Support a '@' operator to perform a grover search from C.

[bennbollay]

Informational at this point in time, only.

[bennbollay]

Here's the generated assembly:

;
; File generated by cc65 v 2.17 - Git b4a95cb0
;
        .fopt           compiler,"cc65 v 2.17 - Git b4a95cb0"
        .setcpu         "6502Q"
        .smart          on
        .autoimport     on
        .case           on
        .debuginfo      off
        .importzp       sp, sreg, regsave, regbank
        .importzp       tmp1, tmp2, tmp3, tmp4, ptr1, ptr2, ptr3, ptr4
        .macpack        longbranch
        .export         _buffer
        .export         _value
        .export         _parameters
        .export         _immediates
        .export         _locals
        .export         _globals
        .export         _example
        .export         _caller

.segment        "DATA"

_value:
        .word   $0031

.segment        "BSS"

_buffer:
        .res    300,$00

; ---------------------------------------------------------------
; void __near__ parameters (__near__ void *, int)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _parameters: near

.segment        "CODE"

;
; {
;
        jsr     pushax
;
; y = buf @ val;
;
        jsr     decsp2
        ldy     #$07
        jsr     pushwysp
        ldy     #$05
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        jsr     pushax
        jsr     _groversearch
        ldy     #$03
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        jsr     stax0sp
;
; }
;
        jmp     incsp6

.endproc

; ---------------------------------------------------------------
; void __near__ immediates (void)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _immediates: near

.segment        "CODE"

;
; y = (void *)0x1000 @ 42;
;
        jsr     decsp2
        ldx     #$10
        lda     #$00
        jsr     pushax
        lda     #$2A
        jsr     pusha0
        jsr     _groversearch
        ldy     #$00
        lda     #$2A
        sta     (sp),y
        tya
        iny
        sta     (sp),y
;
; }
;
        jmp     incsp2

.endproc

; ---------------------------------------------------------------
; void __near__ locals (void)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _locals: near

.segment        "CODE"

;
; char *buf = (char *)0x2000;
;
        jsr     decsp2
        ldx     #$20
        lda     #$00
        jsr     pushax
;
; int val = 129;
;
        lda     #$81
        jsr     pusha0
;
; y = buf @ val;
;
        ldy     #$05
        jsr     pushwysp
        ldy     #$03
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        jsr     pushax
        jsr     _groversearch
        ldy     #$01
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        ldy     #$04
        jsr     staxysp
;
; }
;
        jmp     incsp6

.endproc

; ---------------------------------------------------------------
; void __near__ globals (void)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _globals: near

.segment        "CODE"

;
; y = buffer @ value;
;
        jsr     decsp2
        lda     #<(_buffer)
        ldx     #>(_buffer)
        jsr     pushax
        ldx     #$00
        lda     _value
        bpl     L0015
        dex
L0015:  jsr     pushax
        jsr     _groversearch
        lda     _value
        ldx     _value+1
        jsr     stax0sp
;
; }
;
        jmp     incsp2

.endproc

; ---------------------------------------------------------------
; int __near__ example (__near__ void *, int)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _example: near

.segment        "CODE"

;
; {
;
        jsr     pushax
;
; b = b;
;
        ldy     #$03
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        jsr     staxysp
;
; v = v;
;
        ldy     #$01
        lda     (sp),y
        tax
        dey
        lda     (sp),y
        jsr     stax0sp
;
; return 5;
;
        ldx     #$00
        lda     #$05
;
; }
;
        jmp     incsp4

.endproc

; ---------------------------------------------------------------
; int __near__ caller (void)
; ---------------------------------------------------------------

.segment        "CODE"

.proc   _caller: near

.segment        "CODE"

;
; return example(buffer, value);
;
        lda     #<(_buffer)
        ldx     #>(_buffer)
        jsr     pushax
        lda     _value
        ldx     _value+1
        jmp     _example

.endproc