81 Commits

Author SHA1 Message Date
Matt Arsenault
1a114fa302
RegAlloc: Use new approach to handling failed allocations (#128469)
This fixes an assert after allocation failure.

Rather than collecting failed virtual registers and hacking
on the uses after the fact, directly hack on the uses and rewrite
the registers to the dummy assignment immediately.

Previously we were bypassing LiveRegMatrix and directly assigning
in the VirtRegMap. This resulted in inconsistencies where illegal
overlapping assignments were missing. Rather than try to hack in
some system to manage these in LiveRegMatrix (i.e. hacking around
cases with invalid iterators), avoid this by directly using the
physreg. This should also allow removal of special casing in
virtregrewriter for failed allocations.
2025-02-26 15:34:47 +07:00
Matt Arsenault
e160c35c9e
Reapply "RegAlloc: Fix verifier error after failed allocation (#119690)" (#128400)
Reapply "RegAlloc: Fix verifier error after failed allocation (#119690)"

This reverts commit 0c50054820799578be8f62b6fd2cc3fbc751c01e.

Reapply with more fixes to avoid expensive_checks failures. Make sure to
call splitSeparateComponents after shrinkToUses, and update the VirtRegMap
with the split registers. Also set undef on all physical register aliases to
the assigned register.

Move physreg handling. Not sure if necessary

Remove intervals from regunits. Not sure if necessary
2025-02-26 15:31:48 +07:00
Matt Arsenault
0c50054820 Revert "RegAlloc: Fix verifier error after failed allocation (#119690)"
This reverts commit 34167f99668ce4d4d6a1fb88453a8d5b56d16ed5.

Different set of verifier errors appears after other regalloc failure
tests with EXPENSIVE_CHECKS.
2025-02-22 00:23:21 +07:00
Matt Arsenault
34167f9966
RegAlloc: Fix verifier error after failed allocation (#119690)
In some cases after reporting an allocation failure, this would fail
the verifier. It picks the first allocatable register and assigns it,
but didn't update the liveness appropriately. When VirtRegRewriter
relied on the liveness to set kill flags, it would incorrectly add
kill flags if there was another overlapping kill of the virtual
register.

We can't properly assign the register to an overlapping range, so
break the liveness of the failing register (and any other interfering
registers) instead. Give the virtual register dummy liveness by
effectively deleting all the uses by setting them to undef.

The edge case not tested here which I'm worried about is if the read
of the register is a def of a subregister. I've been unable to come up
with a test where this occurs.

https://reviews.llvm.org/D122616
2025-02-21 22:11:51 +07:00
Matt Arsenault
a3db5910b4
RegAllocBase: Avoid using temporary DiagnosticInfo (#120046) 2024-12-16 14:57:13 +07:00
Matt Arsenault
61f99a1c75
RegAlloc: Do not fatal error if there are no registers in the alloc order (#119640)
Try to use DiagnosticInfo if every register in the class is reserved
by forcing assignment to a reserved register. Also reduces the number
of redundant errors emitted, particularly with fast.

This is still broken in the case of undef uses. There are additional
complications in greedy and fast, so leave it for a separate fix.
2024-12-16 10:52:49 +09:00
Matt Arsenault
bb18e49edb
RegAlloc: Use DiagnosticInfo to report register allocation failures (#119492)
Improve the non-fatal cases to use DiagnosticInfo, which will now
provide a location. The allocators attempt to report different errors
if it happens to see inline assembly is involved (this detection is
quite unreliable) using srcloc instead of dbgloc. For now, leave this
behavior unchanged. I think reporting the full location and context
function would be more useful.
2024-12-16 10:49:08 +09:00
Matt Arsenault
ea632e1b34
Reapply "DiagnosticInfo: Clean up usage of DiagnosticInfoInlineAsm" (#119575) (#119634)
This reverts commit 40986feda8b1437ed475b144d5b9a208b008782a.

Reapply with fix to prevent temporary Twine from going out of scope.
2024-12-11 16:01:48 -08:00
Vitaly Buka
40986feda8
Revert "DiagnosticInfo: Clean up usage of DiagnosticInfoInlineAsm" (#119575)
Reverts llvm/llvm-project#119485

Breaks builders, details in llvm/llvm-project#119485
2024-12-11 07:51:36 -08:00
Matt Arsenault
884f2ad6f9
DiagnosticInfo: Clean up usage of DiagnosticInfoInlineAsm (#119485)
Currently LLVMContext::emitError emits any error as an "inline asm"
error which does not make any sense. InlineAsm appears to be special,
in that it uses a "LocCookie" from srcloc metadata, which looks like
a parallel mechanism to ordinary source line locations. This meant
that other types of failures had degraded source information reported
when available.

Introduce some new generic error types, and only use inline asm
in the appropriate contexts. The DiagnosticInfo types are still
a bit of a mess, and I'm not sure why DiagnosticInfoWithLocationBase
exists instead of just having an optional DiagnosticLocation in the
base class.

DK_Generic is for any error that derives from an IR level instruction,
and thus can pull debug locations directly from it. DK_GenericWithLoc
is functionally the generic codegen error, since it does not depend
on the IR and instead can construct a DiagnosticLocation from the
MI debug location.
2024-12-11 17:16:07 +09:00
Craig Topper
131d73ed34
[RegAlloc] Remove redundant prints of LiveInterval weight. (#116451)
LiveInterval::print has included the weight since early 2018. We don't
need to print again after we print the interval.
2024-11-15 16:43:30 -08:00
Matt Arsenault
0f0cfcff2c
CodeGen: Avoid some references to MachineFunction's getMMI (#99652)
MachineFunction's probably should not include a backreference to
the owning MachineModuleInfo. Most of these references were used
just to query the MCContext, which MachineFunction already directly
stores. Other contexts are using it to query the LLVMContext, which
can already be accessed through the IR function reference.
2024-07-19 22:09:05 +04:00
Kazu Hirata
e5aef72c0a
[CodeGen] Use a range-based for loop (NFC) (#97177)
I++ in the loop might appear to indicate that the loop modifies the
container in some way (deletion or insertion), but the loop just
examines the container.
2024-06-29 17:06:58 -07:00
Nikita Popov
4169338e75
[IR] Don't include Module.h in Analysis.h (NFC) (#97023)
Replace it with a forward declaration instead. Analysis.h is pulled in
by all passes, but not all passes need to access the module.
2024-06-28 14:30:47 +02:00
Alexis Engelke
739a960567
[RegAlloc] Don't call always-true ShouldAllocClass (#96296)
Previously, there was at least one virtual function call for every
allocated register. The only users of this feature are AMDGPU and RISC-V
(RVV), other targets don't use this. To easily identify these cases,
change the default functor to nullptr and don't call it for every
allocated register.
2024-06-21 13:18:35 +02:00
Jay Foad
63a5dc4aed
[CodeGen] Do not pass MF into MachineRegisterInfo methods. NFC. (#84770)
MachineRegisterInfo already knows the MF so there is no need to pass it
in as an argument.
2024-03-11 15:35:05 +00:00
Craig Topper
e72ca520bb [CodeGen] Remove uses of Register::isPhysicalRegister/isVirtualRegister. NFC
Use isPhysical/isVirtual methods.

Reviewed By: foad

Differential Revision: https://reviews.llvm.org/D141715
2023-01-13 14:38:08 -08:00
Kazu Hirata
9e6d1f4b5d [CodeGen] Qualify auto variables in for loops (NFC) 2022-07-17 01:33:28 -07:00
Matt Arsenault
1732242bee RegAlloc: Fix remaining virtual registers after allocation failure
This testcase fails register allocation, but at the failure point
there were also new split virtual registers. Previously this was
assigning the failing register and not enqueueing the newly created
split virtual registers. These would then never be allocated and
assert in VirtRegRewriter.
2022-04-13 16:25:30 -04:00
Mircea Trofin
592f52de33 [nfc][regalloc] const LiveIntervals within the allocator
Once built, LiveIntervals are immutable. This patch captures that.

Differential Revision: https://reviews.llvm.org/D118918
2022-02-03 12:35:36 -08:00
Matt Arsenault
eebe841a47 RegAlloc: Allow targets to split register allocation
AMDGPU normally spills SGPRs to VGPRs. Previously, since all register
classes are handled at the same time, this was problematic. We don't
know ahead of time how many registers will be needed to be reserved to
handle the spilling. If no VGPRs were left for spilling, we would have
to try to spill to memory. If the spilled SGPRs were required for exec
mask manipulation, it is highly problematic because the lanes active
at the point of spill are not necessarily the same as at the restore
point.

Avoid this problem by fully allocating SGPRs in a separate regalloc
run from VGPRs. This way we know the exact number of VGPRs needed, and
can reserve them for a second run.  This fixes the most serious
issues, but it is still possible using inline asm to make all VGPRs
unavailable. Start erroring in the case where we ever would require
memory for an SGPR spill.

This is implemented by giving each regalloc pass a callback which
reports if a register class should be handled or not. A few passes
need some small changes to deal with leftover virtual registers.

In the AMDGPU implementation, a new pass is introduced to take the
place of PrologEpilogInserter for SGPR spills emitted during the first
run.

One disadvantage of this is currently StackSlotColoring is no longer
used for SGPR spills. It would need to be run again, which will
require more work.

Error if the standard -regalloc option is used. Introduce new separate
-sgpr-regalloc and -vgpr-regalloc flags, so the two runs can be
controlled individually. PBQB is not currently supported, so this also
prevents using the unhandled allocator.
2021-07-13 18:49:29 -04:00
Matt Arsenault
7521fcd269 AMDGPU/GlobalISel: Add subtarget to a test
SelectionDAG forces us to have a weird ABI for 16-bit values without
legal 16-bit operations, but currently GlobalISel bypasses this and
sometimes ends up using the gfx8+ ABI in some contexts. Make sure
we're testing the normal ABI to avoid a test change in a future patch.
2021-05-21 23:57:38 +09:00
Matt Arsenault
1801e2aa24 RegAlloc: Fix assert if all registers in class reserved
With a context instruction, this would produce a context
error. However, it would continue on and do an out of bounds access of
the empty allocation order array.
2021-01-31 11:10:04 -05:00
Gaurav Jain
492b1d78d5 [NFC] Use [MC]Register in register allocation
Differential Revision: https://reviews.llvm.org/D90725
2020-11-03 17:34:26 -08:00
Mircea Trofin
43d347995c [NFC][MC] Use MCRegister in LiveRangeMatrix
The change starts from LiveRangeMatrix and also checks the users of the
APIs are typed accordingly.

Differential Revision: https://reviews.llvm.org/D89145
2020-10-12 08:54:36 -07:00
Mircea Trofin
6e85c3d5c7 [NFC][Regalloc] accessors for 'reg' and 'weight'
Also renamed the fields to follow style guidelines.

Accessors help with readability - weight mutation, in particular,
is easier to follow this way.

Differential Revision: https://reviews.llvm.org/D87725
2020-09-16 08:28:57 -07:00
Simon Pilgrim
0128b9505c Revert rG5dd566b7c7b78bd- "PassManager.h - remove unnecessary Function.h/Module.h includes. NFCI."
This reverts commit 5dd566b7c7b78bd385418c72d63c79895be9ae97.

Causing some buildbot failures that I'm not seeing on MSVC builds.
2020-07-24 13:02:33 +01:00
Simon Pilgrim
5dd566b7c7 PassManager.h - remove unnecessary Function.h/Module.h includes. NFCI.
PassManager.h is one of the top headers in the ClangBuildAnalyzer frontend worst offenders list.

This exposes a large number of implicit dependencies on various forward declarations/includes in other headers that need addressing.
2020-07-24 12:40:50 +01:00
Matt Arsenault
b7f6ecf0c7 RegAlloc: Start using Register 2020-06-30 12:13:08 -04:00
Marcello Maggioni
e5205074df Move Spiller.h from lib/ directory path to include/CodeGen. NFC
This allows Spiller.h to be used and included outside of
the lib/CodeGen directory. For example to be used in the
lib/Target directory or other places.
2020-03-09 10:52:28 -07:00
Daniel Sanders
2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Nicolai Haehnle
664ceeda68 RegAlloc: try to fail more gracefully when out of registers
Summary:
The emitError path allows the program to continue, unlike report_fatal_error.
This is friendlier to use cases where LLVM is embedded in a larger program,
because the caller may be able to deal with the error somewhat gracefully.

Change the number of requested NOP bytes in the AArch64 and PowerPC
test cases to avoid triggering an unrelated assertion. The compilation
still fails, as verified by the test.

Change-Id: Iafb9ca341002a597b82e59ddc7a1f13c78758e3d

Reviewers: arsenm, MatzeB

Subscribers: qcolombet, nemanjai, wdng, javed.absar, kristof.beyls, kbarton, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61489

llvm-svn: 360786
2019-05-15 17:29:58 +00:00
Chandler Carruth
2946cd7010 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
2019-01-19 08:50:56 +00:00
Nicola Zaghen
d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Matthias Braun
f842297d50 Rename LiveIntervalAnalysis.h to LiveIntervals.h
Headers/Implementation files should be named after the class they
declare/define.

Also eliminated an `#include "llvm/CodeGen/LiveIntervalAnalysis.h"` in
favor of `class LiveIntarvals;`

llvm-svn: 320546
2017-12-13 02:51:04 +00:00
Zachary Turner
8065f0b975 Mark all library options as hidden.
These command line options are not intended for public use, and often
don't even make sense in the context of a particular tool anyway. About
90% of them are already hidden, but when people add new options they
forget to hide them, so if you were to make a brand new tool today, link
against one of LLVM's libraries, and run tool -help you would get a
bunch of junk that doesn't make sense for the tool you're writing.

This patch hides these options. The real solution is to not have
libraries defining command line options, but that's a much larger effort
and not something I'm prepared to take on.

Differential Revision: https://reviews.llvm.org/D40674

llvm-svn: 319505
2017-12-01 00:53:10 +00:00
David Blaikie
b3bde2ea50 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
2017-11-17 01:07:10 +00:00
Eugene Zelenko
618c555bbe [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 313194
2017-09-13 21:15:20 +00:00
Matt Arsenault
5fbc87021e RA: Replace asserts related to empty live intervals
These don't exactly assert the same thing anymore, and
allow empty live intervals with non-empty uses.

Removed in r308808 and r308813.

llvm-svn: 308906
2017-07-24 18:07:55 +00:00
Matt Arsenault
6a963f76ca RA: Remove assert on empty live intervals
This is possible if there is an undef use when
splitting the vreg during spilling.

Fixes bug 33620.

llvm-svn: 308808
2017-07-21 23:56:13 +00:00
Chandler Carruth
6bda14b313 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
2017-06-06 11:49:48 +00:00
Matthias Braun
9f15a79e5d Timer: Track name and description.
The previously used "names" are rather descriptions (they use multiple
words and contain spaces), use short programming language identifier
like strings for the "names" which should be used when exporting to
machine parseable formats.

Also removed a unused TimerGroup from Hexxagon.

Differential Revision: https://reviews.llvm.org/D25583

llvm-svn: 287369
2016-11-18 19:43:18 +00:00
Krzysztof Parzyszek
a7ed090bba Create subranges for new intervals resulting from live interval splitting
The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.

Differential Revision: http://reviews.llvm.org/D21189

llvm-svn: 279625
2016-08-24 13:37:55 +00:00
Mehdi Amini
b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Wei Mi
9a16d655c7 Recommit r265547, and r265610,r265639,r265657 on top of it, plus
two fixes with one about error verify-regalloc reported, and
another about live range update of phi after rematerialization.

r265547:
Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Patches on top of r265547:
r265610 "Fix the compare-clang diff error introduced by r265547."
r265639 "Fix the sanitizer bootstrap error in r265547."
r265657 "InlineSpiller.cpp: Escap \@ in r265547. [-Wdocumentation]"

Differential Revision: http://reviews.llvm.org/D15302
Differential Revision: http://reviews.llvm.org/D18934
Differential Revision: http://reviews.llvm.org/D18935
Differential Revision: http://reviews.llvm.org/D18936

llvm-svn: 266162
2016-04-13 03:08:27 +00:00
Hans Wennborg
5a7723c7a2 Revert r265547 "Recommit r265309 after fixed an invalid memory reference bug happened"
It caused PR27275: "ARM: Bad machine code: Using an undefined physical register"

Also reverting the following commits that were landed on top:
r265610 "Fix the compare-clang diff error introduced by r265547."
r265639 "Fix the sanitizer bootstrap error in r265547."
r265657 "InlineSpiller.cpp: Escap \@ in r265547. [-Wdocumentation]"

llvm-svn: 265790
2016-04-08 15:17:43 +00:00
Wei Mi
18293bef4e Recommit r265309 after fixed an invalid memory reference bug happened
when DenseMap growed and moved memory. I verified it fixed the bootstrap
problem on x86_64-linux-gnu but I cannot verify whether it fixes
the bootstrap error on clang-ppc64be-linux. I will watch the build-bot
result closely.

Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Differential Revision: http://reviews.llvm.org/D15302

llvm-svn: 265547
2016-04-06 15:41:07 +00:00
Wei Mi
fb5252cac1 Revert r265309 and r265312 because they caused some errors I need to investigate.
llvm-svn: 265317
2016-04-04 17:45:03 +00:00
Wei Mi
ffbc9c7f3b Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Differential Revision: http://reviews.llvm.org/D15302

llvm-svn: 265309
2016-04-04 16:42:40 +00:00
Benjamin Kramer
799003bf8c Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
llvm-svn: 232998
2015-03-23 19:32:43 +00:00