Add loop pass insertion point EP_LateLoopOptimizations

Differential Revision: https://reviews.llvm.org/D28694


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293067 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/IPO/PassManagerBuilder.h

@@ -101,6 +101,14 @@ public:
     /// will be inserted after each instance of the instruction combiner pass.
     EP_Peephole,
 
+    /// EP_LateLoopOptimizations - This extension point allows adding late loop
+    /// canonicalization and simplification passes. This is the last point in
+    /// the loop optimization pipeline before loop deletion. Each pass added
+    /// here must be an instance of LoopPass.
+    /// This is the place to add passes that can remove loops, such as target-
+    /// specific loop idiom recognition.
+    EP_LateLoopOptimizations,
+
     /// EP_CGSCCOptimizerLate - This extension point allows adding CallGraphSCC
     /// passes at the end of the main CallGraphSCC passes and before any
     /// function simplification passes run by CGPassManager.

lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -316,7 +316,9 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   addInstructionCombiningPass(MPM);
   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
+  addExtensionsToPM(EP_LateLoopOptimizations, MPM);
   MPM.add(createLoopDeletionPass());          // Delete dead loops
+
   if (EnableLoopInterchange) {
     MPM.add(createLoopInterchangePass()); // Interchange loops
     MPM.add(createCFGSimplificationPass());