From 8dd26253f54247e77e5accfdd70e7b4bf27b39c2 Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Fri, 10 Feb 2012 04:10:36 +0000 Subject: 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. 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 --- lib/CodeGen/LiveVariables.cpp | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib/CodeGen/LiveVariables.cpp') diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index ae63e767fe..7d98935a7e 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -33,6 +33,7 @@ #include "llvm/Support/Debug.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetMachine.h" +#include "llvm/Support/ErrorHandling.h" #include "llvm/ADT/DepthFirstIterator.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallSet.h" @@ -41,6 +42,7 @@ using namespace llvm; char LiveVariables::ID = 0; +char &llvm::LiveVariablesID = LiveVariables::ID; INITIALIZE_PASS_BEGIN(LiveVariables, "livevars", "Live Variable Analysis", false, false) INITIALIZE_PASS_DEPENDENCY(UnreachableMachineBlockElim) @@ -511,6 +513,12 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) { std::fill(PhysRegUse, PhysRegUse + NumRegs, (MachineInstr*)0); PHIJoins.clear(); + // FIXME: LiveIntervals will be updated to remove its dependence on + // LiveVariables to improve compilation time and eliminate bizarre pass + // dependencies. Until then, we can't change much in -O0. + if (!MRI->isSSA()) + report_fatal_error("regalloc=... not currently supported with -O0"); + analyzePHINodes(mf); // Calculate live variable information in depth first order on the CFG of the -- cgit v1.2.3