[PM] Port the PostOrderFunctionAttrs pass to the new pass manager and

convert one test to use this.

This is a particularly significant milestone because it required
a working per-function AA framework which can be queried over each
function from within a CGSCC transform pass (and additionally a module
analysis to be accessible). This is essentially *the* point of the
entire pass manager rewrite. A CGSCC transform is able to query for
multiple different function's analysis results. It works. The whole
thing appears to actually work and accomplish the original goal. While
we were able to hack function attrs and basic-aa to "work" in the old
pass manager, this port doesn't use any of that, it directly leverages
the new fundamental functionality.

For this to work, the CGSCC framework also has to support SCC-based
behavior analysis, etc. The only part of the CGSCC pass infrastructure
not sorted out at this point are the updates in the face of inlining and
running function passes that mutate the call graph.

The changes are pretty boring and boiler-plate. Most of the work was
factored into more focused preperatory patches. But this is what wires
it all together.

llvm-svn: 261203

4 files changed, 48 insertions, 11 deletions

diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index d350a73980e..3c449427520 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -231,7 +231,7 @@ void initializePostDomOnlyViewerPass(PassRegistry&);
 void initializePostDomPrinterPass(PassRegistry&);
 void initializePostDomViewerPass(PassRegistry&);
 void initializePostDominatorTreePass(PassRegistry&);
-void initializePostOrderFunctionAttrsPass(PassRegistry&);
+void initializePostOrderFunctionAttrsLegacyPassPass(PassRegistry&);
 void initializePostRASchedulerPass(PassRegistry&);
 void initializePostMachineSchedulerPass(PassRegistry&);
 void initializePrintFunctionPassWrapperPass(PassRegistry&);
diff --git a/llvm/include/llvm/LinkAllPasses.h b/llvm/include/llvm/LinkAllPasses.h
index 887cef64d06..91d70f4814a 100644
--- a/llvm/include/llvm/LinkAllPasses.h
+++ b/llvm/include/llvm/LinkAllPasses.h
@@ -36,6 +36,7 @@
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/FunctionAttrs.h"
 #include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
@@ -159,7 +160,7 @@ namespace {
       (void) llvm::createPostDomTree();
       (void) llvm::createInstructionNamerPass();
       (void) llvm::createMetaRenamerPass();
-      (void) llvm::createPostOrderFunctionAttrsPass();
+      (void) llvm::createPostOrderFunctionAttrsLegacyPass();
       (void) llvm::createReversePostOrderFunctionAttrsPass();
       (void) llvm::createMergeFunctionsPass();
       std::string buf;
diff --git a/llvm/include/llvm/Transforms/IPO.h b/llvm/include/llvm/Transforms/IPO.h
index 6d0f9eaefb7..5a12de55d38 100644
--- a/llvm/include/llvm/Transforms/IPO.h
+++ b/llvm/include/llvm/Transforms/IPO.h
@@ -188,15 +188,6 @@ ModulePass *createBlockExtractorPass();
 ModulePass *createStripDeadPrototypesPass();
 
 //===----------------------------------------------------------------------===//
-/// createPostOrderFunctionAttrsPass - This pass walks SCCs of the call graph
-/// in post-order to deduce and propagate function attributes. It can discover
-/// functions that do not access memory, or only read memory, and give them the
-/// readnone/readonly attribute. It also discovers function arguments that are
-/// not captured by the function and marks them with the nocapture attribute.
-///
-Pass *createPostOrderFunctionAttrsPass();
-
-//===----------------------------------------------------------------------===//
 /// createReversePostOrderFunctionAttrsPass - This pass walks SCCs of the call
 /// graph in RPO to deduce and propagate function attributes. Currently it
 /// only handles synthesizing norecurse attributes.
diff --git a/llvm/include/llvm/Transforms/IPO/FunctionAttrs.h b/llvm/include/llvm/Transforms/IPO/FunctionAttrs.h
new file mode 100644
index 00000000000..ad3c603a36d
--- /dev/null
+++ b/llvm/include/llvm/Transforms/IPO/FunctionAttrs.h
@@ -0,0 +1,45 @@
+//===-- FunctionAttrs.h - Compute function attrs --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// Provides passes for computing function attributes based on interprocedural
+/// analyses.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H
+#define LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H
+
+#include "llvm/Analysis/LazyCallGraph.h"
+#include "llvm/Analysis/CGSCCPassManager.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// Computes function attributes in post-order over the call graph.
+///
+/// By operating in post-order, this pass computes precise attributes for
+/// called functions prior to processsing their callers. This "bottom-up"
+/// approach allows powerful interprocedural inference of function attributes
+/// like memory access patterns, etc. It can discover functions that do not
+/// access memory, or only read memory, and give them the readnone/readonly
+/// attribute. It also discovers function arguments that are not captured by
+/// the function and marks them with the nocapture attribute.
+class PostOrderFunctionAttrsPass {
+public:
+  static StringRef name() { return "PostOrderFunctionAttrsPass"; }
+
+  PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager *AM);
+};
+
+/// Create a legacy pass manager instance of a pass to compute function attrs
+/// in post-order.
+Pass *createPostOrderFunctionAttrsLegacyPass();
+
+}
+
+#endif // LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H