llvm/unittests/Analysis/ReplaceWithVecLibTest.cpp

   1 //===--- ReplaceWithVecLibTest.cpp - replace-with-veclib unit tests -------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/CodeGen/ReplaceWithVeclib.h"
  10 #include "llvm/Analysis/TargetLibraryInfo.h"
  11 #include "llvm/AsmParser/Parser.h"
  12 #include "llvm/IR/LLVMContext.h"
  13 #include "llvm/IR/Module.h"
  14 #include "llvm/Passes/PassBuilder.h"
  15 #include "llvm/Support/SourceMgr.h"
  16 #include "gtest/gtest.h"
  17
  18 using namespace llvm;
  19
  20 /// NOTE: Assertions must be enabled for these tests to run.
  21 #ifndef NDEBUG
  22
  23 namespace {
  24
  25 static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
  26   SMDiagnostic Err;
  27   std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
  28   if (!Mod)
  29     Err.print("ReplaceWithVecLibTest", errs());
  30   return Mod;
  31 }
  32
  33 /// Runs ReplaceWithVecLib with different TLIIs that have custom VecDescs. This
  34 /// allows checking that the pass won't crash when the function to replace (from
  35 /// the input IR) does not match the replacement function (derived from the
  36 /// VecDesc mapping).
  37 ///
  38 class ReplaceWithVecLibTest : public ::testing::Test {
  39
  40   std::string getLastLine(std::string Out) {
  41     // remove any trailing '\n'
  42     if (!Out.empty() && *(Out.cend() - 1) == '\n')
  43       Out.pop_back();
  44
  45     size_t LastNL = Out.find_last_of('\n');
  46     return (LastNL == std::string::npos) ? Out : Out.substr(LastNL + 1);
  47   }
  48
  49 protected:
  50   LLVMContext Ctx;
  51
  52   /// Creates TLII using the given \p VD, and then runs the ReplaceWithVeclib
  53   /// pass. The pass should not crash even when the replacement function
  54   /// (derived from the \p VD mapping) does not match the function to be
  55   /// replaced (from the input \p IR).
  56   ///
  57   /// \returns the last line of the standard error to be compared for
  58   /// correctness.
  59   std::string run(const VecDesc &VD, const char *IR) {
  60     // Create TLII and register it with FAM so it's preserved when
  61     // ReplaceWithVeclib pass runs.
  62     TargetLibraryInfoImpl TLII = TargetLibraryInfoImpl(Triple());
  63     TLII.addVectorizableFunctions({VD});
  64     FunctionAnalysisManager FAM;
  65     FAM.registerPass([&TLII]() { return TargetLibraryAnalysis(TLII); });
  66
  67     // Register and run the pass on the 'foo' function from the input IR.
  68     FunctionPassManager FPM;
  69     FPM.addPass(ReplaceWithVeclib());
  70     std::unique_ptr<Module> M = parseIR(Ctx, IR);
  71     PassBuilder PB;
  72     PB.registerFunctionAnalyses(FAM);
  73
  74     // Enable debugging and capture std error
  75     bool DebugFlagPrev = llvm::DebugFlag;
  76     llvm::DebugFlag = true;
  77     testing::internal::CaptureStderr();
  78     FPM.run(*M->getFunction("foo"), FAM);
  79     llvm::DebugFlag = DebugFlagPrev;
  80     return getLastLine(testing::internal::GetCapturedStderr());
  81   }
  82 };
  83
  84 } // end anonymous namespace
  85
  86 static const char *IR = R"IR(
  87 define <vscale x 4 x float> @foo(<vscale x 4 x float> %in){
  88   %call = call <vscale x 4 x float> @llvm.powi.f32.i32(<vscale x 4 x float> %in, i32 3)
  89   ret <vscale x 4 x float> %call
  90 }
  91
  92 declare <vscale x 4 x float> @llvm.powi.f32.i32(<vscale x 4 x float>, i32) #0
  93 )IR";
  94
  95 // The VFABI prefix in TLI describes signature which is matching the powi
  96 // intrinsic declaration.
  97 TEST_F(ReplaceWithVecLibTest, TestValidMapping) {
  98   VecDesc CorrectVD = {"llvm.powi.f32.i32", "_ZGVsMxvu_powi",
  99                        ElementCount::getScalable(4), /*Masked*/ true,
 100                        "_ZGVsMxvu"};
 101   EXPECT_EQ(run(CorrectVD, IR),
 102             "Intrinsic calls replaced with vector libraries: 1");
 103 }
 104
 105 // The VFABI prefix in TLI describes signature which is not matching the powi
 106 // intrinsic declaration.
 107 TEST_F(ReplaceWithVecLibTest, TestInvalidMapping) {
 108   VecDesc IncorrectVD = {"llvm.powi.f32.i32", "_ZGVsMxvv_powi",
 109                          ElementCount::getScalable(4), /*Masked*/ true,
 110                          "_ZGVsMxvv"};
 111   EXPECT_EQ(run(IncorrectVD, IR),
 112             "replace-with-veclib: Will not replace: llvm.powi.f32.i32. Wrong "
 113             "type at index 1: i32");
 114 }
 115 #endif