[CodeGen] Qualify auto variables in for loops (NFC)

[MC] Lower case the first letter of EmitCOFF* EmitWin* EmitCV*. NFC

[CodeGen] Async unwind - add a pass to fix CFI information

This pass inserts the necessary CFI instructions to compensate for the
inconsistency of the call-frame information caused by linear (non-CG

[CodeGen] Async unwind - add a pass to fix CFI information

This pass inserts the necessary CFI instructions to compensate for the
inconsistency of the call-frame information caused by linear (non-CGA
aware) nature of the unwind tables.

Unlike the `CFIInstrInserer` pass, this one almost always emits only
`.cfi_remember_state`/`.cfi_restore_state`, which results in smaller
unwind tables and also transparently handles custom unwind info
extensions like CFA offset adjustement and save locations of SVE
registers.

This pass takes advantage of the constraints taht LLVM imposes on the
placement of save/restore points (cf. `ShrinkWrap.cpp`):

* there is a single basic block, containing the function prologue

* possibly multiple epilogue blocks, where each epilogue block is
complete and self-contained, i.e. CSR restore instructions (and the
corresponding CFI instructions are not split across two or more
blocks.

* prologue and epilogue blocks are outside of any loops

Thus, during execution, at the beginning and at the end of each basic
block the function can be in one of two states:

- "has a call frame", if the function has executed the prologue, or
has not executed any epilogue

- "does not have a call frame", if the function has not executed the
prologue, or has executed an epilogue

These properties can be computed for each basic block by a single RPO
traversal.

From the point of view of the unwind tables, the "has/does not have
call frame" state at beginning of each block is determined by the
state at the end of the previous block, in layout order.

Where these states differ, we insert compensating CFI instructions,
which come in two flavours:

- CFI instructions, which reset the unwind table state to the
initial one. This is done by a target specific hook and is
expected to be trivial to implement, for example it could be:
```
.cfi_def_cfa <sp>, 0
.cfi_same_value <rN>
.cfi_same_value <rN-1>
...
```
where `<rN>` are the callee-saved registers.

- CFI instructions, which reset the unwind table state to the one
created by the function prologue. These are the sequence:
```
.cfi_restore_state
.cfi_remember_state
```
In this case we also insert a `.cfi_remember_state` after the
last CFI instruction in the function prologue.

Reviewed By: MaskRay, danielkiss, chill

Differential Revision: https://reviews.llvm.org/D114545

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Revert "[CodeGen] Async unwind - add a pass to fix CFI information"

This reverts commit 980c3e6dd223a8e628367144b8180117950bb364.

This commit had failing tests with clang crashing across various
AA

Revert "[CodeGen] Async unwind - add a pass to fix CFI information"

This reverts commit 980c3e6dd223a8e628367144b8180117950bb364.

This commit had failing tests with clang crashing across various
AArch64/Linux buildots.

https://lab.llvm.org/buildbot/#/builders/179/builds/3346

Differential Revision: https://reviews.llvm.org/D114545

show more ...

[CodeGen] Async unwind - add a pass to fix CFI information

This pass inserts the necessary CFI instructions to compensate for the
inconsistency of the call-frame information caused by linear (non-CF

[CodeGen] Async unwind - add a pass to fix CFI information

This pass inserts the necessary CFI instructions to compensate for the
inconsistency of the call-frame information caused by linear (non-CFG
aware) nature of the unwind tables.

Unlike the `CFIInstrInserer` pass, this one almost always emits only
`.cfi_remember_state`/`.cfi_restore_state`, which results in smaller
unwind tables and also transparently handles custom unwind info
extensions like CFA offset adjustement and save locations of SVE
registers.

This pass takes advantage of the constraints that LLVM imposes on the
placement of save/restore points (cf. `ShrinkWrap.cpp`):

* there is a single basic block, containing the function prologue

* possibly multiple epilogue blocks, where each epilogue block is
complete and self-contained, i.e. CSR restore instructions (and the
corresponding CFI instructions are not split across two or more
blocks.

* prologue and epilogue blocks are outside of any loops

Thus, during execution, at the beginning and at the end of each basic
block the function can be in one of two states:

- "has a call frame", if the function has executed the prologue, or
has not executed any epilogue

- "does not have a call frame", if the function has not executed the
prologue, or has executed an epilogue

These properties can be computed for each basic block by a single RPO
traversal.

In order to accommodate backends which do not generate unwind info in
epilogues we compute an additional property "strong no call frame on
entry" which is set for the entry point of the function and for every
block reachable from the entry along a path that does not execute the
prologue. If this property holds, it takes precedence over the "has a
call frame" property.

From the point of view of the unwind tables, the "has/does not have
call frame" state at beginning of each block is determined by the
state at the end of the previous block, in layout order.

Where these states differ, we insert compensating CFI instructions,
which come in two flavours:

- CFI instructions, which reset the unwind table state to the
initial one. This is done by a target specific hook and is
expected to be trivial to implement, for example it could be:
```
.cfi_def_cfa <sp>, 0
.cfi_same_value <rN>
.cfi_same_value <rN-1>
...
```
where `<rN>` are the callee-saved registers.

- CFI instructions, which reset the unwind table state to the one
created by the function prologue. These are the sequence:
```
.cfi_restore_state
.cfi_remember_state
```
In this case we also insert a `.cfi_remember_state` after the
last CFI instruction in the function prologue.

Reviewed By: MaskRay, danielkiss, chill

Differential Revision: https://reviews.llvm.org/D114545

show more ...

Cleanup includes: DebugInfo & CodeGen

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121332

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/

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

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[debug-info] refactor emitDwarfUnitLength

remove `Hi` `Lo` argument from `emitDwarfUnitLength`, so we
can make caller of emitDwarfUnitLength easier.

Reviewed By: MaskRay, dblaikie, ikudrin

Differe

[debug-info] refactor emitDwarfUnitLength

remove `Hi` `Lo` argument from `emitDwarfUnitLength`, so we
can make caller of emitDwarfUnitLength easier.

Reviewed By: MaskRay, dblaikie, ikudrin

Differential Revision: https://reviews.llvm.org/D96409

show more ...

[Debug-Info][NFC] move emitDwarfUnitLength to MCStreamer class

We may need to do some customization for DWARF unit length in DWARF
section headers for some targets for some code generation path.

Fo

[Debug-Info][NFC] move emitDwarfUnitLength to MCStreamer class

We may need to do some customization for DWARF unit length in DWARF
section headers for some targets for some code generation path.

For example, for XCOFF in assembly path, AIX assembler does not require
the debug section containing its debug unit length in the header.

Move emitDwarfUnitLength to MCStreamer class so that we can do
customization in different Streamers

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D95932

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[XCOFF][AIX] Generate LSDA data and compact unwind section on AIX

Summary:
AIX uses the existing EH infrastructure in clang and llvm.
The major differences would be
1. AIX do not have CFI instructio

[XCOFF][AIX] Generate LSDA data and compact unwind section on AIX

Summary:
AIX uses the existing EH infrastructure in clang and llvm.
The major differences would be
1. AIX do not have CFI instructions.
2. AIX uses a new personality routine, named __xlcxx_personality_v1.
It doesn't use the GCC personality rountine, because the
interoperability is not there yet on AIX.
3. AIX do not use eh_frame sections. Instead, it would use a eh_info
section (compat unwind section) to store the information about
personality routine and LSDA data address.

Reviewed By: daltenty, hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D91455

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[DebugInfo] Add new emitting methods for values which depend on the DWARF format (3/19).

These methods are going to be used in subsequent patches.

Differential Revision: https://reviews.llvm.org/D8

[DebugInfo] Add new emitting methods for values which depend on the DWARF format (3/19).

These methods are going to be used in subsequent patches.

Differential Revision: https://reviews.llvm.org/D87010

show more ...

[DebugInfo] Fix methods of AsmPrinter to emit values corresponding to the DWARF format (1/19).

These methods are used to emit values which are 32-bit in DWARF32 and
64-bit in DWARF64. The patch fixe

[DebugInfo] Fix methods of AsmPrinter to emit values corresponding to the DWARF format (1/19).

These methods are used to emit values which are 32-bit in DWARF32 and
64-bit in DWARF64. The patch fixes them so that they choose the length
automatically, depending on the DWARF format set in the Context.

Differential Revision: https://reviews.llvm.org/D87008

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[AArch64][SVE] Fix CFA calculation in presence of SVE objects.

The CFA is calculated as (SP/FP + offset), but when there are
SVE objects on the stack the SP offset is partly scalable and
should inst

[AArch64][SVE] Fix CFA calculation in presence of SVE objects.

The CFA is calculated as (SP/FP + offset), but when there are
SVE objects on the stack the SP offset is partly scalable and
should instead be expressed as the DWARF expression:

SP + offset + scalable_offset * VG

where VG is the Vector Granule register, containing the
number of 64bits 'granules' in a scalable vector.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D84043

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[DebugInfo] Fix emitting offsets to CUs with -dwarf-sections-as-references=Enable.

The size of the field depends on the DWARF format, not the address size
of the target.

Differential Revision: http

[DebugInfo] Fix emitting offsets to CUs with -dwarf-sections-as-references=Enable.

The size of the field depends on the DWARF format, not the address size
of the target.

Differential Revision: https://reviews.llvm.org/D82311

show more ...

Support emitting .cfi_undefined in CodeGen

This will be used by AMDGPU.

Differential Revision: https://reviews.llvm.org/D74914

[MCStreamer] De-capitalize EmitValue EmitIntValue{,InHex}

[MC] De-capitalize another set of MCStreamer::Emit* functions

Emit{ValueTo,Code}Alignment Emit{DTP,TP,GP}* EmitSymbolValue etc

[AsmPrinter][MCStreamer] De-capitalize EmitInstruction and EmitCFI*

[AsmPrinter] De-capitalize all AsmPrinter::Emit* but EmitInstruction

Similar to rL328848.

[AsmPrinter] De-capitalize some AsmPrinter::Emit* functions

Similar to rL328848.

[AsmPrinter] Make the encoding of call sites in .gcc_except_table configurable and use for RISC-V

The original behavior was to always emit the offsets to each call site in the
call site table as ule

[AsmPrinter] Make the encoding of call sites in .gcc_except_table configurable and use for RISC-V

The original behavior was to always emit the offsets to each call site in the
call site table as uleb128 values, however on some architectures (eg RISCV)
these uleb128 offsets into the code cannot always be resolved until link time
(because relaxation will invalidate any calculated offsets), and there are no
appropriate relocations for uleb128 values. As a consequence it needs to be
possible to specify an alternative.

This also switches RISCV to use DW_EH_PE_udata4 for call side encodings in
.gcc_except_table

Differential Revision: https://reviews.llvm.org/D63415
Patch by Edward Jones.

llvm-svn: 366329

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Add explicit dependencies on MCSection.h and MCDwarf.h to the .cpp
files rather than rely on transitive includes from MCStreamer.h.

llvm-svn: 358263

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an a

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.

The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.

For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.

This is a recommit of r356442 with trivial fixes for the failing tests.

Differential Revision: https://reviews.llvm.org/D56587

llvm-svn: 356451

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Revert "[DebugInfo] Introduce DW_OP_LLVM_convert"

This reverts commit 1cf4b593a7ebd666fc6775f3bd38196e8e65fafe.

Build bots found failing tests not detected locally.

Failing Tests (3):
LLVM :: De

Revert "[DebugInfo] Introduce DW_OP_LLVM_convert"

This reverts commit 1cf4b593a7ebd666fc6775f3bd38196e8e65fafe.

Build bots found failing tests not detected locally.

Failing Tests (3):
LLVM :: DebugInfo/Generic/convert-debugloc.ll
LLVM :: DebugInfo/Generic/convert-inlined.ll
LLVM :: DebugInfo/Generic/convert-linked.ll

llvm-svn: 356444

show more ...

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an a

[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.

The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.

For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.

Differential Revision: https://reviews.llvm.org/D56587

llvm-svn: 356442

show more ...