[PATCH] D12053: [Polly] Workaround for SDiv/SRem referenced from SCEVExpander

[Johannes Doerfert via llvm-commits]

jdoerfert added a comment.

Some initial questions to get an idea of this patch.


================
Comment at: lib/CodeGen/IslNodeBuilder.cpp:58
@@ -53,1 +57,3 @@
+}
+
 __isl_give isl_ast_expr *
----------------
Why do we need this?

================
Comment at: lib/CodeGen/IslNodeBuilder.cpp:724
@@ +723,3 @@
+      if (isa<SDivOperator>(Inst) || isa<SRemOperator>(Inst))
+        Worklist.push_back(&cast<Instruction>(Inst));
+    }
----------------
What type does Inst have if not Instruction &?

================
Comment at: lib/CodeGen/IslNodeBuilder.cpp:731
@@ +730,3 @@
+    if (ValueReplacer.count(Item))
+      continue; // Already processed
+
----------------
How can we look at an instruction twice (if we always copy the instruction as noted below)?

================
Comment at: lib/CodeGen/IslNodeBuilder.cpp:737
@@ +736,3 @@
+      continue;
+
+    bool DepWithinRegion = false;
----------------
Can we just copy it without all the checks if we can move it?


http://reviews.llvm.org/D12053