SafepointIndex.h (2343B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- 2 * vim: set ts=8 sts=2 et sw=2 tw=80: 3 * This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef jit_SafepointIndex_h 8 #define jit_SafepointIndex_h 9 10 #include <stdint.h> 11 12 #include "jit/IonTypes.h" 13 14 namespace js { 15 namespace jit { 16 17 class LSafepoint; 18 class CodegenSafepointIndex; 19 20 // Two-tuple that lets you look up the safepoint entry given the 21 // displacement of a call instruction within the JIT code. 22 class SafepointIndex { 23 // The displacement is the distance from the first byte of the JIT'd code 24 // to the return address (of the call that the safepoint was generated for). 25 uint32_t displacement_ = 0; 26 27 // Offset within the safepoint buffer. 28 uint32_t safepointOffset_ = 0; 29 30 public: 31 inline explicit SafepointIndex(const CodegenSafepointIndex& csi); 32 33 uint32_t displacement() const { return displacement_; } 34 uint32_t safepointOffset() const { return safepointOffset_; } 35 }; 36 37 class CodegenSafepointIndex { 38 uint32_t displacement_ = 0; 39 40 LSafepoint* safepoint_ = nullptr; 41 42 public: 43 CodegenSafepointIndex(uint32_t displacement, LSafepoint* safepoint) 44 : displacement_(displacement), safepoint_(safepoint) {} 45 46 LSafepoint* safepoint() const { return safepoint_; } 47 uint32_t displacement() const { return displacement_; } 48 49 inline SnapshotOffset snapshotOffset() const; 50 inline bool hasSnapshotOffset() const; 51 }; 52 53 // The OSI point is patched to a call instruction. Therefore, the 54 // returnPoint for an OSI call is the address immediately following that 55 // call instruction. The displacement of that point within the assembly 56 // buffer is the |returnPointDisplacement|. 57 class OsiIndex { 58 uint32_t callPointDisplacement_; 59 uint32_t snapshotOffset_; 60 61 public: 62 OsiIndex(uint32_t callPointDisplacement, uint32_t snapshotOffset) 63 : callPointDisplacement_(callPointDisplacement), 64 snapshotOffset_(snapshotOffset) {} 65 66 uint32_t returnPointDisplacement() const; 67 uint32_t callPointDisplacement() const { return callPointDisplacement_; } 68 uint32_t snapshotOffset() const { return snapshotOffset_; } 69 }; 70 71 } /* namespace jit */ 72 } /* namespace js */ 73 74 #endif /* jit_SafepointIndex_h */