如何在GNAT Ada中定义__builtin_blendvps256并汇编实现vblendvps

我正在基于GNAT开发针对x86 AVX/AVX2扩展的Ada库，已定义以下向量类型和内置函数声明：

-- 256-bit Vector of Single Precision Floating Point Numbers
type Vector_256_Float_32 is array (0 .. 7) of IEEE_Float_32 with
  Alignment => 32, Size => 256, Object_Size => 256;
pragma Machine_Attribute (Vector_256_Float_32, "vector_type");
pragma Machine_Attribute (Vector_256_Float_32, "may_alias");

-- 256-bit Vector of 32-bit Signed Integers
type Vector_256_Integer_32 is array (0 .. 7) of Integer_32 with
  Alignment => 32, Size => 256, Object_Size => 256;
pragma Machine_Attribute (Vector_256_Integer_32, "vector_type");
pragma Machine_Attribute (Vector_256_Integer_32, "may_alias");

-- 256-bit Vector of 32-bit Unsigned Integers
type Vector_256_Unsigned_32 is array (0 .. 7) of Unsigned_32 with
  Alignment => 32, Size => 256, Object_Size => 256;
pragma Machine_Attribute (Vector_256_Unsigned_32, "vector_type");
pragma Machine_Attribute (Vector_256_Unsigned_32, "may_alias");

function vblendvps
  (Left, Right, Mask : Vector_256_Float_32)
   return Vector_256_Float_32 with
  Inline_Always => True, Convention => Intrinsic, Import => True,
  External_Name => "__builtin_ia32_blendvps256";

为了学习，我尝试用System.Machine_Code中的Asm函数手动实现vblendvps，代码如下：

with System.Machine_Code; use System.Machine_Code;

function vblendvps
(Left, Right, Mask : Vector_256_Float_32)
return Vector_256_Float_32
is
result : Vector_256_Float_32;
begin
Asm
(Template => "vblendvps %3, %0, %1, %2",
 Outputs  => Vector_256_Float_32'Asm_Output ("=g", result),
 Inputs   =>
   (Vector_256_Float_32'Asm_Input ("g", Left),
    Vector_256_Float_32'Asm_Input ("g", Right),
    Vector_256_Unsigned_32'Asm_Input ("g", Mask)));
return result;
end vblendvps;

编译时出现错误：

Error: too many memory references for `vblendvps'

我猜测问题出在需要将参数从内存移动到寄存器，但不确定具体操作方法。同时我难以找到vblendvps指令的参数说明，希望获得相关参考资料，以及该函数的正确实现方式（非Ada示例也可）。

内容的提问来源于stack exchange，提问作者user20790983