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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150226 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 556fb40..0ed4c34 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -92,11 +92,15 @@
STATISTIC(NumReused, "Number of reused lowered phis");
char PHIElimination::ID = 0;
-INITIALIZE_PASS(PHIElimination, "phi-node-elimination",
- "Eliminate PHI nodes for register allocation", false, false)
-
char& llvm::PHIEliminationID = PHIElimination::ID;
+INITIALIZE_PASS_BEGIN(PHIElimination, "phi-node-elimination",
+ "Eliminate PHI nodes for register allocation",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(LiveVariables)
+INITIALIZE_PASS_END(PHIElimination, "phi-node-elimination",
+ "Eliminate PHI nodes for register allocation", false, false)
+
void PHIElimination::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addPreserved<LiveVariables>();
AU.addPreserved<MachineDominatorTree>();