72 lines · cpp
1#include "llvm/Transforms/Utils/CodeLayout.h"2#include "gmock/gmock.h"3#include "gtest/gtest.h"4#include <vector>5 6using namespace llvm;7using namespace llvm::codelayout;8using testing::ElementsAreArray;9 10namespace {11TEST(CodeLayout, ThreeFunctions) {12 // Place the most likely successor (2) first.13 {14 const uint64_t Counts[3] = {140, 40, 140};15 const std::vector<uint64_t> Sizes(std::size(Counts), 9);16 const EdgeCount Edges[] = {{0, 1, 40}, {0, 2, 100}, {1, 2, 40}};17 const std::vector<uint64_t> CallOffsets(std::size(Edges), 5);18 auto Order = computeCacheDirectedLayout(Sizes, Counts, Edges, CallOffsets);19 EXPECT_THAT(Order, ElementsAreArray({0, 2, 1}));20 }21 22 // Prefer fallthroughs even in the presence of a heavy successor.23 {24 const uint64_t Counts[3] = {180, 80, 180};25 const std::vector<uint64_t> Sizes(std::size(Counts), 9);26 const EdgeCount Edges[] = {{0, 1, 80}, {0, 2, 100}, {1, 2, 80}};27 const uint64_t CallOffsets[] = {9, 5, 9};28 auto Order = computeCacheDirectedLayout(Sizes, Counts, Edges, CallOffsets);29 EXPECT_THAT(Order, ElementsAreArray({0, 1, 2}));30 }31}32 33TEST(CodeLayout, HotChain) {34 // Place the hot chain (0,3,4,2) continuously.35 {36 const uint64_t Counts[5] = {22, 7, 22, 15, 46};37 const std::vector<uint64_t> Sizes(std::size(Counts), 9);38 const EdgeCount Edges[] = {{0, 1, 7}, {1, 2, 7}, {0, 3, 15},39 {3, 4, 15}, {4, 4, 31}, {4, 2, 15}};40 const std::vector<uint64_t> CallOffsets(std::size(Edges), 5);41 auto Order = computeCacheDirectedLayout(Sizes, Counts, Edges, CallOffsets);42 EXPECT_THAT(Order, ElementsAreArray({0, 3, 4, 2, 1}));43 44 // -cdsort-max-chain-size disables forming a larger chain and therefore may45 // change the result.46 CDSortConfig Config;47 Config.MaxChainSize = 3;48 Order =49 computeCacheDirectedLayout(Config, Sizes, Counts, Edges, CallOffsets);50 EXPECT_THAT(Order, ElementsAreArray({0, 3, 4, 1, 2}));51 }52}53 54TEST(CodeLayout, BreakLoop) {55 // There are two loops (1,2,3) and (1,2,4). It is beneficial to place 456 // elsewhere.57 const uint64_t Counts[6] = {177, 371, 196, 124, 70, 177};58 std::vector<uint64_t> Sizes(std::size(Counts), 9);59 const EdgeCount Edges[] = {{0, 1, 177}, {1, 2, 196}, {2, 3, 124}, {3, 1, 124},60 {1, 5, 177}, {2, 4, 79}, {4, 1, 70}};61 const std::vector<uint64_t> CallOffsets(std::size(Edges), 5);62 auto Order = computeCacheDirectedLayout(Sizes, Counts, Edges, CallOffsets);63 EXPECT_THAT(Order, ElementsAreArray({4, 0, 1, 2, 3, 5}));64 65 // When node 0 is larger, it is beneficial to move node 4 closer to the66 // (1,2,3) loop.67 Sizes[0] = 18;68 Order = computeCacheDirectedLayout(Sizes, Counts, Edges, CallOffsets);69 EXPECT_THAT(Order, ElementsAreArray({0, 4, 1, 2, 3, 5}));70}71} // namespace72