Summary:
Refactor architecture-specific code out of llvm into llvm-bolt.
Introduce MCPlusBuilder, a class that is taking over MCInstrAnalysis
responsibilities, i.e. creating, analyzing, and modifying instructions.
To access the builder use BC->MIB, i.e. substitute MIA with MIB.
MIB is an acronym for MCInstBuilder, that's what MCPlusBuilder used
to be. The name stuck, and I find it better than MPB.
Instructions are still MCInst, and a bunch of BOLT-specific code still
lives in LLVM, but the staff under Target/* is significantly reduced.
(cherry picked from FBD7300101)
Summary:
Move the indirect branch analysis code from BinaryFunction to MCInstrAnalysis/X86MCTargetDesc.cpp.
In the process of doing this, I've added an MCRegInfo to MCInstrAnalysis which allowed me to remove a bunch of extra method parameters. I've also had to refactor how BinaryFunction held on to instructions/offsets so that it would be easy to pass a sequence of instructions to the analysis code (rather than a map keyed by offset).
Note: I think there are a bunch of MCInstrAnalysis methods that have a BitVector output parameter that could be changed to a return value since the size of the vector is based on the number of registers, i.e. from MCRegisterInfo. I haven't done this in order to keep the diff a more manageable size.
(cherry picked from FBD6213556)
Summary:
Some PUSH instructions may contain memory addresses pushed to
the stack. If this memory address is from an object in the stack, cancel
further frame analysis for this function since it may be escaping a
variable.
This fixes a bug with deleting used stores (in frameopt) in hhvm trunk.
(cherry picked from FBD5270590)
Summary:
Split FrameAnalysis into FrameAnalysis and RegAnalysis, since
some optimizations only require register information about functions,
not frame information. Refactor callgraph walking code into the
CallGraphWalker class, allowing any analysis that depend on the call
graph to easily traverse it via a visitor pattern. Also fix
LivenessAnalysis, which was broken because it was not considering
registers read into callees and incorporating this into caller.
(cherry picked from FBD5177901)
