llvm/unittests/Transforms/Utils/UnrollLoopTest.cpp

   1 //===- UnrollLoopTest.cpp - Unit tests for UnrollLoop ---------------------===//
   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/Transforms/Utils/UnrollLoop.h"
  10 #include "llvm/Analysis/AssumptionCache.h"
  11 #include "llvm/Analysis/LoopInfo.h"
  12 #include "llvm/Analysis/ScalarEvolution.h"
  13 #include "llvm/Analysis/TargetLibraryInfo.h"
  14 #include "llvm/AsmParser/Parser.h"
  15 #include "llvm/IR/BasicBlock.h"
  16 #include "llvm/IR/Dominators.h"
  17 #include "llvm/IR/LLVMContext.h"
  18 #include "llvm/Support/SourceMgr.h"
  19 #include "gtest/gtest.h"
  20
  21 using namespace llvm;
  22
  23 static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
  24   SMDiagnostic Err;
  25   std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
  26   if (!Mod)
  27     Err.print("UnrollLoopTests", errs());
  28   return Mod;
  29 }
  30
  31 TEST(LoopUnrollRuntime, Latch) {
  32   LLVMContext C;
  33
  34   std::unique_ptr<Module> M = parseIR(
  35     C,
  36     R"(define i32 @test(i32* %a, i32* %b, i32* %c, i64 %n) {
  37 entry:
  38   br label %while.cond
  39
  40 while.cond:                                       ; preds = %while.body, %entry
  41   %i.0 = phi i64 [ 0, %entry ], [ %inc, %while.body ]
  42   %cmp = icmp slt i64 %i.0, %n
  43   br i1 %cmp, label %while.body, label %while.end
  44
  45 while.body:                                       ; preds = %while.cond
  46   %arrayidx = getelementptr inbounds i32, i32* %b, i64 %i.0
  47   %0 = load i32, i32* %arrayidx
  48   %arrayidx1 = getelementptr inbounds i32, i32* %c, i64 %i.0
  49   %1 = load i32, i32* %arrayidx1
  50   %mul = mul nsw i32 %0, %1
  51   %arrayidx2 = getelementptr inbounds i32, i32* %a, i64 %i.0
  52   store i32 %mul, i32* %arrayidx2
  53   %inc = add nsw i64 %i.0, 1
  54   br label %while.cond
  55
  56 while.end:                                        ; preds = %while.cond
  57   ret i32 0
  58 })"
  59     );
  60
  61   auto *F = M->getFunction("test");
  62   DominatorTree DT(*F);
  63   LoopInfo LI(DT);
  64   AssumptionCache AC(*F);
  65   TargetLibraryInfoImpl TLII;
  66   TargetLibraryInfo TLI(TLII);
  67   ScalarEvolution SE(*F, TLI, AC, DT, LI);
  68
  69   Loop *L = *LI.begin();
  70
  71   bool PreserveLCSSA = L->isRecursivelyLCSSAForm(DT,LI);
  72
  73   bool ret =
  74       UnrollRuntimeLoopRemainder(L, 4, true, false, false, false, &LI, &SE, &DT,
  75                                  &AC, /*TTI=*/nullptr, PreserveLCSSA);
  76   EXPECT_FALSE(ret);
  77 }