PR10386: Don't try to split an edge from an indirectbr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135534 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp
index 92ce50030a5d84cff44a97872f831a0009cb7bb4..803e431f761c9fe8f71da7fc3c8146ffb32e3061 100644 (file)
--- a/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -337,6 +337,8 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
         }
 
         // For each unique exit block...
+        // FIXME: This code is functionally equivalent to the corresponding
+        // loop in LoopSimplify.
         SmallVector<BasicBlock *, 4> ExitBlocks;
         TIL->getExitBlocks(ExitBlocks);
         for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) {
@@ -348,10 +350,15 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
           for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit);
                I != E; ++I) {
             BasicBlock *P = *I;
-            if (TIL->contains(P))
+            if (TIL->contains(P)) {
+              if (isa<IndirectBrInst>(P->getTerminator())) {
+                Preds.clear();
+                break;
+              }
               Preds.push_back(P);
-            else
+            } else {
               HasPredOutsideOfLoop = true;
+            }
           }
           // If there are any preds not in the loop, we'll need to split
           // the edges. The Preds.empty() check is needed because a block

diff --git a/test/Transforms/LoopStrengthReduce/2011-07-19-CritEdgeBreakCrash.ll b/test/Transforms/LoopStrengthReduce/2011-07-19-CritEdgeBreakCrash.ll
new file mode 100644 (file)
index 0000000..b9bd7c9
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/2011-07-19-CritEdgeBreakCrash.ll
@@ -0,0 +1,52 @@
+; ModuleID = '<stdin>'
+; RUN: opt < %s -loop-reduce -S | FileCheck %s
+; PR10386
+
+declare i1 @foo()
+declare i8* @bar(i8*,i8*,i8*,i8*)
+
+define void @f(i64* %a,i64* %b,i64* %c,i64* %d,i64* %e,i64* %f,i64* %g) nounwind uwtable {
+entry:
+  br label %b_throw.preheader
+
+D_BREAK_LBL:                                      ; preds = %indirectgoto
+  call i1 @foo()
+  br label %indirectgoto
+
+H_CONST_LBL:                                      ; preds = %indirectgoto
+  call i1 @foo()
+  br label %body_failed
+
+H_MPZ_LBL:                                        ; preds = %indirectgoto
+  %boo3 = call i1 @foo()
+  br i1 %boo3, label %body_failed, label %while.cond.i
+
+while.cond.i:                                     ; preds = %while.body.i15795, %if.then.i15791
+  %phi = phi i64 [ %tmp20916, %while.body.i15795 ], [ 0, %H_MPZ_LBL ]
+  %tmp20916 = add i64 %phi, 1
+  %incdec.ptr.i15793 = getelementptr i64* %pc.0.lcssa.i1610719352, i64 %tmp20916
+  %boo2 = call i1 @foo()
+  br i1 %boo2, label %indirectgoto, label %while.body.i15795
+
+while.body.i15795:                                ; preds = %while.cond.i
+  %tmp20.i = load i64* %incdec.ptr.i15793, align 8
+  %boo1 = call i1 @foo()
+  br i1 %boo1, label %while.cond.i, label %body_failed
+
+b_throw.preheader:                                ; preds = %body_failed, %entry
+  call i1 @foo()
+  br label %indirectgoto
+
+body_failed:
+  %pc.0.lcssa.i1610719364 = phi i64* [ %pc.0.lcssa.i1610719352, %indirectgoto ], [ %pc.0.lcssa.i1610719352, %H_MPZ_LBL ], [ %b, %H_CONST_LBL ], [ %pc.0.lcssa.i1610719352, %while.body.i15795 ]
+  call i1 @foo()
+  br label %b_throw.preheader
+
+indirectgoto:
+  %pc.0.lcssa.i1610719352 = phi i64* [ %pc.0.lcssa.i1610719352, %D_BREAK_LBL ], [ %a, %b_throw.preheader ], [ %d, %while.cond.i ]
+  %p = call i8* @bar(i8* blockaddress(@f, %D_BREAK_LBL), i8* blockaddress(@f, %H_CONST_LBL), i8* blockaddress(@f, %H_MPZ_LBL), i8* blockaddress(@f, %body_failed) )
+  indirectbr i8* %p, [label %D_BREAK_LBL, label %H_CONST_LBL, label %H_MPZ_LBL, label %body_failed]
+}
+
+; CHECK: %p = call i8* @bar(i8* blockaddress(@f, %D_BREAK_LBL), i8* blockaddress(@f, %H_CONST_LBL), i8* blockaddress(@f, %H_MPZ_LBL), i8* blockaddress(@f, %body_failed))
+; CHECK: indirectbr i8* %p, [label %D_BREAK_LBL, label %H_CONST_LBL, label %H_MPZ_LBL, label %body_failed]