Comment # 1 on bug 117 from Iain Buclaw

__simd requires the compiler to expose D_SIMD.  Which is not implemented in
GDC. And given the nature of the intrinsic, I can't see it ever being
introduced.


To access SIMD instructions, instead use the gcc.builtins module.

---
  import gcc.builtins;
  float4 a = 1, b = 2;
  float4 c = __builtin_ia32_addps(a, b);
---


You can get a list of all builtins gdc exposes using:

echo "module gcc.builtins;" > builtins.d && gdc -fsyntax-only -fintfc
builtins.d

Then open the file 'builtins.di' for viewing.  There is currently no maintained
list of this because what is generated for gcc.builtins may change depending on
target or optimisation flags passed to gdc.