CL-USER> (defvar +a+ 4)
+A+
CL-USER> (defun increment-symbol (src)
(incf (symbol-value src)))
INCREMENT-SYMBOL
CL-USER> (increment-symbol '+a+)
5
CL-USER> +a+
5
CL-USER> (compile 'increment-symbol)
INCREMENT-SYMBOL
NIL
NIL
CL-USER> (disassemble 'increment-symbol)
; disassembly for INCREMENT-SYMBOL
; Size: 109 bytes. Origin: #x1003FB65DC
; 5DC: 498B4C2460 MOV RCX, [R12+96] ; thread.binding-stack-pointer
; no-arg-parsing entry point
; 5E1: 48894DF8 MOV [RBP-8], RCX
; 5E5: 4881FE17001020 CMP RSI, 537919511
; 5EC: 740D JEQ L0
; 5EE: 8D46F1 LEA EAX, [RSI-15]
; 5F1: A80F TEST AL, 15
; 5F3: 7544 JNE L1
; 5F5: 807EF145 CMP BYTE PTR [RSI-15], 69
; 5F9: 753E JNE L1
; 5FB: L0: 8B46F5 MOV EAX, [RSI-11]
; 5FE: 498B1404 MOV RDX, [R12+RAX]
; 602: 83FA61 CMP EDX, 97
; 605: 480F4456F9 CMOVEQ RDX, [RSI-7]
; 60A: 83FA51 CMP EDX, 81
; 60D: 7433 JEQ L2
; 60F: BF02000000 MOV EDI, 2
; 614: 41BBC0010020 MOV R11D, 536871360 ; GENERIC-+
; 61A: 41FFD3 CALL R11
; 61D: 488BFA MOV RDI, RDX
; 620: 488B75F0 MOV RSI, [RBP-16]
; 624: 488BD6 MOV RDX, RSI
; 627: 488B0552FFFFFF MOV RAX, [RIP-174] ; #<FDEFINITION for SET>
; 62E: B904000000 MOV ECX, 4
; 633: FF7508 PUSH QWORD PTR [RBP+8]
; 636: FF6009 JMP QWORD PTR [RAX+9]
; 639: L1: CC0A BREAK 10 ; error trap
; 63B: 04 BYTE #X04
; 63C: 43 BYTE #X43 ; OBJECT-NOT-SYMBOL-ERROR
; 63D: FE1B03 BYTE #XFE, #X1B, #X03 ; RSI
; 640: CC10 BREAK 16 ; Invalid argument count trap
; 642: L2: CC0A BREAK 10 ; error trap
; 644: 04 BYTE #X04
; 645: 05 BYTE #X05 ; UNBOUND-SYMBOL-ERROR
; 646: FE1B03 BYTE #XFE, #X1B, #X03 ; RSI
NIL