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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208461 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 0eb045e628bc032689678fb989b52dc536d472e2..cecb18b918345e2bc734b8844cf971248beebbca 100644 (file)
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -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:

diff --git a/test/Transforms/SLPVectorizer/X86/cse.ll b/test/Transforms/SLPVectorizer/X86/cse.ll
index bbfd6f28ea9741538ea305c587b858e219dc0d6a..d2ad7eb1a82a13b119ce080e8ac3e5253220c41d 100644 (file)
--- a/test/Transforms/SLPVectorizer/X86/cse.ll
+++ b/test/Transforms/SLPVectorizer/X86/cse.ll
@@ -217,3 +217,33 @@ return:                                           ; preds = %entry, %if.end
   ret i32 0
 }
 
+%class.B.53.55 = type { %class.A.52.54, double }
+%class.A.52.54 = type { double, double, double }
+
+@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
+}