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Differential D38960

[Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred.
ClosedPublic

Authored by bmakam on Oct 16 2017, 9:40 AM.

Details

Reviewers
kuhar
• dberlin
hfinkel
Commits
rG925ddf1a93d2: [Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred.
rL316582: [Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred.
Summary

For some irreducible CFG the domtree nodes might be dead, do not update domtree for dead nodes.

Diff Detail

Event Timeline

bmakam created this revision.Oct 16 2017, 9:40 AM
Herald added a subscriber: mcrosier. · View Herald TranscriptOct 16 2017, 9:40 AM
bmakam added a reviewer: kuhar.Oct 16 2017, 9:41 AM
bmakam added a subscriber: llvm-commits.
kuhar edited edge metadata.Oct 16 2017, 9:46 AM

For some irreducible CFG the domtree nodes might be dead, do not update domtree for dead nodes.

Can you show some example of such CFG and add a comment explaining this check?

DomTree::getNode return nullptr only for forward-unreachable CFG nodes.

bmakam added a comment.Oct 16 2017, 9:53 AM
In D38960#898701, @kuhar wrote:

For some irreducible CFG the domtree nodes might be dead, do not update domtree for dead nodes.

Can you show some example of such CFG and add a comment explaining this check?

DomTree::getNode return nullptr only for forward-unreachable CFG nodes.

I found this bug while testing D37343. When D37343 is applied, test/Transforms/CodeGenPrepare/2008-11-24-RAUW-Self.ll will crash because of this.

kuhar added a comment.Oct 16 2017, 9:55 AM

I think that this deserves a comment with a (partial) example, otherwise the change looks suspicious.

bmakam added a comment.Oct 16 2017, 10:05 AM
In D38960#898713, @kuhar wrote:

I think that this deserves a comment with a (partial) example, otherwise the change looks suspicious.

Fair point. All the users of MergeBasicBlockIntoOnlyPred in the tree, do not pass DT to the function, so it is never exposed. Is there a way to test this in tree by passing DT to MergeBasicBlockIntoOnlyPred?

kuhar added a comment.EditedOct 16 2017, 10:09 AM
In D38960#898723, @bmakam wrote:
In D38960#898713, @kuhar wrote:

I think that this deserves a comment with a (partial) example, otherwise the change looks suspicious.

Fair point. All the users of MergeBasicBlockIntoOnlyPred in the tree, do not pass DT to the function, so it is never exposed. Is there a way to test this in tree by passing DT to MergeBasicBlockIntoOnlyPred?

It shouldn't be difficult to turn it into a unit test. I haven't checked how Local.cpp is tested, but you can find some existing dominator tree tests in IRTests/DominatorTree.cpp.

bmakam updated this revision to Diff 119222.Oct 16 2017, 3:50 PM

Add unittest and a comment.

kuhar added a comment.Oct 16 2017, 3:57 PM

Thanks for adding the comment.

The testcase seems really long and it's not obvious why what it tries to exercise -- have you tried reducing it with bugpoint to something shorter and easier to reason about?

bmakam added a comment.Oct 17 2017, 9:11 AM
In D38960#899142, @kuhar wrote:

Thanks for adding the comment.

The testcase seems really long and it's not obvious why what it tries to exercise -- have you tried reducing it with bugpoint to something shorter and easier to reason about?

Sorry for the long testcase, but this untitest was extracted after using bugpoint to reduce the lit test in test/Transforms/CodeGenPrepare/2008-11-24-RAUW-Self.ll. Is there a way to reduce a unittest using bugpoint?

bmakam updated this revision to Diff 119347.Oct 17 2017, 9:37 AM

Reduce unittest.

bmakam added reviewers: • dberlin, hfinkel.Oct 17 2017, 9:50 AM
kuhar accepted this revision.Oct 23 2017, 11:42 AM

This reduced IR is much nicer.

This revision is now accepted and ready to land.Oct 23 2017, 11:42 AM
Closed by commit rL316582: [Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred. (authored by bmakam). · Explain WhyOct 25 2017, 7:56 AM
This revision was automatically updated to reflect the committed changes.
bmakam added a comment.Oct 25 2017, 7:57 AM

Thanks for the reviews.

Revision Contents

PathSize
lib/
Transforms/
Utils/
10 lines
unittests/
Transforms/
Utils/
352 lines

Diff 119222

lib/Transforms/Utils/Local.cpp

Show First 20 Lines • Show All 615 Lines • ▼ Show 20 Linesvoid llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, DominatorTree *DT) {
DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList()); DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
// If the PredBB is the entry block of the function, move DestBB up to // If the PredBB is the entry block of the function, move DestBB up to
// become the entry block after we erase PredBB. // become the entry block after we erase PredBB.
if (PredBB == &DestBB->getParent()->getEntryBlock()) if (PredBB == &DestBB->getParent()->getEntryBlock())
DestBB->moveAfter(PredBB); DestBB->moveAfter(PredBB);
if (DT) { if (DT) {
BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock(); // For some irreducible CFG we end up having forward-unreachable blocks
// so check if getNode returns a valid node before updating the domtree.
if (DomTreeNode *DTN = DT->getNode(PredBB)) {
BasicBlock *PredBBIDom = DTN->getIDom()->getBlock();
DT->changeImmediateDominator(DestBB, PredBBIDom); DT->changeImmediateDominator(DestBB, PredBBIDom);
DT->eraseNode(PredBB); DT->eraseNode(PredBB);
} }
}
// Nuke BB. // Nuke BB.
PredBB->eraseFromParent(); PredBB->eraseFromParent();
} }
/// CanMergeValues - Return true if we can choose one of these values to use /// CanMergeValues - Return true if we can choose one of these values to use
/// in place of the other. Note that we will always choose the non-undef /// in place of the other. Note that we will always choose the non-undef
/// value to keep. /// value to keep.
static bool CanMergeValues(Value *First, Value *Second) { static bool CanMergeValues(Value *First, Value *Second) {
▲ Show 20 Lines • Show All 1,592 Lines • Show Last 20 Lines

unittests/Transforms/Utils/Local.cpp

Show First 20 Lines • Show All 160 Lines • ▼ Show 20 LinesTEST(Local, ReplaceDbgDeclare) {
// There should be exactly two dbg.declares. // There should be exactly two dbg.declares.
int Declares = 0; int Declares = 0;
for (const Instruction &I : F->front()) for (const Instruction &I : F->front())
if (isa<DbgDeclareInst>(I)) if (isa<DbgDeclareInst>(I))
Declares++; Declares++;
EXPECT_EQ(2, Declares); EXPECT_EQ(2, Declares);
} }
/// Build the dominator tree for the function and run the Test.
static void runWithDomTree(
Module &M, StringRef FuncName,
function_ref<void(Function &F, DominatorTree *DT)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
// Compute the dominator tree for the function.
DominatorTree DT(*F);
Test(*F, &DT);
}
TEST(Local, MergeBasicBlockIntoOnlyPred) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(
C,
"define i32 @f(i8* %str) {\n"
"entry:\n"
" br label %bb2.i\n"
"bb2.i: ; preds = %bb4.i, %entry\n"
" br i1 false, label %bb4.i, label %base2flt.exit204\n"
"bb4.i: ; preds = %bb2.i\n"
" br i1 false, label %base2flt.exit204, label %bb2.i\n"
"bb10.i196.bb7.i197_crit_edge: ; No predecessors!\n"
" br label %bb7.i197\n"
"bb7.i197: ; preds = %bb10.i196.bb7.i197_crit_edge\n"
" %.reg2mem.0 = phi i32 [ %.reg2mem.0, %bb10.i196.bb7.i197_crit_edge ]\n"
" br i1 undef, label %base2flt.exit204, label %base2flt.exit204\n"
"base2flt.exit204: ; preds = %bb7.i197, %bb7.i197, %bb2.i, %bb4.i\n"
" br i1 false, label %base2flt.exit204.bb8_crit_edge, label %bb\n"
"base2flt.exit204.bb8_crit_edge: ; preds = %base2flt.exit204\n"
" br label %bb8\n"
"bb: ; preds = %base2flt.exit204\n"
" br i1 false, label %bb.bb18_crit_edge, label %bb1.i\n"
"bb.bb18_crit_edge: ; preds = %bb9, %bb\n"
" br label %bb18\n"
"bb1.i: ; preds = %bb\n"
" br i1 false, label %bb1.i.bb7_crit_edge, label %bb1.i158\n"
"bb1.i.bb7_crit_edge.loopexit: ; preds = %bb2.i164\n"
" br label %bb1.i.bb7_crit_edge\n"
"bb1.i.bb7_crit_edge: ; preds = %bb1.i.bb7_crit_edge.loopexit, %bb1.i\n"
" br label %bb7.preheader\n"
"bb1.i158: ; preds = %bb1.i\n"
" br i1 false, label %bb1.i158.bb10.i179_crit_edge, label %bb1.i158.bb2.i164_crit_edge\n"
"bb1.i158.bb2.i164_crit_edge: ; preds = %bb1.i158\n"
" br label %bb2.i164\n"
"bb1.i158.bb10.i179_crit_edge: ; preds = %bb1.i158\n"
" br label %bb10.i179\n"
"bb2.i164: ; preds = %bb4.i166.bb2.i164_crit_edge, %bb1.i158.bb2.i164_crit_edge\n"
" br i1 false, label %bb4.i166, label %bb1.i.bb7_crit_edge.loopexit\n"
"bb4.i166: ; preds = %bb2.i164\n"
" br i1 false, label %bb4.i166.bb11.i172_crit_edge, label %bb4.i166.bb2.i164_crit_edge\n"
"bb4.i166.bb2.i164_crit_edge: ; preds = %bb4.i166\n"
" br label %bb2.i164\n"
"bb4.i166.bb11.i172_crit_edge: ; preds = %bb4.i166\n"
" br label %bb11.i172\n"
"bb11.i172: ; preds = %bb10.i179.bb11.i172_crit_edge, %bb4.i166.bb11.i172_crit_edge\n"
" br label %bb7.preheader\n"
"bb10.i179: ; preds = %bb9.i182, %bb1.i158.bb10.i179_crit_edge\n"
" br i1 false, label %bb7.i180, label %bb10.i179.bb11.i172_crit_edge\n"
"bb10.i179.bb11.i172_crit_edge: ; preds = %bb10.i179\n"
" br label %bb11.i172\n"
"bb7.i180: ; preds = %bb10.i179\n"
" br i1 false, label %bb7.i180.bb7_crit_edge, label %bb9.i182\n"
"bb7.i180.bb7_crit_edge: ; preds = %bb7.i180\n"
" br label %bb7.preheader\n"
"bb7.preheader: ; preds = %bb7.i180.bb7_crit_edge, %bb11.i172, %bb1.i.bb7_crit_edge\n"
" br label %bb7\n"
"bb9.i182: ; preds = %bb7.i180\n"
" br label %bb10.i179\n"
"bb7: ; preds = %addflt.exit114, %bb7.preheader\n"
" switch i8 0, label %bb4 [\n"
" i8 0, label %bb7.bb8_crit_edge\n"
" i8 46, label %bb7.bb8_crit_edge\n"
" ]\n"
"bb7.bb8_crit_edge: ; preds = %bb7, %bb7\n"
" br label %bb8\n"
"bb4: ; preds = %bb7\n"
" br i1 false, label %bb18.loopexit1, label %bb1.i5\n"
"bb1.i5: ; preds = %bb4\n"
" br i1 false, label %bb1.i5.mulflt.exit157_crit_edge, label %bb3.i147\n"
"bb1.i5.mulflt.exit157_crit_edge: ; preds = %bb5.i148, %bb1.i5\n"
" br label %mulflt.exit157\n"
"bb3.i147: ; preds = %bb1.i5\n"
" br i1 false, label %bb3.i147.mulflt.exit157_crit_edge, label %bb5.i148\n"
"bb3.i147.mulflt.exit157_crit_edge: ; preds = %bb8.i150, %bb3.i147\n"
" br label %mulflt.exit157\n"
"bb5.i148: ; preds = %bb3.i147\n"
" br i1 false, label %bb1.i5.mulflt.exit157_crit_edge, label %bb7.i149\n"
"bb7.i149: ; preds = %bb5.i148\n"
" br i1 false, label %bb8.i150, label %bb7.i149.bb12.i154_crit_edge\n"
"bb7.i149.bb12.i154_crit_edge: ; preds = %bb7.i149\n"
" br label %bb12.i154\n"
"bb8.i150: ; preds = %bb7.i149\n"
" br i1 false, label %bb3.i147.mulflt.exit157_crit_edge, label %bb10.i151\n"
"bb10.i151: ; preds = %bb8.i150\n"
" br label %bb12.i154\n"
"bb12.i154: ; preds = %bb10.i151, %bb7.i149.bb12.i154_crit_edge\n"
" br label %mulflt.exit157\n"
"mulflt.exit157: ; preds = %bb12.i154, %bb3.i147.mulflt.exit157_crit_edge, %bb1.i5.mulflt.exit157_crit_edge\n"
" br i1 false, label %mulflt.exit157.base2flt.exit144_crit_edge, label %bb1.i115\n"
"mulflt.exit157.base2flt.exit144_crit_edge.loopexit: ; preds = %bb2.i121\n"
" br label %mulflt.exit157.base2flt.exit144_crit_edge\n"
"mulflt.exit157.base2flt.exit144_crit_edge: ; preds = %mulflt.exit157.base2flt.exit144_crit_edge.loopexit, %mulflt.exit157\n"
" br label %base2flt.exit144\n"
"bb1.i115: ; preds = %mulflt.exit157\n"
" br i1 false, label %bb1.i115.bb10.i136_crit_edge, label %bb1.i115.bb2.i121_crit_edge\n"
"bb1.i115.bb2.i121_crit_edge: ; preds = %bb1.i115\n"
" br label %bb2.i121\n"
"bb1.i115.bb10.i136_crit_edge: ; preds = %bb1.i115\n"
" br label %bb10.i136\n"
"bb2.i121: ; preds = %bb4.i123.bb2.i121_crit_edge, %bb1.i115.bb2.i121_crit_edge\n"
" br i1 false, label %bb4.i123, label %mulflt.exit157.base2flt.exit144_crit_edge.loopexit\n"
"bb4.i123: ; preds = %bb2.i121\n"
" br i1 false, label %bb4.i123.bb11.i129_crit_edge, label %bb4.i123.bb2.i121_crit_edge\n"
"bb4.i123.bb2.i121_crit_edge: ; preds = %bb4.i123\n"
" br label %bb2.i121\n"
"bb4.i123.bb11.i129_crit_edge: ; preds = %bb4.i123\n"
" br label %bb11.i129\n"
"bb11.i129: ; preds = %bb10.i136.bb11.i129_crit_edge, %bb4.i123.bb11.i129_crit_edge\n"
" br label %base2flt.exit144\n"
"bb10.i136: ; preds = %bb9.i139, %bb1.i115.bb10.i136_crit_edge\n"
" br i1 false, label %bb7.i137, label %bb10.i136.bb11.i129_crit_edge\n"
"bb10.i136.bb11.i129_crit_edge: ; preds = %bb10.i136\n"
" br label %bb11.i129\n"
"bb7.i137: ; preds = %bb10.i136\n"
" br i1 false, label %bb7.i137.base2flt.exit144_crit_edge, label %bb9.i139\n"
"bb7.i137.base2flt.exit144_crit_edge: ; preds = %bb7.i137\n"
" br label %base2flt.exit144\n"
"bb9.i139: ; preds = %bb7.i137\n"
" br label %bb10.i136\n"
"base2flt.exit144: ; preds = %bb7.i137.base2flt.exit144_crit_edge, %bb11.i129, %mulflt.exit157.base2flt.exit144_crit_edge\n"
" br i1 false, label %base2flt.exit144.addflt.exit114_crit_edge, label %bb3.i105\n"
"base2flt.exit144.addflt.exit114_crit_edge: ; preds = %bb3.i105, %base2flt.exit144\n"
" br label %addflt.exit114\n"
"bb3.i105: ; preds = %base2flt.exit144\n"
" br i1 false, label %base2flt.exit144.addflt.exit114_crit_edge, label %bb5.i106\n"
"bb5.i106: ; preds = %bb3.i105\n"
" br i1 false, label %bb5.i106.bb9.i111_crit_edge, label %bb6.i107\n"
"bb5.i106.bb9.i111_crit_edge: ; preds = %bb5.i106\n"
" br label %bb9.i111\n"
"bb6.i107: ; preds = %bb5.i106\n"
" br i1 false, label %bb6.i107.addflt.exit114_crit_edge, label %bb8.i108\n"
"bb6.i107.addflt.exit114_crit_edge: ; preds = %bb6.i107\n"
" br label %addflt.exit114\n"
"bb8.i108: ; preds = %bb6.i107\n"
" br label %bb9.i111\n"
"bb9.i111: ; preds = %bb8.i108, %bb5.i106.bb9.i111_crit_edge\n"
" br label %addflt.exit114\n"
"addflt.exit114: ; preds = %bb9.i111, %bb6.i107.addflt.exit114_crit_edge, %base2flt.exit144.addflt.exit114_crit_edge\n"
" br label %bb7\n"
"bb18.loopexit1: ; preds = %bb4\n"
" ret i32 -1\n"
"bb18: ; preds = %bb8.bb18_crit_edge, %bb.bb18_crit_edge\n"
" ret i32 0\n"
"bb8: ; preds = %bb7.bb8_crit_edge, %base2flt.exit204.bb8_crit_edge\n"
" br i1 false, label %bb9, label %bb8.bb18_crit_edge\n"
"bb8.bb18_crit_edge: ; preds = %bb8\n"
" br label %bb18\n"
"bb9: ; preds = %bb8\n"
" br i1 false, label %bb.bb18_crit_edge, label %bb1.i13\n"
"bb1.i13: ; preds = %bb9\n"
" br i1 false, label %bb1.i13.base2flt.exit102_crit_edge, label %bb1.i73\n"
"bb1.i13.base2flt.exit102_crit_edge.loopexit: ; preds = %bb2.i79\n"
" br label %bb1.i13.base2flt.exit102_crit_edge\n"
"bb1.i13.base2flt.exit102_crit_edge: ; preds = %bb1.i13.base2flt.exit102_crit_edge.loopexit, %bb1.i13\n"
" br label %base2flt.exit102\n"
"bb1.i73: ; preds = %bb1.i13\n"
" br i1 false, label %bb1.i73.bb10.i94_crit_edge, label %bb1.i73.bb2.i79_crit_edge\n"
"bb1.i73.bb2.i79_crit_edge: ; preds = %bb1.i73\n"
" br label %bb2.i79\n"
"bb1.i73.bb10.i94_crit_edge: ; preds = %bb1.i73\n"
" br label %bb10.i94\n"
"bb2.i79: ; preds = %bb4.i81.bb2.i79_crit_edge, %bb1.i73.bb2.i79_crit_edge\n"
" br i1 false, label %bb4.i81, label %bb1.i13.base2flt.exit102_crit_edge.loopexit\n"
"bb4.i81: ; preds = %bb2.i79\n"
" br i1 false, label %bb4.i81.bb11.i87_crit_edge, label %bb4.i81.bb2.i79_crit_edge\n"
"bb4.i81.bb2.i79_crit_edge: ; preds = %bb4.i81\n"
" br label %bb2.i79\n"
"bb4.i81.bb11.i87_crit_edge: ; preds = %bb4.i81\n"
" br label %bb11.i87\n"
"bb11.i87: ; preds = %bb10.i94.bb11.i87_crit_edge, %bb4.i81.bb11.i87_crit_edge\n"
" br label %base2flt.exit102\n"
"bb10.i94: ; preds = %bb9.i97, %bb1.i73.bb10.i94_crit_edge\n"
" br i1 false, label %bb7.i95, label %bb10.i94.bb11.i87_crit_edge\n"
"bb10.i94.bb11.i87_crit_edge: ; preds = %bb10.i94\n"
" br label %bb11.i87\n"
"bb7.i95: ; preds = %bb10.i94\n"
" br i1 false, label %bb7.i95.base2flt.exit102_crit_edge, label %bb9.i97\n"
"bb7.i95.base2flt.exit102_crit_edge: ; preds = %bb7.i95\n"
" br label %base2flt.exit102\n"
"bb9.i97: ; preds = %bb7.i95\n"
" br label %bb10.i94\n"
"base2flt.exit102: ; preds = %bb7.i95.base2flt.exit102_crit_edge, %bb11.i87, %bb1.i13.base2flt.exit102_crit_edge\n"
" br i1 false, label %base2flt.exit102.mulflt.exit72_crit_edge, label %bb3.i62\n"
"base2flt.exit102.mulflt.exit72_crit_edge: ; preds = %bb5.i63, %base2flt.exit102\n"
" br label %mulflt.exit72\n"
"bb3.i62: ; preds = %base2flt.exit102\n"
" br i1 false, label %bb3.i62.mulflt.exit72_crit_edge, label %bb5.i63\n"
"bb3.i62.mulflt.exit72_crit_edge: ; preds = %bb8.i65, %bb3.i62\n"
" br label %mulflt.exit72\n"
"bb5.i63: ; preds = %bb3.i62\n"
" br i1 false, label %base2flt.exit102.mulflt.exit72_crit_edge, label %bb7.i64\n"
"bb7.i64: ; preds = %bb5.i63\n"
" br i1 false, label %bb8.i65, label %bb7.i64.bb12.i69_crit_edge\n"
"bb7.i64.bb12.i69_crit_edge: ; preds = %bb7.i64\n"
" br label %bb12.i69\n"
"bb8.i65: ; preds = %bb7.i64\n"
" br i1 false, label %bb3.i62.mulflt.exit72_crit_edge, label %bb10.i66\n"
"bb10.i66: ; preds = %bb8.i65\n"
" br label %bb12.i69\n"
"bb12.i69: ; preds = %bb10.i66, %bb7.i64.bb12.i69_crit_edge\n"
" br label %mulflt.exit72\n"
"mulflt.exit72: ; preds = %bb12.i69, %bb3.i62.mulflt.exit72_crit_edge, %base2flt.exit102.mulflt.exit72_crit_edge\n"
" br i1 false, label %mulflt.exit72.bb10.i58_crit_edge, label %bb3.i50\n"
"mulflt.exit72.bb10.i58_crit_edge: ; preds = %bb3.i50, %mulflt.exit72\n"
" br label %bb10.i58\n"
"bb3.i50: ; preds = %mulflt.exit72\n"
" br i1 false, label %mulflt.exit72.bb10.i58_crit_edge, label %bb5.i51\n"
"bb5.i51: ; preds = %bb3.i50\n"
" br i1 false, label %bb5.i51.bb9.i56_crit_edge, label %bb6.i52\n"
"bb5.i51.bb9.i56_crit_edge: ; preds = %bb5.i51\n"
" br label %bb9.i56\n"
"bb6.i52: ; preds = %bb5.i51\n"
" br i1 false, label %bb6.i52.bb10.i58_crit_edge, label %bb8.i53\n"
"bb6.i52.bb10.i58_crit_edge: ; preds = %bb6.i52\n"
" br label %bb10.i58\n"
"bb8.i53: ; preds = %bb6.i52\n"
" br label %bb9.i56\n"
"bb9.i56: ; preds = %bb8.i53, %bb5.i51.bb9.i56_crit_edge\n"
" br label %bb15.preheader\n"
"bb10.i58: ; preds = %bb6.i52.bb10.i58_crit_edge, %mulflt.exit72.bb10.i58_crit_edge\n"
" br label %bb15.preheader\n"
"bb15.preheader: ; preds = %bb10.i58, %bb9.i56\n"
" br label %bb15\n"
"bb15: ; preds = %addflt.exit, %bb15.preheader\n"
" br i1 false, label %bb15.bb18.loopexit_crit_edge, label %bb12\n"
"bb15.bb18.loopexit_crit_edge: ; preds = %bb15\n"
" br label %bb18.loopexit\n"
"bb12: ; preds = %bb15\n"
" br i1 false, label %bb12.bb18.loopexit_crit_edge, label %bb1.i21\n"
"bb12.bb18.loopexit_crit_edge: ; preds = %bb12\n"
" br label %bb18.loopexit\n"
"bb1.i21: ; preds = %bb12\n"
" br i1 false, label %bb1.i21.mulflt.exit47_crit_edge, label %bb3.i37\n"
"bb1.i21.mulflt.exit47_crit_edge: ; preds = %bb5.i38, %bb1.i21\n"
" br label %mulflt.exit47\n"
"bb3.i37: ; preds = %bb1.i21\n"
" br i1 false, label %bb3.i37.mulflt.exit47_crit_edge, label %bb5.i38\n"
"bb3.i37.mulflt.exit47_crit_edge: ; preds = %bb8.i40, %bb3.i37\n"
" br label %mulflt.exit47\n"
"bb5.i38: ; preds = %bb3.i37\n"
" br i1 false, label %bb1.i21.mulflt.exit47_crit_edge, label %bb7.i39\n"
"bb7.i39: ; preds = %bb5.i38\n"
" br i1 false, label %bb8.i40, label %bb7.i39.bb12.i44_crit_edge\n"
"bb7.i39.bb12.i44_crit_edge: ; preds = %bb7.i39\n"
" br label %bb12.i44\n"
"bb8.i40: ; preds = %bb7.i39\n"
" br i1 false, label %bb3.i37.mulflt.exit47_crit_edge, label %bb10.i41\n"
"bb10.i41: ; preds = %bb8.i40\n"
" br label %bb12.i44\n"
"bb12.i44: ; preds = %bb10.i41, %bb7.i39.bb12.i44_crit_edge\n"
" br label %mulflt.exit47\n"
"mulflt.exit47: ; preds = %bb12.i44, %bb3.i37.mulflt.exit47_crit_edge, %bb1.i21.mulflt.exit47_crit_edge\n"
" br i1 false, label %mulflt.exit47.base2flt.exit34_crit_edge, label %bb1.i15\n"
"mulflt.exit47.base2flt.exit34_crit_edge.loopexit: ; preds = %bb2.i20\n"
" br label %mulflt.exit47.base2flt.exit34_crit_edge\n"
"mulflt.exit47.base2flt.exit34_crit_edge: ; preds = %mulflt.exit47.base2flt.exit34_crit_edge.loopexit, %mulflt.exit47\n"
" br label %base2flt.exit34\n"
"bb1.i15: ; preds = %mulflt.exit47\n"
" br i1 false, label %bb1.i15.bb10.i31_crit_edge, label %bb1.i15.bb2.i20_crit_edge\n"
"bb1.i15.bb2.i20_crit_edge: ; preds = %bb1.i15\n"
" br label %bb2.i20\n"
"bb1.i15.bb10.i31_crit_edge: ; preds = %bb1.i15\n"
" br label %bb10.i31\n"
"bb2.i20: ; preds = %bb4.i22.bb2.i20_crit_edge, %bb1.i15.bb2.i20_crit_edge\n"
" br i1 false, label %bb4.i22, label %mulflt.exit47.base2flt.exit34_crit_edge.loopexit\n"
"bb4.i22: ; preds = %bb2.i20\n"
" br i1 false, label %bb4.i22.bb11.i28_crit_edge, label %bb4.i22.bb2.i20_crit_edge\n"
"bb4.i22.bb2.i20_crit_edge: ; preds = %bb4.i22\n"
" br label %bb2.i20\n"
"bb4.i22.bb11.i28_crit_edge: ; preds = %bb4.i22\n"
" br label %bb11.i28\n"
"bb11.i28: ; preds = %bb10.i31.bb11.i28_crit_edge, %bb4.i22.bb11.i28_crit_edge\n"
" br label %base2flt.exit34\n"
"bb10.i31: ; preds = %bb9.i33, %bb1.i15.bb10.i31_crit_edge\n"
" br i1 false, label %bb7.i32, label %bb10.i31.bb11.i28_crit_edge\n"
"bb10.i31.bb11.i28_crit_edge: ; preds = %bb10.i31\n"
" br label %bb11.i28\n"
"bb7.i32: ; preds = %bb10.i31\n"
" br i1 false, label %bb7.i32.base2flt.exit34_crit_edge, label %bb9.i33\n"
"bb7.i32.base2flt.exit34_crit_edge: ; preds = %bb7.i32\n"
" br label %base2flt.exit34\n"
"bb9.i33: ; preds = %bb7.i32\n"
" br label %bb10.i31\n"
"base2flt.exit34: ; preds = %bb7.i32.base2flt.exit34_crit_edge, %bb11.i28, %mulflt.exit47.base2flt.exit34_crit_edge\n"
" br i1 false, label %base2flt.exit34.mulflt.exit_crit_edge, label %bb3.i9\n"
"base2flt.exit34.mulflt.exit_crit_edge: ; preds = %bb5.i10, %base2flt.exit34\n"
" br label %mulflt.exit\n"
"bb3.i9: ; preds = %base2flt.exit34\n"
" br i1 false, label %bb3.i9.mulflt.exit_crit_edge, label %bb5.i10\n"
"bb3.i9.mulflt.exit_crit_edge: ; preds = %bb8.i11, %bb3.i9\n"
" br label %mulflt.exit\n"
"bb5.i10: ; preds = %bb3.i9\n"
" br i1 false, label %base2flt.exit34.mulflt.exit_crit_edge, label %bb7.i\n"
"bb7.i: ; preds = %bb5.i10\n"
" br i1 false, label %bb8.i11, label %bb7.i.bb12.i_crit_edge\n"
"bb7.i.bb12.i_crit_edge: ; preds = %bb7.i\n"
" br label %bb12.i\n"
"bb8.i11: ; preds = %bb7.i\n"
" br i1 false, label %bb3.i9.mulflt.exit_crit_edge, label %bb10.i12\n"
"bb10.i12: ; preds = %bb8.i11\n"
" br label %bb12.i\n"
"bb12.i: ; preds = %bb10.i12, %bb7.i.bb12.i_crit_edge\n"
" br label %mulflt.exit\n"
"mulflt.exit: ; preds = %bb12.i, %bb3.i9.mulflt.exit_crit_edge, %base2flt.exit34.mulflt.exit_crit_edge\n"
" br i1 false, label %mulflt.exit.addflt.exit_crit_edge, label %bb3.i\n"
"mulflt.exit.addflt.exit_crit_edge: ; preds = %bb3.i, %mulflt.exit\n"
" br label %addflt.exit\n"
"bb3.i: ; preds = %mulflt.exit\n"
" br i1 false, label %mulflt.exit.addflt.exit_crit_edge, label %bb5.i\n"
"bb5.i: ; preds = %bb3.i\n"
" br i1 false, label %bb5.i.bb9.i_crit_edge, label %bb6.i\n"
"bb5.i.bb9.i_crit_edge: ; preds = %bb5.i\n"
" br label %bb9.i\n"
"bb6.i: ; preds = %bb5.i\n"
" br i1 false, label %bb6.i.addflt.exit_crit_edge, label %bb8.i\n"
"bb6.i.addflt.exit_crit_edge: ; preds = %bb6.i\n"
" br label %addflt.exit\n"
"bb8.i: ; preds = %bb6.i\n"
" br label %bb9.i\n"
"bb9.i: ; preds = %bb8.i, %bb5.i.bb9.i_crit_edge\n"
" br label %addflt.exit\n"
"addflt.exit: ; preds = %bb9.i, %bb6.i.addflt.exit_crit_edge, %mulflt.exit.addflt.exit_crit_edge\n"
" br label %bb15\n"
"bb18.loopexit: ; preds = %bb12.bb18.loopexit_crit_edge, %bb15.bb18.loopexit_crit_edge\n"
" ret i32 0\n"
"}\n");
runWithDomTree(
*M, "f", [&](Function &F, DominatorTree *DT) {
for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
BasicBlock *BB = &*I++;
BasicBlock *SinglePred = BB->getSinglePredecessor();
if (!SinglePred || SinglePred == BB || BB->hasAddressTaken()) continue;
BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
if (Term && !Term->isConditional())
MergeBasicBlockIntoOnlyPred(BB, DT);
}
EXPECT_TRUE(DT->verify());
});
}