dmd: if still there

[Chris via Digitalmars-d]

Out of curiosity. dmd still produces the if statement, although 
it ain't gonna happen. Same is true of "DoIt.yes". I know, it's 
an unlikely and marginal example.

[code]
import std.stdio;
enum DoIt {
  yes,
  no
}

void main() {
  doit(DoIt.no);
}

void doit(DoIt flag) {
  if (flag == DoIt.yes) {
    writeln("I'm doing it!");
  }
  else {
    writeln("No, I won't");
  }
}

[asm]

_Dmain:
                push    RBP
                mov     RBP,RSP
                mov     EDI,1
                call      _D7dump_if4doitFE7dump_if4DoItZv@PC32
                xor     EAX,EAX
                pop     RBP
                ret
                0f1f
                add     [RAX],R8B
.text._Dmain    ends
.text._D7dump_if4doitFE7dump_if4DoItZv  segment
        assume  CS:.text._D7dump_if4doitFE7dump_if4DoItZv
_D7dump_if4doitFE7dump_if4DoItZv:
                push    RBP
                mov     RBP,RSP
                sub     RSP,010h
                mov     -8[RBP],EDI
                cmp     dword ptr -8[RBP],0
                jne     L29
                mov     RDX,FLAT:.rodata[00h][RIP]
                mov     RDI,FLAT:.rodata[00h][RIP]
                mov     RSI,RDX
                call      _D3std5stdio16__T7writelnTAyaZ7writelnFAyaZv@PC32
                jmp short       L3F
L29:            mov     RDX,FLAT:.rodata[00h][RIP]
                mov     RDI,FLAT:.rodata[00h][RIP]
                mov     RSI,RDX
                call      _D3std5stdio16__T7writelnTAyaZ7writelnFAyaZv@PC32
L3F:            leave
                ret
                0f1f
                add     byte ptr [RAX],0
                add     [RAX],AL
.text._D7dump_if4doitFE7dump_if4DoItZv  ends

[asm dmd (2.066) -release -boundscheck=off -O -inline]

_Dmain:
                push    RBP
                mov     RBP,RSP
                mov     RDX,FLAT:.rodata[00h][RIP]
                mov     RDI,FLAT:.rodata[00h][RIP]
                mov     RSI,RDX
                call      _D3std5stdio16__T7writelnTAyaZ7writelnFAyaZv@PC32
                xor     EAX,EAX
                pop     RBP
                ret
                nop
.text._Dmain    ends
.text._D7dump_if4doitFE7dump_if4DoItZv  segment
        assume  CS:.text._D7dump_if4doitFE7dump_if4DoItZv
_D7dump_if4doitFE7dump_if4DoItZv:
                push    RBP
                mov     RBP,RSP
                sub     RSP,010h
                mov     -8[RBP],EDI
                cmp     dword ptr -8[RBP],0
                jne     L29
                mov     RDX,FLAT:.rodata[00h][RIP]
                mov     RDI,FLAT:.rodata[00h][RIP]
                mov     RSI,RDX
                call      _D3std5stdio16__T7writelnTAyaZ7writelnFAyaZv@PC32
                jmp short       L3F
L29:            mov     RDX,FLAT:.rodata[00h][RIP]
                mov     RDI,FLAT:.rodata[00h][RIP]
                mov     RSI,RDX
                call      _D3std5stdio16__T7writelnTAyaZ7writelnFAyaZv@PC32
L3F:            mov     RSP,RBP
                pop     RBP
                ret
                0f1f
                add     0[RCX],SPL
.text._D7dump_if4doitFE7dump_if4DoItZv  ends