From ed87831113c0edf32eb5c0e4d2e1f5d7d2f3d2a9 Mon Sep 17 00:00:00 2001
From: Johannes Doerfert <jdoerfert@codeaurora.org>
Date: Sun, 3 Aug 2014 01:50:50 +0000
Subject: [PATCH] Allow the IslExprBuilder to generate access operations

llvm-svn: 214658
---
 polly/include/polly/CodeGen/IslExprBuilder.h |  1 +
 polly/lib/CodeGen/IslExprBuilder.cpp         | 35 +++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/polly/include/polly/CodeGen/IslExprBuilder.h b/polly/include/polly/CodeGen/IslExprBuilder.h
index f8eb6fa8d772..c87cd5725e82 100644
--- a/polly/include/polly/CodeGen/IslExprBuilder.h
+++ b/polly/include/polly/CodeGen/IslExprBuilder.h
@@ -120,6 +120,7 @@ private:
 
   llvm::Value *createOp(__isl_take isl_ast_expr *Expr);
   llvm::Value *createOpUnary(__isl_take isl_ast_expr *Expr);
+  llvm::Value *createOpAccess(__isl_take isl_ast_expr *Expr);
   llvm::Value *createOpBin(__isl_take isl_ast_expr *Expr);
   llvm::Value *createOpNAry(__isl_take isl_ast_expr *Expr);
   llvm::Value *createOpSelect(__isl_take isl_ast_expr *Expr);
diff --git a/polly/lib/CodeGen/IslExprBuilder.cpp b/polly/lib/CodeGen/IslExprBuilder.cpp
index 6275c1439d40..8890e4552805 100644
--- a/polly/lib/CodeGen/IslExprBuilder.cpp
+++ b/polly/lib/CodeGen/IslExprBuilder.cpp
@@ -91,6 +91,38 @@ Value *IslExprBuilder::createOpNAry(__isl_take isl_ast_expr *Expr) {
   return V;
 }
 
+Value *IslExprBuilder::createOpAccess(isl_ast_expr *Expr) {
+  assert(isl_ast_expr_get_type(Expr) == isl_ast_expr_op &&
+         "isl ast expression not of type isl_ast_op");
+  assert(isl_ast_expr_get_op_type(Expr) == isl_ast_op_access &&
+         "not an access isl ast expression");
+  assert(isl_ast_expr_get_op_n_arg(Expr) >= 2 &&
+         "We need at least two operands to create a member access.");
+
+  // TODO: Support for multi-dimensional array.
+  assert(isl_ast_expr_get_op_n_arg(Expr) == 2 &&
+         "Multidimensional access functions are not supported yet");
+
+  Value *Base = create(isl_ast_expr_get_op_arg(Expr, 0));
+  assert(Base->getType()->isPointerTy() && "Access base should be a pointer");
+
+  Value *Index = create(isl_ast_expr_get_op_arg(Expr, 1));
+  assert(Index->getType()->isIntegerTy() &&
+         "Access index should be an integer");
+
+  // TODO: Change the type of base before we create the GEP.
+  Type *PtrElTy = Base->getType()->getPointerElementType();
+  assert((PtrElTy->isIntOrIntVectorTy() || PtrElTy->isFPOrFPVectorTy()) &&
+         "We do not yet change the type of the access base during code "
+         "generation.");
+
+  Twine Name = "polly.access." + Base->getName();
+  Value *Access = Builder.CreateGEP(Base, Index, Name);
+
+  isl_ast_expr_free(Expr);
+  return Access;
+}
+
 Value *IslExprBuilder::createOpBin(__isl_take isl_ast_expr *Expr) {
   Value *LHS, *RHS, *Res;
   Type *MaxType;
@@ -303,8 +335,9 @@ Value *IslExprBuilder::createOp(__isl_take isl_ast_expr *Expr) {
   case isl_ast_op_or_else:
   case isl_ast_op_call:
   case isl_ast_op_member:
-  case isl_ast_op_access:
     llvm_unreachable("Unsupported isl ast expression");
+  case isl_ast_op_access:
+    return createOpAccess(Expr);
   case isl_ast_op_max:
   case isl_ast_op_min:
     return createOpNAry(Expr);