Re-commit optimization bisect support (r267022) without new pass manager support.

The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231

1 files changed, 10 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/LoopPass.cpp b/llvm/lib/Analysis/LoopPass.cpp
index 8163231c332..3181e4f9921 100644
--- a/llvm/lib/Analysis/LoopPass.cpp
+++ b/llvm/lib/Analysis/LoopPass.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/OptBisect.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Timer.h"
@@ -335,11 +336,16 @@ void LoopPass::assignPassManager(PMStack &PMS,
   LPPM->add(this);
 }
 
-// Containing function has Attribute::OptimizeNone and transformation
-// passes should skip it.
-bool LoopPass::skipOptnoneFunction(const Loop *L) const {
+bool LoopPass::skipLoop(const Loop *L) const {
   const Function *F = L->getHeader()->getParent();
-  if (F && F->hasFnAttribute(Attribute::OptimizeNone)) {
+  if (!F)
+    return false;
+  // Check the opt bisect limit.
+  LLVMContext &Context = F->getContext();
+  if (!Context.getOptBisect().shouldRunPass(this, *L))
+    return true;
+  // Check for the OptimizeNone attribute.
+  if (F->hasFnAttribute(Attribute::OptimizeNone)) {
     // FIXME: Report this to dbgs() only once per function.
     DEBUG(dbgs() << "Skipping pass '" << getPassName()
           << "' in function " << F->getName() << "\n");