llvm-project

0cd523e5 - [PHIElimination] Declare MachineLoopInfo dependency for Legacy PM (#169693)

[PHIElimination] Declare MachineLoopInfo dependency for Legacy PM (#169693) PHIElimination uses MachineLoopInfo for loop-exiting critical edge splitting but wasn't declaring this dependency via addUsedIfAvailable() in getAnalysisUsage(). Without this declaration, the pass manager does not make MachineLoopInfo accessible to PHIElimination, causing getAnalysisIfAvailable() to return nullptr. Without MachineLoopInfo, the loop-exiting edge optimization doesn't fire, resulting in fewer critical edge splits and potentially suboptimal code placement. This patch adds: - MachineLoopInfo as an optional dependency - A test that verifies the optimization fires when MLI is accessible