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digitalmars.D - Druntime DMD/LDC/GDC architecture

reply "Ilya Yaroshenko" <ilyayaroshenko gmail.com> writes:
Hello all!

very simple code:

------------------
double[] a, c;
...
c[] += a[];
------------------

The DMD version I can find in _arraySliceSliceAddass_d, 
https://github.com/D-Programming-Language/druntime/blob/master/
rc/rt/arraydouble.d 
.

What about LDC and GDC?
The _arraySliceSliceAddass_d is the same, no any version(LDC).

When I compile code into assembler I found other code then in asm 
scope.

So I suppose LDC has it's own architecture.
Is it right?

Where I can find it for understanding what optimization can be 
done by LLVM optimizer?

Have GDC it's own architecture too?

Best Regards,
Ilya
Jun 23 2014
next sibling parent reply "John Colvin" <john.loughran.colvin gmail.com> writes:
On Monday, 23 June 2014 at 18:09:46 UTC, Ilya Yaroshenko wrote:
 Hello all!

 very simple code:

 ------------------
 double[] a, c;
 ...
 c[] += a[];
 ------------------

 The DMD version I can find in _arraySliceSliceAddass_d, 
 https://github.com/D-Programming-Language/druntime/blob/master/
rc/rt/arraydouble.d 
 .

 What about LDC and GDC?
 The _arraySliceSliceAddass_d is the same, no any version(LDC).

 When I compile code into assembler I found other code then in 
 asm scope.

 So I suppose LDC has it's own architecture.
 Is it right?

 Where I can find it for understanding what optimization can be 
 done by LLVM optimizer?

 Have GDC it's own architecture too?

 Best Regards,
 Ilya

If you look at the bottom of those _array functions you will find a regular loop doing the cleanup for anything missed by the inline asm. If I remember correctly, for gdc it is this loop doing the whole operation as the asm is versioned out.
Jun 23 2014
parent "Ilya Yaroshenko" <ilyayaroshenko gmail.com> writes:
 If you look at the bottom of those _array functions you will 
 find a regular loop doing the cleanup for anything missed by 
 the inline asm. If I remember correctly, for gdc it is this 
 loop doing the whole operation as the asm is versioned out.

I think it is something different. LDC has standard D inline asm.
Jun 23 2014
prev sibling parent "Kai Nacke" <kai redstar.de> writes:
On Monday, 23 June 2014 at 18:09:46 UTC, Ilya Yaroshenko wrote:
 Hello all!

 very simple code:

 ------------------
 double[] a, c;
 ...
 c[] += a[];
 ------------------

 The DMD version I can find in _arraySliceSliceAddass_d, 
 https://github.com/D-Programming-Language/druntime/blob/master/
rc/rt/arraydouble.d 
 .

 What about LDC and GDC?
 The _arraySliceSliceAddass_d is the same, no any version(LDC).

 When I compile code into assembler I found other code then in 
 asm scope.

 So I suppose LDC has it's own architecture.
 Is it right?

 Where I can find it for understanding what optimization can be 
 done by LLVM optimizer?

 Have GDC it's own architecture too?

 Best Regards,
 Ilya

Hi Ilya, I am not sure if I understand your question. I compiled this code with ldc void main() { double[] a, c; a[] = 1; c[] = 2; c[] += a[]; } (options ldc2 -c -output-ll -output-s -release -O0) and get in the main function movq 120(%rsp), %r8 movq 128(%rsp), %r9 movq 104(%rsp), %rcx movq 112(%rsp), %rdx callq _arraySliceSliceAddass_d Using -O1 or higher optimizes the call away, maybe that is the problem. Could you post the source code you are using? Regards, Kai
Jun 24 2014