({2}) MOD 256)
   end if
end macro
        
macro cmp16 mem, mem
   lda {1}+1
   cmp {2}+1
   if zero then
      lda {1}
      cmp {2}
   end if
end macro
            
macro shl16 mem
    asl {1}
    rol {1}+1
end macro

macro shr16 mem
    lsr {1}
    ror {1}+1
end macro

macro push16 mem
    lda {1}
    pha
    lda {1}+1
    pha
end macro
        
macro push16 const
    lda #(({1}) MOD 256)
    pha
    lda #(({1})/256)
    pha
end macro

macro pop16 mem
    pla 
    sta {1}+1
    pla 
    sta {1}
end macro

macro mul16 mem, const
   ECHO "to be implemented"
end macro

macro mul16 mem, mem
   ECHO "to be implemented"
end macro