From f5cd4f0d70f2da83626cb1eeefe4ae10382c584d Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Thu, 23 Oct 2008 20:43:13 +0000
Subject: Committing a good chunk of the pre-register allocation live interval
 splitting pass. It's handling simple cases and appear to do good things.
 Next: avoid splitting an interval multiple times; renumber registers when
 possible; record stack slot live intervals for coloring; rematerialize defs
 when possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58044 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/RegAllocLinearScan.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'lib/CodeGen/RegAllocLinearScan.cpp')

diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index ede387e7b7..c382a4a33f 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -49,6 +49,11 @@ NewHeuristic("new-spilling-heuristic",
              cl::desc("Use new spilling heuristic"),
              cl::init(false), cl::Hidden);
 
+static cl::opt<bool>
+PreSplitIntervals("pre-alloc-split",
+                  cl::desc("Pre-register allocation live interval splitting"),
+                  cl::init(false), cl::Hidden);
+
 static RegisterRegAlloc
 linearscanRegAlloc("linearscan", "linear scan register allocator",
                    createLinearScanRegisterAllocator);
@@ -113,6 +118,8 @@ namespace {
       // Make sure PassManager knows which analyses to make available
       // to coalescing and which analyses coalescing invalidates.
       AU.addRequiredTransitive<RegisterCoalescer>();
+      if (PreSplitIntervals)
+        AU.addRequiredID(PreAllocSplittingID);
       AU.addRequired<LiveStacks>();
       AU.addPreserved<LiveStacks>();
       AU.addRequired<MachineLoopInfo>();
-- 
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