xref: /llvm-project/llvm/unittests/Target/AMDGPU/ExecMayBeModifiedBeforeAnyUse.cpp (revision 63e1647827f3427c5f3ad37461d84a63ba5fcdaf)
1 //===- llvm/unittests/Target/AMDGPU/ExecMayBeModifiedBeforeAnyUse.cpp -----===//
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 "AMDGPUTargetMachine.h"
10 #include "AMDGPUUnitTests.h"
11 #include "llvm/CodeGen/MachineModuleInfo.h"
12 #include "gtest/gtest.h"
13 
14 using namespace llvm;
15 
16 TEST(AMDGPU, ExecMayBeModifiedBeforeAnyUse) {
17   auto TM = createAMDGPUTargetMachine("amdgcn-amd-", "gfx906", "");
18   if (!TM)
19     GTEST_SKIP();
20 
21   GCNSubtarget ST(TM->getTargetTriple(), std::string(TM->getTargetCPU()),
22                   std::string(TM->getTargetFeatureString()), *TM);
23 
24   LLVMContext Ctx;
25   Module Mod("Module", Ctx);
26   Mod.setDataLayout(TM->createDataLayout());
27 
28   auto *Type = FunctionType::get(Type::getVoidTy(Ctx), false);
29   auto *F = Function::Create(Type, GlobalValue::ExternalLinkage, "Test", &Mod);
30 
31   MachineModuleInfo MMI(TM.get());
32   auto MF =
33       std::make_unique<MachineFunction>(*F, *TM, ST, MMI.getContext(), 42);
34   auto *BB = MF->CreateMachineBasicBlock();
35   MF->push_back(BB);
36 
37   auto E = BB->end();
38   DebugLoc DL;
39   const auto &TII = *ST.getInstrInfo();
40   auto &MRI = MF->getRegInfo();
41 
42   // create machine IR
43   Register R = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
44 
45   MachineInstr *DefMI =
46       BuildMI(*BB, E, DL, TII.get(AMDGPU::S_MOV_B32), R).addImm(42).getInstr();
47 
48   auto First =
49       BuildMI(*BB, E, DL, TII.get(AMDGPU::S_NOP)).addReg(R, RegState::Implicit);
50 
51   BuildMI(*BB, E, DL, TII.get(AMDGPU::S_NOP)).addReg(R, RegState::Implicit);
52 
53   // this violates the continuous sequence of R's uses for the first S_NOP
54   First.addReg(R, RegState::Implicit);
55 
56 #ifdef DEBUG_THIS_TEST
57   MF->dump();
58   MRI.dumpUses(R);
59 #endif
60 
61   // make sure execMayBeModifiedBeforeAnyUse doesn't crash
62   ASSERT_FALSE(execMayBeModifiedBeforeAnyUse(MRI, R, *DefMI));
63 }
64