Nikita Popov [Tue, 18 Dec 2018 19:59:50 +0000 (19:59 +0000)]
[InstCombine] Simplify cttz/ctlz + icmp eq/ne into mask check
Checking whether a number has a certain number of trailing / leading
zeros means checking whether it is of the form XXXX1000 / 0001XXXX,
which can be done with an and+icmp.
Related to https://bugs.llvm.org/show_bug.cgi?id=28668. As a next
step, this can be extended to non-equality predicates.
Farhana Aleen [Tue, 18 Dec 2018 19:58:39 +0000 (19:58 +0000)]
[AMDGPU] Removed the unnecessary operand size-check-assert from processBaseWithConstOffset().
Summary: 32bit operand sizes are guaranteed by the opcode check AMDGPU::V_ADD_I32_e64 and
AMDGPU::V_ADDC_U32_e64. Therefore, we don't any additional operand size-check-assert.
Sanjay Patel [Tue, 18 Dec 2018 19:07:38 +0000 (19:07 +0000)]
[InstCombine] refactor isCheapToScalarize(); NFC
As the FIXME indicates, this has the potential to go
overboard. So I'm not sure if it's even worth keeping
this vs. iteratively doing simple matches, but we might
as well clean it up.
Nikita Popov [Tue, 18 Dec 2018 18:28:22 +0000 (18:28 +0000)]
[X86] Use SADDSAT/SSUBSAT instead of ADDS/SUBS
Migrate the X86 backend from X86ISD opcodes ADDS and SUBS to generic
ISD opcodes SADDSAT and SSUBSAT. This also improves scodegen for
@llvm.sadd.sat() and @llvm.ssub.sat() intrinsics.
Alexandre Ganea [Tue, 18 Dec 2018 18:17:00 +0000 (18:17 +0000)]
[CMake] Default options for faster executables on MSVC
- Disable incremental linking by default. /INCREMENTAL adds extra thunks in the EXE, which makes execution slower.
- Set /MT (static CRT lib) by default instead of CMake's default /MD (dll CRT lib). The previous default /MD makes all DLL functions to be thunked, thus making execution slower (memcmp, memset, etc.)
- Adds LLVM_ENABLE_INCREMENTAL_LINK which is set to OFF by default.
Michael Berg [Tue, 18 Dec 2018 17:54:52 +0000 (17:54 +0000)]
Add FMF management to common fp intrinsics in GlobalIsel
Summary: This the initial code change to facilitate managing FMF flags from Instructions to MI wrt Intrinsics in Global Isel. Eventually the GlobalObserver interface will be added as well, where FMF additions can be tracked for the builder and CSE.
Michael Kruse [Tue, 18 Dec 2018 17:46:09 +0000 (17:46 +0000)]
[LoopVectorize] Rename pass options. NFC.
Rename:
NoUnrolling to InterleaveOnlyWhenForced
and
AlwaysVectorize to !VectorizeOnlyWhenForced
Contrary to what the name 'AlwaysVectorize' suggests, it does not
unconditionally vectorize all loops, but applies a cost model to
determine whether vectorization is profitable to all loops. Hence,
passing false will disable the cost model, except when a loop is marked
with llvm.loop.vectorize.enable. The 'OnlyWhenForced' suffix (suggested
by @hfinkel in D55716) better matches this behavior.
Similarly, 'NoUnrolling' disables the profitability cost model for
interleaving (a term to distinguish it from unrolling by the
LoopUnrollPass); rename it for consistency.
Michael Kruse [Tue, 18 Dec 2018 17:16:05 +0000 (17:16 +0000)]
[LoopUnroll] Honor '#pragma unroll' even with -fno-unroll-loops.
When using clang with `-fno-unroll-loops` (implicitly added with `-O1`),
the LoopUnrollPass is not not added to the (legacy) pass pipeline. This
also means that it will not process any loop metadata such as
llvm.loop.unroll.enable (which is generated by #pragma unroll or
WarnMissedTransformationsPass emits a warning that a forced
transformation has not been applied (see
https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20181210/610833.html).
Such explicit transformations should take precedence over disabling
heuristics.
This patch unconditionally adds LoopUnrollPass to the optimizing
pipeline (that is, it is still not added with `-O0`), but passes a flag
indicating whether automatic unrolling is dis-/enabled. This is the same
approach as LoopVectorize uses.
The new pass manager's pipeline builder has no option to disable
unrolling, hence the problem does not apply.
Petar Avramovic [Tue, 18 Dec 2018 15:59:51 +0000 (15:59 +0000)]
[MIPS GlobalISel] Select G_SDIV, G_UDIV, G_SREM and G_UREM
Add support for s64 libcalls for G_SDIV, G_UDIV, G_SREM and G_UREM
and use integer type of correct size when creating arguments for
CLI.lowerCall.
Select G_SDIV, G_UDIV, G_SREM and G_UREM for types s8, s16, s32 and s64
on MIPS32.
Nico Weber [Tue, 18 Dec 2018 13:52:21 +0000 (13:52 +0000)]
[gn build] Add build files for llvm-ar, llvm-nm, llvm-objdump, llvm-readelf
Also add build files for deps DebugInfo/Symbolize, ToolDrivers/dll-tool.
Also add gn/build/libs/xar (needed by llvm-objdump).
Also delete an incorrect part of the symlink description in //BUILD.gn (it used
to be true before I made the symlink step write a stamp file; now it's no
longer true).
These are all binaries needed by check-lld that need symlinks.
Nikita Popov [Tue, 18 Dec 2018 13:23:03 +0000 (13:23 +0000)]
[X86] Use UADDSAT/USUBSAT instead of ADDUS/SUBUS
Replace the X86ISD opcodes ADDUS and SUBUS with generic ISD opcodes
UADDSAT and USUBSAT. As a side-effect, this also makes codegen for
the @llvm.uadd.sat and @llvm.usub.sat intrinsics reasonable.
This only replaces use in the X86 backend, and does not move any of
the ADDUS/SUBUS X86 specific combines into generic codegen.
Peter Smith [Tue, 18 Dec 2018 12:40:19 +0000 (12:40 +0000)]
[docs] Improve HowToCrossCompilerBuiltinsOnArm
Some recent experience on llvm-dev pointed out some errors in the document:
- Assumption of ninja
- Use of --march rather than -march
- Problems with host include files when a multiarch setup was used
- Insufficient target information passed to assembler
- Instructions on using the cmake cache file BaremetalARM.cmake were
incomplete
There was also insufficient guidance on what to do when various stages
failed due to misconfiguration or missing steps.
Summary of changes:
- Fixed problems above
- Added a troubleshooting section with common errors.
- Cleared up one "at time of writing" that is no longer a problem.
George Rimar [Tue, 18 Dec 2018 12:15:01 +0000 (12:15 +0000)]
[llvm-dwarfdump] - Do not error out on R_X86_64_DTPOFF64/R_X86_64_DTPOFF32 relocations.
This is https://bugs.llvm.org/show_bug.cgi?id=39992,
If we have the following code (test.cpp):
thread_local int tdata = 24;
and build an .o file with debug information:
clang --target=x86_64-pc-linux -c bar.cpp -g
Then object produced may have R_X86_64_DTPOFF64/R_X86_64_DTPOFF32 relocations.
(clang emits R_X86_64_DTPOFF64 and gcc emits R_X86_64_DTPOFF32 for the code above for me)
Currently, llvm-dwarfdump fails to compute this TLS relocation when dumping
object and reports an
error:
failed to compute relocation: R_X86_64_DTPOFF64, Invalid data was encountered while parsing the file
This relocation represents the offset in the TLS block and resolved by the linker,
but this info is unavailable at the
point when the object file is dumped by this tool.
The patch adds the simple evaluation for such relocations to avoid emitting errors.
Resulting behavior seems to be equal to GNU dwarfdump.
Luke Cheeseman [Tue, 18 Dec 2018 10:37:42 +0000 (10:37 +0000)]
[AArch64] - Return address signing dwarf support
- Reapply changes intially introduced in r343089
- The archtecture info is no longer loaded whenever a DWARFContext is created
- The runtimes libraries (santiziers) make use of the dwarf context classes but
do not intialise the target info
- The architecture of the object can be obtained without loading the target info
- Adding a method to the dwarf context to get this information and multiplex the
string printing later on
Tim Northover [Tue, 18 Dec 2018 09:29:39 +0000 (09:29 +0000)]
SROA: preserve alignment tags on loads and stores.
When splitting up an alloca's uses we were dropping any explicit
alignment tags, which means they default to the ABI-required default
alignment and this can cause miscompiles if the real value was smaller.
Also refactor the TBAA metadata into a parent class since it's shared by
both children anyway.
This fold was incredibly specific - replace with a SimplifyDemandedBits fold to remove a VSRAI if only the original sign bit is demanded (its guaranteed to stay the same).
Kristof Beyls [Tue, 18 Dec 2018 08:50:02 +0000 (08:50 +0000)]
Introduce control flow speculation tracking pass for AArch64
The pass implements tracking of control flow miss-speculation into a "taint"
register. That taint register can then be used to mask off registers with
sensitive data when executing under miss-speculation, a.k.a. "transient
execution".
This pass is aimed at mitigating against SpectreV1-style vulnarabilities.
At the moment, it implements the tracking of miss-speculation of control
flow into a taint register, but doesn't implement a mechanism yet to then
use that taint register to mask off vulnerable data in registers (something
for a follow-on improvement). Possible strategies to mask out vulnerable
data that can be implemented on top of this are:
- speculative load hardening to automatically mask of data loaded
in registers.
- using intrinsics to mask of data in registers as indicated by the
programmer (see https://lwn.net/Articles/759423/).
For AArch64, the following implementation choices are made.
Some of these are different than the implementation choices made in
the similar pass implemented in X86SpeculativeLoadHardening.cpp, as
the instruction set characteristics result in different trade-offs.
- The speculation hardening is done after register allocation. With a
relative abundance of registers, one register is reserved (X16) to be
the taint register. X16 is expected to not clash with other register
reservation mechanisms with very high probability because:
. The AArch64 ABI doesn't guarantee X16 to be retained across any call.
. The only way to request X16 to be used as a programmer is through
inline assembly. In the rare case a function explicitly demands to
use X16/W16, this pass falls back to hardening against speculation
by inserting a DSB SYS/ISB barrier pair which will prevent control
flow speculation.
- It is easy to insert mask operations at this late stage as we have
mask operations available that don't set flags.
- The taint variable contains all-ones when no miss-speculation is detected,
and contains all-zeros when miss-speculation is detected. Therefore, when
masking, an AND instruction (which only changes the register to be masked,
no other side effects) can easily be inserted anywhere that's needed.
- The tracking of miss-speculation is done by using a data-flow conditional
select instruction (CSEL) to evaluate the flags that were also used to
make conditional branch direction decisions. Speculation of the CSEL
instruction can be limited with a CSDB instruction - so the combination of
CSEL + a later CSDB gives the guarantee that the flags as used in the CSEL
aren't speculated. When conditional branch direction gets miss-speculated,
the semantics of the inserted CSEL instruction is such that the taint
register will contain all zero bits.
One key requirement for this to work is that the conditional branch is
followed by an execution of the CSEL instruction, where the CSEL
instruction needs to use the same flags status as the conditional branch.
This means that the conditional branches must not be implemented as one
of the AArch64 conditional branches that do not use the flags as input
(CB(N)Z and TB(N)Z). This is implemented by ensuring in the instruction
selectors to not produce these instructions when speculation hardening
is enabled. This pass will assert if it does encounter such an instruction.
- On function call boundaries, the miss-speculation state is transferred from
the taint register X16 to be encoded in the SP register as value 0.
Future extensions/improvements could be:
- Implement this functionality using full speculation barriers, akin to the
x86-slh-lfence option. This may be more useful for the intrinsics-based
approach than for the SLH approach to masking.
Note that this pass already inserts the full speculation barriers if the
function for some niche reason makes use of X16/W16.
- no indirect branch misprediction gets protected/instrumented; but this
could be done for some indirect branches, such as switch jump tables.
Kewen Lin [Tue, 18 Dec 2018 08:11:32 +0000 (08:11 +0000)]
[PowerPC][NFC]Update vabsd cases with vselect test cases
Power9 VABSDU* instructions can be exploited for some special vselect sequences.
Check in the orignal test case here, later the exploitation patch will update this
and reviewers can check the differences easily.
Kewen Lin [Tue, 18 Dec 2018 03:16:43 +0000 (03:16 +0000)]
[PowerPC] Improve vec_abs on P9
Improve the current vec_abs support on P9, generate ISD::ABS node for vector types,
combine ABS node to VABSD node for some special cases to make use of P9 VABSD* insns,
do custom lowering to vsub(vneg later)+vmax if it has no combination opportunity.
Reid Kleckner [Tue, 18 Dec 2018 01:14:05 +0000 (01:14 +0000)]
[codeview] Align symbol records to save 441MB during linking clang.pdb
In PDBs, symbol records must be aligned to four bytes. However, in the
object file, symbol records may not be aligned. MSVC does not pad out
symbol records to make sure they are aligned. That means the linker has
to do extra work to insert the padding. Currently, LLD calculates the
required space with alignment, and copies each record one at a time
while padding them out to the correct size. It has a fast path that
avoids this copy when the records are already aligned.
This change fixes a bug in that codepath so that the copy is actually
saved, and tweaks LLVM's symbol record emission to align symbol records.
Here's how things compare when doing a plain clang Release+PDB build:
- objs are 0.65% bigger (negligible)
- link is 3.3% faster (negligible)
- saves allocating 441MB
- new LLD high water mark is ~1.05GB
David Blaikie [Tue, 18 Dec 2018 01:06:09 +0000 (01:06 +0000)]
Recommit r348806: DebugInfo: Use symbol difference for CU length to simplify assembly reading/editing
Mucking about simplifying a test case ( https://reviews.llvm.org/D55261 ) I stumbled across something I've hit before - that LLVM's (GCC's does too, FWIW) assembly output includes a hardcode length for a DWARF unit in its header. Instead we could emit a label difference - making the assembly easier to read/edit (though potentially at a slight (I haven't tried to observe it) performance cost of delaying/sinking the length computation into the MC layer).
Fix: Predicated all the changes (including creating the labels, even if they aren't used/needed) behind the NVPTX useSectionsAsReferences, avoiding emitting labels in NVPTX where ptxas can't parse them.
Joel E. Denny [Tue, 18 Dec 2018 00:03:36 +0000 (00:03 +0000)]
[FileCheck] Annotate input dump (7/7)
This patch implements annotations for diagnostics reporting CHECK-NOT
failed matches. These diagnostics are enabled by -vv. As for
diagnostics reporting failed matches for other directives, these
annotations mark the search ranges using `X~~`. The difference here
is that failed matches for CHECK-NOT are successes not errors, so they
are green not red when colors are enabled.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- CHECK-DAG overlapping match (discarded, reported if -vv)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- CHECK-NOT not found (success, reported if -vv)
- CHECK-DAG not found after discarded matches (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, discarded match, unmatched input
If you are not seeing color above or in input dumps, try: -color
Joel E. Denny [Tue, 18 Dec 2018 00:03:19 +0000 (00:03 +0000)]
[FileCheck] Annotate input dump (6/7)
This patch implements input annotations for diagnostics reporting
CHECK-DAG discarded matches. These diagnostics are enabled by -vv.
These annotations mark discarded match ranges using `!~~` because they
are bad matches even though they are not errors.
CHECK-DAG discarded matches create another case where there can be
multiple match results for the same directive.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- CHECK-DAG overlapping match (discarded, reported if -vv)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- CHECK-DAG not found after discarded matches (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, discarded match, unmatched input
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -vv -dump-input=always check4 < input4 |& sed -n '/^<<<</,$p'
<<<<<<
1: abcdef
dag:1 ^~~~
dag:2'0 !~~~ discard: overlaps earlier match
2: cdefgh
dag:2'1 ^~~~
check:3 X~ error: no match found
>>>>>>
This shows that the line 3 CHECK fails to match even though its
pattern appears in the input because its search range starts after the
line 2 CHECK-DAG's match range. The trouble might be that the line 2
CHECK-DAG's match range is later than expected because its first match
range overlaps with the line 1 CHECK-DAG match range and thus is
discarded.
Because `!~~` for CHECK-DAG does not indicate an error, it is not
colored red. Instead, when colors are enabled, it is colored cyan,
which suggests a match that went cold.
Joel E. Denny [Tue, 18 Dec 2018 00:03:03 +0000 (00:03 +0000)]
[FileCheck] Annotate input dump (5/7)
This patch implements input annotations for diagnostics enabled by -v,
which report good matches for directives. These annotations mark
match ranges using `^~~`.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, unmatched input
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check3 < input3 |& sed -n '/^<<<</,$p'
<<<<<<
1: abc foobar def
check:1 ^~~
not:2 !~~~~~ error: no match expected
check:3 ^~~
>>>>>>
-vv enables these annotations for FileCheck's implicit EOF patterns as
well. For an example where EOF patterns become relevant, see patch 7
in this series.
If colors are enabled, `^~~` is green to suggest success.
-v plus color enables highlighting of input text that has no final
match for any expected pattern. The highlight uses a cyan background
to suggest a cold section. This highlighting can make it easier to
spot text that was intended to be matched but that failed to be
matched in a long series of good matches.
CHECK-COUNT-<num> good matches are another case where there can be
multiple match results for the same directive.
Joel E. Denny [Tue, 18 Dec 2018 00:02:47 +0000 (00:02 +0000)]
[FileCheck] Annotate input dump (4/7)
This patch implements input annotations for diagnostics that report
unexpected matches for CHECK-NOT. Like wrong-line matches for
CHECK-NEXT, CHECK-SAME, and CHECK-EMPTY, these annotations mark match
ranges using red `!~~` to indicate bad matches that are errors.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check3 < input3 |& sed -n '/^<<<</,$p'
<<<<<<
1: abc foobar def
not:2 !~~~~~ error: no match expected
>>>>>>
Joel E. Denny [Tue, 18 Dec 2018 00:02:22 +0000 (00:02 +0000)]
[FileCheck] Annotate input dump (3/7)
This patch implements input annotations for diagnostics that report
wrong-line matches for the directives CHECK-NEXT, CHECK-SAME, and
CHECK-EMPTY. Instead of the usual `^~~`, which is used by later
patches for good matches, these annotations use `!~~` to mark the bad
match ranges so that this category of errors is visually distinct.
Because such matches are errors, these annotates are red when colors
are enabled.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check2 < input2 |& sed -n '/^<<<</,$p'
<<<<<<
1: foo bar
next:2 !~~ error: match on wrong line
>>>>>>
Joel E. Denny [Tue, 18 Dec 2018 00:02:04 +0000 (00:02 +0000)]
[FileCheck] Annotate input dump (2/7)
This patch implements input annotations for diagnostics that suggest
fuzzy matches for directives for which no matches were found. Instead
of using the usual `^~~`, which is used by later patches for good
matches, these annotations use `?` so that fuzzy matches are visually
distinct. No tildes are included as these diagnostics (independently
of this patch) currently identify only the start of the match.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- X~~ marks search range when no match is found
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check1 < input1 |& sed -n '/^<<<</,$p'
<<<<<<
1: ; abc def
2: ; ghI jkl
next:3'0 X~~~~~~~~ error: no match found
next:3'1 ? possible intended match
>>>>>>
This patch introduces the concept of multiple "match results" per
directive. In the above example, the first match result for the
CHECK-NEXT directive is the failed match, for which the annotation
shows the search range. The second match result is the fuzzy match.
Later patches will introduce other cases of multiple match results per
directive.
When colors are enabled, `?` is colored magenta. That is, it doesn't
indicate the actual error, which a red `X~~` marker indicates, but its
color suggests it's closely related.
Joel E. Denny [Tue, 18 Dec 2018 00:01:39 +0000 (00:01 +0000)]
[FileCheck] Annotate input dump (1/7)
Extend FileCheck to dump its input annotated with FileCheck's
diagnostics: errors, good matches if -v, and additional information if
-vv. The goal is to make it easier to visualize FileCheck's matching
behavior when debugging.
Each patch in this series implements input annotations for a
particular category of FileCheck diagnostics. While the first few
patches alone are somewhat useful, the annotations become much more
useful as later patches implement annotations for -v and -vv
diagnostics, which show the matching behavior leading up to the error.
This first patch implements boilerplate plus input annotations for
error diagnostics reporting that no matches were found for a
directive. These annotations mark the search ranges of the failed
directives. Instead of using the usual `^~~`, which is used by later
patches for good matches, these annotations use `X~~` so that this
category of errors is visually distinct.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the match result for a pattern of type T from line L of
the check file
- X~~ marks search range when no match is found
- colors error
If you are not seeing color above or in input dumps, try: -color
Some additional details related to the boilerplate:
* Enabling: The annotated input dump is enabled by `-dump-input`,
which can also be set via the `FILECHECK_OPTS` environment variable.
Accepted values are `help`, `always`, `fail`, or `never`. As shown
above, `help` describes the format of the dump. `always` is helpful
when you want to investigate a successful FileCheck run, perhaps for
an unexpected pass. `-dump-input-on-failure` and
`FILECHECK_DUMP_INPUT_ON_FAILURE` remain as a deprecated alias for
`-dump-input=fail`.
* Diagnostics: The usual diagnostics are not suppressed in this mode
and are printed first. For brevity in the example above, I've
omitted them using a sed command. Sometimes they're perfectly
sufficient, and then they make debugging quicker than if you were
forced to hunt through a dump of long input looking for the error.
If you think they'll get in the way sometimes, keep in mind that
it's pretty easy to grep for the start of the input dump, which is
`<<<`.
* Colored Annotations: The annotated input is colored if colors are
enabled (enabling colors can be forced using -color). For example,
errors are red. However, as in the above example, colors are not
vital to reading the annotations.
I don't know how to test color in the output, so any hints here would
be appreciated.
Summary:
We use `variable_ops` in the tablegen defs to denote the list of
branch targets in `br_table`, but unlike other uses of `variable_ops`
(e.g. call) the these branch targets need to actually be encoded in the
instruction. The existing tables for `variable_ops` cause not operands
to be accepted by the assembly matcher.
Following the example of ARM:
https://github.com/llvm-mirror/llvm/blob/2cc0a7da876c1d8c32775b0119e1e15aaa759b9e/lib/Target/ARM/ARMInstrInfo.td#L550-L555
we introduce a new operand type to capture this list, and we use the
same {} syntax as ARM as well to differentiate them from regular
integer operands.
Also removed definition and use of TSFlags in tablegen defs, since
`br_table` now has a non-variable_ops immediate operand, so the
previous logic of only the variable_ops arguments being labels didn't
make sense anymore.
Sanjay Patel [Mon, 17 Dec 2018 21:14:51 +0000 (21:14 +0000)]
[AggressiveInstCombine] convert rotate with guard branch into funnel shift (PR34924)
Now, that we have funnel shift intrinsics, it should be safe to convert this form of rotate to it.
In the worst case (a target that doesn't have rotate instructions), we will expand this into a
branch-less sequence of ALU ops (neg/and/and/lshr/shl/or) in the backend, so it's still very
likely to be a perf improvement over the original code.
The motivating source code pattern for this is shown in:
https://bugs.llvm.org/show_bug.cgi?id=34924
Background:
I looked at several different options before deciding where to try this - instcombine, simplifycfg,
CGP - because it doesn't fit cleanly anywhere AFAIK.
The backend (CGP, SDAG, GlobalIsel?) is too late for what we're trying to accomplish. We want to
have the IR converted before we reach things like vectorization because the reduced code can make a
loop much simpler to transform.
Technically, this could be included in instcombine, but it's a large pattern match that includes
control-flow, so it just felt wrong to stuff into there (although I have a draft of that patch).
Similarly, this could be part of simplifycfg, but all of this pattern matching is a stretch.
So we're left with our relatively new dumping ground for homeless transforms: aggressive-instcombine.
This only runs at -O3, but that seems like a reasonable limitation given that source code has many
options to avoid this pattern (including the recently added clang intrinsics for rotates).
I'm including a PhaseOrdering test because we require the teamwork of 3 passes (aggressive-instcombine,
instcombine, simplifycfg) to get this into the minimal IR form that we want. That test shows a bug
with the new pass manager that's independent of this change (but it will be masked if we canonicalize
harder to funnel shift intrinsics in instcombine).
Craig Topper [Mon, 17 Dec 2018 20:29:13 +0000 (20:29 +0000)]
[SelectionDAG] Fix noop detection for vectors in AssertZext/AssertSext in getNode
The assertion type is always supposed to be a scalar type. So if the result VT of the assertion is a vector, we need to get the scalar VT before we can compare them.
Similarly for the assert above it.
I don't have a test case because I don't know of any place we violate this today. A coworker found this while trying to use r347287 on the 6.0 branch without also having r336868
Sanjay Patel [Mon, 17 Dec 2018 20:27:43 +0000 (20:27 +0000)]
[InstCombine] don't widen an arbitrary sequence of vector ops (PR40032)
The problem is shown specifically for a case with vector multiply here:
https://bugs.llvm.org/show_bug.cgi?id=40032
...and this might mask the original backend bug for ARM shown in:
https://bugs.llvm.org/show_bug.cgi?id=39967
As the test diffs here show, we were (and probably still aren't) doing
these kinds of transforms in a principled way. We are producing more or
equal wide instructions than we started with in some cases, so we still
need to restrict/correct other transforms from overstepping.
If there are perf regressions from this change, we can either carve out
exceptions to the general IR rules, or improve the backend to do these
transforms when we know the transform is profitable. That's probably
similar to a change like D55448.
Craig Topper [Mon, 17 Dec 2018 20:02:16 +0000 (20:02 +0000)]
Convert (CMP (srl/shl X, C), 0) to (CMP (and X, C'), 0) when only the zero flag is used.
This allows a TEST to be used and can be combined with any AND that may already exist as an input to the shift.
This was already done in EmitTest, but was easily tricked by multiple uses because the setcc might be used by multiple instructions. Once the SETCC and users are legalized then we can look for the shift to be used by a single CMP, but the CMP itself can have multiple users.
JF Bastien [Mon, 17 Dec 2018 18:54:22 +0000 (18:54 +0000)]
AsmParser: test .double NaN and .double inf
Summary: It looks like this support was added to match GNU AS, but only tests
.float and not .double. I asked RedHat folks to confirm that 0x7fffffffffffffff
was indeed the right value for NaN.
Same for infinity, but it only has positive / negative encodings.
Simon Pilgrim [Mon, 17 Dec 2018 18:43:43 +0000 (18:43 +0000)]
[TargetLowering] Add DemandedElts mask to SimplifyDemandedBits (PR40000)
This is an initial patch to add the necessary support for a DemandedElts argument to SimplifyDemandedBits, more closely matching computeKnownBits and to help improve vector codegen.
I've added only a small amount of the changes necessary to get at least one test to update - a lot more can be done but I'd like to add these methodically with proper test coverage, at the same time the hope is to slowly move some/all of SimplifyDemandedVectorElts into SimplifyDemandedBits as well.
Nikita Popov [Mon, 17 Dec 2018 17:45:18 +0000 (17:45 +0000)]
[InstSimplify] Simplify saturating add/sub + icmp
If a saturating add/sub has one constant operand, then we can
determine the possible range of outputs it can produce, and simplify
an icmp comparison based on that.
The implementation is based on a similar existing mechanism for
simplifying binary operator + icmps.
Tim Northover [Mon, 17 Dec 2018 17:25:53 +0000 (17:25 +0000)]
FastIsel: take care to update iterators when removing instructions.
We keep a few iterators into the basic block we're selecting while
performing FastISel. Usually this is fine, but occasionally code wants
to remove already-emitted instructions. When this happens we have to be
careful to update those iterators so they're not pointint at dangling
memory.
Tim Northover [Mon, 17 Dec 2018 15:05:32 +0000 (15:05 +0000)]
ARM: use acquire/release instruction variants when available.
These features (fairly) recently got split out into their own feature, so we
should make CodeGen use them when available. The main change here is that the
check used to be based on the triple, but now it's based on CPU features.
Andrea Di Biagio [Mon, 17 Dec 2018 14:00:37 +0000 (14:00 +0000)]
[MCA] Don't assume that createMCInstrAnalysis() always returns a valid pointer.
Class InstrBuilder wrongly assumed that llvm targets were always able to return
a non-null pointer when createMCInstrAnalysis() was called on them.
This was causing crashes when simulating executions for targets that don't
provide an MCInstrAnalysis object.
This patch fixes the issue by making MCInstrAnalysis optional.
[AArch64] Re-run load/store optimizer after aggressive tail duplication
The Load/Store Optimizer runs before Machine Block Placement. At O3 the
Tail Duplication Threshold is set to 4 instructions and this can create
new opportunities for the Load/Store Optimizer. It seems worthwhile to
run it once again.
David Blaikie [Mon, 17 Dec 2018 08:27:19 +0000 (08:27 +0000)]
DebugInfo: Assume an absence of ranges or high_pc on a CU means the CU is empty (devoid of code addresses)
GCC emitted these unconditionally on/before 4.4/March 2012
Clang emitted these unconditionally on/before 3.5/March 2014
This improves performance when parsing CUs (especially those using split
DWARF) that contain no code ranges (such as the mini CUs that may be
created by ThinLTO importing - though generally they should be/are
avoided, especially for Split DWARF because it produces a lot of very
small CUs, which don't scale well in a bunch of other ways too
(including size)).
projects / llvm / log