From 04b909fccaa4741901cb39c486dda7e9e2345114 Mon Sep 17 00:00:00 2001
From: Tobias Grosser <tobias@grosser.es>
Date: Thu, 21 Jul 2016 13:15:51 +0000
Subject: [PATCH] IslExprBuilder: allow to specify an external isl_id to
 ScopArrayInfo mapping

This is useful for external users using IslExprBuilder, in case they cannot
embed ScopArrayInfo data into their isl_ids, because the isl_ids either already
carry other information or the isl_ids have been created and their user pointers
cannot be updated any more.

llvm-svn: 276268
---
 polly/include/polly/CodeGen/IslExprBuilder.h | 20 ++++++++++++++++++++
 polly/lib/CodeGen/IslExprBuilder.cpp         | 13 ++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/polly/include/polly/CodeGen/IslExprBuilder.h b/polly/include/polly/CodeGen/IslExprBuilder.h
index 12ed91518ca4..b9e6c38fb9ea 100644
--- a/polly/include/polly/CodeGen/IslExprBuilder.h
+++ b/polly/include/polly/CodeGen/IslExprBuilder.h
@@ -39,6 +39,7 @@ public:
 } // namespace llvm
 
 namespace polly {
+class ScopArrayInfo;
 
 /// @brief LLVM-IR generator for isl_ast_expr[essions]
 ///
@@ -92,6 +93,25 @@ public:
   /// @brief A map from isl_ids to llvm::Values.
   typedef llvm::MapVector<isl_id *, llvm::AssertingVH<llvm::Value>> IDToValueTy;
 
+  typedef llvm::MapVector<isl_id *, const ScopArrayInfo *> IDToScopArrayInfoTy;
+
+  /// @brief A map from isl_ids to ScopArrayInfo objects.
+  ///
+  /// This map is used to obtain ScopArrayInfo objects for isl_ids which do not
+  /// carry a ScopArrayInfo object in their user pointer. This is useful if the
+  /// construction of ScopArrayInfo objects happens only after references (e.g.
+  /// in an AST) to an isl_id are generated and the user pointer of the isl_id
+  /// can not be changed any more.
+  ///
+  /// This is useful for external users who just use the IslExprBuilder for
+  /// code generation.
+  IDToScopArrayInfoTy *IDToSAI = nullptr;
+
+  /// @brief Set the isl_id to ScopArrayInfo map.
+  ///
+  /// @param NewIDToSAI The new isl_id to ScopArrayInfo map to use.
+  void setIDToSAI(IDToScopArrayInfoTy *NewIDToSAI) { IDToSAI = NewIDToSAI; }
+
   /// @brief Construct an IslExprBuilder.
   ///
   /// @param Builder The IRBuilder used to construct the isl_ast_expr[ession].
diff --git a/polly/lib/CodeGen/IslExprBuilder.cpp b/polly/lib/CodeGen/IslExprBuilder.cpp
index e7f8de2ba0df..75e35076ddee 100644
--- a/polly/lib/CodeGen/IslExprBuilder.cpp
+++ b/polly/lib/CodeGen/IslExprBuilder.cpp
@@ -223,7 +223,18 @@ Value *IslExprBuilder::createAccessAddress(isl_ast_expr *Expr) {
   BaseId = isl_ast_expr_get_id(BaseExpr);
   isl_ast_expr_free(BaseExpr);
 
-  const ScopArrayInfo *SAI = ScopArrayInfo::getFromId(BaseId);
+  const ScopArrayInfo *SAI = nullptr;
+
+  if (IDToSAI)
+    SAI = (*IDToSAI)[BaseId];
+
+  if (!SAI)
+    SAI = ScopArrayInfo::getFromId(BaseId);
+  else
+    isl_id_free(BaseId);
+
+  assert(SAI && "No ScopArrayInfo found for this isl_id.");
+
   Base = SAI->getBasePtr();
 
   if (auto NewBase = GlobalMap.lookup(Base))