llvm/unittests/Analysis/LoopInfoTest.cpp
Chandler Carruth 6b547686c5 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00

213 lines
7.6 KiB
C++

//===- LoopInfoTest.cpp - LoopInfo unit tests -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
/// Build the loop info for the function and run the Test.
static void
runWithLoopInfo(Module &M, StringRef FuncName,
function_ref<void(Function &F, LoopInfo &LI)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
// Compute the dominator tree and the loop info for the function.
DominatorTree DT(*F);
LoopInfo LI(DT);
Test(*F, LI);
}
static std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
const char *ModuleStr) {
SMDiagnostic Err;
return parseAssemblyString(ModuleStr, Err, Context);
}
// This tests that for a loop with a single latch, we get the loop id from
// its only latch, even in case the loop may not be in a simplified form.
TEST(LoopInfoTest, LoopWithSingleLatch) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n) {\n"
"entry:\n"
" br i1 undef, label %for.cond, label %for.end\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cmp, label %for.inc, label %for.end\n"
"for.inc:\n"
" %inc = add nsw i32 %i.0, 1\n"
" br label %for.cond, !llvm.loop !0\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
// This loop is not in simplified form.
EXPECT_FALSE(L->isLoopSimplifyForm());
// Analyze the loop metadata id.
bool loopIDFoundAndSet = false;
// Try to get and set the metadata id for the loop.
if (MDNode *D = L->getLoopID()) {
L->setLoopID(D);
loopIDFoundAndSet = true;
}
// We must have successfully found and set the loop id in the
// only latch the loop has.
EXPECT_TRUE(loopIDFoundAndSet);
});
}
// Test loop id handling for a loop with multiple latches.
TEST(LoopInfoTest, LoopWithMultipleLatches) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n) {\n"
"entry:\n"
" br i1 undef, label %for.cond, label %for.end\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %latch.1 ], [ %inc, %latch.2 ]\n"
" %inc = add nsw i32 %i.0, 1\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cmp, label %latch.1, label %for.end\n"
"latch.1:\n"
" br i1 undef, label %for.cond, label %latch.2, !llvm.loop !0\n"
"latch.2:\n"
" br label %for.cond, !llvm.loop !0\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
// This loop is not in simplified form.
EXPECT_FALSE(L->isLoopSimplifyForm());
// Try to get and set the metadata id for the loop.
MDNode *OldLoopID = L->getLoopID();
EXPECT_NE(OldLoopID, nullptr);
MDNode *NewLoopID = MDNode::get(Context, {nullptr});
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
L->setLoopID(NewLoopID);
EXPECT_EQ(L->getLoopID(), NewLoopID);
EXPECT_NE(L->getLoopID(), OldLoopID);
L->setLoopID(OldLoopID);
EXPECT_EQ(L->getLoopID(), OldLoopID);
EXPECT_NE(L->getLoopID(), NewLoopID);
});
}
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]);
}