1 //===- ReduceIRReferences.cpp - Specialized Delta Pass --------------------===//
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 // This file implements a function which calls the Generic Delta pass in order
10 // to remove backreferences to the IR from MIR. In particular, this will remove
11 // the Value references in MachineMemOperands.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "ReduceIRReferences.h"
16 #include "Delta.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineModuleInfo.h"
20
21 using namespace llvm;
22
dropIRReferencesFromInstructions(Oracle & O,MachineFunction & MF)23 static void dropIRReferencesFromInstructions(Oracle &O, MachineFunction &MF) {
24 for (MachineBasicBlock &MBB : MF) {
25 for (MachineInstr &MI : MBB) {
26 if (!O.shouldKeep()) {
27 for (MachineMemOperand *MMO : MI.memoperands()) {
28 // Leave behind pseudo source values.
29 // TODO: Removing all MemOperand values is a further reduction step.
30 if (MMO->getPointerInfo().V.is<const Value *>())
31 MMO->setValue(static_cast<const Value *>(nullptr));
32 }
33
34 // TODO: Try to remove GlobalValue references and metadata
35 }
36 }
37 }
38 }
39
stripIRFromInstructions(Oracle & O,ReducerWorkItem & WorkItem)40 static void stripIRFromInstructions(Oracle &O, ReducerWorkItem &WorkItem) {
41 for (const Function &F : WorkItem.getModule()) {
42 if (auto *MF = WorkItem.MMI->getMachineFunction(F))
43 dropIRReferencesFromInstructions(O, *MF);
44 }
45 }
46
stripIRFromBlocks(Oracle & O,ReducerWorkItem & WorkItem)47 static void stripIRFromBlocks(Oracle &O, ReducerWorkItem &WorkItem) {
48 for (const Function &F : WorkItem.getModule()) {
49 if (auto *MF = WorkItem.MMI->getMachineFunction(F)) {
50 for (MachineBasicBlock &MBB : *MF) {
51 if (!O.shouldKeep())
52 MBB.clearBasicBlock();
53 }
54 }
55 }
56 }
57
stripIRFromFunctions(Oracle & O,ReducerWorkItem & WorkItem)58 static void stripIRFromFunctions(Oracle &O, ReducerWorkItem &WorkItem) {
59 for (const Function &F : WorkItem.getModule()) {
60 if (!O.shouldKeep()) {
61 if (auto *MF = WorkItem.MMI->getMachineFunction(F)) {
62 MachineFrameInfo &MFI = MF->getFrameInfo();
63 for (int I = MFI.getObjectIndexBegin(), E = MFI.getObjectIndexEnd();
64 I != E; ++I)
65 MFI.clearObjectAllocation(I);
66 }
67 }
68 }
69 }
70
reduceIRInstructionReferencesDeltaPass(TestRunner & Test)71 void llvm::reduceIRInstructionReferencesDeltaPass(TestRunner &Test) {
72 runDeltaPass(Test, stripIRFromInstructions,
73 "Reducing IR references from instructions");
74 }
75
reduceIRBlockReferencesDeltaPass(TestRunner & Test)76 void llvm::reduceIRBlockReferencesDeltaPass(TestRunner &Test) {
77 runDeltaPass(Test, stripIRFromBlocks, "Reducing IR references from blocks");
78 }
79
reduceIRFunctionReferencesDeltaPass(TestRunner & Test)80 void llvm::reduceIRFunctionReferencesDeltaPass(TestRunner &Test) {
81 runDeltaPass(Test, stripIRFromFunctions,
82 "Reducing IR references from functions");
83 }
84