Reverting patch r244235.

This patch will be redone in a different way. See
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20150810/292978.html
for more details.

llvm-svn: 245071

1 files changed, 21 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index f3a81e8dc0f..4e68cbdd7f5 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -56,6 +56,9 @@ static cl::opt<bool> DisableMachineLICM("disable-machine-licm", cl::Hidden,
     cl::desc("Disable Machine LICM"));
 static cl::opt<bool> DisableMachineCSE("disable-machine-cse", cl::Hidden,
     cl::desc("Disable Machine Common Subexpression Elimination"));
+static cl::opt<cl::boolOrDefault>
+    EnableShrinkWrapOpt("enable-shrink-wrap", cl::Hidden,
+                        cl::desc("enable the shrink-wrapping pass"));
 static cl::opt<cl::boolOrDefault> OptimizeRegAlloc(
     "optimize-regalloc", cl::Hidden,
     cl::desc("Enable optimized register allocation compilation path."));
@@ -218,7 +221,7 @@ TargetPassConfig::TargetPassConfig(TargetMachine *tm, PassManagerBase &pm)
     : ImmutablePass(ID), PM(&pm), StartBefore(nullptr), StartAfter(nullptr),
       StopAfter(nullptr), Started(true), Stopped(false),
       AddingMachinePasses(false), TM(tm), Impl(nullptr), Initialized(false),
-      DisableVerify(false), EnableTailMerge(true) {
+      DisableVerify(false), EnableTailMerge(true), EnableShrinkWrap(false) {
 
   Impl = new PassConfigImpl();
 
@@ -540,8 +543,8 @@ void TargetPassConfig::addMachinePasses() {
   addPostRegAlloc();
 
   // Insert prolog/epilog code.  Eliminate abstract frame index references...
-  if (getOptLevel() != CodeGenOpt::None)
-    addPass(createShrinkWrapPass());
+  if (getEnableShrinkWrap())
+    addPass(&ShrinkWrapID);
   addPass(&PrologEpilogCodeInserterID);
 
   /// Add passes that optimize machine instructions after register allocation.
@@ -620,6 +623,21 @@ void TargetPassConfig::addMachineSSAOptimization() {
   addPass(&DeadMachineInstructionElimID);
 }
 
+bool TargetPassConfig::getEnableShrinkWrap() const {
+  switch (EnableShrinkWrapOpt) {
+  case cl::BOU_UNSET:
+    return EnableShrinkWrap && getOptLevel() != CodeGenOpt::None;
+  // If EnableShrinkWrap is set, it takes precedence on whatever the
+  // target sets. The rational is that we assume we want to test
+  // something related to shrink-wrapping.
+  case cl::BOU_TRUE:
+    return true;
+  case cl::BOU_FALSE:
+    return false;
+  }
+  llvm_unreachable("Invalid shrink-wrapping state");
+}
+
 //===---------------------------------------------------------------------===//
 /// Register Allocation Pass Configuration
 //===---------------------------------------------------------------------===//