[polly] migrate -polly-show to the new pass manager

[Meinersbur]

polly/lib/Support/RegisterPasses.cpp

333–340

The legacy pass manger is till present and people are still using it (which includes me). That is, the old functionality should not be removed, especially without giving any notification (such as report_fatal_error as with the NPM).

In other places, common code was extracted into a separate function such as runSimplifyUsingNPM or wrapper passes provided. Could you do the same?

[YangKeao]

Restore the pass of legacy pass manager.

[YangKeao]

Fixed in the newest diff.

[YangKeao]

Remove duplicated implementation

[YangKeao]

polly/include/polly/ScopGraphPrinter.h

53

I realized that this specialization doesn't take effect. I should use DOTGraphTraits<ScopDetection>.

[Meinersbur]

polly/include/polly/ScopGraphPrinter.h

53

Are you going to make this change?

[YangKeao]

polly/include/polly/ScopGraphPrinter.h

53

Yes. I'm doing it right now (after the Labor Day holiday 😄 )

[YangKeao]

fix and add test for the specialization

[YangKeao]

format codes

[Meinersbur]

When compiling under Windows with cmake -DPOLLY_ENABLE_GPGPU_CODEGEN=ON, I get a linker error:

Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTOnlyPrinterPass(void)" (?createDOTOnlyPrinterPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinki
ng::PollyForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTOnlyViewerPass(void)" (?createDOTOnlyViewerPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking
::PollyForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTPrinterPass(void)" (?createDOTPrinterPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking::Poll
yForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTViewerPass(void)" (?createDOTViewerPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking::PollyF
orcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
C:\Users\meinersbur\build\llvm-project\debug_vs17\Debug\bin\opt.exe : fatal error LNK1120: 4 unresolved externals [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]

I could not yet find a config that also fails under Linux, but it looks like some library dependencies are wrong.

polly/lib/Analysis/ScopGraphPrinter.cpp

73–76

I get a compiler error here:

/home/meinersbur/src/llvm-project/polly/lib/Analysis/ScopGraphPrinter.cpp:73:6: error: redeclaration of ‘static void llvm::DOTGraphTraits<polly::ScopDetection>::printRegionCluster(const polly::ScopDetection&, const llvm::Region*, llvm::raw_ostream&, unsigned int)’ may not have default arguments [-fpermissive]
   73 | void DOTGraphTraits<ScopDetection>::printRegionCluster(const ScopDetection &SD,
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The compiler is correct here, default parameters belong to the declaration, not definition. The pre-merge check does not seem to have caught this, maybe using a different compiler version (I am using gcc 11.2)

[YangKeao]

In D123678#3490386, @Meinersbur wrote:

When compiling under Windows with cmake -DPOLLY_ENABLE_GPGPU_CODEGEN=ON, I get a linker error:

Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTOnlyPrinterPass(void)" (?createDOTOnlyPrinterPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinki
ng::PollyForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTOnlyViewerPass(void)" (?createDOTOnlyViewerPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking
::PollyForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTPrinterPass(void)" (?createDOTPrinterPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking::Poll
yForcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
Polly.lib(PPCGCodeGeneration.obj) : error LNK2019: unresolved external symbol "class llvm::Pass * __cdecl polly::createDOTViewerPass(void)" (?createDOTViewerPass@polly@@YAPEAVPass@llvm@@XZ) referenced in function "public: __cdecl `anonymous namespace'::PollyForcePassLinking::PollyF
orcePassLinking(void)" (??0PollyForcePassLinking@?A0x3c23cca7@@QEAA@XZ) [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]
C:\Users\meinersbur\build\llvm-project\debug_vs17\Debug\bin\opt.exe : fatal error LNK1120: 4 unresolved externals [C:\Users\meinersbur\build\llvm-project\debug_vs17\tools\opt\opt.vcxproj]

I could not yet find a config that also fails under Linux, but it looks like some library dependencies are wrong.

Is it a clean build? I guess there are some cache breaks the linking. The function createDOTOnlyViewerPass is removed and replaced by createDOTOnlyViewerWrapperPass in this commit. Check the PollyForcePassLinking, it only calls the createDOTOnlyViewerWrapperPass.

I'm not sure whether this problem shows potential "dependencies issues" (as it seems failed to invalidate the cache) in the build system.

[YangKeao]

move the default parameters to the declaration

[YangKeao]

Nice catch. Fixed in the latest commit.

[Meinersbur]

llvm/include/llvm/Analysis/RegionPrinter.h

30 ↗

(On Diff #426927)

Nothing unusual of a declaration in RegionPrinter.h to be implemented in RegionPrinter.cpp.

polly/include/polly/ScopGraphPrinter.h

34

Looking at other specializations, all GraphTraits of an analysis are a pointer of the the analysis (GraphTraits<ScopDetection>). Why the change? I fear that GraphTraits users may accidentally try to copy the object.

63

Consider using llvm::StringRef

65–66

Use doxygen comments for API documentation.

polly/lib/Analysis/ScopGraphPrinter.cpp

95

Consider DOTGraphTraits<ScopDetection*>

[Meinersbur]

In D123678#3490391, @YangKeao wrote:

I'm not sure whether this problem shows potential "dependencies issues" (as it seems failed to invalidate the cache) in the build system.

This was correct. A clean build fixed the issue.

[YangKeao]

Use GraphTraits<ScopDetection *>, remove redundant comments

[YangKeao]

polly/include/polly/ScopGraphPrinter.h

34

Why the change?

Because we could get the reference to ScopDetection from FAM.getResult, and it's quite straightforward to pass the reference to everywhere.

I fear that GraphTraits users may accidentally try to copy the object.

When will it happen? The arguments of the functions are all passing through reference.

But as I'm not familiar with GraphTraits and its other usage, I think it's fine not to touch it in this commit. I will use GraphTraits<ScopDetection *> instead.

[Meinersbur]

LGTM. Thanks for your work! Do I have permission to commit for you?

[YangKeao]

In D123678#3497332, @Meinersbur wrote:

LGTM. Thanks for your work! Do I have permission to commit for you?

Yes. Please commit these two patches. Thank you 🍻

[RKSimon]

polly/include/polly/ScopGraphPrinter.h

29

@YangKeao Can you remove the 'using namespace' from the header and move them internally to each source file? This might be the cause of the namespace resolution build failures on:

https://github.com/compiler-explorer/compiler-workflows/runs/6452927622

[Meinersbur]

polly/include/polly/ScopGraphPrinter.h

29

I was just looking into it when I noticed you already changed it. Thanks you.

[phosek]

Polly :: ScopDetect/dot-scops-npm.ll test has been flaking on our bots since this change landed with the following test error:

Script:
--
: 'RUN: at line 1';   /opt/s/w/ir/x/w/staging/llvm_build/bin/opt  -polly-process-unprofitable  -polly-remarks-minimal  -polly-use-llvm-names  -polly-import-jscop-dir=/opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect  -polly-codegen-verify  "-passes=polly-scop-printer" -disable-output < /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll
: 'RUN: at line 2';   /opt/s/w/ir/x/w/staging/llvm_build/bin/FileCheck /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot
--
Exit Code: 2

Command Output (stderr):
--
Writing 'scops.func.dot'...
FileCheck error: 'scops.func.dot' is empty.
FileCheck command line:  /opt/s/w/ir/x/w/staging/llvm_build/bin/FileCheck /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot

--

Would it be possible to take a look?

[YangKeao]

In D123678#3538963, @phosek wrote:

Polly :: ScopDetect/dot-scops-npm.ll test has been flaking on our bots since this change landed with the following test error:

Script:
--
: 'RUN: at line 1';   /opt/s/w/ir/x/w/staging/llvm_build/bin/opt  -polly-process-unprofitable  -polly-remarks-minimal  -polly-use-llvm-names  -polly-import-jscop-dir=/opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect  -polly-codegen-verify  "-passes=polly-scop-printer" -disable-output < /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll
: 'RUN: at line 2';   /opt/s/w/ir/x/w/staging/llvm_build/bin/FileCheck /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot
--
Exit Code: 2

Command Output (stderr):
--
Writing 'scops.func.dot'...
FileCheck error: 'scops.func.dot' is empty.
FileCheck command line:  /opt/s/w/ir/x/w/staging/llvm_build/bin/FileCheck /opt/s/w/ir/x/w/llvm-llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot

--

Would it be possible to take a look?

@phosek Where can I find more information about the test execution? I want to know the platform, architecture, compiler...

I tried to execute the same command (with the latest llvm and polly) several times, but none of them produce this error.

@Meinersbur Do you have any idea about why it could fail or how to debug this problem 🤔 ?

[Meinersbur]

I could only observe a single failure with my own buildbot was assuming it was something else.

https://lab.llvm.org/buildbot/#/builders/10/builds/15406

******************** TEST 'Polly :: ScopDetect/dot-scops-npm.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   /home/worker/buildbot-workers/polly-x86_64-gce1/rundir/llvm.obj/bin/opt  -polly-process-unprofitable  -polly-remarks-minimal  -polly-use-llvm-names  -polly-import-jscop-dir=/home/worker/src/llvm-project/polly/test/ScopDetect  -polly-codegen-verify  "-passes=polly-scop-printer" -disable-output < /home/worker/src/llvm-project/polly/test/ScopDetect/dot-scops-npm.ll
: 'RUN: at line 2';   /home/worker/buildbot-workers/polly-x86_64-gce1/rundir/llvm.obj/bin/FileCheck /home/worker/src/llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot
--
Exit Code: 2
Command Output (stderr):
--
Writing 'scops.func.dot'...
FileCheck error: 'scops.func.dot' is empty.
FileCheck command line:  /home/worker/buildbot-workers/polly-x86_64-gce1/rundir/llvm.obj/bin/FileCheck /home/worker/src/llvm-project/polly/test/ScopDetect/dot-scops-npm.ll -input-file=scops.func.dot
--
********************

The test is suspicious in that it does not use %t for its temporary file, it could potentially clash with another test using the same file concurrently. I suspect it is ScopDetect/dot-scops-npm.ll. Don't we have a means to specify which file to write?

[Meinersbur]

polly/test/ScopDetect/dot-scops-npm.ll

32–60 ↗

(On Diff #428152)

CHECK_NEXT is uneffective. It was fixed in rGad1d60c3befd606d6864b367f939238e50fb0f7e.

[Meinersbur]

I hope I fixed the race condition issue in rGcc871cf6b50f6a76f2083d192e2254a16832224b. Another possibility would have been to put both tests into the same file.

polly/include/polly/LinkAllPasses.h

 llvm::Pass *createDependenceInfoWrapperPassPass();
 llvm::Pass *
 createDependenceInfoPrinterLegacyFunctionPass(llvm::raw_ostream &OS);
-llvm::Pass *createDOTOnlyPrinterPass();
-llvm::Pass *createDOTOnlyViewerPass();
-llvm::Pass *createDOTPrinterPass();
-llvm::Pass *createDOTViewerPass();
 llvm::Pass *createJSONExporterPass();
 llvm::Pass *createJSONImporterPass();
 llvm::Pass *createJSONImporterPrinterLegacyPass(llvm::raw_ostream &OS);

     polly::createDependenceInfoPrinterLegacyPass(llvm::outs());
     polly::createDependenceInfoWrapperPassPass();
     polly::createDependenceInfoPrinterLegacyFunctionPass(llvm::outs());
-    polly::createDOTOnlyPrinterPass();
-    polly::createDOTOnlyViewerPass();
-    polly::createDOTPrinterPass();
-    polly::createDOTViewerPass();
     polly::createJSONExporterPass();
     polly::createJSONImporterPass();
     polly::createJSONImporterPrinterLegacyPass(llvm::outs());

polly/include/polly/ScopGraphPrinter.h

+//===- GraphPrinter.h - Create a DOT output describing the Scop. ----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Create a DOT output describing the Scop.
+//
+// For each function a dot file is created that shows the control flow graph of
+// the function and highlights the detected Scops.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef POLLY_SCOP_GRAPH_PRINTER_H
+#define POLLY_SCOP_GRAPH_PRINTER_H
+
+#include "polly/ScopDetection.h"
+#include "polly/Support/ScopLocation.h"
+#include "llvm/Analysis/DOTGraphTraitsPass.h"
+#include "llvm/Analysis/RegionInfo.h"
+#include "llvm/Analysis/RegionIterator.h"
+#include "llvm/IR/PassManager.h"
+
+using namespace polly;
+using namespace llvm;
+
+namespace llvm {
+
+template <>
+struct GraphTraits<ScopDetection> : public GraphTraits<RegionInfo *> {
+  static NodeRef getEntryNode(const ScopDetection &SD) {
+    return GraphTraits<RegionInfo *>::getEntryNode(SD.getRI());
+  }
+  static nodes_iterator nodes_begin(const ScopDetection &SD) {
+    return nodes_iterator::begin(getEntryNode(SD));
+  }
+  static nodes_iterator nodes_end(const ScopDetection &SD) {
+    return nodes_iterator::end(getEntryNode(SD));
+  }
+};
+
+template <> struct DOTGraphTraits<RegionNode *> : public DefaultDOTGraphTraits {
+  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+
+  std::string getNodeLabel(RegionNode *Node, RegionNode *Graph);
+};
+
+template <>
+struct DOTGraphTraits<ScopDetection *> : public DOTGraphTraits<RegionNode *> {
+  DOTGraphTraits(bool isSimple = false)
+      : DOTGraphTraits<RegionNode *>(isSimple) {}
+  static std::string getGraphName(ScopDetection *SD) { return "Scop Graph"; }
+
+  std::string getEdgeAttributes(RegionNode *srcNode,
+                                GraphTraits<RegionInfo *>::ChildIteratorType CI,
+                                ScopDetection *SD);
+
+  std::string getNodeLabel(RegionNode *Node, ScopDetection *SD) {
+    return DOTGraphTraits<RegionNode *>::getNodeLabel(
+        Node, reinterpret_cast<RegionNode *>(SD->getRI()->getTopLevelRegion()));
+  }
+
+  static std::string escapeString(std::string String);
+
+  // Print the cluster of the subregions. This groups the single basic blocks
+  // and adds a different background color for each group.
+  static void printRegionCluster(ScopDetection *SD, const Region *R,
+                                 raw_ostream &O, unsigned depth);
+
+  static void addCustomGraphFeatures(ScopDetection *SD,
+                                     GraphWriter<ScopDetection> &GW);
+};
+} // end namespace llvm
+
+namespace polly {
+
+struct ScopViewer : public DOTGraphTraitsViewer<ScopAnalysis, false> {
+  ScopViewer() : DOTGraphTraitsViewer<ScopAnalysis, false>("scops") {}
+
+  bool processFunction(Function &F, const ScopDetection &SD) override;
+};
+
+struct ScopOnlyViewer : public DOTGraphTraitsViewer<ScopAnalysis, false> {
+  ScopOnlyViewer() : DOTGraphTraitsViewer<ScopAnalysis, false>("scops-only") {}
+};
+
+struct ScopPrinter : public DOTGraphTraitsPrinter<ScopAnalysis, false> {
+  ScopPrinter() : DOTGraphTraitsPrinter<ScopAnalysis, false>("scops") {}
+};
+
+struct ScopOnlyPrinter : public DOTGraphTraitsPrinter<ScopAnalysis, true> {
+  ScopOnlyPrinter() : DOTGraphTraitsPrinter<ScopAnalysis, true>("scopsonly") {}
+};
+
+} // end namespace polly
+
+#endif /* POLLY_SCOP_GRAPH_PRINTER_H */

polly/lib/Analysis/ScopGraphPrinter.cpp

 //
 //===----------------------------------------------------------------------===//
 
+#include "polly/ScopGraphPrinter.h"
 #include "polly/LinkAllPasses.h"
 #include "polly/ScopDetection.h"
-#include "polly/Support/ScopLocation.h"
-#include "llvm/Analysis/DOTGraphTraitsPass.h"
-#include "llvm/Analysis/RegionInfo.h"
-#include "llvm/Analysis/RegionIterator.h"
 #include "llvm/Support/CommandLine.h"
 
 using namespace polly;

                              cl::Hidden, cl::init(false), cl::ZeroOrMore);
 
 namespace llvm {
-template <>
-struct GraphTraits<ScopDetection *> : public GraphTraits<RegionInfo *> {
-  static NodeRef getEntryNode(ScopDetection *SD) {
-    return GraphTraits<RegionInfo *>::getEntryNode(SD->getRI());
-  }
-  static nodes_iterator nodes_begin(ScopDetection *SD) {
-    return nodes_iterator::begin(getEntryNode(SD));
-  }
-  static nodes_iterator nodes_end(ScopDetection *SD) {
-    return nodes_iterator::end(getEntryNode(SD));
-  }
-};
-
-template <>
-struct GraphTraits<ScopDetectionWrapperPass *>
-    : public GraphTraits<ScopDetection *> {
-  static NodeRef getEntryNode(ScopDetectionWrapperPass *P) {
-    return GraphTraits<ScopDetection *>::getEntryNode(&P->getSD());
-  }
-  static nodes_iterator nodes_begin(ScopDetectionWrapperPass *P) {
-    return nodes_iterator::begin(getEntryNode(P));
-  }
-  static nodes_iterator nodes_end(ScopDetectionWrapperPass *P) {
-    return nodes_iterator::end(getEntryNode(P));
-  }
-};
 
-template <> struct DOTGraphTraits<RegionNode *> : public DefaultDOTGraphTraits {
-  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+std::string DOTGraphTraits<RegionNode *>::getNodeLabel(RegionNode *Node,
+                                                       RegionNode *Graph) {
+  if (!Node->isSubRegion()) {
+    BasicBlock *BB = Node->getNodeAs<BasicBlock>();
 
-  std::string getNodeLabel(RegionNode *Node, RegionNode *Graph) {
-    if (!Node->isSubRegion()) {
-      BasicBlock *BB = Node->getNodeAs<BasicBlock>();
+    if (isSimple())
+      return DOTGraphTraits<DOTFuncInfo *>::getSimpleNodeLabel(BB, nullptr);
 
-      if (isSimple())
-        return DOTGraphTraits<DOTFuncInfo *>::getSimpleNodeLabel(BB, nullptr);
-
-      else
-        return DOTGraphTraits<DOTFuncInfo *>::getCompleteNodeLabel(BB, nullptr);
-    }
-
-    return "Not implemented";
-  }
-};
-
-template <>
-struct DOTGraphTraits<ScopDetectionWrapperPass *>
-    : public DOTGraphTraits<RegionNode *> {
-  DOTGraphTraits(bool isSimple = false)
-      : DOTGraphTraits<RegionNode *>(isSimple) {}
-  static std::string getGraphName(ScopDetectionWrapperPass *SD) {
-    return "Scop Graph";
+    else
+      return DOTGraphTraits<DOTFuncInfo *>::getCompleteNodeLabel(BB, nullptr);
   }
 
-  std::string getEdgeAttributes(RegionNode *srcNode,
-                                GraphTraits<RegionInfo *>::ChildIteratorType CI,
-                                ScopDetectionWrapperPass *P) {
-    RegionNode *destNode = *CI;
-    auto *SD = &P->getSD();
-
-    if (srcNode->isSubRegion() || destNode->isSubRegion())
-      return "";
-
-    // In case of a backedge, do not use it to define the layout of the nodes.
-    BasicBlock *srcBB = srcNode->getNodeAs<BasicBlock>();
-    BasicBlock *destBB = destNode->getNodeAs<BasicBlock>();
-
-    RegionInfo *RI = SD->getRI();
-    Region *R = RI->getRegionFor(destBB);
+  return "Not implemented";
+}
 
-    while (R && R->getParent())
-      if (R->getParent()->getEntry() == destBB)
-        R = R->getParent();
-      else
-        break;
-
-    if (R && R->getEntry() == destBB && R->contains(srcBB))
-      return "constraint=false";
+std::string DOTGraphTraits<ScopDetection *>::getEdgeAttributes(
+    RegionNode *srcNode, GraphTraits<RegionInfo *>::ChildIteratorType CI,
+    ScopDetection *SD) {
+  RegionNode *destNode = *CI;
 
+  if (srcNode->isSubRegion() || destNode->isSubRegion())
     return "";
-  }
-
-  std::string getNodeLabel(RegionNode *Node, ScopDetectionWrapperPass *P) {
-    return DOTGraphTraits<RegionNode *>::getNodeLabel(
-        Node, reinterpret_cast<RegionNode *>(
-                  P->getSD().getRI()->getTopLevelRegion()));
-  }
 
-  static std::string escapeString(std::string String) {
-    std::string Escaped;
-
-    for (const auto &C : String) {
-      if (C == '"')
-        Escaped += '\\';
-
-      Escaped += C;
-    }
-    return Escaped;
-  }
+  // In case of a backedge, do not use it to define the layout of the nodes.
+  BasicBlock *srcBB = srcNode->getNodeAs<BasicBlock>();
+  BasicBlock *destBB = destNode->getNodeAs<BasicBlock>();
 
-  // Print the cluster of the subregions. This groups the single basic blocks
-  // and adds a different background color for each group.
-  static void printRegionCluster(ScopDetection *SD, const Region *R,
-                                 raw_ostream &O, unsigned depth = 0) {
-    O.indent(2 * depth) << "subgraph cluster_" << static_cast<const void *>(R)
-                        << " {\n";
-    unsigned LineBegin, LineEnd;
-    std::string FileName;
+  RegionInfo *RI = SD->getRI();
+  Region *R = RI->getRegionFor(destBB);
 
-    getDebugLocation(R, LineBegin, LineEnd, FileName);
+  while (R && R->getParent())
+    if (R->getParent()->getEntry() == destBB)
+      R = R->getParent();
+    else
+      break;
 
-    std::string Location;
-    if (LineBegin != (unsigned)-1) {
-      Location = escapeString(FileName + ":" + std::to_string(LineBegin) + "-" +
-                              std::to_string(LineEnd) + "\n");
-    }
+  if (R && R->getEntry() == destBB && R->contains(srcBB))
+    return "constraint=false";
 
-    std::string ErrorMessage = SD->regionIsInvalidBecause(R);
-    ErrorMessage = escapeString(ErrorMessage);
-    O.indent(2 * (depth + 1))
-        << "label = \"" << Location << ErrorMessage << "\";\n";
+  return "";
+}
 
-    if (SD->isMaxRegionInScop(*R)) {
-      O.indent(2 * (depth + 1)) << "style = filled;\n";
+std::string DOTGraphTraits<ScopDetection *>::escapeString(std::string String) {
+  std::string Escaped;
 
-      // Set color to green.
-      O.indent(2 * (depth + 1)) << "color = 3";
-    } else {
-      O.indent(2 * (depth + 1)) << "style = solid;\n";
+  for (const auto &C : String) {
+    if (C == '"')
+      Escaped += '\\';
 
-      int color = (R->getDepth() * 2 % 12) + 1;
+    Escaped += C;
+  }
+  return Escaped;
+}
+
+void DOTGraphTraits<ScopDetection *>::printRegionCluster(ScopDetection *SD,
+                                                         const Region *R,
+                                                         raw_ostream &O,
+                                                         unsigned depth = 0) {
+  O.indent(2 * depth) << "subgraph cluster_" << static_cast<const void *>(R)
+                      << " {\n";
+  unsigned LineBegin, LineEnd;
+  std::string FileName;
+
+  getDebugLocation(R, LineBegin, LineEnd, FileName);
+
+  std::string Location;
+  if (LineBegin != (unsigned)-1) {
+    Location = escapeString(FileName + ":" + std::to_string(LineBegin) + "-" +
+                            std::to_string(LineEnd) + "\n");
+  }
 
-      // We do not want green again.
-      if (color == 3)
-        color = 6;
+  std::string ErrorMessage = SD->regionIsInvalidBecause(R);
+  ErrorMessage = escapeString(ErrorMessage);
+  O.indent(2 * (depth + 1))
+      << "label = \"" << Location << ErrorMessage << "\";\n";
 
-      O.indent(2 * (depth + 1)) << "color = " << color << "\n";
-    }
+  if (SD->isMaxRegionInScop(*R)) {
+    O.indent(2 * (depth + 1)) << "style = filled;\n";
 
-    for (const auto &SubRegion : *R)
-      printRegionCluster(SD, SubRegion.get(), O, depth + 1);
+    // Set color to green.
+    O.indent(2 * (depth + 1)) << "color = 3";
+  } else {
+    O.indent(2 * (depth + 1)) << "style = solid;\n";
 
-    RegionInfo *RI = R->getRegionInfo();
+    int color = (R->getDepth() * 2 % 12) + 1;
 
-    for (BasicBlock *BB : R->blocks())
-      if (RI->getRegionFor(BB) == R)
-        O.indent(2 * (depth + 1))
-            << "Node"
-            << static_cast<void *>(RI->getTopLevelRegion()->getBBNode(BB))
-            << ";\n";
+    // We do not want green again.
+    if (color == 3)
+      color = 6;
 
-    O.indent(2 * depth) << "}\n";
-  }
-  static void
-  addCustomGraphFeatures(const ScopDetectionWrapperPass *SD,
-                         GraphWriter<ScopDetectionWrapperPass *> &GW) {
-    raw_ostream &O = GW.getOStream();
-    O << "\tcolorscheme = \"paired12\"\n";
-    printRegionCluster(&SD->getSD(), SD->getSD().getRI()->getTopLevelRegion(),
-                       O, 4);
+    O.indent(2 * (depth + 1)) << "color = " << color << "\n";
   }
-};
-} // end namespace llvm
-
-struct ScopViewer
-    : public DOTGraphTraitsViewer<ScopDetectionWrapperPass, false> {
-  static char ID;
-  ScopViewer()
-      : DOTGraphTraitsViewer<ScopDetectionWrapperPass, false>("scops", ID) {}
-  bool processFunction(Function &F, ScopDetectionWrapperPass &SD) override {
-    if (ViewFilter != "" && !F.getName().count(ViewFilter))
-      return false;
-
-    if (ViewAll)
-      return true;
-
-    // Check that at least one scop was detected.
-    return std::distance(SD.getSD().begin(), SD.getSD().end()) > 0;
-  }
-};
-char ScopViewer::ID = 0;
-
-struct ScopOnlyViewer
-    : public DOTGraphTraitsViewer<ScopDetectionWrapperPass, true> {
-  static char ID;
-  ScopOnlyViewer()
-      : DOTGraphTraitsViewer<ScopDetectionWrapperPass, true>("scopsonly", ID) {}
-};
-char ScopOnlyViewer::ID = 0;
-
-struct ScopPrinter
-    : public DOTGraphTraitsPrinter<ScopDetectionWrapperPass, false> {
-  static char ID;
-  ScopPrinter()
-      : DOTGraphTraitsPrinter<ScopDetectionWrapperPass, false>("scops", ID) {}
-};
-char ScopPrinter::ID = 0;
-
-struct ScopOnlyPrinter
-    : public DOTGraphTraitsPrinter<ScopDetectionWrapperPass, true> {
-  static char ID;
-  ScopOnlyPrinter()
-      : DOTGraphTraitsPrinter<ScopDetectionWrapperPass, true>("scopsonly", ID) {
-  }
-};
-char ScopOnlyPrinter::ID = 0;
 
-static RegisterPass<ScopViewer> X("view-scops",
-                                  "Polly - View Scops of function");
+  for (const auto &SubRegion : *R)
+    printRegionCluster(SD, SubRegion.get(), O, depth + 1);
+
+  RegionInfo *RI = R->getRegionInfo();
 
-static RegisterPass<ScopOnlyViewer>
-    Y("view-scops-only",
-      "Polly - View Scops of function (with no function bodies)");
+  for (BasicBlock *BB : R->blocks())
+    if (RI->getRegionFor(BB) == R)
+      O.indent(2 * (depth + 1))
+          << "Node"
+          << static_cast<void *>(RI->getTopLevelRegion()->getBBNode(BB))
+          << ";\n";
 
-static RegisterPass<ScopPrinter> M("dot-scops",
-                                   "Polly - Print Scops of function");
+  O.indent(2 * depth) << "}\n";
+}
 
-static RegisterPass<ScopOnlyPrinter>
-    N("dot-scops-only",
-      "Polly - Print Scops of function (with no function bodies)");
+void DOTGraphTraits<ScopDetection *>::addCustomGraphFeatures(
+    ScopDetection *SD, GraphWriter<ScopDetection> &GW) {
+  raw_ostream &O = GW.getOStream();
+  O << "\tcolorscheme = \"paired12\"\n";
+  printRegionCluster(SD, SD->getRI()->getTopLevelRegion(), O, 4);
+}
 
-Pass *polly::createDOTViewerPass() { return new ScopViewer(); }
+} // namespace llvm
 
-Pass *polly::createDOTOnlyViewerPass() { return new ScopOnlyViewer(); }
+bool ScopViewer::processFunction(Function &F, const ScopDetection &SD) {
+  if (ViewFilter != "" && !F.getName().count(ViewFilter))
+    return false;
 
-Pass *polly::createDOTPrinterPass() { return new ScopPrinter(); }
+  if (ViewAll)
+    return true;
 
-Pass *polly::createDOTOnlyPrinterPass() { return new ScopOnlyPrinter(); }
+  // Check that at least one scop was detected.
+  return std::distance(SD.begin(), SD.end()) > 0;
+}

polly/lib/Support/PollyPasses.def

 FUNCTION_PASS("polly-prepare", CodePreparationPass())
 FUNCTION_PASS("print<polly-detect>", ScopAnalysisPrinterPass(llvm::errs()))
 FUNCTION_PASS("print<polly-function-scops>", ScopInfoPrinterPass(llvm::errs()))
+FUNCTION_PASS("polly-scop-viewer", ScopViewer())
+FUNCTION_PASS("polly-scop-only-viewer", ScopOnlyViewer())
+FUNCTION_PASS("polly-scop-printer", ScopPrinter())
+FUNCTION_PASS("polly-scop-only-printer", ScopOnlyPrinter())
 #undef FUNCTION_PASS
 
 #ifndef SCOP_ANALYSIS

polly/lib/Support/RegisterPasses.cpp

 #include "polly/PruneUnprofitable.h"
 #include "polly/ScheduleOptimizer.h"
 #include "polly/ScopDetection.h"
+#include "polly/ScopGraphPrinter.h"
 #include "polly/ScopInfo.h"
 #include "polly/Simplify.h"
 #include "polly/Support/DumpFunctionPass.h"

   if (PollyDetectOnly)
     return;
 
-  if (PollyViewer)
-    PM.add(polly::createDOTViewerPass());
-  if (PollyOnlyViewer)
-    PM.add(polly::createDOTOnlyViewerPass());
-  if (PollyPrinter)
-    PM.add(polly::createDOTPrinterPass());
-  if (PollyOnlyPrinter)
-    PM.add(polly::createDOTOnlyPrinterPass());
-
   PM.add(polly::createScopInfoRegionPassPass());
   if (EnablePolyhedralInfo)
     PM.add(polly::createPolyhedralInfoPass());

   }
 
   if (PollyViewer)
-    llvm::report_fatal_error("Option -polly-show not supported with NPM",
-                             false);
+    PM.addPass(ScopViewer());
   if (PollyOnlyViewer)
-    llvm::report_fatal_error("Option -polly-show-only not supported with NPM",
-                             false);
+    PM.addPass(ScopOnlyViewer());
   if (PollyPrinter)
-    llvm::report_fatal_error("Option -polly-dot not supported with NPM", false);
+    PM.addPass(ScopPrinter());
   if (PollyOnlyPrinter)
-    llvm::report_fatal_error("Option -polly-dot-only not supported with NPM",
-                             false);
+    PM.addPass(ScopOnlyPrinter());
   if (EnablePolyhedralInfo)
     llvm::report_fatal_error(
         "Option -polly-enable-polyhedralinfo not supported with NPM", false);

polly/test/ScopDetect/dot-scops.ll

-; RUN: opt %loadPolly -polly-scops -dot-scops -disable-output < %s
+; RUN: opt %loadPolly "-passes=polly-scop-viewer" -disable-output < %s
 ;
 ; Check that the ScopPrinter does not crash.
 ; ScopPrinter needs the ScopDetection pass, which should depend on