[Polly][NFC] Partially refactoring of IslAstInfo and IslNodeBuilder to use isl++

[patacca]

Summary

Polly use algorithms from the Integer Set Library (isl), which is a library written in C and which is incompatible with the rest of the LLVM as it is written in C++.

Changes made:

• Refactoring the following methods of class IslAstInfo
  • isParallel() isExecutedInParallel() isReductionParallel() getSchedule() getMinimalDependenceDistance() getBrokenReductions()
• Refactoring the following methods of class IslNodeBuilder
  • getReferencesInSubtree() getScheduleForAstNode()
• Refactoring function getBrokenReductionsStr()
• Fixed the mismatching function declaration for getScheduleForAstNode()

[patacca]

[Polly] Using is_null() from C++ isl bindings

EDIT: This is an erroneous diff. Please ignore it

[patacca]

Using is_null() from isl C++ bindings.
The previous diff was erroneous.

EDIT: This is an erroneous diff. Please ignore it

[patacca]

Using is_null() from isl C++ bindings.

EDIT: This is an erroneous diff. Please ignore it

[patacca]

I had some difficulties with arcanist. This is the right diff.

Changes made:

• Refactoring isParallel() isExecutedInParallel() isReductionParallel() getSchedule() getBrokenReductions() getReferencesInSubtree() getScheduleForAstNode() getBrokenReductionsStr() to take C++ bindings instead of the plain isl C api.
• Fixed the mismatching function declaration for getScheduleForAstNode()
• Using is_null() from isl C++ bindings

[patacca]

Refactoring method getMinimalDependenceDistance()

[Meinersbur]

Thank. Patch itself looks good.

Could you remove the duplicate the repeated title from the summary and append NFC. to the title? (I think I forgot to mention this in the last commit).

Would you like me to push this patch to main?

[patacca]

Changes done.
Please go ahead and push it

polly/lib/CodeGen/IslNodeBuilder.cpp

void IslNodeBuilder::createForVector(__isl_take isl_ast_node *For,
 
   std::vector<Value *> IVS(VectorWidth);
   IVS[0] = ValueLB;
 
   for (int i = 1; i < VectorWidth; i++)
     IVS[i] = Builder.CreateAdd(IVS[i - 1], ValueInc, "p_vector_iv");
 
   isl::union_map Schedule = getScheduleForAstNode(isl::manage_copy(For));
-  assert(Schedule.get() &&
+  assert(!Schedule.is_null() &&
          "For statement annotation does not contain its schedule");
 
   IDToValue[IteratorID] = ValueLB;
 
   switch (isl_ast_node_get_type(Body)) {
   case isl_ast_node_user:
     createUserVector(Body, IVS, isl_id_copy(IteratorID), Schedule.copy());
     break;