Add codegen for VSX word extract conversion from signed/unsigned to single/double
precision.
For UINT_TO_FP:
Extract word unsigned and convert to float was implemented in https://reviews.llvm.org/D20239.
Here we will add the missing extract integer and conversion to double. This
utilizes the new P9 instruction xxextractuw to extracting an integer element
when the result will be converted to double thereby saving 2 direct moves
(VSR <-> GPR).
For SINT_TO_FP:
We will implement the following sequence which will also reduce the number of
instructions by saving 2 direct moves.
v4i32->f32:
xxspltw
xvcvsxwsp
xscvspdpn
v4i32->f64:
xxspltw
xvcvsxwdp
Differential Revision: https://reviews.llvm.org/D35859
llvm-svn: 310866
This patch corresponds to review:
https://reviews.llvm.org/D21354
We use direct moves for extracting integer elements from vectors. We also use
direct moves when converting integers to FP. When these operations are chained,
we get a direct move out of a VSR followed by a direct move back into a VSR.
These are redundant - all we need to do is line up the element and convert.
llvm-svn: 275796
Lei Huang