BIC is generally faster, and it can put the output in a different
register from the input.
We already do this in Thumb2 mode; not sure why the equivalent fix
never got applied to ARM mode.
Differential Revision: https://reviews.llvm.org/D31797
llvm-svn: 299803
This is especially visible in softfp mode, for example in the implementation of libm fabs/fneg functions. If we have:
%1 = vmovdrr r0, r1
%2 = fabs %1
then move the fabs before the vmovdrr:
%1 = and r1, #0x7FFFFFFF
%2 = vmovdrr r0, r1
This is never a lose, and could be a serious win because the vmovdrr may be followed by a vmovrrd, which would enable us to remove the conversion into FPRs completely.
We already do this for f32, but not for f64. Tests are added for both.
llvm-svn: 246360
Eli Friedman