• bearophile (17/17) Jul 18 2013 As a final step to compute the product of two complex numbers I
• jerro (1/1) Jul 18 2013 Try adding flag -mattr=sse3.
• bearophile (5/6) Jul 18 2013 Now it's accepted, thank you. So is LDC2 assuming a very old CPU?
• Kai Nacke (10/16) Jul 22 2013 Hi,

"bearophile" <bearophileHUGS lycos.com> writes:

As a final step to compute the product of two complex numbers I 
perform a simd operation on double2:

x3 = [x3.array[1] - x2.array[1], x3.array[0] + x2.array[0]];

But ldc2 compiles that quite badly (I don't know who's to blame, 
if necessary I will open a LLVM bug report), so I have tried to 
use an instruction addsubpd.

To do it I have imported ldc.gccbuiltins_x86 and then I use:

x3 = __builtin_ia32_addsubpd(x3, x2);

but ldc2 gives me:

LLVM ERROR: Cannot select: intrinsic %llvm.x86.sse3.addsub.pd
Stack dump:
0.      Running pass 'X86 DAG->DAG Instruction Selection' on 
function 
' "\01__D12complex_mul217__T8compMul6Vk12Z8compMul6FNaNbNfKG12NhG2dKG12NhG2dKG12NhG2dZv"'

Can you help me?

Bye,
bearophile

"jerro" <a a.com> writes:

Try adding flag -mattr=sse3.

"bearophile" <bearophileHUGS lycos.com> writes:

jerro:

 Try adding flag -mattr=sse3.

Now it's accepted, thank you. So is LDC2 assuming a very old CPU? 
:-)

Bye,
bearophile

"Kai Nacke" <kai redstar.de> writes:

On Thursday, 18 July 2013 at 21:30:12 UTC, bearophile wrote:
 jerro:

 Try adding flag -mattr=sse3.

 Now it's accepted, thank you. So is LDC2 assuming a very old 
 CPU? :-)

 Bye,
 bearophile

Hi,

the behaviour was changed because you can't create a generic 
package if you optimize for your CPU.


(https://github.com/ldc-developers/ldc/issues/414).

With LLVM 3.3, the auto vectorizer is not enabled. You have to 
specify -vectorize on the command line. Maybe you want to try 
that with your original code.

Kai