1 //===-- AMDGPUMachineFunctionInfo.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 "AMDGPUMachineFunction.h"
10 #include "AMDGPUSubtarget.h"
11 #include "AMDGPUPerfHintAnalysis.h"
12 #include "llvm/CodeGen/MachineModuleInfo.h"
13 
14 using namespace llvm;
15 
16 AMDGPUMachineFunction::AMDGPUMachineFunction(const MachineFunction &MF)
17     : MachineFunctionInfo(), Mode(MF.getFunction()),
18       IsEntryFunction(
19           AMDGPU::isEntryFunctionCC(MF.getFunction().getCallingConv())),
20       IsModuleEntryFunction(
21           AMDGPU::isModuleEntryFunctionCC(MF.getFunction().getCallingConv())),
22       NoSignedZerosFPMath(MF.getTarget().Options.NoSignedZerosFPMath) {
23   const AMDGPUSubtarget &ST = AMDGPUSubtarget::get(MF);
24 
25   // FIXME: Should initialize KernArgSize based on ExplicitKernelArgOffset,
26   // except reserved size is not correctly aligned.
27   const Function &F = MF.getFunction();
28 
29   Attribute MemBoundAttr = F.getFnAttribute("amdgpu-memory-bound");
30   MemoryBound = MemBoundAttr.isStringAttribute() &&
31                 MemBoundAttr.getValueAsString() == "true";
32 
33   Attribute WaveLimitAttr = F.getFnAttribute("amdgpu-wave-limiter");
34   WaveLimiter = WaveLimitAttr.isStringAttribute() &&
35                 WaveLimitAttr.getValueAsString() == "true";
36 
37   CallingConv::ID CC = F.getCallingConv();
38   if (CC == CallingConv::AMDGPU_KERNEL || CC == CallingConv::SPIR_KERNEL)
39     ExplicitKernArgSize = ST.getExplicitKernArgSize(F, MaxKernArgAlign);
40 }
41 
42 unsigned AMDGPUMachineFunction::allocateLDSGlobal(const DataLayout &DL,
43                                                   const GlobalVariable &GV) {
44   auto Entry = LocalMemoryObjects.insert(std::make_pair(&GV, 0));
45   if (!Entry.second)
46     return Entry.first->second;
47 
48   Align Alignment =
49       DL.getValueOrABITypeAlignment(GV.getAlign(), GV.getValueType());
50 
51   /// TODO: We should sort these to minimize wasted space due to alignment
52   /// padding. Currently the padding is decided by the first encountered use
53   /// during lowering.
54   unsigned Offset = StaticLDSSize = alignTo(StaticLDSSize, Alignment);
55 
56   Entry.first->second = Offset;
57   StaticLDSSize += DL.getTypeAllocSize(GV.getValueType());
58 
59   // Update the LDS size considering the padding to align the dynamic shared
60   // memory.
61   LDSSize = alignTo(StaticLDSSize, DynLDSAlign);
62 
63   return Offset;
64 }
65 
66 void AMDGPUMachineFunction::setDynLDSAlign(const DataLayout &DL,
67                                            const GlobalVariable &GV) {
68   assert(DL.getTypeAllocSize(GV.getValueType()).isZero());
69 
70   Align Alignment =
71       DL.getValueOrABITypeAlignment(GV.getAlign(), GV.getValueType());
72   if (Alignment <= DynLDSAlign)
73     return;
74 
75   LDSSize = alignTo(StaticLDSSize, Alignment);
76   DynLDSAlign = Alignment;
77 }
78