Difference between revisions of "The code generator"
From Free Pascal wiki
Jump to navigationJump to searchm (typo fix) |
m (Merge code boxes) |
||
| Line 10: | Line 10: | ||
pmmshuffle = ^tmmshuffle; | pmmshuffle = ^tmmshuffle; | ||
| − | |||
{ this record describes shuffle operations for mm operations; if a pointer a shuffle record | { this record describes shuffle operations for mm operations; if a pointer a shuffle record | ||
passed to an mm operation is nil, it means that the whole location is moved } | passed to an mm operation is nil, it means that the whole location is moved } | ||
Revision as of 20:15, 13 September 2020
With the version 1.9.x of FPC the code generator has been completly rewritten to fit the needs of a compiler with multiple processor target support.
MM support
The FPC code generator supports the usage of multimedia registers as they are implemented by modern processors.
The shuffle operand
Most multimedia units support scalar as well as vector operations on the multimedia registers. To distinguish between these different operations, the mm methods of tcg take a so-called shuffle parameter. This parameter allows to specify how the data is processed when generating multimedia code.
pmmshuffle = ^tmmshuffle;
{ this record describes shuffle operations for mm operations; if a pointer a shuffle record
passed to an mm operation is nil, it means that the whole location is moved }
tmmshuffle = record
{ describes how many shuffles are actually described, if len=0 then
moving the scalar with index 0 to the scalar with index 0 is meant }
len : byte;
{ lower nibble of each entry of this array describes index of the source data index while
the upper nibble describes the destination index }
shuffles : array[1..1] of byte;
end;
