1 //===- ValueTrackingTest.cpp - ValueTracking tests ------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "llvm/Analysis/ValueTracking.h" 11 #include "llvm/AsmParser/Parser.h" 12 #include "llvm/IR/Function.h" 13 #include "llvm/IR/InstIterator.h" 14 #include "llvm/IR/LLVMContext.h" 15 #include "llvm/IR/Module.h" 16 #include "llvm/Support/ErrorHandling.h" 17 #include "llvm/Support/SourceMgr.h" 18 #include "gtest/gtest.h" 19 20 using namespace llvm; 21 22 namespace { 23 24 class MatchSelectPatternTest : public testing::Test { 25 protected: parseAssembly(const char * Assembly)26 void parseAssembly(const char *Assembly) { 27 SMDiagnostic Error; 28 M = parseAssemblyString(Assembly, Error, getGlobalContext()); 29 30 std::string errMsg; 31 raw_string_ostream os(errMsg); 32 Error.print("", os); 33 34 // A failure here means that the test itself is buggy. 35 if (!M) 36 report_fatal_error(os.str()); 37 38 Function *F = M->getFunction("test"); 39 if (F == nullptr) 40 report_fatal_error("Test must have a function named @test"); 41 42 A = nullptr; 43 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) { 44 if (I->hasName()) { 45 if (I->getName() == "A") 46 A = &*I; 47 } 48 } 49 if (A == nullptr) 50 report_fatal_error("@test must have an instruction %A"); 51 } 52 expectPattern(const SelectPatternResult & P)53 void expectPattern(const SelectPatternResult &P) { 54 Value *LHS, *RHS; 55 Instruction::CastOps CastOp; 56 SelectPatternResult R = matchSelectPattern(A, LHS, RHS, &CastOp); 57 EXPECT_EQ(P.Flavor, R.Flavor); 58 EXPECT_EQ(P.NaNBehavior, R.NaNBehavior); 59 EXPECT_EQ(P.Ordered, R.Ordered); 60 } 61 62 std::unique_ptr<Module> M; 63 Instruction *A, *B; 64 }; 65 66 } 67 TEST_F(MatchSelectPatternTest,SimpleFMin)68 TEST_F(MatchSelectPatternTest, SimpleFMin) { 69 parseAssembly( 70 "define float @test(float %a) {\n" 71 " %1 = fcmp ult float %a, 5.0\n" 72 " %A = select i1 %1, float %a, float 5.0\n" 73 " ret float %A\n" 74 "}\n"); 75 expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false}); 76 } 77 TEST_F(MatchSelectPatternTest,SimpleFMax)78 TEST_F(MatchSelectPatternTest, SimpleFMax) { 79 parseAssembly( 80 "define float @test(float %a) {\n" 81 " %1 = fcmp ogt float %a, 5.0\n" 82 " %A = select i1 %1, float %a, float 5.0\n" 83 " ret float %A\n" 84 "}\n"); 85 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); 86 } 87 TEST_F(MatchSelectPatternTest,SwappedFMax)88 TEST_F(MatchSelectPatternTest, SwappedFMax) { 89 parseAssembly( 90 "define float @test(float %a) {\n" 91 " %1 = fcmp olt float 5.0, %a\n" 92 " %A = select i1 %1, float %a, float 5.0\n" 93 " ret float %A\n" 94 "}\n"); 95 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false}); 96 } 97 TEST_F(MatchSelectPatternTest,SwappedFMax2)98 TEST_F(MatchSelectPatternTest, SwappedFMax2) { 99 parseAssembly( 100 "define float @test(float %a) {\n" 101 " %1 = fcmp olt float %a, 5.0\n" 102 " %A = select i1 %1, float 5.0, float %a\n" 103 " ret float %A\n" 104 "}\n"); 105 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false}); 106 } 107 TEST_F(MatchSelectPatternTest,SwappedFMax3)108 TEST_F(MatchSelectPatternTest, SwappedFMax3) { 109 parseAssembly( 110 "define float @test(float %a) {\n" 111 " %1 = fcmp ult float %a, 5.0\n" 112 " %A = select i1 %1, float 5.0, float %a\n" 113 " ret float %A\n" 114 "}\n"); 115 expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); 116 } 117 TEST_F(MatchSelectPatternTest,FastFMin)118 TEST_F(MatchSelectPatternTest, FastFMin) { 119 parseAssembly( 120 "define float @test(float %a) {\n" 121 " %1 = fcmp nnan olt float %a, 5.0\n" 122 " %A = select i1 %1, float %a, float 5.0\n" 123 " ret float %A\n" 124 "}\n"); 125 expectPattern({SPF_FMINNUM, SPNB_RETURNS_ANY, false}); 126 } 127 TEST_F(MatchSelectPatternTest,FMinConstantZero)128 TEST_F(MatchSelectPatternTest, FMinConstantZero) { 129 parseAssembly( 130 "define float @test(float %a) {\n" 131 " %1 = fcmp ole float %a, 0.0\n" 132 " %A = select i1 %1, float %a, float 0.0\n" 133 " ret float %A\n" 134 "}\n"); 135 // This shouldn't be matched, as %a could be -0.0. 136 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 137 } 138 TEST_F(MatchSelectPatternTest,FMinConstantZeroNsz)139 TEST_F(MatchSelectPatternTest, FMinConstantZeroNsz) { 140 parseAssembly( 141 "define float @test(float %a) {\n" 142 " %1 = fcmp nsz ole float %a, 0.0\n" 143 " %A = select i1 %1, float %a, float 0.0\n" 144 " ret float %A\n" 145 "}\n"); 146 // But this should be, because we've ignored signed zeroes. 147 expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true}); 148 } 149 TEST_F(MatchSelectPatternTest,DoubleCastU)150 TEST_F(MatchSelectPatternTest, DoubleCastU) { 151 parseAssembly( 152 "define i32 @test(i8 %a, i8 %b) {\n" 153 " %1 = icmp ult i8 %a, %b\n" 154 " %2 = zext i8 %a to i32\n" 155 " %3 = zext i8 %b to i32\n" 156 " %A = select i1 %1, i32 %2, i32 %3\n" 157 " ret i32 %A\n" 158 "}\n"); 159 // We should be able to look through the situation where we cast both operands 160 // to the select. 161 expectPattern({SPF_UMIN, SPNB_NA, false}); 162 } 163 TEST_F(MatchSelectPatternTest,DoubleCastS)164 TEST_F(MatchSelectPatternTest, DoubleCastS) { 165 parseAssembly( 166 "define i32 @test(i8 %a, i8 %b) {\n" 167 " %1 = icmp slt i8 %a, %b\n" 168 " %2 = sext i8 %a to i32\n" 169 " %3 = sext i8 %b to i32\n" 170 " %A = select i1 %1, i32 %2, i32 %3\n" 171 " ret i32 %A\n" 172 "}\n"); 173 // We should be able to look through the situation where we cast both operands 174 // to the select. 175 expectPattern({SPF_SMIN, SPNB_NA, false}); 176 } 177 TEST_F(MatchSelectPatternTest,DoubleCastBad)178 TEST_F(MatchSelectPatternTest, DoubleCastBad) { 179 parseAssembly( 180 "define i32 @test(i8 %a, i8 %b) {\n" 181 " %1 = icmp ult i8 %a, %b\n" 182 " %2 = zext i8 %a to i32\n" 183 " %3 = sext i8 %b to i32\n" 184 " %A = select i1 %1, i32 %2, i32 %3\n" 185 " ret i32 %A\n" 186 "}\n"); 187 // The cast types here aren't the same, so we cannot match an UMIN. 188 expectPattern({SPF_UNKNOWN, SPNB_NA, false}); 189 } 190