Idea: extend gcc to save C from the hell of intel vector instructions

[Warren D Smith <warren dot wds at gmail dot com>]

There are a lot of weird intel vector instructions like
#include <emmintrin.h>

__m128i alignas(16) A, B, C, D, X, Y;
A = _mm_shuffle_epi8(D, Y);
C = _mm_unpackhi_epi16(A, B);
where my gcc seems to know about the latter but not the former
(I have no idea why, and it is very annoying to arbitrarily support the second
and not the first).

Anyhow.  If you write code like that, it is horrible to read.

But here is a simple idea for improving the C language which would make
lots of such code easy to read.  And write.

First of all, there should be (and pretty much are, see   stdint.h, inttypes.h)
int and uint types of various power of 2 bit sizes, e.g.

int16 a;
uint64 b;
uint128 c;

uint256 d;
uint512 e;
uint4 f;

where again my gcc supports the first 3 (after appropriate renamings)
but not the last 3.  (Again, very annoying arbitrariness.)

But more importantly, we should add new types like this:

uint128.16 a, b;
meaning a is 128 bits wide, and consists of 16 chunks, each 8 bits wide,
each regarded as an 8-bit-wide unsigned int.

uint256.8 y, z;
and so on.

Note the use of DOTS inside the type name.  You could consider other notations,
I am not fixated on this one.  Another might be  uint128{16}.

OK, now we could do
uint128.16 a, b, c;
c = a+b;   //adds the 16-element vectors a and b elementwise
c = a-b;  //subtracts vectors
etc.

Life is SO much nicer now. It's practically sane again.

Don't have to keep coming up with all the horrible
names for each possible kind of vector operation, the compiler does it for you.
Compiler can check type compatibility and complain if try to
add incompatible types.  etc etc.

And for stuff that really should have funny names,
   b = shuffle(c, d)
will have meaning pretty obvious from the types of b,c,d,
and again can complain about type mismatches.
And the type names will no longer be horrible unreadable strings of
nonsense characters.
They will be perfectly readable and logical simple names like uint128.16.

The present hellish situation is partly intel's fault and partly gcc's fault,
but it is absurd, that is for sure, and this hell is entirely
unnecessary, that is
what really rubs your face in it over and over.

-- 
Warren D. Smith
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