[RuntimeDyld] Don't allocate unnecessary stub buffer space
Summary:
For relocation types that are known to not require stub functions, there
is no need to allocate extra space for the stub functions.
Reviewers: lhames, reames, maksfb
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14676
llvm-svn: 253920
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 93de920..dd02ece 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -432,10 +432,9 @@
if (!(RelSecI == Section))
continue;
- for (const RelocationRef &Reloc : SI->relocations()) {
- (void)Reloc;
- StubBufSize += StubSize;
- }
+ for (const RelocationRef &Reloc : SI->relocations())
+ if (relocationNeedsStub(Reloc))
+ StubBufSize += StubSize;
}
// Get section data size and alignment
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index fea9b96..6f8cb10 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -1851,4 +1851,23 @@
return Obj.isELF();
}
+bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
+ if (Arch != Triple::x86_64)
+ return true; // Conservative answer
+
+ switch (R.getType()) {
+ default:
+ return true; // Conservative answer
+
+
+ case ELF::R_X86_64_GOTPCREL:
+ case ELF::R_X86_64_PC32:
+ case ELF::R_X86_64_PC64:
+ case ELF::R_X86_64_64:
+ // We know that these reloation types won't need a stub function. This list
+ // can be extended as needed.
+ return false;
+ }
+}
+
} // namespace llvm
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
index 22f0214..041811d 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
@@ -152,6 +152,8 @@
SmallVector<SID, 2> UnregisteredEHFrameSections;
SmallVector<SID, 2> RegisteredEHFrameSections;
+ bool relocationNeedsStub(const RelocationRef &R) const override;
+
public:
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
RuntimeDyld::SymbolResolver &Resolver);
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
index 6838648..2bb6dec 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
@@ -416,6 +416,11 @@
// \brief Implementation of the generic part of the loadObject algorithm.
ObjSectionToIDMap loadObjectImpl(const object::ObjectFile &Obj);
+ // \brief Return true if the relocation R may require allocating a stub.
+ virtual bool relocationNeedsStub(const RelocationRef &R) const {
+ return true; // Conservative answer
+ }
+
public:
RuntimeDyldImpl(RuntimeDyld::MemoryManager &MemMgr,
RuntimeDyld::SymbolResolver &Resolver)