[llvm] r231788 - Fix a memory corruption in Dependency Analysis.
Karthik Bhat
kv.bhat at samsung.com
Tue Mar 10 07:32:02 PDT 2015
Author: karthik
Date: Tue Mar 10 09:32:02 2015
New Revision: 231788
URL: http://llvm.org/viewvc/llvm-project?rev=231788&view=rev
Log:
Fix a memory corruption in Dependency Analysis.
This crash occurs due to memory corruption when trying to update dependency
direction based on Constraints.
This crash was observed during lnt regression of Polybench benchmark test case dynprog.
Review: http://reviews.llvm.org/D8059
Added:
llvm/trunk/test/Analysis/DependenceAnalysis/Constraints.ll
Modified:
llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
Modified: llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/DependenceAnalysis.cpp?rev=231788&r1=231787&r2=231788&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/DependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/DependenceAnalysis.cpp Tue Mar 10 09:32:02 2015
@@ -3651,6 +3651,8 @@ DependenceAnalysis::depends(Instruction
DEBUG(dbgs() << " updating\n");
for (int SJ = ConstrainedLevels.find_first(); SJ >= 0;
SJ = ConstrainedLevels.find_next(SJ)) {
+ if (SJ > (int)CommonLevels)
+ break;
updateDirection(Result.DV[SJ - 1], Constraints[SJ]);
if (Result.DV[SJ - 1].Direction == Dependence::DVEntry::NONE)
return nullptr;
Added: llvm/trunk/test/Analysis/DependenceAnalysis/Constraints.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/DependenceAnalysis/Constraints.ll?rev=231788&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/DependenceAnalysis/Constraints.ll (added)
+++ llvm/trunk/test/Analysis/DependenceAnalysis/Constraints.ll Tue Mar 10 09:32:02 2015
@@ -0,0 +1,103 @@
+; RUN: opt < %s -analyze -basicaa -da
+;; Check that this code doesn't abort. Test case is reduced version of lnt Polybench benchmark test case dynprog.
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at sum_c = common global [10 x [10 x [10 x i32]]] zeroinitializer
+ at c = common global [10 x [10 x i32]] zeroinitializer
+ at W = common global [10 x [10 x i32]] zeroinitializer
+ at out_l = common global i32 0
+
+; Function Attrs: nounwind uwtable
+define void @dep_constraint_crash_test(i32 %M, i32 %N) {
+ %1 = icmp sgt i32 %N, 0
+ br i1 %1, label %.preheader.lr.ph, label %35
+
+.preheader.lr.ph: ; preds = %0
+ %2 = add nsw i32 %M, -2
+ %3 = icmp slt i32 %M, 2
+ %4 = add nsw i32 %M, -1
+ %5 = sext i32 %4 to i64
+ %6 = getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* @c, i64 0, i64 0, i64 %5
+ %7 = add nsw i32 %M, -1
+ %out_l.promoted = load i32, i32* @out_l
+ %8 = sext i32 %7 to i64
+ %9 = sext i32 %2 to i64
+ br label %.preheader
+
+.preheader: ; preds = %._crit_edge7, %.preheader.lr.ph
+ %10 = phi i32 [ %out_l.promoted, %.preheader.lr.ph ], [ %33, %._crit_edge7 ]
+ %iter.08 = phi i32 [ 0, %.preheader.lr.ph ], [ %34, %._crit_edge7 ]
+ br i1 %3, label %._crit_edge7, label %.lr.ph6
+
+.loopexit: ; preds = %._crit_edge, %.lr.ph6
+ %11 = icmp slt i64 %indvars.iv23, %9
+ %indvars.iv.next18 = add nuw nsw i64 %indvars.iv17, 1
+ %indvars.iv.next14 = add nuw i32 %indvars.iv13, 1
+ br i1 %11, label %.lr.ph6, label %._crit_edge7
+
+.lr.ph6: ; preds = %.preheader, %.loopexit
+ %indvars.iv23 = phi i64 [ %indvars.iv.next24, %.loopexit ], [ 0, %.preheader ]
+ %indvars.iv17 = phi i64 [ %indvars.iv.next18, %.loopexit ], [ 1, %.preheader ]
+ %indvars.iv13 = phi i32 [ %indvars.iv.next14, %.loopexit ], [ 1, %.preheader ]
+ %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
+ %12 = icmp slt i64 %indvars.iv23, %8
+ br i1 %12, label %.lr.ph4, label %.loopexit
+
+.lr.ph4: ; preds = %.lr.ph6, %._crit_edge
+ %indvars.iv19 = phi i64 [ %indvars.iv.next20, %._crit_edge ], [ %indvars.iv17, %.lr.ph6 ]
+ %indvars.iv15 = phi i32 [ %indvars.iv.next16, %._crit_edge ], [ %indvars.iv13, %.lr.ph6 ]
+ %13 = getelementptr inbounds [10 x [10 x [10 x i32]]], [10 x [10 x [10 x i32]]]* @sum_c, i64 0, i64 %indvars.iv23, i64 %indvars.iv19, i64 %indvars.iv23
+ store i32 0, i32* %13
+ %14 = add nsw i64 %indvars.iv19, -1
+ %15 = icmp slt i64 %indvars.iv23, %14
+ br i1 %15, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %.lr.ph4, %.lr.ph
+ %indvars.iv11 = phi i64 [ %indvars.iv.next12, %.lr.ph ], [ %indvars.iv17, %.lr.ph4 ]
+ %16 = add nsw i64 %indvars.iv11, -1
+ %17 = getelementptr inbounds [10 x [10 x [10 x i32]]], [10 x [10 x [10 x i32]]]* @sum_c, i64 0, i64 %indvars.iv23, i64 %indvars.iv19, i64 %16
+ %18 = load i32, i32* %17
+ %19 = getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* @c, i64 0, i64 %indvars.iv23, i64 %indvars.iv11
+ %20 = load i32, i32* %19
+ %21 = add nsw i32 %20, %18
+ %22 = getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* @c, i64 0, i64 %indvars.iv11, i64 %indvars.iv19
+ %23 = load i32, i32* %22
+ %24 = add nsw i32 %21, %23
+ %25 = getelementptr inbounds [10 x [10 x [10 x i32]]], [10 x [10 x [10 x i32]]]* @sum_c, i64 0, i64 %indvars.iv23, i64 %indvars.iv19, i64 %indvars.iv11
+ store i32 %24, i32* %25
+ %indvars.iv.next12 = add nuw nsw i64 %indvars.iv11, 1
+ %lftr.wideiv = trunc i64 %indvars.iv.next12 to i32
+ %exitcond = icmp eq i32 %lftr.wideiv, %indvars.iv15
+ br i1 %exitcond, label %._crit_edge, label %.lr.ph
+
+._crit_edge: ; preds = %.lr.ph, %.lr.ph4
+ %26 = getelementptr inbounds [10 x [10 x [10 x i32]]], [10 x [10 x [10 x i32]]]* @sum_c, i64 0, i64 %indvars.iv23, i64 %indvars.iv19, i64 %14
+ %27 = load i32, i32* %26
+ %28 = getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* @W, i64 0, i64 %indvars.iv23, i64 %indvars.iv19
+ %29 = load i32, i32* %28
+ %30 = add nsw i32 %29, %27
+ %31 = getelementptr inbounds [10 x [10 x i32]], [10 x [10 x i32]]* @c, i64 0, i64 %indvars.iv23, i64 %indvars.iv19
+ store i32 %30, i32* %31
+ %indvars.iv.next16 = add nuw i32 %indvars.iv15, 1
+ %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+ %lftr.wideiv21 = trunc i64 %indvars.iv.next20 to i32
+ %exitcond22 = icmp eq i32 %lftr.wideiv21, %M
+ br i1 %exitcond22, label %.loopexit, label %.lr.ph4
+
+._crit_edge7: ; preds = %.loopexit, %.preheader
+ %32 = load i32, i32* %6
+ %33 = add nsw i32 %10, %32
+ %34 = add nuw nsw i32 %iter.08, 1
+ %exitcond25 = icmp eq i32 %34, %N
+ br i1 %exitcond25, label %._crit_edge9, label %.preheader
+
+._crit_edge9: ; preds = %._crit_edge7
+ store i32 %33, i32* @out_l
+ br label %35
+
+; <label>:35 ; preds = %._crit_edge9, %0
+ ret void
+}
+
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