From 56d7bc03dd465434eef03ac6f86e9f4e4ae1ca6a Mon Sep 17 00:00:00 2001
From: Andreas Bolka <a@bolka.at>
Date: Thu, 30 Jul 2009 02:26:01 +0000
Subject: [PATCH] Equal SCEVs of a subscript give rise to dependence.

llvm-svn: 77570
---
 lib/Analysis/LoopDependenceAnalysis.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/Analysis/LoopDependenceAnalysis.cpp b/lib/Analysis/LoopDependenceAnalysis.cpp
index 51f6c3aafd9..0c8bbd7a568 100644
--- a/lib/Analysis/LoopDependenceAnalysis.cpp
+++ b/lib/Analysis/LoopDependenceAnalysis.cpp
@@ -127,7 +127,17 @@ LoopDependenceAnalysis::DependenceResult
 LoopDependenceAnalysis::analyseSubscript(const SCEV *A,
                                          const SCEV *B,
                                          Subscript *S) const {
-  return Unknown; // TODO: Implement.
+  DEBUG(errs() << "  Testing subscript: " << *A << ", " << *B << "\n");
+
+  if (A == B) {
+    DEBUG(errs() << "  -> [D] same SCEV\n");
+    return Dependent;
+  }
+
+  // TODO: Implement ZIV/SIV/MIV testers.
+
+  DEBUG(errs() << "  -> [?] cannot analyse subscript\n");
+  return Unknown;
 }
 
 LoopDependenceAnalysis::DependenceResult