Re: StructType.init and StructType() cause a allocation

[Benjamin Thaut]

Am 30.06.2012 13:52, schrieb bearophile:
I don't know if that bug fix (in dmd 2.060alpha) has fixed your
problem too.

I have compiled this code from your issue 7271 with the latest beta:


struct MemoryBlockInfo {
     size_t size;
     long[10] backtrace;
     int backtraceSize;

     this(size_t size) {
         this.size = size;
     }
}
void main() {
     MemoryBlockInfo info;
     info = MemoryBlockInfo.init; //array allocation here
}


Compiling it with no optimization it gives:


_D4temp15MemoryBlockInfo6__ctorMFkZS4temp15MemoryBlockInfo
         enter   4,0
         mov ECX,8[EBP]
         mov [EAX],ECX
         leave
         ret 4

__Dmain comdat
         enter   060h,0
         push    ESI
         push    EDI
         mov ECX,018h
         xor EAX,EAX
         lea EDI,-060h[EBP]
         rep
         stosd
         mov ESI,offset FLAT:_D4temp15MemoryBlockInfo6__initZ
         lea EDI,-060h[EBP]
         mov CL,018h
         rep
         movsd
         pop EDI
         pop ESI
         leave
         ret


With -O -release -inline it becomes:


_D4temp15MemoryBlockInfo6__ctorMFkZS4temp15MemoryBlockInfo  comdat
         push    EAX
         mov ECX,8[ESP]
         mov [EAX],ECX
         pop ECX
         ret 4

__Dmain comdat
         sub ESP,064h
         mov ECX,018h
         xor EAX,EAX
         push    EDI
         lea EDI,4[ESP]
         rep
         stosd
         pop EDI
         add ESP,064h
         ret


In both cases I don't see a memory allocation.

Bye,
bearophile

Thank you, Its very nice to know that this got fixed. Someone might want 
to close the ticket as duplicate then.

Kind Regards
Benjamin Thaut