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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253920
91177308-0d34-0410-b5e6-
96231b3b80d8
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
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
SmallVector<SID, 2> UnregisteredEHFrameSections;
SmallVector<SID, 2> RegisteredEHFrameSections;
+ bool relocationNeedsStub(const RelocationRef &R) const override;
+
public:
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
RuntimeDyld::SymbolResolver &Resolver);
// \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)
--- /dev/null
+# RUN: llvm-mc -triple=x86_64-apple-macosx10.10.0 -filetype=obj -o %T/test_ELF_x86_64_StubBuf.o %s
+# RUN: llvm-rtdyld -print-alloc-requests -triple=x86_64-pc-linux -dummy-extern _g=196608 -verify %T/test_ELF_x86_64_StubBuf.o
+
+# Compiled from Inputs/ELF/ELF_x86_64_StubBuf.ll
+
+# CHECK: allocateCodeSection(Size = 42, Alignment = 16, SectionName = __text)
+
+ .section __TEXT,__text,regular,pure_instructions
+ .macosx_version_min 10, 10
+ .globl _f
+ .align 4, 0x90
+_f: ## @f
+ .cfi_startproc
+## BB#0: ## %entry
+ pushq %rax
+Ltmp0:
+ .cfi_def_cfa_offset 16
+ callq _g
+ callq _g
+ callq _g
+ popq %rax
+ retq
+ .cfi_endproc
+
+
+.subsections_via_symbols
--- /dev/null
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+declare void @g()
+
+define void @f() {
+ entry:
+ call void @g()
+ call void @g()
+ call void @g()
+ ret void
+}
cl::ZeroOrMore,
cl::Hidden);
+static cl::opt<bool>
+PrintAllocationRequests("print-alloc-requests",
+ cl::desc("Print allocation requests made to the memory "
+ "manager by RuntimeDyld"),
+ cl::Hidden);
+
/* *** */
// A trivial memory manager that doesn't do anything fancy, just uses the
unsigned Alignment,
unsigned SectionID,
StringRef SectionName) {
+ if (PrintAllocationRequests)
+ outs() << "allocateCodeSection(Size = " << Size << ", Alignment = "
+ << Alignment << ", SectionName = " << SectionName << ")\n";
+
if (UsePreallocation)
return allocateFromSlab(Size, Alignment, true /* isCode */);
unsigned SectionID,
StringRef SectionName,
bool IsReadOnly) {
+ if (PrintAllocationRequests)
+ outs() << "allocateDataSection(Size = " << Size << ", Alignment = "
+ << Alignment << ", SectionName = " << SectionName << ")\n";
+
if (UsePreallocation)
return allocateFromSlab(Size, Alignment, false /* isCode */);