tree 39ff2117a183e4609e10bb1d182f4aa80bc4c0de
parent 09c206b6fb79ae1c2c542e30225739b938c880a5
author Victor Lomuller <victor@codeplay.com> 1523975469 +0100
committer Diego Novillo <dnovillo@google.com> 1524231915 -0400

Add register liveness analysis.

For each function, the analysis determine which SSA registers are live
at the beginning of each basic block and which one are killed at
the end of the basic block.

It also includes utilities to simulate the register pressure for loop
fusion and fission.

The implementation is based on the paper "A non-iterative data-flow
algorithm for computing liveness sets in strict ssa programs" from
Boissinot et al.