summaryrefslogtreecommitdiffstats
path: root/llvm/lib/MC/MCObjectStreamer.cpp
Commit message (Collapse)AuthorAgeFilesLines
* [BranchAlign] Compiler support for suppressing branch alignPhilip Reames2020-01-081-1/+4
| | | | | | | | | | | | As discussed heavily in the original review (D70157), there's a need for the compiler to be able to selective suppress padding (either nop or prefix) to respect assumptions about the meaning of labels and instructions in generated code. Rather than wait for syntax to be finalized - which appears to be a very slow process - this patch focuses on the compiler use case and *only* worries about the integrated assembler. To my knowledge, this covers all cases mentioned to date for clang/JIT support. For testing purposes, I wired it up so that if the integrated assembler was using autopadding for branch alignment (e.g. enabled at command line) then the textual assembly output would contain a comment for each location where padding was enabled or disabled. This seemed like the least painful choice overall. Note that the result of this patch effective disables the jcc errata mitigation for many constructs (statepoints, implicit null checks, xray, etc...) which is non ideal. It is at least *correct* and should allow us to enable the mitigation for the compiler. Once that's done, and a few other items are worked through, we probably want to come back to this an explore a bundling based approach instead so that we can pad instructions while keeping labels in the right place. Differential Revision: https://reviews.llvm.org/D72303
* [MC][ARM] Delete MCSection::HasData and move SHF_ARM_PURECODE logic to ↵Fangrui Song2020-01-051-6/+0
| | | | | | | | ARMELFObjectWriter::addTargetSectionFlags This simplifies the generic interface and also makes SHF_ARM_PURECODE more robust (fixes a TODO). Inspecting MCDataFragment contents covers more cases than MCObjectStreamer::EmitBytes.
* Align branches within 32-Byte boundary (NOP padding)Philip Reames2019-12-201-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: If you're looking at this patch because you're looking for a full performace mitigation of the Intel JCC Erratum, this is not it! This is a preliminary patch on the patch towards mitigating the performance regressions caused by Intel's microcode update for Jump Conditional Code Erratum. For context, see: https://www.intel.com/content/www/us/en/support/articles/000055650.html The patch adds the required assembler infrastructure and command line options needed to exercise the logic for INTERNAL TESTING. These are NOT public flags, and should not be used for anything other than LLVM's own testing/debugging purposes. They are likely to change both in spelling and meaning. WARNING: This patch is knowingly incorrect in some cornercases. We need, and do not yet provide, a mechanism to selective enable/disable the padding. Conversation on this will continue in parellel with work on extending this infrastructure to support prefix padding. The goal here is to have the assembler align specific instructions such that they neither cross or end at a 32 byte boundary. The impacted instructions are: a. Conditional jump. b. Fused conditional jump. c. Unconditional jump. d. Indirect jump. e. Ret. f. Call. The new options for llvm-mc are: -x86-align-branch-boundary=NUM aligns branches within NUM byte boundary. -x86-align-branch=TYPE[+TYPE...] specifies types of branches to align. A new MCFragment type, MCBoundaryAlignFragment, is added, which may emit NOP to align the fused/unfused branch. alignBranchesBegin inserts MCBoundaryAlignFragment before instructions, alignBranchesEnd marks the end of the branch to be aligned, relaxBoundaryAlign grows or shrinks sizes of NOP to align the target branch. Nop padding is disabled when the instruction may be rewritten by the linker, such as TLS Call. Process Note: I am landing a patch by skan as it has been LGTMed, and continuing to iterate on the review is simply slowing us down at this point. We can and will continue to iterate in tree. Patch By: skan Differential Revision: https://reviews.llvm.org/D70157
* [ MC ] Match labels to existing fragments even when switching sections.Michael Trent2019-12-181-14/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (This commit restores the original branch (4272372c571) and applies an additional change dropped from the original in a bad merge. This change should address the previous bot failures. Both changes reviewed by pete.) Summary: This commit builds upon Derek Schuff's 2014 commit for attaching labels to existing fragments ( Diff Revision: http://reviews.llvm.org/D5915 ) When temporary labels appear ahead of a fragment, MCObjectStreamer will track the temporary label symbol in a "Pending Labels" list. Labels are associated with fragments when a real fragment arrives; otherwise, an empty data fragment will be created if the streamer's section changes or if the stream finishes. This commit moves the "Pending Labels" list into each MCStream, so that this label-fragment matching process is resilient to section changes. If the streamer emits a label in a new section, switches to another section to do other work, then switches back to the first section and emits a fragment, that initial label will be associated with this new fragment. Labels will only receive empty data fragments in the case where no other fragment exists for that section. The downstream effects of this can be seen in Mach-O relocations. The previous approach could produce local section relocations and external symbol relocations for the same data in an object file, and this mix of relocation types resulted in problems in the ld64 Mach-O linker. This commit ensures relocations triggered by temporary labels are consistent. Reviewers: pete, ab, dschuff Reviewed By: pete, dschuff Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71368
* Revert "[ MC ] Match labels to existing fragments even when switching sections."Mitch Phillips2019-12-171-59/+13
| | | | | | | This reverts commit 4272372c571cd33edc77a8844b0a224ad7339138. Caused an MSan buildbot failure. More information available in the patch that introduced the bug: https://reviews.llvm.org/D71368
* [ MC ] Match labels to existing fragments even when switching sections.Michael Trent2019-12-171-13/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This commit builds upon Derek Schuff's 2014 commit for attaching labels to existing fragments ( Diff Revision: http://reviews.llvm.org/D5915 ) When temporary labels appear ahead of a fragment, MCObjectStreamer will track the temporary label symbol in a "Pending Labels" list. Labels are associated with fragments when a real fragment arrives; otherwise, an empty data fragment will be created if the streamer's section changes or if the stream finishes. This commit moves the "Pending Labels" list into each MCStream, so that this label-fragment matching process is resilient to section changes. If the streamer emits a label in a new section, switches to another section to do other work, then switches back to the first section and emits a fragment, that initial label will be associated with this new fragment. Labels will only receive empty data fragments in the case where no other fragment exists for that section. The downstream effects of this can be seen in Mach-O relocations. The previous approach could produce local section relocations and external symbol relocations for the same data in an object file, and this mix of relocation types resulted in problems in the ld64 Mach-O linker. This commit ensures relocations triggered by temporary labels are consistent. Reviewers: pete, ab, dschuff Reviewed By: pete, dschuff Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71368
* [MC] Delete MCCodePadderFangrui Song2019-12-091-27/+0
| | | | | | | | | | | | | | | | | | | | | D34393 added MCCodePadder as an infrastructure for padding code with NOP instructions. It lacked tests and was not being worked on since then. Intel has now worked on an assembler patch to mitigate performance loss after applying microcode update for the Jump Conditional Code Erratum. https://www.intel.com/content/www/us/en/support/articles/000055650/processors.html This new patch shares similarity with MCCodePadder, but has a concrete use case in mind and is being actively developed. The infrastructure it introduces can potentially be used for general performance improvement via alignment. Delete the unused MCCodePadder so that people can develop the new feature from a clean state. Reviewed By: jyknight, skan Differential Revision: https://reviews.llvm.org/D71106
* MCObjectStreamer: assign MCSymbols in the dummy fragment to offset 0.James Y Knight2019-11-161-3/+17
| | | | | | | | | | | | | | | | | In MCObjectStreamer, when there is no current fragment, initially symbols are created in a "pending" state and assigned to a dummy empty fragment. Previously, they were not being assigned an offset, and thus evaluateAbsolute would fail if trying to evaluate an expression 'a - b', where both 'a' and 'b' were in this pending state. Also slightly refactored the EmitLabel overload which takes an MCFragment for clarity. Fixes: https://llvm.org/PR41825 Differential Revision: https://reviews.llvm.org/D70062
* [Alignment][NFC] Remove unneeded llvm:: scoping on Align typesGuillaume Chatelet2019-09-271-1/+1
| | | | llvm-svn: 373081
* [Alignment] Introduce llvm::Align to MCSectionGuillaume Chatelet2019-09-131-1/+1
| | | | | | | | | | | | | | | | | Summary: This is patch is part of a series to introduce an Alignment type. See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html See this patch for the introduction of the type: https://reviews.llvm.org/D64790 Reviewers: courbet, JDevlieghere Subscribers: arsenm, sdardis, jvesely, nhaehnle, sbc100, hiraditya, aheejin, jrtc27, atanasyan, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67486 llvm-svn: 371831
* [llvm] Migrate llvm::make_unique to std::make_uniqueJonas Devlieghere2019-08-151-1/+1
| | | | | | | | Now that we've moved to C++14, we no longer need the llvm::make_unique implementation from STLExtras.h. This patch is a mechanical replacement of (hopefully) all the llvm::make_unique instances across the monorepo. llvm-svn: 369013
* [AsmPrinter] Remove hidden flag -print-schedule.Andrea Di Biagio2019-02-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes hidden codegen flag -print-schedule effectively reverting the logic originally committed as r300311 (https://llvm.org/viewvc/llvm-project?view=revision&revision=300311). Flag -print-schedule was originally introduced by r300311 to address PR32216 (https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better testing of schedule model instruction latencies/throughputs". These days, we can use llvm-mca to test scheduling models. So there is no longer a need for flag -print-schedule in LLVM. The main use case for PR32216 is now addressed by llvm-mca. Flag -print-schedule is mainly used for debugging purposes, and it is only actually used by x86 specific tests. We already have extensive (latency and throughput) tests under "test/tools/llvm-mca" for X86 processor models. That means, most (if not all) existing -print-schedule tests for X86 are redundant. When flag -print-schedule was first added to LLVM, several files had to be modified; a few APIs gained new arguments (see for example method MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained a couple of getSchedInfoStr() methods. Method getSchedInfoStr() had to originally work for both MCInst and MachineInstr. The original implmentation of getSchedInfoStr() introduced a subtle layering violation (reported as PR37160 and then fixed/worked-around by r330615). In retrospect, that new API could have been designed more optimally. We can always query MCSchedModel to get the latency and throughput. More importantly, the "sched-info" string should not have been generated by the subtarget. Note, r317782 fixed an issue where "print-schedule" didn't work very well in the presence of inline assembly. That commit is also reverted by this change. Differential Revision: https://reviews.llvm.org/D57244 llvm-svn: 353043
* Update the file headers across all of the LLVM projects in the monorepoChandler Carruth2019-01-191-4/+3
| | | | | | | | | | | | | | | | | to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
* [codeview] Flush labels before S_DEFRANGE* fragmentsReid Kleckner2018-12-171-1/+5
| | | | | | | | | | | | | This was a pre-existing bug that could be triggered with assembly like this: .p2align 2 .LtmpN: .cv_def_range "..." I noticed this when attempting to change clang to emit aligned symbol records. llvm-svn: 349403
* [MC] Support labels as offsets in .reloc directiveVladimir Stefanovic2018-11-211-11/+46
| | | | | | | | | | | | | | | | | Currently, expressions like .reloc 1f, R_MIPS_JALR, foo 1: nop are not allowed, ie. an offset in .reloc can only be absolute value. This patch adds support for labels as offsets. If offset is a forward declared label, MCObjectStreamer keeps the fixup locally and adds it to the fixups vector after the label (and its offset) is defined. label+number is not supported yet. Differential revision: https://reviews.llvm.org/D53990 llvm-svn: 347397
* Revert BTF commit series.Eli Friedman2018-10-121-34/+0
| | | | | | | | | | The initial patch was not reviewed, and does not have any tests; it should not have been merged. This reverts 344395, 344390, 344387, 344385, 344381, 344376, and 344366. llvm-svn: 344405
* [BPF] Add BTF generation for BPF targetYonghong Song2018-10-121-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BTF is the debug format for BPF, a kernel virtual machine and widely used for tracing, networking and security, etc ([1]). Currently only instruction streams are passed to kernel, the kernel verifier verifies them before execution. In order to provide better visibility of bpf programs to user space tools, some debug information, e.g., function names and debug line information are desirable for kernel so tools can get such information with better annotation for jited instructions for performance or other reasons. The dwarf is too complicated in kernel and for BPF. Hence, BTF is designed to be the debug format for BPF ([2]). Right now, pahole supports BTF for types, which are generated based on dwarf sections in the ELF file. In order to annotate performance metrics for jited bpf insns, it is necessary to pass debug line info to the kernel. Furthermore, we want to pass the actual code to the kernel because of the following reasons: . bpf program typically is small so storage overhead should be small. . in bpf land, it is totally possible that an application loads the bpf program into the kernel and then that application quits, so holding debug info by the user space application is not practical. . having source codes directly kept by kernel would ease deployment since the original source code does not need ship on every hosts and kernel-devel package does not need to be deployed even if kernel headers are used. The only reliable time to get the source code is during compilation time. This will result in both more accurate information and easier deployment as stated in the above. Another consideration is for JIT. The project like bcc use MCJIT to compile a C program into bpf insns and load them to the kernel ([3]). The generated BTF sections will be readily available for such cases as well. This patch implemented generation of BTF info in llvm compiler. The BTF related sections will be generated when both -target bpf and -g are specified. Two sections are generated: .BTF contains all the type and string information, and .BTF.ext contains the func_info and line_info. The separation is related to how two sections are used differently in bpf loader, e.g., linux libbpf ([4]). The .BTF section can be loaded into the kernel directly while .BTF.ext needs loader manipulation before loading to the kernel. The format of the each section is roughly defined in llvm:include/llvm/MC/MCBTFContext.h and from the implementation in llvm:lib/MC/MCBTFContext.cpp. A later example also shows the contents in each section. The type and func_info are gathered during CodeGen/AsmPrinter by traversing dwarf debug_info. The line_info is gathered in MCObjectStreamer before writing to the object file. After all the information is gathered, the two sections are emitted in MCObjectStreamer::finishImpl. With cmake CMAKE_BUILD_TYPE=Debug, the compiler can dump out all the tables except insn offset, which will be resolved later as relocation records. The debug type "btf" is used for BTFContext dump. Dwarf tests the debug info generation with llvm-dwarfdump to decode the binary sections and check whether the result is expected. Currently we do not have such a tool yet. We will implement btf dump functionality in bpftool ([5]) as the bpftool is considered the recommended tool for bpf introspection. The implementation for type and func_info is tested with linux kernel test cases. The line_info is visually checked with dump from linux kernel libbpf ([4]) and checked with readelf dumping section raw data. Note that the .BTF and .BTF.ext information will not be emitted to assembly code and there is no assembler support for BTF either. In the below, with a clang/llvm built with CMAKE_BUILD_TYPE=Debug, Each table contents are shown for a simple C program. -bash-4.2$ cat -n test.c 1 struct A { 2 int a; 3 char b; 4 }; 5 6 int test(struct A *t) { 7 return t->a; 8 } -bash-4.2$ clang -O2 -target bpf -g -mllvm -debug-only=btf -c test.c Type Table: [1] FUNC name_off=1 info=0x0c000001 size/type=2 param_type=3 [2] INT name_off=12 info=0x01000000 size/type=4 desc=0x01000020 [3] PTR name_off=0 info=0x02000000 size/type=4 [4] STRUCT name_off=16 info=0x04000002 size/type=8 name_off=18 type=2 bit_offset=0 name_off=20 type=5 bit_offset=32 [5] INT name_off=22 info=0x01000000 size/type=1 desc=0x02000008 String Table: 0 : 1 : test 6 : .text 12 : int 16 : A 18 : a 20 : b 22 : char 27 : test.c 34 : int test(struct A *t) { 58 : return t->a; FuncInfo Table: sec_name_off=6 insn_offset=<Omitted> type_id=1 LineInfo Table: sec_name_off=6 insn_offset=<Omitted> file_name_off=27 line_off=34 line_num=6 column_num=0 insn_offset=<Omitted> file_name_off=27 line_off=58 line_num=7 column_num=3 -bash-4.2$ readelf -S test.o ...... [12] .BTF PROGBITS 0000000000000000 0000028d 00000000000000c1 0000000000000000 0 0 1 [13] .BTF.ext PROGBITS 0000000000000000 0000034e 0000000000000050 0000000000000000 0 0 1 [14] .rel.BTF.ext REL 0000000000000000 00000648 0000000000000030 0000000000000010 16 13 8 ...... -bash-4.2$ The latest linux kernel ([6]) can already support .BTF with type information. The [7] has the reference implementation in linux kernel side to support .BTF.ext func_info. The .BTF.ext line_info support is not implemented yet. If you have difficulty accessing [6], you can manually do the following to access the code: git clone https://github.com/yonghong-song/bpf-next-linux.git cd bpf-next-linux git checkout btf The change will push to linux kernel soon once this patch is landed. References: [1]. https://www.kernel.org/doc/Documentation/networking/filter.txt [2]. https://lwn.net/Articles/750695/ [3]. https://github.com/iovisor/bcc [4]. https://github.com/torvalds/linux/tree/master/tools/lib/bpf [5]. https://github.com/torvalds/linux/tree/master/tools/bpf/bpftool [6]. https://github.com/torvalds/linux [7]. https://github.com/yonghong-song/bpf-next-linux/tree/btf Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Differential Revision: https://reviews.llvm.org/D52950 llvm-svn: 344366
* The initial .text section generated in object files was missing theEric Christopher2018-09-061-0/+6
| | | | | | | | | | | | | | | | | | | | SHF_ARM_PURECODE flag when being built with the -mexecute-only flag. All code sections of an ELF must have the flag set for the final .text section to be execute-only, otherwise the flag gets removed. A HasData flag is added to MCSection to aid in the determination that the section is empty. A virtual setTargetSectionFlags is added to MCELFObjectTargetWriter to allow subclasses to set target specific section flags to be added to sections which we then use in the ARM backend to set SHF_ARM_PURECODE. Patch by Ivan Lozano! Reviewed By: echristo Differential Revision: https://reviews.llvm.org/D48792 llvm-svn: 341593
* [codeview] Clean up machinery for deferring .cv_loc emissionReid Kleckner2018-08-281-10/+10
| | | | | | | | | | | Now that we create the label at the point of the directive, we don't need to set the "current CV location", and then later when we emit the next instruction, create a label for it and emit it. DWARF still defers the labels used in .debug_loc until the next instruction or value, for reasons unknown. llvm-svn: 340883
* [codeview] Emit labels for .cv_loc immediatelyReid Kleckner2018-08-281-4/+4
| | | | | | | | | | | | | | | Previously we followed the DWARF implementation, which waits until the next instruction or data to emit the label to use in the .debug_loc section. We might want to consider re-evaluating that design choice as well, since it means the .loc skips alignment padding, for better or worse. This was the most minimal fix I could come up with, but we should be able to do a lot of cleanups now that we don't need to save a pending CV location on the CodeViewContext. I plan to do those next, but this immediately fixes an assertion for some of our users. llvm-svn: 340878
* [RISCV][MC] Don't fold symbol differences if ↵Alex Bradbury2018-08-161-4/+7
| | | | | | | | | | | | | | | | | | | | | | requiresDiffExpressionRelocations is true When emitting the difference between two symbols, the standard behavior is that the difference will be resolved to an absolute value if both of the symbols are offsets from the same data fragment. This is undesirable on architectures such as RISC-V where relaxation in the linker may cause the computed difference to become invalid. This caused an issue when compiling to object code, where the size of a function in the debug information was already calculated even though it could change as a consequence of relaxation in the subsequent linking stage. This patch inhibits the resolution of symbol differences to absolute values where the target's AsmBackend has declared that it does not want these to be folded. Differential Revision: https://reviews.llvm.org/D45773 Patch by Edward Jones. llvm-svn: 339864
* MC: Implement support for new .addrsig and .addrsig_sym directives.Peter Collingbourne2018-07-171-0/+9
| | | | | | | | | Part of the address-significance tables proposal: http://lists.llvm.org/pipermail/llvm-dev/2018-May/123514.html Differential Revision: https://reviews.llvm.org/D47744 llvm-svn: 337328
* Use debug-prefix-map for AT_NAMEJonas Devlieghere2018-07-111-2/+1
| | | | | | | | | | | | | | | | | | AT_NAME was being emitted before the directory paths were remapped. This ensures that all paths are remapped before anything is emitted. An additional test case has been added. Note that this only works if the replacement string is an absolute path. If not, then AT_decl_file believes the new path is a relative path, and joins that path with the compilation directory. I do not know of a good way to resolve this. Patch by: Siddhartha Bagaria (starsid) Differential revision: https://reviews.llvm.org/D49169 llvm-svn: 336793
* [MC] Add interface to finish pending labels.Jonas Devlieghere2018-07-101-1/+1
| | | | | | | | | | | When manually finishing the object writer in dsymutil, it's possible that there are pending labels that haven't been resolved. This results in an assertion when the assembler tries to fixup a label that doesn't have an address yet. Differential revision: https://reviews.llvm.org/D49131 llvm-svn: 336688
* Support -fdebug-prefix-map in llvm-mc. This is useful to omit thePaul Robinson2018-07-101-0/+3
| | | | | | | | | | | debug compilation dir when compiling assembly files with -g. Part of PR38050. Patch by Siddhartha Bagaria! Differential Revision: https://reviews.llvm.org/D48988 llvm-svn: 336680
* Revert "[MC] Factor MCObjectStreamer::addFragmentAtoms out of MachO streamer."Sam Clegg2018-06-141-26/+0
| | | | | | | | | This reverts rL331412. We didn't up using fragment atoms in the wasm object writer after all. Differential Revision: https://reviews.llvm.org/D48173 llvm-svn: 334734
* [MC] Pass MCSubtargetInfo to fixupNeedsRelaxation and applyFixupPeter Smith2018-06-061-8/+21
| | | | | | | | | | | | | | | | | | On targets like Arm some relaxations may only be performed when certain architectural features are available. As functions can be compiled with differing levels of architectural support we must make a judgement on whether we can relax based on the MCSubtargetInfo for the function. This change passes through the MCSubtargetInfo for the function to fixupNeedsRelaxation so that the decision on whether to relax can be made per function. In this patch, only the ARM backend makes use of this information. We must also pass the MCSubtargetInfo to applyFixup because some fixups skip error checking on the assumption that relaxation has occurred, to prevent code-generation errors applyFixup must see the same MCSubtargetInfo as fixupNeedsRelaxation. Differential Revision: https://reviews.llvm.org/D44928 llvm-svn: 334078
* MC: Change the streamer ctors to take an object writer instead of a stream. ↵Peter Collingbourne2018-05-181-4/+3
| | | | | | | | | | | | | | NFCI. The idea is that a client that wants split dwarf would create a specific kind of object writer that creates two files, and use it to create the streamer. Part of PR37466. Differential Revision: https://reviews.llvm.org/D47050 llvm-svn: 332749
* [MC] Relax .fill size requirementsNirav Dave2018-05-181-16/+22
| | | | | | | | | | | | | | | Avoid requirement that number of values must be known at assembler time. Fixes PR33586. Reviewers: rnk, peter.smith, echristo, jyknight Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D46703 llvm-svn: 332741
* [MC] Factor MCObjectStreamer::addFragmentAtoms out of MachO streamer.Sam Clegg2018-05-021-0/+26
| | | | | | | | | This code previously existed only in MCMachOStreamer but is useful for WebAssembly too. See: D46335 Differential Revision: https://reviews.llvm.org/D46297 llvm-svn: 331412
* [MC] Change AsmParser to leverage Assembler during evaluationNirav Dave2018-04-301-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | Teach AsmParser to check with Assembler for when evaluating constant expressions. This improves the handing of preprocessor expressions that must be resolved at parse time. This idiom can be found as assembling-time assertion checks in source-level assemblers. Note that this relies on the MCStreamer to keep sufficient tabs on Section / Fragment information which the MCAsmStreamer does not. As a result the textual output may fail where the equivalent object generation would pass. This can most easily be resolved by folding the MCAsmStreamer and MCObjectStreamer together which is planned for in a separate patch. Currently, this feature is only enabled for assembly input, keeping IR compilation consistent between assembly and object generation. Reviewers: echristo, rnk, probinson, espindola, peter.smith Reviewed By: peter.smith Subscribers: eraman, peter.smith, arichardson, jyknight, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D45164 llvm-svn: 331218
* [MC] Undo spurious commit added into r331052.Nirav Dave2018-04-271-16/+7
| | | | llvm-svn: 331055
* [MC] Provide default value for IsResolved.Nirav Dave2018-04-271-7/+16
| | | | llvm-svn: 331052
* [MC] Allow MCAssembler to be constructed without all subcomponents. NFCI.Nirav Dave2018-04-271-4/+4
| | | | llvm-svn: 331047
* [codeview] Ignore .cv_loc directives at the end of a functionReid Kleckner2018-04-251-0/+1
| | | | | | | | | | If no data or instructions are emitted after a location directive, we should clear the cv_loc when we change sections, or it will be emitted at the beginning of the next section. This violates our invariant that all .cv_loc directives belong to the same section. Add clearer assertions for this. llvm-svn: 330884
* Re-land r327620 "[CodeView] Initial support for emitting S_BLOCK32 symbols ↵Reid Kleckner2018-03-151-0/+1
| | | | | | | | | for lexical scopes" This is safe to land now that we don't copy FunctionInfo when rehashing the DenseMap. llvm-svn: 327670
* Use assembler expressions to lay out the EH LSDA.Rafael Espindola2018-02-091-5/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rely on the assembler to finalize the layout of the DWARF/Itanium exception-handling LSDA. Rather than calculate the exact size of each thing in the LSDA, use assembler directives: To emit the offset to the TTBase label: .uleb128 .Lttbase0-.Lttbaseref0 .Lttbaseref0: To emit the size of the call site table: .uleb128 .Lcst_end0-.Lcst_begin0 .Lcst_begin0: ... call site table entries ... .Lcst_end0: To align the type info table: ... action table ... .balign 4 .long _ZTIi .long _ZTIl .Lttbase0: Using assembler directives simplifies the compiler and allows switching the encoding of offsets in the call site table from udata4 to uleb128 for a large code size savings. (This commit does not change the encoding.) The combination of the uleb128 followed by a balign creates an unfortunate dependency cycle that the assembler must sometimes resolve either by padding an LEB or by inserting zero padding before the type table. See PR35809 or GNU as bug 4029. Patch by Ryan Prichard! llvm-svn: 324749
* Use a MCExpr for the size of MCFillFragment.Rafael Espindola2018-01-091-12/+1
| | | | | | | This allows the size to be found during ralaxation. This fixes pr35858. llvm-svn: 322131
* Inline a emitFill variant that is only used once. NFC.Rafael Espindola2018-01-091-1/+7
| | | | llvm-svn: 322111
* Make one of the emitFill methods non virtual. NFC.Rafael Espindola2018-01-091-7/+3
| | | | | | This is just preparatory work to fix PR35858. llvm-svn: 322108
* Remove redundant includes from lib/MC.Michael Zolotukhin2017-12-131-2/+0
| | | | llvm-svn: 320624
* [MC] Adding code padding for performance stability - infrastructure. NFC.Omer Paparo Bivas2017-10-241-0/+27
| | | | | | | | | | | | | | | | | Infrastructure designed for padding code with nop instructions in key places such that preformance improvement will be achieved. The infrastructure is implemented such that the padding is done in the Assembler after the layout is done and all IPs and alignments are known. This patch by itself in a NFC. Future patches will make use of this infrastructure to implement required policies for code padding. Reviewers: aaboud zvi craig.topper gadi.haber Differential revision: https://reviews.llvm.org/D34393 Change-Id: I92110d0c0a757080a8405636914a93ef6f8ad00e llvm-svn: 316413
* [MC] Have MCObjectStreamer take its MCAsmBackend argument via unique_ptr.Lang Hames2017-10-111-6/+5
| | | | | | | | MCObjectStreamer owns its MCCodeEmitter -- this fixes the types to reflect that, and allows us to remove the last instance of MCObjectStreamer's weird "holding ownership via someone else's reference" trick. llvm-svn: 315531
* [MC] Have MCObjectStreamer take its MCAsmBackend argument via unique_ptr.Lang Hames2017-10-111-5/+5
| | | | | | | | MCObjectStreamer owns its MCAsmBackend -- this fixes the types to reflect that, and allows us to remove another instance of MCObjectStreamer's weird "holding ownership via someone else's reference" trick. llvm-svn: 315410
* [MC] Thread unique_ptr<MCObjectWriter> through the create.*ObjectWriterLang Hames2017-10-101-3/+2
| | | | | | | | | | functions. This makes the ownership of the resulting MCObjectWriter clear, and allows us to remove one instance of MCObjectStreamer's bizarre "holding ownership via someone else's reference" trick. llvm-svn: 315327
* [MC] Suppress .Lcfi labels when emitting textual assemblyReid Kleckner2017-10-101-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This suppresses the generation of .Lcfi labels in our textual assembler. It was annoying that this generated cascading .Lcfi labels: llc foo.ll -o - | llvm-mc | llvm-mc After three trips through MCAsmStreamer, we'd have three labels in the output when none are necessary. We should only bother creating the labels and frame data when making a real object file. This supercedes D38605, which moved the entire .seh_ implementation into MCObjectStreamer. This has the advantage that we do more checking when emitting textual assembly, as a minor efficiency cost. Outputting textual assembly is not performance critical, so this shouldn't matter. Reviewers: majnemer, MatzeB Subscribers: qcolombet, nemanjai, javed.absar, eraman, hiraditya, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D38638 llvm-svn: 315259
* [MC] Use a unique_ptr<MCAssembler> for MCObjectStreamer's Assembler member.Lang Hames2017-10-091-3/+2
| | | | | | Removes manual new/delete. llvm-svn: 315225
* Re-land "Fix Bug 30978 by emitting cv file checksums."Reid Kleckner2017-09-191-0/+3
| | | | | | | This reverts r313431 and brings back r313374 with a fix to write checksums as binary data and not ASCII hex strings. llvm-svn: 313657
* Revert "Fix Bug 30978 by emitting cv file checksums."Eric Beckmann2017-09-161-3/+0
| | | | | | | | | | | This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54. There is a bug in this implementation where the string value of the checksum is outputted, instead of the actual hex bytes. Therefore the checksum is incorrect, and this prevent pdbs from being loaded by visual studio. Revert this until the checksum is emitted correctly. llvm-svn: 313431
* Fix Bug 30978 by emitting cv file checksums.Eric Beckmann2017-09-151-0/+3
| | | | | | | | | | | | Summary: The checksums had already been placed in the IR, this patch allows MCCodeView to actually write it out to an MCStreamer. Subscribers: llvm-commits, hiraditya Differential Revision: https://reviews.llvm.org/D37157 llvm-svn: 313374
OpenPOWER on IntegriCloud