[Issue 15629] [REG] wrong code with "-O -inline" but correct with "-O"

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15629

--- Comment #1 from Ivan Kazmenko <gassa at mail.ru> ---
Here is the relevant disassembly of the object file produced 2.070.0:

-----
__Dmain PROC NEAR
;  COMDEF __Dmain
        sub     esp, 44                                 ; 0000 _ 83. EC, 2C
        mov     eax, 3                                  ; 0003 _ B8, 00000003
        mov     ecx, 1                                  ; 0008 _ B9, 00000001
        mov     dword ptr [esp+0CH], ebx                ; 000D _ 89. 5C 24, 0C
        mov     edx, offset FLAT:_D11TypeInfo_Ai6__initZ; 0011 _ BA,
00000000(segrel)
        mov     dword ptr [esp+10H], esi                ; 0016 _ 89. 74 24, 10
        mov     dword ptr [esp+18H], eax                ; 001A _ 89. 44 24, 18
        mov     dword ptr [esp+4H], ecx                 ; 001E _ 89. 4C 24, 04
        mov     dword ptr [esp], edx                    ; 0022 _ 89. 14 24
        call    __d_arrayliteralTX                      ; 0025 _ E8,
00000000(rel)
        mov     ebx, eax                                ; 002A _ 89. C3
        mov     eax, dword ptr [esp+18H]                ; 002C _ 8B. 44 24, 18
        mov     dword ptr [ebx], eax                    ; 0030 _ 89. 03
        mov     dword ptr [esp+20H], ebx                ; 0032 _ 89. 5C 24, 20
        mov     dword ptr [esp+1CH], 1                  ; 0036 _ C7. 44 24, 1C,
00000001
        mov     dword ptr [esp+4H], 1                   ; 003E _ C7. 44 24, 04,
00000001
        mov     dword ptr [esp], offset FLAT:_D11TypeInfo_Ai6__initZ; 0046 _
C7. 04 24, 00000000(segrel)
        call    __d_arrayliteralTX                      ; 004D _ E8,
00000000(rel)
        mov     esi, dword ptr [esp+20H]                ; 0052 _ 8B. 74 24, 20
        mov     edx, dword ptr [esp+14H]                ; 0056 _ 8B. 54 24, 14
        mov     dword ptr [eax], 9                      ; 005A _ C7. 00,
00000009
        mov     dword ptr [esp+28H], eax                ; 0060 _ 89. 44 24, 28
        mov     eax, dword ptr [esi]                    ; 0064 _ 8B. 06
        mov     ecx, eax                                ; 0066 _ 89. C1
        sar     ecx, 31                                 ; 0068 _ C1. F9, 1F
        xor     eax, ecx                                ; 006B _ 33. C1
        sub     eax, ecx                                ; 006D _ 2B. C1
        mov     dword ptr [esp+24H], 1                  ; 006F _ C7. 44 24, 24,
00000001
        cmp     edx, 3                                  ; 0077 _ 83. FA, 03
        jz      ?_0056                                  ; 007A _ 74, 2E
        push    eax                                     ; 007C _ 50
        mov     ecx, offset FLAT:?_0001                 ; 007D _ B9,
00000000(segrel)
        mov     ebx, 1                                  ; 0082 _ BB, 00000001
        push    ecx                                     ; 0087 _ 51
        push    ebx                                     ; 0088 _ 53
        push    dword ptr [esp+2CH]                     ; 0089 _ FF. 74 24, 2C
        push    dword ptr [esp+2CH]                     ; 008D _ FF. 74 24, 2C
        push    ecx                                     ; 0091 _ 51
        push    ebx                                     ; 0092 _ 53
        push    dword ptr [esp+44H]                     ; 0093 _ FF. 74 24, 44
        push    dword ptr [esp+44H]                     ; 0097 _ FF. 74 24, 44
        call   
_D3std5stdio28__T7writelnTiTAyaTAiTAyaTAiZ7writelnFNfiAyaAiAyaAiZv; 009B _ E8,
00000000(rel)
        mov     eax, 12                                 ; 00A0 _ B8, 0000000C
        call    _D10testmodule8__assertFiZv             ; 00A5 _ E8,
00000000(rel)
?_0056: mov     ebx, dword ptr [esp+0CH]                ; 00AA _ 8B. 5C 24, 0C
        mov     esi, dword ptr [esp+10H]                ; 00AE _ 8B. 74 24, 10
        add     esp, 44                                 ; 00B2 _ 83. C4, 2C
        xor     eax, eax                                ; 00B5 _ 31. C0
        ret                                             ; 00B7 _ C3
__Dmain ENDP
-----

Looks like these lines are responsible:
-----
        mov     dword ptr [esp+18H], eax                ; 001A
        ...
        mov     edx, dword ptr [esp+14H]                ; 0056
        ...
        cmp     edx, 3                                  ; 0077
        jz      ?_0056                                  ; 007A
-----
I don't understand why the line at 0056 uses "dword ptr [esp+14H]" and not
"dword ptr [esp+18H]".

(Disclaimer: I'm not fluent in asm.)

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