It is generally beneficial to prefer "movi d0, #0" over "fmov s0, wzr" as this
is most efficient across all cores; it is recognised as a zeroing idiom. For
newer cores, fmov instructions can also be eliminated early and there is no
difference with movi, but some implementations lack this so is not true for
other/older cores. Thus this standardises on using movi as this should always
gives the same or better performance than the fmov with wzr.
Differential Revision: https://reviews.llvm.org/D99586
This was using the .2d variant which zeros 128 bits, but using the .2s variant
that zeros 64 bits is faster on some cores.
This is a prep step for D99586 to always using movi for zeroing floats.
Differential Revision: https://reviews.llvm.org/D99710
Printing floating point number in decimal is inconvenient for humans.
Verbose asm output will print out floating point values in comments, it
helps.
But in lots of cases, users still need additional work to covert the
decimal back to hex or binary to check the bit patterns,
especially when there are small precision difference.
Hexadecimal form is one of the supported form in LLVM IR, and easier for
debugging.
This patch try to print all FP constant in hex form instead.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D73566
Instead of loading 0 from a constant pool, it's of course much better to
materialize it using an fmov and the zero register.
Thanks to Ahmed Bougacha for the suggestion.
Differential Revision: https://reviews.llvm.org/D37102
llvm-svn: 311662
Armv8.2-A adds FP16 support, i.e. f16 is not only a storage-only type, but it
also supports performing data processing on 16-bit floating-point quantities.
All the necessary (tablegen) groundwork of adding the ARMv8.2-A FP16 (scalar)
instructions was done in D15014. To take advantage of this, this patch avoids
promotion of f16 to f32 types when the subtarget supports FullFP16, which
enables instruction selection of these FP16 instructions.
Differential Revision: https://reviews.llvm.org/D36396
llvm-svn: 311154
Sjoerd Meijer