Looks good to me.<div><br></div><div>Thanks,</div><div>Preston</div><div><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
From: Benjamin Kramer <<a href="mailto:benny.kra@googlemail.com" target="_blank">benny.kra@googlemail.com</a>><br>
To: <a href="mailto:llvm-commits@cs.uiuc.edu" target="_blank">llvm-commits@cs.uiuc.edu</a><br>
Subject: [llvm-commits] [llvm] r167110 - in /llvm/trunk:<br>
        lib/Analysis/DependenceAnalysis.cpp test/Transforms/LoopIdiom/crash.ll<br>
Message-ID: <<a href="mailto:20121031092038.AFE792A6C065@llvm.org" target="_blank">20121031092038.AFE792A6C065@llvm.org</a>><br>
Content-Type: text/plain; charset="utf-8"<br>
<br>
Author: d0k<br>
Date: Wed Oct 31 04:20:38 2012<br>
New Revision: 167110<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=167110&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=167110&view=rev</a><br>
Log:<br>
DependenceAnalysis: Don't crash if there is no constant operand.<br>
<br>
This makes the code match the comments. Resolves a crash in loop idiom (PR14219).<br>
<br>
Added:<br>
    llvm/trunk/test/Transforms/LoopIdiom/crash.ll<br>
Modified:<br>
    llvm/trunk/lib/Analysis/DependenceAnalysis.cpp<br>
<br>
Modified: llvm/trunk/lib/Analysis/DependenceAnalysis.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/DependenceAnalysis.cpp?rev=167110&r1=167109&r2=167110&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/DependenceAnalysis.cpp?rev=167110&r1=167109&r2=167110&view=diff</a><br>


==============================================================================<br>
--- llvm/trunk/lib/Analysis/DependenceAnalysis.cpp (original)<br>
+++ llvm/trunk/lib/Analysis/DependenceAnalysis.cpp Wed Oct 31 04:20:38 2012<br>
@@ -2278,11 +2278,12 @@<br>
         assert(!Constant && "Surprised to find multiple constants");<br>
         Constant = cast<SCEVConstant>(Operand);<br>
       }<br>
-      else if (isa<SCEVMulExpr>(Operand)) {<br>
+      else if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Operand)) {<br>
         // Search for constant operand to participate in GCD;<br>
         // If none found; return false.<br>
-        const SCEVConstant *ConstOp =<br>
-          getConstantPart(cast<SCEVMulExpr>(Operand));<br>
+        const SCEVConstant *ConstOp = getConstantPart(Product);<br>
+        if (!ConstOp)<br>
+          return false;<br>
         APInt ConstOpValue = ConstOp->getValue()->getValue();<br>
         ExtraGCD = APIntOps::GreatestCommonDivisor(ExtraGCD,<br>
                                                    ConstOpValue.abs());<br>
<br>
Added: llvm/trunk/test/Transforms/LoopIdiom/crash.ll<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopIdiom/crash.ll?rev=167110&view=auto" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopIdiom/crash.ll?rev=167110&view=auto</a><br>


==============================================================================<br>
--- llvm/trunk/test/Transforms/LoopIdiom/crash.ll (added)<br>
+++ llvm/trunk/test/Transforms/LoopIdiom/crash.ll Wed Oct 31 04:20:38 2012<br>
@@ -0,0 +1,25 @@<br>
+; RUN: opt -basicaa -loop-idiom -S < %s<br>
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"<br>
+target triple = "x86_64-apple-macosx10.8.0"<br>
+<br>
+; Don't crash inside DependenceAnalysis<br>
+; PR14219<br>
+define void @test1(i64* %iwork, i64 %x)  {<br>
+bb0:<br>
+  %mul116 = mul nsw i64 %x, %x<br>
+  %incdec.ptr6.sum175 = add i64 42, %x<br>
+  %arrayidx135 = getelementptr inbounds i64* %iwork, i64 %incdec.ptr6.sum175<br>
+  br label %bb1<br>
+bb1:<br>
+  %storemerge4226 = phi i64 [ 0, %bb0 ], [ %inc139, %bb1 ]<br>
+  store i64 1, i64* %arrayidx135, align 8<br>
+  %incdec.ptr6.sum176 = add i64 %mul116, %storemerge4226<br>
+  %arrayidx137 = getelementptr inbounds i64* %iwork, i64 %incdec.ptr6.sum176<br>
+  store i64 1, i64* %arrayidx137, align 8<br>
+  %inc139 = add nsw i64 %storemerge4226, 1<br>
+  %cmp131 = icmp sgt i64 %storemerge4226, 42<br>
+  br i1 %cmp131, label %bb2, label %bb1<br>
+bb2:<br>
+  ret void<br>
+}<br><br></blockquote></div>
</div>