As a minor additional note, I think some of the mm types are declared
incorrectly in compiler/psystem.pas - e.g. line 411:
tarraydef(x86_m128itype).elementdef:=s32floattype;
Shouldn't that be s32inttype or some other Integer type? m128i is for
when you're storing integers in the XMM registers.
Gareth aka. Kit
On 16/01/2020 22:22, J. Gareth Moreton wrote:
Hey everyone,
Maybe I'm being a bit pedantic with this, but must we abide by C/C++
standards and go by the name __m128 etc. for the 128-bit data type?
Being as how Pascal tended to go for more readable and BASIC-inspired
names like Integer and Single, might it be better to name them TM128
instead? If not that, then is it possible to add a union-like record
type to the System unit or the inc files that contain all of the
intrinsics?
My vectorcall tests (e.g. tests\test\cg\tvectorcall1.pp) have
something like this:
{$PUSH}
{$CODEALIGN RECORDMIN=16}
{$PACKRECORDS C}
type
TM128 = record
case Byte of
0: (M128_F32: array[0..3] of Single);
1: (M128_F64: array[0..1] of Double);
end;
{$POP}
Granted, given that __m128 will be automatically aligned, all of the
codealign directives may not be necessary - for example:
type
TM128 = record
case Byte of
0: (M128_F32: array[0..3] of Single);
2: (M128_F64: array[0..1] of Double);
3: (M128_Internal: __m128);
end;
The main thing I'm thinking about is that it's actually rather
difficult to modify the elements of a variable of type __m128 directly
in C/C++ because of the type being opaque and difficult to typecast
sometimes (some compilers will treat it as an array, others will treat
it as a record type like the above (Visual C++ does this), while
others may not allow access to its elements at all). Often, I might
want to map a 4-component vector with Single-type fields x, y, z and w
to an aligned __m128 type, or Double-type fields Re and Im when
dealing with complex numbers. That way, I can read from and write to
them outside of intrinsic calls.
I suppose I'm suggesting we introduce something more usable than what
C has so people can actually use intrinsics more easily.
Gareth aka. Kit
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