In MVE, as of rL371218, we are attempting to sink chains of instructions such as:
%l1 = insertelement <8 x i8> undef, i8 %l0, i32 0
%broadcast.splat26 = shufflevector <8 x i8> %l1, <8 x i8> undef, <8 x i32> zeroinitializer
In certain situations though, we can end up breaking the dominance relations of
instructions. This happens when we sink the instruction into a loop, but cannot
remove the originals. The Use is updated, which might in fact be a Use from the
second instruction to the first.
This attempts to fix that by reversing the order of instruction that are sunk,
and ensuring that we update the uses on new instructions if they have already
been sunk, not the old ones.
Differential Revision: https://reviews.llvm.org/D67366
llvm-svn: 371743
This patch sinks add/mul(shufflevector(insertelement())) into the basic block in which they are used so that they can then be selected together.
This is useful for various MVE instructions, such as vmla and others that take R registers.
Loop tests have been added to the vmla test file to make sure vmlas are generated in loops.
Differential revision: https://reviews.llvm.org/D66295
llvm-svn: 371218
David Green