RegAlloc superpass: includes phi elimination, coalescing, and scheduling.

Creates a configurable regalloc pipeline.

Ensure specific llc options do what they say and nothing more: -reglloc=... has no effect other than selecting the allocator pass itself. This patch introduces a new umbrella flag, "-optimize-regalloc", to enable/disable the optimizing regalloc "superpass". This allows for example testing coalscing and scheduling under -O0 or vice-versa.

When a CodeGen pass requires the MachineFunction to have a particular property, we need to explicitly define that property so it can be directly queried rather than naming a specific Pass. For example, to check for SSA, use MRI->isSSA, not addRequired<PHIElimination>.

CodeGen transformation passes are never "required" as an analysis

ProcessImplicitDefs does not require LiveVariables.

We have a plan to massively simplify some of the early passes within the regalloc superpass.

llvm-svn: 150226

1 files changed, 0 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 49c6cec23a9..ba87f5a7ab3 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -69,8 +69,6 @@ INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
 INITIALIZE_PASS_DEPENDENCY(LiveDebugVariables)
-INITIALIZE_PASS_DEPENDENCY(StrongPHIElimination)
-INITIALIZE_PASS_DEPENDENCY(RegisterCoalescer)
 INITIALIZE_PASS_END(MachineScheduler, "misched",
                     "Machine Instruction Scheduler", false, false)
 
@@ -91,12 +89,6 @@ void MachineScheduler::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addPreserved<LiveIntervals>();
   AU.addRequired<LiveDebugVariables>();
   AU.addPreserved<LiveDebugVariables>();
-  if (StrongPHIElim) {
-    AU.addRequiredID(StrongPHIEliminationID);
-    AU.addPreservedID(StrongPHIEliminationID);
-  }
-  AU.addRequiredID(RegisterCoalescerPassID);
-  AU.addPreservedID(RegisterCoalescerPassID);
   MachineFunctionPass::getAnalysisUsage(AU);
 }