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| //===- BasicBlockUtils.cpp - Unit tests for BasicBlockUtils ---------------===//
//
// 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/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
SMDiagnostic Err;
std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
if (!Mod)
Err.print("BasicBlockUtilsTests", errs());
return Mod;
}
TEST(BasicBlockUtils, EliminateUnreachableBlocks) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(
C,
"define i32 @has_unreachable(i1 %cond) {\n"
"entry:\n"
" br i1 %cond, label %bb0, label %bb1\n"
"bb0:\n"
" br label %bb1\n"
"bb1:\n"
" %phi = phi i32 [ 0, %entry ], [ 1, %bb0 ]"
" ret i32 %phi\n"
"bb2:\n"
" ret i32 42\n"
"}\n"
"\n"
);
auto *F = M->getFunction("has_unreachable");
DominatorTree DT(*F);
DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
EXPECT_EQ(F->size(), (size_t)4);
bool Result = EliminateUnreachableBlocks(*F, &DTU);
EXPECT_TRUE(Result);
EXPECT_EQ(F->size(), (size_t)3);
EXPECT_TRUE(DT.verify());
}
TEST(BasicBlockUtils, NoUnreachableBlocksToEliminate) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(
C,
"define i32 @no_unreachable(i1 %cond) {\n"
"entry:\n"
" br i1 %cond, label %bb0, label %bb1\n"
"bb0:\n"
" br label %bb1\n"
"bb1:\n"
" %phi = phi i32 [ 0, %entry ], [ 1, %bb0 ]"
" ret i32 %phi\n"
"}\n"
"\n"
);
auto *F = M->getFunction("no_unreachable");
DominatorTree DT(*F);
DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
EXPECT_EQ(F->size(), (size_t)3);
bool Result = EliminateUnreachableBlocks(*F, &DTU);
EXPECT_FALSE(Result);
EXPECT_EQ(F->size(), (size_t)3);
EXPECT_TRUE(DT.verify());
}
TEST(BasicBlockUtils, SplitBlockPredecessors) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(
C,
"define i32 @basic_func(i1 %cond) {\n"
"entry:\n"
" br i1 %cond, label %bb0, label %bb1\n"
"bb0:\n"
" br label %bb1\n"
"bb1:\n"
" %phi = phi i32 [ 0, %entry ], [ 1, %bb0 ]"
" ret i32 %phi\n"
"}\n"
"\n"
);
auto *F = M->getFunction("basic_func");
DominatorTree DT(*F);
// Make sure the dominator tree is properly updated if calling this on the
// entry block.
SplitBlockPredecessors(&F->getEntryBlock(), {}, "split.entry", &DT);
EXPECT_TRUE(DT.verify());
}
TEST(BasicBlockUtils, SplitCriticalEdge) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(
C,
"define void @crit_edge(i1 %cond0, i1 %cond1) {\n"
"entry:\n"
" br i1 %cond0, label %bb0, label %bb1\n"
"bb0:\n"
" br label %bb1\n"
"bb1:\n"
" br label %bb2\n"
"bb2:\n"
" ret void\n"
"}\n"
"\n"
);
auto *F = M->getFunction("crit_edge");
DominatorTree DT(*F);
PostDominatorTree PDT(*F);
CriticalEdgeSplittingOptions CESO(&DT, nullptr, nullptr, &PDT);
EXPECT_EQ(1u, SplitAllCriticalEdges(*F, CESO));
EXPECT_TRUE(DT.verify());
EXPECT_TRUE(PDT.verify());
}
|