This patch adds clang options:
-fbasic-block-sections={all,<filename>,labels,none} and
-funique-basic-block-section-names.
LLVM Support for basic block sections is already enabled.
+ -fbasic-block-sections={all, <file>, labels, none} : Enables/Disables basic
block sections for all or a subset of basic blocks. "labels" only enables
basic block symbols.
+ -funique-basic-block-section-names: Enables unique section names for
basic block sections, disabled by default.
Differential Revision: https://reviews.llvm.org/D68049
Since on AIX, our strategy is to not use -u to suppress any undefined
symbols, we need to emit .extern for the symbols with AvailableExternally
linkage.
Differential Revision: https://reviews.llvm.org/D80642
Use getFunctionEntryPointSymbol whenever possible to enclose the
implementation detail and reduce duplicate logic.
Differential Revision: https://reviews.llvm.org/D80402
Fixes a build issue with libc++ configured with _LIBCPP_RAW_ITERATORS (ADL not effective)
```
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp:1602:3: error: no matching function for call to 'transform'
transform(HexString.begin(), HexString.end(), HexString.begin(), tolower);
^~~~~~~~~
```
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D80475
GNU ld's internal linker script uses (https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=add44f8d5c5c05e08b11e033127a744d61c26aee)
.text :
{
*(.text.unlikely .text.*_unlikely .text.unlikely.*)
*(.text.exit .text.exit.*)
*(.text.startup .text.startup.*)
*(.text.hot .text.hot.*)
*(SORT(.text.sorted.*))
*(.text .stub .text.* .gnu.linkonce.t.*)
/* .gnu.warning sections are handled specially by elf.em. */
*(.gnu.warning)
}
Because `*(.text.exit .text.exit.*)` is ordered before `*(.text .text.*)`, in a -ffunction-sections build, the C library function `exit` will be placed before other functions.
gold's `-z keep-text-section-prefix` has the same problem.
In lld, `-z keep-text-section-prefix` recognizes `.text.{exit,hot,startup,unlikely,unknown}.*`, but not `.text.{exit,hot,startup,unlikely,unknown}`, to avoid the strange placement problem.
In -fno-function-sections or -fno-unique-section-names mode, a function whose `function_section_prefix` is set to `.exit"`
will go to the output section `.text` instead of `.text.exit` when linked by lld.
To address the problem, append a dot to become `.text.exit.`
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D79600
Summary:
Instead of adding a ".unlikely" or ".eh" suffix for machine basic blocks,
this change updates the behaviour to use an appropriate prefix
instead. This allows lld to group basic block sections together
when -z,keep-text-section-prefix is specified and matches the behaviour
observed in gcc.
Reviewers: tmsriram, mtrofin, efriedma
Reviewed By: tmsriram, efriedma
Subscribers: eli.friedman, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78742
Summary:
AIX symbol have qualname and unqualified name. The stock getSymbol
could only return unqualified name, which leads us to patch many
caller side(lowerConstant, getMCSymbolForTOCPseudoMO).
So we should try to address this problem in the callee
side(getSymbol) and clean up the caller side instead.
Note: this is a "mostly" NFC patch, with a fix for the original
lowerConstant behavior.
Differential Revision: https://reviews.llvm.org/D78045
Ensure that symbols explicitly* assigned a section name are placed into
a section with a compatible entry size.
This is done by creating multiple sections with the same name** if
incompatible symbols are explicitly given the name of an incompatible
section, whilst:
- Avoiding using uniqued sections where possible (for readability and
to maximize compatibly with assemblers).
- Creating as few SHF_MERGE sections as possible (for efficiency).
Given that each symbol is assigned to a section in a single pass, we
must decide which section each symbol is assigned to without seeing the
properties of all symbols. A stable and easy to understand assignment is
desirable. The following rules facilitate this: The "generic" section
for a given section name will be mergeable if the name is a mergeable
"default" section name (such as .debug_str), a mergeable "implicit"
section name (such as .rodata.str2.2), or MC has already created a
mergeable "generic" section for the given section name (e.g. in response
to a section directive in inline assembly). Otherwise, the "generic"
section for a given name is non-mergeable; and, non-mergeable symbols
are assigned to the "generic" section, while mergeable symbols are
assigned to uniqued sections.
Terminology:
"default" sections are those always created by MC initially, e.g. .text
or .debug_str.
"implicit" sections are those created normally by MC in response to the
symbols that it encounters, i.e. in the absence of an explicit section
name assignment on the symbol, e.g. a function foo might be placed into
a .text.foo section.
"generic" sections are those that are referred to when a unique section
ID is not supplied, e.g. if there are multiple unique .bob sections then
".quad .bob" will reference the generic .bob section. Typically, the
generic section is just the first section of a given name to be created.
Default sections are always generic.
* Typically, section names might be explicitly assigned in source code
using a language extension e.g. a section attribute: _attribute_
((section ("section-name"))) -
https://clang.llvm.org/docs/AttributeReference.html
** I refer to such sections as unique/uniqued sections. In assembly the
", unique," assembly syntax is used to express such sections.
Fixes https://bugs.llvm.org/show_bug.cgi?id=43457.
See https://reviews.llvm.org/D68101 for previous discussions leading to
this patch.
Some minor fixes were required to LLVM's tests, for tests had been using
the old behavior - which allowed for explicitly assigning globals with
incompatible entry sizes to a section.
This fix relies on the ",unique ," assembly feature. This feature is not
available until bintuils version 2.35
(https://sourceware.org/bugzilla/show_bug.cgi?id=25380). If the
integrated assembler is not being used then we avoid using this feature
for compatibility and instead try to place mergeable symbols into
non-mergeable sections or issue an error otherwise.
Differential Revision: https://reviews.llvm.org/D72194
in the same section.
This allows specifying BasicBlock clusters like the following example:
!foo
!!0 1 2
!!4
This places basic blocks 0, 1, and 2 in one section in this order, and
places basic block #4 in a single section of its own.
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.
Reviewers: stoklund, sdesmalen, efriedma
Reviewed By: sdesmalen
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77272
SUMMARY:
SUMMARY
for a source file "test.c"
void foo() {};
llc will generate assembly code as (assembly patch)
.globl foo
.globl .foo
.csect foo[DS]
foo:
.long .foo
.long TOC[TC0]
.long 0
and symbol table as (xcoff object file)
[4] m 0x00000004 .data 1 unamex foo
[5] a4 0x0000000c 0 0 SD DS 0 0
[6] m 0x00000004 .data 1 extern foo
[7] a4 0x00000004 0 0 LD DS 0 0
After first patch, the assembly will be as
.globl foo[DS] # -- Begin function foo
.globl .foo
.align 2
.csect foo[DS]
.long .foo
.long TOC[TC0]
.long 0
and symbol table will as
[6] m 0x00000004 .data 1 extern foo
[7] a4 0x00000004 0 0 DS DS 0 0
Change the code for the assembly path and xcoff objectfile patch for llc.
Reviewers: Jason Liu
Subscribers: wuzish, nemanjai, hiraditya
Differential Revision: https://reviews.llvm.org/D76162
-fuse-init-array is now the CC1 default but TargetLoweringObjectFileELF::UseInitArray still defaults to false.
The following two unknown OS target triples continue using .ctors/.dtors because InitializeELF is not called.
clang -target i386 -c a.c
clang -target x86_64 -c a.c
This cleanup fixes this as a bonus.
X86SpeculativeLoadHardeningPass::tracePredStateThroughCall can call
MCContext::createTempSymbol before TargetLoweringObjectFileELF::Initialize().
We need to call TargetLoweringObjectFileELF::Initialize() ealier.
test/CodeGen/X86/speculative-load-hardening-indirect.ll
Differential Revision: https://reviews.llvm.org/D71360
UseInitArray is now the CC1 default but TargetLoweringObjectFileELF::UseInitArray still defaults to false.
The following two unknown OS target triples continue using .ctors/.dtors because InitializeELF is not called.
clang -target i386 -c a.c
clang -target x86_64 -c a.c
This cleanup fixes this as a bonus.
Differential Revision: https://reviews.llvm.org/D71360
This is the second patch in a series of patches to enable basic block
sections support.
This patch adds support for:
* Creating direct jumps at the end of basic blocks that have fall
through instructions.
* New pass, bbsections-prepare, that analyzes placement of basic blocks
in sections.
* Actual placing of a basic block in a unique section with special
handling of exception handling blocks.
* Supports placing a subset of basic blocks in a unique section.
* Support for MIR serialization and deserialization with basic block
sections.
Parent patch : D68063
Differential Revision: https://reviews.llvm.org/D73674
Summary:
The change is to fix conflict value for metadata "Objective-C Garbage Collection" in the mix of swift and Objective-C bitcode.
The purpose is to provide the support of LTO for swift and Objective-C mixed project.
Reviewers: rjmccall, ahatanak, steven_wu
Reviewed By: rjmccall, steven_wu
Subscribers: manmanren, mehdi_amini, hiraditya, dexonsmith, llvm-commits, jinlin
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71219
Handle LinkOnceODRLinkage;
Handle AppendingLinkage type for llvm.global_ctors/dtors static init global arrays;
Differential Revision: https://reviews.llvm.org/D75305
Try again with an up-to-date version of D69471 (99317124 was a stale
revision).
---
Revise the coverage mapping format to reduce binary size by:
1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.
This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).
Rationale for changes to the format:
- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.
- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.
- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).
See CoverageMappingFormat.rst for the details on what exactly has
changed.
Fixes PR34533 [2], hopefully.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533
Differential Revision: https://reviews.llvm.org/D69471
Revise the coverage mapping format to reduce binary size by:
1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.
This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).
Rationale for changes to the format:
- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.
- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.
- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).
See CoverageMappingFormat.rst for the details on what exactly has
changed.
Fixes PR34533 [2], hopefully.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533
Differential Revision: https://reviews.llvm.org/D69471
I believe this was carried over from getELFKindForNamedSection since
the wasm backend originally used ELF object writing as a template.
Differential Revision: https://reviews.llvm.org/D74565
SUMMARY:
The patch is enable to support Mergeable2ByteCString and Mergeable4ByteCString
Reviewers: daltenty
Subscribers: wuzish, nemanjai, hiraditya
Differential Revision: https://reviews.llvm.org/D74164
"linked-to section" is used by the ELF spec. By analogy, "linked-to
symbol" is a good name for the signature symbol. The word "linked-to"
implies a directed edge and makes it clear its relation with "sh_link",
while one can argue that "associated" means an undirected edge.
Also, combine tests and add precise SMLoc to improve diagnostics.
Reviewed By: eugenis, grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D74082
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
We create a number of standard types of control sections in multiple places for
things like the function descriptors, external references and the TOC anchor
among others, so it is possible for their properties to be defined
inconsistently in different places. This refactor moves their creation and
properties into functions in the TargetLoweringObjectFile class hierarchy, where
functions for retrieving various special types of sections typically seem
to reside.
Note: There is one case in PPCISelLowering which is specific to function entry
points which we don't address since we don't have access to the TLOF there.
Reviewers: DiggerLin, jasonliu, hubert.reinterpretcast
Reviewed By: jasonliu, hubert.reinterpretcast
Subscribers: wuzish, nemanjai, hiraditya, kbarton, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72347
SUMMARY:
In this patch we put the global variable in a Csect which's SectionKind is "ReadOnlyWithRel" into Data Section.
Reviewers: hubert.reinterpretcast,jasonliu,Xiangling_L
Subscribers: wuzish, nemanjai, hiraditya
Differential Revision: https://reviews.llvm.org/D72461
SUMMARY:
In this patch, we map mergeable const objects to the read-only section in the same manner as const objects that are not mergeable.
Reviewers: hubert.reinterpretcast,jasonliu
Subscribers: wuzish, nemanjai, hiraditya
Differential Revision: https://reviews.llvm.org/D71551
Currently -fuse-init-array option is not effective when target triple
does not specify os, on x86,x86_64.
i.e.
// -fuse-init-array is not honored.
$ clang -target i386 -fuse-init-array test.c -S
// -fuse-init-array is honored.
$ clang -target i386-linux -fuse-init-array test.c -S
This patch fixes first case.
And does cleanup.
Reviewers: rnk, craig.topper, fhahn, echristo
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D71360
Revise the coverage mapping format to reduce binary size by:
1. Naming function records and marking them `linkonce_odr`, and
2. Compressing filenames.
This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB)
and speeds up end-to-end single-threaded report generation by 10%. For
reference the compressed name data in llc is 81MB (__llvm_prf_names).
Rationale for changes to the format:
- With the current format, most coverage function records are discarded.
E.g., more than 97% of the records in llc are *duplicate* placeholders
for functions visible-but-not-used in TUs. Placeholders *are* used to
show under-covered functions, but duplicate placeholders waste space.
- We reached general consensus about giving (1) a try at the 2017 code
coverage BoF [1]. The thinking was that using `linkonce_odr` to merge
duplicates is simpler than alternatives like teaching build systems
about a coverage-aware database/module/etc on the side.
- Revising the format is expensive due to the backwards compatibility
requirement, so we might as well compress filenames while we're at it.
This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB).
See CoverageMappingFormat.rst for the details on what exactly has
changed.
Fixes PR34533 [2], hopefully.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html
[2] https://bugs.llvm.org/show_bug.cgi?id=34533
Differential Revision: https://reviews.llvm.org/D69471
This patch lowering jump table, constant pool and block address in assembly.
1. On AIX, jump table index is always relative;
2. Put CPI and JTI into ReadOnlySection until we support unique data sections;
3. Create the temp symbol for block address symbol;
4. Update MIR testcases and add related assembly part;
Differential Revision: https://reviews.llvm.org/D70243
For XCOFF, globals mapped into the .bss section are linked as COMMON
definitions. This behaviour is incorrect for zero initialized data, so
emit those to the .data section instead.
Differential Revision: https://reviews.llvm.org/D69528
Sriraman Tallam