Re: [arm-gnu] Advanced SIMD instruction support

[Mark Mitchell <mark@xxxxxxxxxxxxxxxx>]

Akshay Joshi wrote:

> I tried using this instruction but I get another error while assembling;
> viz, "Error: selected FPU does not support instruction -- 'msr fpexc,r1'".
> We pass the following options to the compiler / assembler :
> 	-march=armv7a
> 	-mfpu=neon

Empirically, you also need the "-mfloat-abi=softfp" to gcc.  With that,
I can compile this:

void f() {
  asm ("msr fpexc, r1");
}

Paul, is that what you'd expect?

> The document(DDI 0406B) says that "fmxr" is a former ARM assembly mnemonic
> which has been replaced by the UAL mnemonic "vmsr". And it states that "msr"
> instruction can modify only APSR / CPSR register bits.

Like I said, we don't have those docs.  But, we're working with ARM on
that, so hopefully we'll have them soon.  In the meantime, I suggest
using "msr", since it does seem to be the right opcode.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@xxxxxxxxxxxxxxxx
(650) 331-3385 x713