Commit Graph

535 Commits

Author SHA1 Message Date
Sami Tolvanen 9a74c753fe [ThinLTO][MC] Use conditional assignments for promotion aliases
Inline assembly refererences to static functions with ThinLTO+CFI were
fixed in D104058 by creating aliases for promoted functions. Creating
the aliases unconditionally resulted in an unexpected size increase in
a Chrome helper binary:

https://bugs.chromium.org/p/chromium/issues/detail?id=1261715

This is caused by the compiler being unable to drop unused code now
referenced by the alias in module-level inline assembly. This change
adds a .set_conditional assembly extension, which emits an assignment
only if the target symbol is also emitted, avoiding phantom references
to functions that could have otherwise been dropped.

This is an alternative to the solution proposed in D112761.

Reviewed By: pcc, nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D113613
2021-12-10 12:21:37 -08:00
Alex Lorenz 0756aa3978 [macho] add support for emitting macho files with two build version load commands
This patch extends LLVM IR to add metadata that can be used to emit macho files with two build version load commands.
It utilizes "darwin.target_variant.triple" and "darwin.target_variant.SDK Version" metadata names for that,
which will be set by a future patch in clang.

MachO uses two build version load commands to represent an object file / binary that is targeting both the macOS target,
and the Mac Catalyst target. At runtime, a dynamic library that supports both targets can be loaded from either a native
macOS or a Mac Catalyst app on a macOS system. We want to add support to this to upstream to LLVM to be able to build
compiler-rt for both targets, to finish the complete support for the Mac Catalyst platform, which is right now targetable
by upstream clang, but the compiler-rt bits aren't supported because of the lack of this multiple build version support.

Differential Revision: https://reviews.llvm.org/D112189
2021-12-07 18:17:47 -08:00
Kazu Hirata 262dd1e42d [llvm] Use range-based for loops (NFC) 2021-12-02 09:27:47 -08:00
Reid Kleckner 89b57061f7 Move TargetRegistry.(h|cpp) from Support to MC
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.

This allows us to ensure that Support doesn't have includes from MC/*.

Differential Revision: https://reviews.llvm.org/D111454
2021-10-08 14:51:48 -07:00
Peter Smith 5e71839f77 [MC] Add MCSubtargetInfo to MCAlignFragment
In preparation for passing the MCSubtargetInfo (STI) through to writeNops
so that it can use the STI in operation at the time, we need to record the
STI in operation when a MCAlignFragment may write nops as padding. The
STI is currently unused, a further patch will pass it through to
writeNops.

There are many places that can create an MCAlignFragment, in most cases
we can find out the STI in operation at the time. In a few places this
isn't possible as we are in initialisation or finalisation, or are
emitting constant pools. When possible I've tried to find the most
appropriate existing fragment to obtain the STI from, when none is
available use the per module STI.

For constant pools we don't actually need to use EmitCodeAlign as the
constant pools are data anyway so falling through into it via an
executable NOP is no better than falling through into data padding.

This is a prerequisite for D45962 which uses the STI to emit the
appropriate NOP for the STI. Which can differ per fragment.

Note that involves an interface change to InitSections. It is now
called initSections and requires a SubtargetInfo as a parameter.

Differential Revision: https://reviews.llvm.org/D45961
2021-09-07 15:46:19 +01:00
Jinsong Ji 28fb69e00a [AIX] Emit version string in .file directive
AIX .file directive support including compiler version string.
https://www.ibm.com/docs/en/aix/7.2?topic=ops-file-pseudo-op

This patch adds the support so that it will be easier to identify build
compiler in objects.

Reviewed By: #powerpc, shchenz

Differential Revision: https://reviews.llvm.org/D105743
2021-07-12 17:03:52 +00:00
Jonas Paulsson 7aef99351a [MCStreamer] Move emission of attributes section into MCELFStreamer
Enable the emission of a GNU attributes section by reusing the code for
emitting the ARM build attributes section.

The GNU attributes follow the exact same section format as the ARM
BuildAttributes section, so this can be factored out and reused for GNU
attributes generally.

The immediate motivation for this is to emit a GNU attributes section for the
vector ABI on SystemZ (https://reviews.llvm.org/D105067).

Review: Logan Chien, Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D102894
2021-06-30 16:00:27 -05:00
RamNalamothu 167e7afcd5 Implement DW_CFA_LLVM_* for Heterogeneous Debugging
Add support in MC/MIR for writing/parsing, and DebugInfo.

This is part of the Extensions for Heterogeneous Debugging defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html

Specifically the CFI instructions implemented here are defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html#cfa-definition-instructions

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D76877
2021-06-14 08:51:50 +05:30
Jinsong Ji edf4d69d38 [AIX] Print printable byte list as quoted string
.byte supports string, so if the whole byte list are printable,
we can actually print the string for readability and LIT tests maintainence.

        .byte 'H,'e,'l,'l,'o,',,' ,'w,'o,'r,'l,'d
->
        .byte "Hello, world"

Reviewed By: hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D102814
2021-05-21 02:37:55 +00:00
Chen Zheng a95473c563 [XCOFF] handle string constants generation for AIX
This follows https://www.ibm.com/docs/en/aix/7.2?topic=constants-string

Reviewed By: hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D101280
2021-05-07 06:43:36 +00:00
Philipp Krones 632ebc4ab4 [MC] Untangle MCContext and MCObjectFileInfo
This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.

This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:

- TargetTriple
- ObjectFileType
- SubtargetInfo

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D101462
2021-05-05 10:03:02 -07:00
Fangrui Song d96af2ed2d [MC] Support .symver *, *, remove
As a resolution to https://sourceware.org/bugzilla/show_bug.cgi?id=25295 , GNU as
from binutils 2.35 supports the optional third argument for the .symver directive.

'remove' for a non-default version is useful:
`.symver def_v1, def@v1, remove` => def_v1 is not retained in the symbol table.
Previously the user has to strip the original symbol or specify a `local:`
version node in a version script to localize the symbol.

`.symver def, def@@v1, remove` and `.symver def, def@@@v1, remove` are supported
as well, though they are identical to `.symver def, def@@@v1`.

local/hidden are not useful so this patch does not implement them.
2021-03-06 15:23:02 -08:00
Chen Zheng 87bbf3d1f8 [XCOFF][DebugInfo] support DWARF for XCOFF for assembly output.
Reviewed By: jasonliu

Differential Revision: https://reviews.llvm.org/D95518
2021-03-04 21:07:52 -05:00
Hongtao Yu 705a4c149d [CSSPGO] Pseudo probe encoding and emission.
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s

Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections.  The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead. 

**ELF object emission**

The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.

Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication.  A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.

The format of `.pseudo_probe_desc` section looks like:

```
.section   .pseudo_probe_desc,"",@progbits
.quad   6309742469962978389  // Func GUID
.quad   4294967295           // Func Hash
.byte   9                    // Length of func name
.ascii  "_Z5funcAi"          // Func name
.quad   7102633082150537521
.quad   138828622701
.byte   12
.ascii  "_Z8funcLeafi"
.quad   446061515086924981
.quad   4294967295
.byte   9
.ascii  "_Z5funcBi"
.quad   -2016976694713209516
.quad   72617220756
.byte   7
.ascii  "_Z3fibi"
```

For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :

```
FUNCTION BODY (one for each outlined function present in the text section)
    GUID (uint64)
        GUID of the function
    NPROBES (ULEB128)
        Number of probes originating from this function.
    NUM_INLINED_FUNCTIONS (ULEB128)
        Number of callees inlined into this function, aka number of
        first-level inlinees
    PROBE RECORDS
        A list of NPROBES entries. Each entry contains:
          INDEX (ULEB128)
          TYPE (uint4)
            0 - block probe, 1 - indirect call, 2 - direct call
          ATTRIBUTE (uint3)
            reserved
          ADDRESS_TYPE (uint1)
            0 - code address, 1 - address delta
          CODE_ADDRESS (uint64 or ULEB128)
            code address or address delta, depending on ADDRESS_TYPE
    INLINED FUNCTION RECORDS
        A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
        callees.  Each record contains:
          INLINE SITE
            GUID of the inlinee (uint64)
            ID of the callsite probe (ULEB128)
          FUNCTION BODY
            A FUNCTION BODY entry describing the inlined function.
```

To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.

**Assembling**

Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.

A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.

A example assembly looks like:

```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```

With inlining turned on, the assembly may look different around %bb2 with an inlined probe:

```
# %bb.2:                                # %bb2
.pseudoprobe    837061429793323041 3 0
.pseudoprobe    6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe    837061429793323041 4 0
popq    %rax
retq
```

**Disassembling**

We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.

An example disassembly looks like:

```
00000000002011a0 <foo2>:
  2011a0: 50                    push   rax
  2011a1: 85 ff                 test   edi,edi
  [Probe]:  FUNC: foo2  Index: 1  Type: Block
  2011a3: 74 02                 je     2011a7 <foo2+0x7>
  [Probe]:  FUNC: foo2  Index: 3  Type: Block
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  [Probe]:  FUNC: foo   Index: 1  Type: Block  Inlined: @ foo2:6
  2011a5: 58                    pop    rax
  2011a6: c3                    ret
  [Probe]:  FUNC: foo2  Index: 2  Type: Block
  2011a7: bf 01 00 00 00        mov    edi,0x1
  [Probe]:  FUNC: foo2  Index: 5  Type: IndirectCall
  2011ac: ff d6                 call   rsi
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  2011ae: 58                    pop    rax
  2011af: c3                    ret
```

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D91878
2020-12-10 17:29:28 -08:00
Mitch Phillips 7ead5f5aa3 Revert "[CSSPGO] Pseudo probe encoding and emission."
This reverts commit b035513c06.

Reason: Broke the ASan buildbots:
  http://lab.llvm.org:8011/#/builders/5/builds/2269
2020-12-10 15:53:39 -08:00
Hongtao Yu b035513c06 [CSSPGO] Pseudo probe encoding and emission.
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s

Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections.  The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead. 

**ELF object emission**

The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.

Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication.  A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.

The format of `.pseudo_probe_desc` section looks like:

```
.section   .pseudo_probe_desc,"",@progbits
.quad   6309742469962978389  // Func GUID
.quad   4294967295           // Func Hash
.byte   9                    // Length of func name
.ascii  "_Z5funcAi"          // Func name
.quad   7102633082150537521
.quad   138828622701
.byte   12
.ascii  "_Z8funcLeafi"
.quad   446061515086924981
.quad   4294967295
.byte   9
.ascii  "_Z5funcBi"
.quad   -2016976694713209516
.quad   72617220756
.byte   7
.ascii  "_Z3fibi"
```

For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :

```
FUNCTION BODY (one for each outlined function present in the text section)
    GUID (uint64)
        GUID of the function
    NPROBES (ULEB128)
        Number of probes originating from this function.
    NUM_INLINED_FUNCTIONS (ULEB128)
        Number of callees inlined into this function, aka number of
        first-level inlinees
    PROBE RECORDS
        A list of NPROBES entries. Each entry contains:
          INDEX (ULEB128)
          TYPE (uint4)
            0 - block probe, 1 - indirect call, 2 - direct call
          ATTRIBUTE (uint3)
            reserved
          ADDRESS_TYPE (uint1)
            0 - code address, 1 - address delta
          CODE_ADDRESS (uint64 or ULEB128)
            code address or address delta, depending on ADDRESS_TYPE
    INLINED FUNCTION RECORDS
        A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
        callees.  Each record contains:
          INLINE SITE
            GUID of the inlinee (uint64)
            ID of the callsite probe (ULEB128)
          FUNCTION BODY
            A FUNCTION BODY entry describing the inlined function.
```

To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.

**Assembling**

Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.

A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.

A example assembly looks like:

```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```

With inlining turned on, the assembly may look different around %bb2 with an inlined probe:

```
# %bb.2:                                # %bb2
.pseudoprobe    837061429793323041 3 0
.pseudoprobe    6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe    837061429793323041 4 0
popq    %rax
retq
```

**Disassembling**

We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.

An example disassembly looks like:

```
00000000002011a0 <foo2>:
  2011a0: 50                    push   rax
  2011a1: 85 ff                 test   edi,edi
  [Probe]:  FUNC: foo2  Index: 1  Type: Block
  2011a3: 74 02                 je     2011a7 <foo2+0x7>
  [Probe]:  FUNC: foo2  Index: 3  Type: Block
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  [Probe]:  FUNC: foo   Index: 1  Type: Block  Inlined: @ foo2:6
  2011a5: 58                    pop    rax
  2011a6: c3                    ret
  [Probe]:  FUNC: foo2  Index: 2  Type: Block
  2011a7: bf 01 00 00 00        mov    edi,0x1
  [Probe]:  FUNC: foo2  Index: 5  Type: IndirectCall
  2011ac: ff d6                 call   rsi
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  2011ae: 58                    pop    rax
  2011af: c3                    ret
```

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D91878
2020-12-10 09:50:08 -08:00
Florian Hahn a9adb62a64
[AsmPrinter] Use getMnemonic for instruction-mix remark.
This patch uses the new `getMnemonic` helper from D90039
to display mnemonics instead of the internal opcodes.

The main motivation behind using the mnemonics is that they
are more user-friendly and more directly related to the assembly
the users will be presented.

Reviewed By: paquette

Differential Revision: https://reviews.llvm.org/D90040
2020-11-17 12:12:47 +00:00
Fangrui Song 395c8bed64 [MC] Make MCStreamer aware of AsmParser's StartTokLoc
A SMLoc allows MCStreamer to report location-aware diagnostics, which
were previously done by adding SMLoc to various methods (e.g. emit*) in an ad-hoc way.

Since the file:line is most important, the column is less important and
the start token location suffices in many cases, this patch reverts
b7e7131af2

```
// old
symbol-binding-changed.s:6:8: error: local changed binding to STB_GLOBAL
.globl local
       ^
// new
symbol-binding-changed.s:6:1: error: local changed binding to STB_GLOBAL
.globl local
^
```

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D90511
2020-11-02 12:32:07 -08:00
Fangrui Song b7e7131af2 [MC] Add SMLoc to MCStreamer::emitSymbolAttribute and report changed binding warnings/errors for ELF 2020-10-29 19:43:11 -07:00
Hubert Tong 0a146a9d0b [AIX] asm output: use character literals in byte lists for strings
This patch improves the assembly output produced for string literals by
using character literals in byte lists. This provides the benefits of
having printable characters appear as such in the assembly output and of
having strings kept as logical units on the same line.

Reviewed By: daltenty

Differential Revision: https://reviews.llvm.org/D80953
2020-09-29 21:14:41 -04:00
Martin Storsjö 5b86d130e2 [AArch64] Generate and parse SEH assembly directives
This ensures that you get the same output regardless if generating
code directly to an object file or if generating assembly and
assembling that.

Add implementations of the EmitARM64WinCFI*() methods in
AArch64TargetAsmStreamer, and fill in one blank in MCAsmStreamer.

Add corresponding directive handlers in AArch64AsmParser and
COFFAsmParser.

Some SEH directive names have been picked to match the prior art
for SEH assembly directives for x86_64, e.g. the spelling of
".seh_startepilogue" matching the preexisting ".seh_endprologue".

For the directives for saving registers, the exact spelling
from the arm64 documentation is picked, e.g. ".seh_save_reg" (to follow
that naming for all the other ones, e.g. ".seh_save_fregp_x"), while
the corresponding one for x86_64 is plain ".seh_savereg" without the
second underscore.

Directives in the epilogues have the same names as in prologues,
e.g. .seh_savereg, even though the registers are restored, not
saved, at that point.

Differential Revision: https://reviews.llvm.org/D86529
2020-08-29 15:15:22 +03:00
jasonliu f48eced390 [XCOFF] emit .rename for .lcomm when necessary
Summary:

This is a follow up for D82481. For .lcomm directive, although it's
not necessary to have .rename emitted, it's still desirable to do
it so that we do not see internal 'Rename..' gets print out in
symbol table. And we could have consistent naming between TC entry
and .lcomm. And also have consistent naming between IR and final
object file.

Reviewed By: hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D86075
2020-08-18 15:32:45 +00:00
Greg McGary eef41efe00 [MachO] Add skeletal support for DriverKit platform
Define the platform ID = 10, and simple mappings between platform ID & name.

Reviewed By: MaskRay, cishida

Differential Revision: https://reviews.llvm.org/D85594
2020-08-14 12:36:43 -07:00
jasonliu 7866442b3f [XCOFF] Adjust .rename emission sequence
Summary:
AIX assembler does not generate correct relocation when .rename
appear between tc entry label and .tc directive.
So only emit .rename after .tc/.comm or other linkage is emitted.

Reviewed By: daltenty, hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D85317
2020-08-10 14:48:24 +00:00
Fangrui Song b71ef0c50a [MC] Support .reloc sym+constant, *, *
For `.reloc offset, *, *`, currently offset can be a constant or symbol.
This patch makes it support any expression which can be folded to sym+constant.

Reviewed By: stefanp

Differential Revision: https://reviews.llvm.org/D83751
2020-07-14 13:44:00 -07:00
jasonliu 6d3ae365bd [XCOFF][AIX] Give symbol an internal name when desired symbol name contains invalid character(s)
Summary:

When a desired symbol name contains invalid character that the
system assembler could not process, we need to emit .rename
directive in assembly path in order for that desired symbol name
to appear in the symbol table.

Reviewed By: hubert.reinterpretcast, DiggerLin, daltenty, Xiangling_L

Differential Revision: https://reviews.llvm.org/D82481
2020-07-06 15:49:15 +00:00
diggerlin edd819c757 [AIX] supporting the visibility attribute for aix assembly
SUMMARY:

in the aix assembly , it do not have .hidden and .protected directive.
in current llvm. if a function or a variable which has visibility attribute, it will generate something like the .hidden or .protected , it can not recognize by aix as.
in aix assembly, the visibility attribute are support in the pseudo-op like
.extern Name [ , Visibility ]
.globl Name [, Visibility ]
.weak Name [, Visibility ]

in this patch, we implement the visibility attribute for the global variable, function or extern function .

for example.

extern __attribute__ ((visibility ("hidden"))) int
  bar(int* ip);
__attribute__ ((visibility ("hidden"))) int b = 0;
__attribute__ ((visibility ("hidden"))) int
  foo(int* ip){
   return (*ip)++;
}
the visibility of .comm linkage do not support , we will have a separate patch for it.
we have the unsupported cases ("default" and "internal") , we will implement them in a a separate patch for it.

Reviewers: Jason Liu ,hubert.reinterpretcast,James Henderson

Differential Revision: https://reviews.llvm.org/D75866
2020-06-09 16:15:06 -04:00
diggerlin a2c8cd1812 [AIX] emit .extern and .weak directive linkage
SUMMARY:

emit .extern and .weak directive linkage

Reviewers: hubert.reinterpretcast, Jason Liu
Subscribers: wuzish, nemanjai, hiraditya

Differential Revision: https://reviews.llvm.org/D76932
2020-04-30 09:54:10 -04:00
Shengchen Kan c031378ce0 [MC][NFC] Use camelCase style for functions in MCObjectStreamer 2020-04-20 20:09:20 -07:00
Fangrui Song 7d1ff446b6 [MC] Rename MCSection*::getSectionName() to getName(). NFC
A pending change will merge MCSection*::getName() to MCSection::getName().
2020-04-15 16:48:14 -07:00
Fangrui Song b61a4aaca5 [MC] Default MCContext::UseNamesOnTempLabels to false and only set it to true for MCAsmStreamer
Only MCAsmStreamer (assembly output) needs to keep names of temporary labels created by
MCContext::createTempSymbol().

This change made the rL236642 optimization available for cc2as and
probably some other users.

This eliminates a behavior difference between llvm-mc -filetype=obj and cc1as, which caused
https://reviews.llvm.org/D74006#1890487

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D75097
2020-02-25 18:23:10 -08:00
Scott Linder 7f3afd480d Emit register names in cfi assembly directives
Update .cfi_undefined, .cfi_register, and .cfi_return_column to
print symbolic register arguments.

Differential Revision: https://reviews.llvm.org/D74914
2020-02-25 14:00:01 -05:00
Fangrui Song 549b436beb [MC] De-capitalize MCStreamer::Emit{Bundle,Addrsig}* etc
So far, all non-COFF-related Emit* functions have been de-capitalized.
2020-02-15 09:11:48 -08:00
Fangrui Song 774971030d [MCStreamer] De-capitalize EmitValue EmitIntValue{,InHex} 2020-02-14 23:08:40 -08:00
Fangrui Song 6d2d589b06 [MC] De-capitalize another set of MCStreamer::Emit* functions
Emit{ValueTo,Code}Alignment Emit{DTP,TP,GP}* EmitSymbolValue etc
2020-02-14 19:26:52 -08:00
Fangrui Song a55daa1461 [MC] De-capitalize some MCStreamer::Emit* functions 2020-02-14 19:11:53 -08:00
Fangrui Song bcd24b2d43 [AsmPrinter][MCStreamer] De-capitalize EmitInstruction and EmitCFI* 2020-02-13 22:08:55 -08:00
Fangrui Song 0bc77a0f0d [AsmPrinter] De-capitalize some AsmPrinter::Emit* functions
Similar to rL328848.
2020-02-13 13:38:33 -08:00
Jinsong Ji 01edae1271 [AsmPrinter] Print FP constant in hexadecimal form instead
Printing floating point number in decimal is inconvenient for humans.
Verbose asm output will print out floating point values in comments, it
helps.

But in lots of cases, users still need additional work to covert the
decimal back to hex or binary to check the bit patterns,
especially when there are small precision difference.

Hexadecimal form is one of the supported form in LLVM IR, and easier for
debugging.

This patch try to print all FP constant in hex form instead.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D73566
2020-02-07 16:00:55 +00:00
David Tenty 77e71c5217 [AIX] Don't use a zero fill with a second parameter
Summary:
The AIX assembler .space directive can't take a second non-zero argument to fill
with. But LLVM emitFill currently assumes it can. We add a flag to the AsmInfo
to check if non-zero fill is supported, and if we can't zerofill non-zero values
we just splat the .byte directives.

Reviewers: stevewan, sfertile, DiggerLin, jasonliu, Xiangling_L

Reviewed By: jasonliu

Subscribers: Xiangling_L, wuzish, nemanjai, hiraditya, kbarton, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73554
2020-02-03 15:16:08 -05:00
Philip Reames 29ccb12e2c [BranchAlign] Compiler support for suppressing branch align
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
2020-01-08 10:03:30 -08:00
Fangrui Song aa708763d3 [MC] Add parameter `Address` to MCInstPrinter::printInst
printInst prints a branch/call instruction as `b offset` (there are many
variants on various targets) instead of `b address`.

It is a convention to use address instead of offset in most external
symbolizers/disassemblers. This difference makes `llvm-objdump -d`
output unsatisfactory.

Add `uint64_t Address` to printInst(), so that it can pass the argument to
printInstruction(). `raw_ostream &OS` is moved to the last to be
consistent with other print* methods.

The next step is to pass `Address` to printInstruction() (generated by
tablegen from the instruction set description). We can gradually migrate
targets to print addresses instead of offsets.

In any case, downstream projects which don't know `Address` can pass 0 as
the argument.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D72172
2020-01-06 20:42:22 -08:00
Jason Liu 0dc0572b48 [XCOFF][AIX] Differentiate usage of label symbol and csect symbol
Summary:
 We are using symbols to represent label and csect interchangeably before, and that could be a problem.
There are cases we would need to add storage mapping class to the symbol if that symbol is actually the name of a csect, but it's hard for us to figure out whether that symbol is a label or csect.

This patch intend to do the following:
    1. Construct a QualName (A name include the storage mapping class)
       MCSymbolXCOFF for every MCSectionXCOFF.
    2. Keep a pointer to that QualName inside of MCSectionXCOFF.
    3. Use that QualName whenever we need a symbol refers to that
       MCSectionXCOFF.
    4. Adapt the snowball effect from the above changes in
       XCOFFObjectWriter.cpp.

Reviewers: xingxue, DiggerLin, sfertile, daltenty, hubert.reinterpretcast

Reviewed By: DiggerLin, daltenty

Subscribers: wuzish, nemanjai, mgorny, hiraditya, kbarton, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69633
2019-11-08 09:30:10 -05:00
Reid Kleckner 7bbe711fb1 Avoid including CodeView/SymbolRecord.h from MCStreamer.h
Move the types needed out so they can be forward declared instead.

llvm-svn: 375325
2019-10-19 01:44:09 +00:00
Xiangling Liao 3b808fb330 [AIX]Emit function descriptor csect in assembly
This patch emits the function descriptor csect for functions with definitions
under both 32-bit/64-bit mode on AIX.

Differential Revision: https://reviews.llvm.org/D66724

llvm-svn: 373009
2019-09-26 19:38:32 +00:00
Pavel Labath aaff1a631a MCRegisterInfo: Merge getLLVMRegNum and getLLVMRegNumFromEH
Summary:
The functions different in two ways:
- getLLVMRegNum could return both "eh" and "other" dwarf register
  numbers, while getLLVMRegNumFromEH only returned the "eh" number.
- getLLVMRegNum asserted if the register was not found, while the second
  function returned -1.

The second distinction was pretty important, but it was very hard to
infer that from the function name. Aditionally, for the use case of
dumping dwarf expressions, we needed a function which can work with both
kinds of number, but does not assert.

This patch solves both of these issues by merging the two functions into
one, returning an Optional<unsigned> value. While the same thing could
be achieved by adding an "IsEH" argument to the (renamed)
getLLVMRegNumFromEH function, it seemed better to avoid the confusion of
two functions and put the choice of asserting into the hands of the
caller -- if he checks the Optional value, he can safely process
"untrusted" input, and if he blindly dereferences the Optional, he gets
the assertion.

I've updated all call sites to the new API, choosing between the two
options according to the function they were calling originally, except
that I've updated the usage in DWARFExpression.cpp to use the "safe"
method instead, and added a test case which would have previously
triggered an assertion failure when processing (incorrect?) dwarf
expressions.

Reviewers: dsanders, arsenm, JDevlieghere

Subscribers: wdng, aprantl, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67154

llvm-svn: 372710
2019-09-24 09:31:02 +00:00
Reid Kleckner 657a06c619 [MC] Avoid crashes from improperly nested or wrong target .seh_handlerdata directives
llvm-svn: 370540
2019-08-30 22:25:55 +00:00
Reid Kleckner a33474d595 [X86] Print register names in .seh_* directives
Also improve assembler parser register validation for .seh_ directives.
This requires moving X86-specific seh directive handling into the x86
backend, which addresses some assembler FIXMEs.

Differential Revision: https://reviews.llvm.org/D66625

llvm-svn: 370533
2019-08-30 21:23:05 +00:00
Xing Xue ef039a3ccd [PowerPC][AIX] Adds support for writing the .data section in assembly files
Summary:
Adds support for generating the .data section in assembly files for global variables with a non-zero initialization. The support for writing the .data section in XCOFF object files will be added in a follow-on patch. Any relocations are not included in this patch.

Reviewers: hubert.reinterpretcast, sfertile, jasonliu, daltenty, Xiangling_L

Reviewed by: hubert.reinterpretcast

Subscribers: nemanjai, hiraditya, kbarton, MaskRay, jsji, wuzish, shchenz, DiggerLin, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66154

llvm-svn: 369869
2019-08-25 15:17:25 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
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
2019-08-15 15:54:37 +00:00