[CodeGen][X86] Fix lowering of tailcalls when `-ms-hotpatch` is used (#77245)

Previously, tail jump pseudo-opcodes were skipped by the
`encodeInstruction()` call inside `X86AsmPrinter::LowerPATCHAB

[CodeGen][X86] Fix lowering of tailcalls when `-ms-hotpatch` is used (#77245)

Previously, tail jump pseudo-opcodes were skipped by the
`encodeInstruction()` call inside `X86AsmPrinter::LowerPATCHABLE_OP`.
This caused emission of a 2-byte NOP and dropping of the tail jump.

With this PR, we change `PATCHABLE_OP` to not wrap the first
`MachineInstr` anymore, but inserting itself before,
leaving the instruction unaltered. At lowering time in `X86AsmPrinter`,
we now "look ahead" for the next non-pseudo `MachineInstr` and
lower+encode it, to inspect its size. If the size is below what
`PATCHABLE_OP` expects, it inserts NOPs; otherwise it does nothing. That
way, now the first `MachineInstr` is always lowered as usual even if
`"patchable-function"="prologue-short-redirect"` is used.

Fixes https://github.com/llvm/llvm-project/issues/76879,
https://github.com/llvm/llvm-project/issues/76958 and
https://github.com/llvm/llvm-project/issues/59039

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[CodeGen][X86] Crash fixes for "patchable-function" pass

This patch fixes crashes related with how PatchableFunction selects the instruction to make patchable:
- Ensure PatchableFunction skips all i

[CodeGen][X86] Crash fixes for "patchable-function" pass

This patch fixes crashes related with how PatchableFunction selects the instruction to make patchable:
- Ensure PatchableFunction skips all instructions that don't generate actual machine instructions.
- Handle the case where the first MachineBasicBlock is empty
- Removed support for 16 bit x86 architectures.

Note: another issue remains related with PatchableFunction, in the lowering part.
See https://github.com/llvm/llvm-project/issues/59039

Differential Revision: https://reviews.llvm.org/D137642

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Cleanup codegen includes

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after: 1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-in

Cleanup codegen includes

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after: 1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121681

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Revert "Cleanup codegen includes"

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https:/

Revert "Cleanup codegen includes"

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169

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Cleanup codegen includes

after: 1061034926
before: 1063332844

Differential Revision: https://reviews.llvm.org/D121169

[PatchableFunction] Use an empty DebugLoc

The current FirstMI.getDebugLoc() is actually null in almost all cases.
If it isn't, the generated .loc will be considered initial. The .loc
will have the p

[PatchableFunction] Use an empty DebugLoc

The current FirstMI.getDebugLoc() is actually null in almost all cases.
If it isn't, the generated .loc will be considered initial. The .loc
will have the prologue_end flag and terminate the prologue prematurely.

Also use an overload of BuildMI that will not prepend
PATCHABLE_FUNCTION_ENTRY to a MachineInstr bundle.

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[PatchableFunction] Allow empty entry MachineBasicBlock

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D73301

[AArch64] Add function attribute "patchable-function-entry" to add NOPs at function entry

The Linux kernel uses -fpatchable-function-entry to implement DYNAMIC_FTRACE_WITH_REGS
for arm64 and parisc.

[AArch64] Add function attribute "patchable-function-entry" to add NOPs at function entry

The Linux kernel uses -fpatchable-function-entry to implement DYNAMIC_FTRACE_WITH_REGS
for arm64 and parisc. GCC 8 implemented
-fpatchable-function-entry, which can be seen as a generalized form of
-mnop-mcount. The N,M form (function entry points before the Mth NOP) is
currently only used by parisc.

This patch adds N,0 support to AArch64 codegen. N is represented as the
function attribute "patchable-function-entry". We will use a different
function attribute for M, if we decide to implement it.

The patch reuses the existing patchable-function pass, and
TargetOpcode::PATCHABLE_FUNCTION_ENTER which is currently used by XRay.

When the integrated assembler is used, __patchable_function_entries will
be created for each text section with the SHF_LINK_ORDER flag to prevent
--gc-sections (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93197) and
COMDAT (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93195) issues.

Retrospectively, __patchable_function_entries should use a PC-relative
relocation type to avoid the SHF_WRITE flag and dynamic relocations.

"patchable-function-entry"'s interaction with Branch Target
Identification is still unclear (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 for GCC discussions).

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D72215

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Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of reco

Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211

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[Alignment][NFC] Remove unneeded llvm:: scoping on Align types

llvm-svn: 373081

[Alignment] Use llvm::Align in MachineFunction and TargetLowering - fixes mir parsing

Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.l

[Alignment] Use llvm::Align in MachineFunction and TargetLowering - fixes mir parsing

Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.llvm.org/D65945 for reference,

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

Subscribers: MatzeB, qcolombet, dschuff, arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67433

llvm-svn: 371608

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[LLVM][Alignment] Make functions using log of alignment explicit

Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Alig

[LLVM][Alignment] Make functions using log of alignment explicit

Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:

- `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
- `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
- `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,

Reviewers: lattner, thegameg, courbet

Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65945

llvm-svn: 371045

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
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

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[DebugInfo] Convert intrinsic llvm.dbg.label to MachineInstr.

In order to convert LLVM IR to MachineInstr, we need a new TargetOpcode,
DBG_LABEL, to ‘lower’ intrinsic llvm.dbg.label. The patch
creat

[DebugInfo] Convert intrinsic llvm.dbg.label to MachineInstr.

In order to convert LLVM IR to MachineInstr, we need a new TargetOpcode,
DBG_LABEL, to ‘lower’ intrinsic llvm.dbg.label. The patch
creates this new TargetOpcode and convert intrinsic llvm.dbg.label to
MachineInstr through SelectionDAG.

In SelectionDAG, debug information is stored in SDDbgInfo. We create a
new data member of SDDbgInfo for labels and use the new data member,
SDDbgLabel, to create DBG_LABEL MachineInstr.

The new DBG_LABEL MachineInstr uses label metadata from LLVM IR as its
parameter. So, the backend could get metadata information of labels from
DBG_LABEL MachineInstr.

Differential Revision: https://reviews.llvm.org/D45341

Patch by Hsiangkai Wang.

llvm-svn: 331842

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MachineFunction: Return reference from getFunction(); NFC

The Function can never be nullptr so we can return a reference.

llvm-svn: 320884

Fix a bunch more layering of CodeGen headers that are in Target

All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, n

Fix a bunch more layering of CodeGen headers that are in Target

All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490

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Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering

This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the

Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering

This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647

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Move TargetFrameLowering.h to CodeGen where it's implemented

This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link er

Move TargetFrameLowering.h to CodeGen where it's implemented

This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.

llvm-svn: 317379

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Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line

Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787

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[CodeGen] Rename MachineInstrBuilder::addOperand. NFC

Rename from addOperand to just add, to match the other method that has been
added to MachineInstrBuilder for adding more than just 1 operand.

S

[CodeGen] Rename MachineInstrBuilder::addOperand. NFC

Rename from addOperand to just add, to match the other method that has been
added to MachineInstrBuilder for adding more than just 1 operand.

See https://reviews.llvm.org/D28057 for the whole discussion.

Differential Revision: https://reviews.llvm.org/D28556

llvm-svn: 291891

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MachineFunctionProperties/MIRParser: Rename AllVRegsAllocated->NoVRegs, compute it

Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes tha

MachineFunctionProperties/MIRParser: Rename AllVRegsAllocated->NoVRegs, compute it

Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.

Differential Revision: http://reviews.llvm.org/D23850

llvm-svn: 279698

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Revert "[X86] Support the "ms-hotpatch" attribute."

This reverts commit r278048. Something changed between the last time I
built this--it takes awhile on my ridiculously slow and ancient
computer--a

Revert "[X86] Support the "ms-hotpatch" attribute."

This reverts commit r278048. Something changed between the last time I
built this--it takes awhile on my ridiculously slow and ancient
computer--and now that broke this.

llvm-svn: 278053

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[X86] Support the "ms-hotpatch" attribute.

Summary:
Based on two patches by Michael Mueller.

This is a target attribute that causes a function marked with it to be
emitted as "hotpatchable". This p

[X86] Support the "ms-hotpatch" attribute.

Summary:
Based on two patches by Michael Mueller.

This is a target attribute that causes a function marked with it to be
emitted as "hotpatchable". This particular mechanism was originally
devised by Microsoft for patching their binaries (which they are
constantly updating to stay ahead of crackers, script kiddies, and other
ne'er-do-wells on the Internet), but is now commonly abused by Windows
programs to hook API functions.

This mechanism is target-specific. For x86, a two-byte no-op instruction
is emitted at the function's entry point; the entry point must be
immediately preceded by 64 (32-bit) or 128 (64-bit) bytes of padding.
This padding is where the patch code is written. The two byte no-op is
then overwritten with a short jump into this code. The no-op is usually
a `movl %edi, %edi` instruction; this is used as a magic value
indicating that this is a hotpatchable function.

Reviewers: majnemer, sanjoy, rnk

Subscribers: dberris, llvm-commits

Differential Revision: https://reviews.llvm.org/D19908

llvm-svn: 278048

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PatchableFunction: Skip pseudos that do not create code

This fixes http://llvm.org/PR28524

llvm-svn: 275278

Delete unused includes. NFC.

llvm-svn: 274225