From bb36a438722d4d56febc07c6472c8446bb6faafe Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Fri, 21 Sep 2012 20:04:28 +0000
Subject: [PATCH] Fix a significant recent(?) regression. StackSlotColoring no
 longer did anything because LiveStackAnalysis was not preserved by
 VirtRegWriter. This caused big stack usage regression in some cases.

rdar://12340383


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164408 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveStackAnalysis.cpp | 5 ++++-
 lib/CodeGen/RegAllocGreedy.cpp    | 2 +-
 lib/CodeGen/StackSlotColoring.cpp | 2 +-
 lib/CodeGen/VirtRegMap.cpp        | 4 ++++
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/CodeGen/LiveStackAnalysis.cpp b/lib/CodeGen/LiveStackAnalysis.cpp
index 939e795b4a3..f0b522bd7d3 100644
--- a/lib/CodeGen/LiveStackAnalysis.cpp
+++ b/lib/CodeGen/LiveStackAnalysis.cpp
@@ -25,7 +25,10 @@
 using namespace llvm;
 
 char LiveStacks::ID = 0;
-INITIALIZE_PASS(LiveStacks, "livestacks",
+INITIALIZE_PASS_BEGIN(LiveStacks, "livestacks",
+                "Live Stack Slot Analysis", false, false)
+INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
+INITIALIZE_PASS_END(LiveStacks, "livestacks",
                 "Live Stack Slot Analysis", false, false)
 
 char &llvm::LiveStacksID = LiveStacks::ID;
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 20ba8044464..06f69c1e0d1 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -330,9 +330,9 @@ void RAGreedy::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addPreserved<SlotIndexes>();
   AU.addRequired<LiveDebugVariables>();
   AU.addPreserved<LiveDebugVariables>();
-  AU.addRequired<CalculateSpillWeights>();
   AU.addRequired<LiveStacks>();
   AU.addPreserved<LiveStacks>();
+  AU.addRequired<CalculateSpillWeights>();
   AU.addRequired<MachineDominatorTree>();
   AU.addPreserved<MachineDominatorTree>();
   AU.addRequired<MachineLoopInfo>();
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index 9d0fd0aa205..d349abc3577 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -11,7 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "stackcoloring"
+#define DEBUG_TYPE "stackslotcoloring"
 #include "llvm/Module.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 5bdc1fff682..a69a8169d30 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -20,6 +20,7 @@
 #include "VirtRegMap.h"
 #include "LiveDebugVariables.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveStackAnalysis.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
@@ -171,6 +172,7 @@ INITIALIZE_PASS_BEGIN(VirtRegRewriter, "virtregrewriter",
 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
 INITIALIZE_PASS_DEPENDENCY(LiveDebugVariables)
+INITIALIZE_PASS_DEPENDENCY(LiveStacks)
 INITIALIZE_PASS_DEPENDENCY(VirtRegMap)
 INITIALIZE_PASS_END(VirtRegRewriter, "virtregrewriter",
                     "Virtual Register Rewriter", false, false)
@@ -183,6 +185,8 @@ void VirtRegRewriter::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<SlotIndexes>();
   AU.addPreserved<SlotIndexes>();
   AU.addRequired<LiveDebugVariables>();
+  AU.addRequired<LiveStacks>();
+  AU.addPreserved<LiveStacks>();
   AU.addRequired<VirtRegMap>();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
-- 
2.34.1