[llvm] r208461 - SLPVectorizer: When sorting by domination for CSE don't assert on unreachable code.

[Benjamin Kramer]

Author: d0k
Date: Fri May  9 18:28:49 2014
New Revision: 208461

URL: http://llvm.org/viewvc/llvm-project?rev=208461&view=rev
Log:
SLPVectorizer: When sorting by domination for CSE don't assert on unreachable code.

There is no total ordering if the CFG is disconnected. We don't care if we
catch all CSE opportunities in dead code either so just exclude ignore them in
the assert.

PR19646

Modified:
    llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
    llvm/trunk/test/Transforms/SLPVectorizer/X86/cse.ll

Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=208461&r1=208460&r2=208461&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Fri May  9 18:28:49 2014
@@ -1827,7 +1827,8 @@ void BoUpSLP::optimizeGatherSequence() {
   for (SmallVectorImpl<BasicBlock *>::iterator I = CSEWorkList.begin(),
                                                E = CSEWorkList.end();
        I != E; ++I) {
-    assert((I == CSEWorkList.begin() || !DT->dominates(*I, *std::prev(I))) &&
+    assert((I == CSEWorkList.begin() || !DT->isReachableFromEntry(*I) ||
+            !DT->dominates(*I, *std::prev(I))) &&
            "Worklist not sorted properly!");
     BasicBlock *BB = *I;
     // For all instructions in blocks containing gather sequences:

Modified: llvm/trunk/test/Transforms/SLPVectorizer/X86/cse.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/cse.ll?rev=208461&r1=208460&r2=208461&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/cse.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/cse.ll Fri May  9 18:28:49 2014
@@ -217,3 +217,33 @@ return:
   ret i32 0
 }
 
+%class.B.53.55 = type { %class.A.52.54, double }
+%class.A.52.54 = type { double, double, double }
+
+ at a = external global double, align 8
+
+define void @PR19646(%class.B.53.55* %this) {
+entry:
+  br i1 undef, label %if.end13, label %if.end13
+
+sw.epilog7:                                       ; No predecessors!
+  %.in = getelementptr inbounds %class.B.53.55* %this, i64 0, i32 0, i32 1
+  %0 = load double* %.in, align 8
+  %add = fadd double undef, 0.000000e+00
+  %add6 = fadd double %add, %0
+  %1 = load double* @a, align 8
+  %add8 = fadd double %1, 0.000000e+00
+  %_dy = getelementptr inbounds %class.B.53.55* %this, i64 0, i32 0, i32 2
+  %2 = load double* %_dy, align 8
+  %add10 = fadd double %add8, %2
+  br i1 undef, label %if.then12, label %if.end13
+
+if.then12:                                        ; preds = %sw.epilog7
+  %3 = load double* undef, align 8
+  br label %if.end13
+
+if.end13:                                         ; preds = %if.then12, %sw.epilog7, %entry
+  %x.1 = phi double [ 0.000000e+00, %if.then12 ], [ %add6, %sw.epilog7 ], [ undef, %entry ], [ undef, %entry ]
+  %b.0 = phi double [ %3, %if.then12 ], [ %add10, %sw.epilog7 ], [ undef, %entry], [ undef, %entry ]
+  unreachable
+}