Commit Graph

13 Commits

Author SHA1 Message Date
David Spickett f152472af5 [lldb] Require x86 for various NativePDB, Breakpad and Minidump tests
These tests fail if you build without the x86 llvm backend.
Either because they use an x86 triple or try to backtrace which
requires some x86 knowledge to see all frames.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D100194
2021-04-13 12:51:48 +00:00
Paul Robinson c161775dec [FastISel] Flush local value map on every instruction
Local values are constants or addresses that can't be folded into
the instruction that uses them. FastISel materializes these in a
"local value" area that always dominates the current insertion
point, to try to avoid materializing these values more than once
(per block).

https://reviews.llvm.org/D43093 added code to sink these local
value instructions to their first use, which has two beneficial
effects. One, it is likely to avoid some unnecessary spills and
reloads; two, it allows us to attach the debug location of the
user to the local value instruction. The latter effect can
improve the debugging experience for debuggers with a "set next
statement" feature, such as the Visual Studio debugger and PS4
debugger, because instructions to set up constants for a given
statement will be associated with the appropriate source line.

There are also some constants (primarily addresses) that could be
produced by no-op casts or GEP instructions; the main difference
from "local value" instructions is that these are values from
separate IR instructions, and therefore could have multiple users
across multiple basic blocks. D43093 avoided sinking these, even
though they were emitted to the same "local value" area as the
other instructions. The patch comment for D43093 states:

  Local values may also be used by no-op casts, which adds the
  register to the RegFixups table. Without reversing the RegFixups
  map direction, we don't have enough information to sink these
  instructions.

This patch undoes most of D43093, and instead flushes the local
value map after(*) every IR instruction, using that instruction's
debug location. This avoids sometimes incorrect locations used
previously, and emits instructions in a more natural order.

In addition, constants materialized due to PHI instructions are
not assigned a debug location immediately; instead, when the
local value map is flushed, if the first local value instruction
has no debug location, it is given the same location as the
first non-local-value-map instruction.  This prevents PHIs
from introducing unattributed instructions, which would either
be implicitly attributed to the location for the preceding IR
instruction, or given line 0 if they are at the beginning of
a machine basic block.  Neither of those consequences is good
for debugging.

This does mean materialized values are not re-used across IR
instruction boundaries; however, only about 5% of those values
were reused in an experimental self-build of clang.

(*) Actually, just prior to the next instruction. It seems like
it would be cleaner the other way, but I was having trouble
getting that to work.

This reapplies commits cf1c774d and dc35368c, and adds the
modification to PHI handling, which should avoid problems
with debugging under gdb.

Differential Revision: https://reviews.llvm.org/D91734
2021-01-11 08:32:36 -08:00
David Blaikie 615f63e149 Revert "[FastISel] Flush local value map on ever instruction" and dependent patches
This reverts commit cf1c774d6a.

This change caused several regressions in the gdb test suite - at least
a sample of which was due to line zero instructions making breakpoints
un-lined. I think they're worth investigating/understanding more (&
possibly addressing) before moving forward with this change.

Revert "[FastISel] NFC: Clean up unnecessary bookkeeping"
This reverts commit 3fd39d3694.

Revert "[FastISel] NFC: Remove obsolete -fast-isel-sink-local-values option"
This reverts commit a474657e30.

Revert "Remove static function unused after cf1c774."
This reverts commit dc35368ccf.

Revert "[lldb] Fix TestThreadStepOut.py after "Flush local value map on every instruction""
This reverts commit 53a14a47ee.
2020-12-01 14:26:23 -08:00
Paul Robinson cf1c774d6a [FastISel] Flush local value map on ever instruction
Local values are constants or addresses that can't be folded into
the instruction that uses them. FastISel materializes these in a
"local value" area that always dominates the current insertion
point, to try to avoid materializing these values more than once
(per block).

https://reviews.llvm.org/D43093 added code to sink these local
value instructions to their first use, which has two beneficial
effects. One, it is likely to avoid some unnecessary spills and
reloads; two, it allows us to attach the debug location of the
user to the local value instruction. The latter effect can
improve the debugging experience for debuggers with a "set next
statement" feature, such as the Visual Studio debugger and PS4
debugger, because instructions to set up constants for a given
statement will be associated with the appropriate source line.

There are also some constants (primarily addresses) that could be
produced by no-op casts or GEP instructions; the main difference
from "local value" instructions is that these are values from
separate IR instructions, and therefore could have multiple users
across multiple basic blocks. D43093 avoided sinking these, even
though they were emitted to the same "local value" area as the
other instructions. The patch comment for D43093 states:

  Local values may also be used by no-op casts, which adds the
  register to the RegFixups table. Without reversing the RegFixups
  map direction, we don't have enough information to sink these
  instructions.

This patch undoes most of D43093, and instead flushes the local
value map after(*) every IR instruction, using that instruction's
debug location. This avoids sometimes incorrect locations used
previously, and emits instructions in a more natural order.

This does mean materialized values are not re-used across IR
instruction boundaries; however, only about 5% of those values
were reused in an experimental self-build of clang.

(*) Actually, just prior to the next instruction. It seems like
it would be cleaner the other way, but I was having trouble
getting that to work.

Differential Revision: https://reviews.llvm.org/D91734
2020-11-25 13:05:00 -05:00
Matt Arsenault 89baeaef2f Reapply "RegAllocFast: Rewrite and improve"
This reverts commit 73a6a164b8.
2020-09-30 10:35:25 -04:00
Muhammad Omair Javaid 73a6a164b8 Revert "Reapply Revert "RegAllocFast: Rewrite and improve""
This reverts commit 55f9f87da2.

Breaks following buildbots:
http://lab.llvm.org:8011/builders/lldb-arm-ubuntu/builds/4306
http://lab.llvm.org:8011/builders/lldb-aarch64-ubuntu/builds/9154
2020-09-22 14:40:06 +05:00
Matt Arsenault 55f9f87da2 Reapply Revert "RegAllocFast: Rewrite and improve"
This reverts commit dbd53a1f0c.

Needed lldb test updates
2020-09-21 15:45:27 -04:00
Martin Storsjö 1739c7c10c Reapply [LLDB] [test] Use %clang_cl instead of build.py in a few tests
This allows explicitly specifying the intended target architecture,
for tests that aren't supposed to be executed, and that don't
require MSVC headers or libraries to be available.

(These tests already implicitly assumed to be built for x86; one
didn't specify anything, assuming x86_64, while the other specified
--arch=32, which only picks the 32 bit variant of the default target
architecture).

Join two comment lines in disassembly.cpp, to keep row numbers
checked in the test unchanged.

This fixes running check-lldb on arm linux.

Previously when this was applied (in 95980409e6), it broke
macos buildbots, as they added "-isysroot <path>" to all %clang*
substitutions, and clang-cl didn't support that.

Reapplying it without further changes to this patch, after D69619
(9c73925226), because now, such extra parameters are added to
%clang_host*, but not to plain %clang_cl.

Differential Revision: https://reviews.llvm.org/D69031
2019-11-01 20:49:13 +02:00
Martin Storsjo 54017d0f52 Revert "[LLDB] [test] Use %clang_cl instead of build.py in a few tests"
This reverts SVN r375156, as it seems to have broken tests when run
on macOS: http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/2706/console

llvm-svn: 375163
2019-10-17 20:14:19 +00:00
Martin Storsjo 95980409e6 [LLDB] [test] Use %clang_cl instead of build.py in a few tests
This allows explicitly specifying the intended target architecture,
for tests that aren't supposed to be executed, and that don't
require MSVC headers or libraries to be available.

(These tests already implicitly assumed to be built for x86; one
didn't specify anything, assuming x86_64, while the other specified
--arch=32, which only picks the 32 bit variant of the default target
architecture).

Join two comment lines in disassembly.cpp, to keep row numbers
checked in the test unchanged.

This fixes running check-lldb on arm linux.

Differential Revision: https://reviews.llvm.org/D69031

llvm-svn: 375156
2019-10-17 19:22:50 +00:00
Jonas Devlieghere 87aa9c9e4d Re-land "[test] Split LLDB tests into API, Shell & Unit"
The original patch got reverted because it broke `check-lldb` on a clean
build. This fixes that.

llvm-svn: 374201
2019-10-09 19:22:02 +00:00
Adrian Prantl 0115c10328 Revert [test] Split LLDB tests into API, Shell & Unit
as it appears to have broken check-lldb.

This reverts r374184 (git commit 22314179f0)

llvm-svn: 374187
2019-10-09 17:35:43 +00:00
Jonas Devlieghere 22314179f0 [test] Split LLDB tests into API, Shell & Unit
LLDB has three major testing strategies: unit tests, tests that exercise
the SB API though dotest.py and what we currently call lit tests. The
later is rather confusing as we're now using lit as the driver for all
three types of tests. As most of this grew organically, the directory
structure in the LLDB repository doesn't really make this clear.

The 'lit' tests are part of the root and among these tests there's a
Unit and Suite folder for the unit and dotest-tests. This layout makes
it impossible to run just the lit tests.

This patch changes the directory layout to match the 3 testing
strategies, each with their own directory and their own configuration
file. This means there are now 3 directories under lit with 3
corresponding targets:

 - API (check-lldb-api): Test exercising the SB API.
 - Shell (check-lldb-shell): Test exercising command line utilities.
 - Unit (check-lldb-unit): Unit tests.

Finally, there's still the `check-lldb` target that runs all three test
suites.

Finally, this also renames the lit folder to `test` to match the LLVM
repository layout.

Differential revision: https://reviews.llvm.org/D68606

llvm-svn: 374184
2019-10-09 16:38:47 +00:00