A landing pad can have live-in registers that are defined by the runtime,
not the program (exception pointer register and exception selector
register). Make sure to recognize that case and not link these registers
with any defs in the program.
Each landing pad will have phi nodes added at the beginning to provide
definitions of these registers, but the uses of those phi nodes will not
have any reaching defs.
llvm-svn: 282519
- FuncNode::findBlock traverses the function every time. Avoid using it,
and keep a cache of block addresses in DataFlowGraph instead.
- The operator[] in the map of definition stacks was very slow. Replace
the map with unordered_map.
llvm-svn: 276429
Dead phi nodes are needed for code motion (such as copy propagation),
where a new use would be placed in a location that would be dominated
by a dead phi. Such a transformation is not legal for copy propagation,
and the existence of the phi would prevent it, but if the phi is not
there, it may appear to be valid.
llvm-svn: 267932
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest). All of these
functions require non-null parameters already, so references are more
clear. As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.
No functionality change intended.
llvm-svn: 261605
Target independent, SSA-based data flow framework for representing
data flow between physical registers.
This commit implements the creation of the actual data flow graph.
llvm-svn: 257477
Krzysztof Parzyszek