LoopInfo LoopAnalysis::run(Function &F, FunctionAnalysisManager &AM) {
// FIXME: Currently we create a LoopInfo from scratch for every function.
// This may prove to be too wasteful due to deallocating and re-allocating
// memory each time for the underlying map and vector datastructures. At some
// point it may prove worthwhile to use a freelist and recycle LoopInfo
// objects. I don't want to add that kind of complexity until the scope of
// the problem is better understood.
LoopInfo LI;
LI.analyze(AM.getResult<DominatorTreeAnalysis>(F));
return LI;
}
OptimizationRemarkEmitter::OptimizationRemarkEmitter(const Function *F)
: F(F), BFI(nullptr) {
if (!F->getContext().getDiagnosticHotnessRequested())
return;
// First create a dominator tree.
DominatorTree DT;
DT.recalculate(*const_cast<Function *>(F));
// Generate LoopInfo from it.
LoopInfo LI;
LI.analyze(DT);
// Then compute BranchProbabilityInfo.
BranchProbabilityInfo BPI;
BPI.calculate(*F, LI);
// Finally compute BFI.
OwnedBFI = llvm::make_unique<BlockFrequencyInfo>(*F, BPI, LI);
BFI = OwnedBFI.get();
}
TEST(LoopInfoTest, PreorderTraversals) {
const char *ModuleStr = "define void @f() {\n"
"entry:\n"
" br label %loop.0\n"
"loop.0:\n"
" br i1 undef, label %loop.0.0, label %loop.1\n"
"loop.0.0:\n"
" br i1 undef, label %loop.0.0, label %loop.0.1\n"
"loop.0.1:\n"
" br i1 undef, label %loop.0.1, label %loop.0.2\n"
"loop.0.2:\n"
" br i1 undef, label %loop.0.2, label %loop.0\n"
"loop.1:\n"
" br i1 undef, label %loop.1.0, label %end\n"
"loop.1.0:\n"
" br i1 undef, label %loop.1.0, label %loop.1.1\n"
"loop.1.1:\n"
" br i1 undef, label %loop.1.1, label %loop.1.2\n"
"loop.1.2:\n"
" br i1 undef, label %loop.1.2, label %loop.1\n"
"end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
Function &F = *M->begin();
DominatorTree DT(F);
LoopInfo LI;
LI.analyze(DT);
Function::iterator I = F.begin();
ASSERT_EQ("entry", I->getName());
++I;
Loop &L_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0", L_0.getHeader()->getName());
Loop &L_0_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.0", L_0_0.getHeader()->getName());
Loop &L_0_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.1", L_0_1.getHeader()->getName());
Loop &L_0_2 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.2", L_0_2.getHeader()->getName());
Loop &L_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1", L_1.getHeader()->getName());
Loop &L_1_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.0", L_1_0.getHeader()->getName());
Loop &L_1_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.1", L_1_1.getHeader()->getName());
Loop &L_1_2 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.2", L_1_2.getHeader()->getName());
auto Preorder = LI.getLoopsInPreorder();
ASSERT_EQ(8u, Preorder.size());
EXPECT_EQ(&L_0, Preorder[0]);
EXPECT_EQ(&L_0_0, Preorder[1]);
EXPECT_EQ(&L_0_1, Preorder[2]);
EXPECT_EQ(&L_0_2, Preorder[3]);
EXPECT_EQ(&L_1, Preorder[4]);
EXPECT_EQ(&L_1_0, Preorder[5]);
EXPECT_EQ(&L_1_1, Preorder[6]);
EXPECT_EQ(&L_1_2, Preorder[7]);
auto ReverseSiblingPreorder = LI.getLoopsInReverseSiblingPreorder();
ASSERT_EQ(8u, ReverseSiblingPreorder.size());
EXPECT_EQ(&L_1, ReverseSiblingPreorder[0]);
EXPECT_EQ(&L_1_2, ReverseSiblingPreorder[1]);
EXPECT_EQ(&L_1_1, ReverseSiblingPreorder[2]);
EXPECT_EQ(&L_1_0, ReverseSiblingPreorder[3]);
EXPECT_EQ(&L_0, ReverseSiblingPreorder[4]);
EXPECT_EQ(&L_0_2, ReverseSiblingPreorder[5]);
EXPECT_EQ(&L_0_1, ReverseSiblingPreorder[6]);
EXPECT_EQ(&L_0_0, ReverseSiblingPreorder[7]);
}
