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