Fangrui Song f36616f7db [AArch64] Add function attribute "patchable-function-entry" to add NOPs at function entry ... The Linux kernel uses -fpatchable-function-entry to implement DYNAMIC_FTRACE_WITH_REGS for arm64 and parisc. GCC 8 implemented -fpatchable-function-entry, which can be seen as a generalized form of -mnop-mcount. The N,M form (function entry points before the Mth NOP) is currently only used by parisc. This patch adds N,0 support to AArch64 codegen. N is represented as the function attribute "patchable-function-entry". We will use a different function attribute for M, if we decide to implement it. The patch reuses the existing patchable-function pass, and TargetOpcode::PATCHABLE_FUNCTION_ENTER which is currently used by XRay. When the integrated assembler is used, __patchable_function_entries will be created for each text section with the SHF_LINK_ORDER flag to prevent --gc-sections (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93197) and COMDAT (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93195) issues. Retrospectively, __patchable_function_entries should use a PC-relative relocation type to avoid the SHF_WRITE flag and dynamic relocations. "patchable-function-entry"'s interaction with Branch Target Identification is still unclear (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 for GCC discussions). Reviewed By: peter.smith Differential Revision: https://reviews.llvm.org/D72215		2020-01-10 09:55:51 -08:00
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AbstractCallSite.cpp	[Attributor] Use abstract call sites to determine associated arguments	2019-12-31 01:33:22 -06:00
AsmWriter.cpp	OpaquePtr: print byval types containing anonymous types correctly.	2020-01-07 15:11:43 +00:00
AttributeImpl.h
Attributes.cpp
AttributesCompatFunc.td
AutoUpgrade.cpp	Add Triple::isX86()	2020-01-06 15:51:02 -08:00
BasicBlock.cpp
CMakeLists.txt
Comdat.cpp
ConstantFold.cpp
ConstantFold.h
ConstantRange.cpp	[ConstantRange] Respect destination bitwidth for cast results.	2019-12-27 17:38:34 +00:00
Constants.cpp
ConstantsContext.h
Core.cpp	IR: remove "else" after "return". NFCI.	2020-01-09 15:00:54 +00:00
DataLayout.cpp
DebugInfo.cpp	reland "[DebugInfo] Support to emit debugInfo for extern variables"	2019-12-22 18:28:50 -08:00
DebugInfoMetadata.cpp	Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot	2019-12-20 13:11:17 -08:00
DebugLoc.cpp
DiagnosticHandler.cpp
DiagnosticInfo.cpp
DiagnosticPrinter.cpp
DIBuilder.cpp	Fix case style warnings in DIBuilder. NFC.	2019-12-23 07:27:18 +00:00
Dominators.cpp
FPEnv.cpp
Function.cpp
Globals.cpp
GVMaterializer.cpp
InlineAsm.cpp
Instruction.cpp
Instructions.cpp
IntrinsicInst.cpp
IRBuilder.cpp	[Alignment][NFC] Align compatible methods for CreateElementUnorderedAtomicMemSet	2019-12-19 20:03:35 +01:00
IRPrintingPasses.cpp
LegacyPassManager.cpp
LLVMBuild.txt
LLVMContext.cpp
LLVMContextImpl.cpp
LLVMContextImpl.h	Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot	2019-12-20 13:11:17 -08:00
Mangler.cpp
MDBuilder.cpp
Metadata.cpp	[Metadata] Add TBAA struct metadata to AAMDNode	2020-01-06 11:05:15 +03:00
MetadataImpl.h
Module.cpp
ModuleSummaryIndex.cpp
Operator.cpp
OptBisect.cpp
Pass.cpp
PassInstrumentation.cpp
PassManager.cpp
PassRegistry.cpp
PassTimingInfo.cpp
ProfileSummary.cpp
RemarkStreamer.cpp
SafepointIRVerifier.cpp
Statepoint.cpp
SymbolTableListTraitsImpl.h
Type.cpp
TypeFinder.cpp	[NFC] Fixes -Wrange-loop-analysis warnings	2020-01-01 20:01:37 +01:00
Use.cpp
User.cpp
Value.cpp
ValueSymbolTable.cpp
Verifier.cpp	[AArch64] Add function attribute "patchable-function-entry" to add NOPs at function entry	2020-01-10 09:55:51 -08:00