From ab37f50838350e1104579fbd1f7c8820473485a5 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Mon, 2 Aug 2010 23:49:30 +0000
Subject: Make SCEVUnknown a CallbackVH, so that it can be notified directly of
 Value deletions and RAUWs, instead of relying on ScalarEvolution's Scalars
 map being notified, as that's complicated at best, and insufficient in
 general.

This means SCEVUnknown needs a non-trivial destructor, so introduce
a mechanism to allow ScalarEvolution to locate all the SCEVUnknowns.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110086 91177308-0d34-0410-b5e6-96231b3b80d8
---
 unittests/Analysis/Makefile                | 15 ++++++
 unittests/Analysis/ScalarEvolutionTest.cpp | 82 ++++++++++++++++++++++++++++++
 unittests/Makefile                         |  2 +-
 3 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 unittests/Analysis/Makefile
 create mode 100644 unittests/Analysis/ScalarEvolutionTest.cpp

(limited to 'unittests')

diff --git a/unittests/Analysis/Makefile b/unittests/Analysis/Makefile
new file mode 100644
index 0000000000..f89240ec70
--- /dev/null
+++ b/unittests/Analysis/Makefile
@@ -0,0 +1,15 @@
+##===- unittests/Analysis/Makefile -------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+TESTNAME = Analysis
+LINK_COMPONENTS := core support target analysis ipa
+
+include $(LEVEL)/Makefile.config
+include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
diff --git a/unittests/Analysis/ScalarEvolutionTest.cpp b/unittests/Analysis/ScalarEvolutionTest.cpp
new file mode 100644
index 0000000000..b7341603cf
--- /dev/null
+++ b/unittests/Analysis/ScalarEvolutionTest.cpp
@@ -0,0 +1,82 @@
+//===- ScalarEvolutionsTest.cpp - ScalarEvolution unit tests --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <llvm/Analysis/ScalarEvolutionExpressions.h>
+#include <llvm/GlobalVariable.h>
+#include <llvm/Constants.h>
+#include <llvm/LLVMContext.h>
+#include <llvm/Module.h>
+#include <llvm/PassManager.h>
+#include "gtest/gtest.h"
+
+namespace llvm {
+namespace {
+
+TEST(ScalarEvolutionsTest, SCEVUnknownRAUW) {
+  LLVMContext Context;
+  Module M("world", Context);
+
+  const FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
+                                              std::vector<const Type *>(), false);
+  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
+  ReturnInst::Create(Context, 0, BB);
+
+  const Type *Ty = Type::getInt1Ty(Context);
+  Constant *Init = Constant::getNullValue(Ty);
+  Value *V0 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V0");
+  Value *V1 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V1");
+  Value *V2 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V2");
+
+  // Create a ScalarEvolution and "run" it so that it gets initialized.
+  PassManager PM;
+  ScalarEvolution &SE = *new ScalarEvolution();
+  PM.add(&SE);
+  PM.run(M);
+
+  const SCEV *S0 = SE.getSCEV(V0);
+  const SCEV *S1 = SE.getSCEV(V1);
+  const SCEV *S2 = SE.getSCEV(V2);
+
+  const SCEV *P0 = SE.getAddExpr(S0, S0);
+  const SCEV *P1 = SE.getAddExpr(S1, S1);
+  const SCEV *P2 = SE.getAddExpr(S2, S2);
+
+  const SCEVMulExpr *M0 = cast<SCEVMulExpr>(P0);
+  const SCEVMulExpr *M1 = cast<SCEVMulExpr>(P1);
+  const SCEVMulExpr *M2 = cast<SCEVMulExpr>(P2);
+
+  EXPECT_EQ(cast<SCEVConstant>(M0->getOperand(0))->getValue()->getZExtValue(),
+            2u);
+  EXPECT_EQ(cast<SCEVConstant>(M1->getOperand(0))->getValue()->getZExtValue(),
+            2u);
+  EXPECT_EQ(cast<SCEVConstant>(M2->getOperand(0))->getValue()->getZExtValue(),
+            2u);
+
+  // Before the RAUWs, these are all pointing to separate values.
+  EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
+  EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V1);
+  EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V2);
+
+  // Do some RAUWs.
+  V2->replaceAllUsesWith(V1);
+  V1->replaceAllUsesWith(V0);
+
+  // After the RAUWs, these should all be pointing to V0.
+  EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
+  EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V0);
+  EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V0);
+
+  // Manually clean up, since we allocated new SCEV objects after the
+  // pass was finished.
+  SE.releaseMemory();
+}
+
+}  // end anonymous namespace
+}  // end namespace llvm
diff --git a/unittests/Makefile b/unittests/Makefile
index 9f377cd744..0401cd1c67 100644
--- a/unittests/Makefile
+++ b/unittests/Makefile
@@ -9,7 +9,7 @@
 
 LEVEL = ..
 
-PARALLEL_DIRS = ADT ExecutionEngine Support Transforms VMCore
+PARALLEL_DIRS = ADT ExecutionEngine Support Transforms VMCore Analysis
 
 include $(LEVEL)/Makefile.common
 
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