We have a loop-rerolling optimization which can be enabled by using
-freroll-loops. While sometimes loops are hand-unrolled for performance
reasons, when optimizing for size, we should always undo this manual
optimization to produce smaller code (our optimizer's unroller will still
unroll the rerolled loops if it thinks that is a good idea).
llvm-svn: 283685
Clang has the default FP contraction setting of “-ffp-contract=on”, which
doesn't really mean “on” in the conventional sense of the word, but rather
really means “according to the per-statement effective value of the relevant
pragma”.
Before this patch, Clang has that pragma defaulting to “off”. Since the
“-ffp-contract=on” mode is really an AND of two booleans and the second of them
defaults to “off”, the whole thing effectively defaults to “off”. This patch
changes the default value of the pragma to “on”, thus making the default pair of
booleans (on, on) rather than (on, off). This makes FP optimization slightly
more aggressive than before when not using either “-Ofast”, “-ffast-math”, or
“-ffp-contract=fast”. Even with this patch the compiler still respects
“-ffp-contract=off”.
As per a suggestion by Steve Canon, the added code does _not_ require “-O3” or
higher. This is so as to try our best to preserve identical floating-point
results for unchanged source code compiling for an unchanged target when only
changing from any optimization level in the set (“-O0”, “-O1”, “-O2”, “-O3”) to
any other optimization level in that set. “-Os” and “-Oz” seem to be behaving
identically, i.e. should probably be considered a part of the aforementioned
set, but I have not reviewed this rigorously. “-Ofast” is explicitly _not_ a
member of that set.
Patch authored by Abe Skolnik [a.skolnik@samsung.com] and Stephen Canon [scanon@apple.com].
Differential Revision: https://reviews.llvm.org/D24481
llvm-svn: 282259
-fprofile-dir=path allows the user to specify where .gcda files should be
emitted when the program is run. In particular, this is the first flag that
causes the .gcno and .o files to have different paths, LLVM is extended to
support this. -fprofile-dir= does not change the file name in the .gcno (and
thus where lcov looks for the source) but it does change the name in the .gcda
(and thus where the runtime library writes the .gcda file). It's different from
a GCOV_PREFIX because a user can observe that the GCOV_PREFIX_STRIP will strip
paths off of -fprofile-dir= but not off of a supplied GCOV_PREFIX.
To implement this we split -coverage-file into -coverage-data-file and
-coverage-notes-file to specify the two different names. The !llvm.gcov
metadata node grows from a 2-element form {string coverage-file, node dbg.cu}
to 3-elements, {string coverage-notes-file, string coverage-data-file, node
dbg.cu}. In the 3-element form, the file name is already "mangled" with
.gcno/.gcda suffixes, while the 2-element form left that to the middle end
pass.
llvm-svn: 280306
-finline-functions and /Ob2 are currently ignored by Clang. The only way to
enable inlining is to use the global O flags, which also enable other options,
or to emit LLVM bitcode using Clang, then running opt by hand with the inline
pass.
This patch allows to simply use the -finline-functions flag (same as GCC) or
/Ob2 in clang-cl mode to enable inlining without other optimizations.
This is the first patch of a serie to improve support for the /Ob flags.
Patch by Rudy Pons <rudy.pons@ilod.org>!
Differential Revision: http://reviews.llvm.org/D20576
llvm-svn: 270609
This patch changes cc1 option for PGO profile use from
-fprofile-instr-use=<path> to -fprofile-instrument-use-path=<path>.
-fprofile-instr-use=<path> is now a driver only option.
In addition to decouple the cc1 option from the driver level option, this patch
also enables IR level profile use. cc1 option handling now reads the profile
header and sets CodeGenOpt ProfileUse (valid values are {None, Clang, LLVM}
-- this is a common enum for -fprofile-instrument={}, for the profile
instrumentation), and invoke the pipeline to enable the respective PGO use pass.
Reviewers: silvas, davidxl
Differential Revision: http://reviews.llvm.org/D17737
llvm-svn: 262515
This patch changes cc1 option -fprofile-instr-generate to an enum option
-fprofile-instrument={clang|none}. It also changes cc1 options
-fprofile-instr-generate= to -fprofile-instrument-path=.
The driver level option -fprofile-instr-generate and -fprofile-instr-generate=
remain intact. This change will pave the way to integrate new PGO
instrumentation in IR level.
Review: http://reviews.llvm.org/D16730
llvm-svn: 259811
Support for the -fno-math-builtin option was added in r186899. The codegen side
is being tested in test/CodeGen/nomathbuiltin.c. The missing part was just
passing the option through the driver.
PR26317
llvm-svn: 258814
This reverts commit r253269.
This leads to assert / segfault triggering on the following reduced example:
float foo(float U, float base, float cell) { return (U = 2 * base) - cell; }
llvm-svn: 253337
This recommits r250398 with fixes to the tests for bot failures.
Add "-target x86_64-unknown-linux" to the clang invocations that
check for the gold plugin.
llvm-svn: 250455
Rolling this back for now since there are a couple of bot failures on
the new tests I added, and I won't have a chance to look at them in detail
until later this afternoon. I think the new tests need some restrictions on
having the gold plugin available.
This reverts commit r250398.
llvm-svn: 250402
Summary:
Add clang support for -flto=thin option, which is used to set the
EmitFunctionSummary code gen option on compiles.
Add -flto=full as an alias to the existing -flto.
Add tests to check for proper overriding of -flto variants on the
command line, and convert grep tests to FileCheck.
Reviewers: dexonsmith, joker.eph
Subscribers: davidxl, cfe-commits
Differential Revision: http://reviews.llvm.org/D11908
llvm-svn: 250398
This patch adds flags -fno-profile-instr-generate and
-fno-profile-instr-use, and the GCC aliases -fno-profile-generate and
-fno-profile-use.
These flags are used in situations where users need to disable profile
generation or use for specific files in a build, without affecting other
files.
llvm-svn: 244153
This seems preferable to printing two warnings per unsupported option-
one warning about not supporting it, and one about not using it.
It also makes the '-Wno-' option do what you mean.
Differential Revision: http://reviews.llvm.org/D11766
llvm-svn: 244079
This patch adds support for specifying where the profile is emitted in a
way similar to GCC. These flags are used to specify directories instead
of filenames. When -fprofile-generate=DIR is used, the compiler will
generate code to write to <DIR>/default.profraw.
The patch also adds a couple of extensions: LLVM_PROFILE_FILE can still be
used to override the directory and file name to use and -fprofile-use
accepts both directories and filenames.
To simplify the set of flags used in the backend, all the flags get
canonicalized to -fprofile-instr-{generate,use} when passed to the
backend. The decision to use a default name for the profile is done
in the driver.
llvm-svn: 241825
If the linker is gcc (the default for Generic_ELF toolchains), we end up
passing most of the arguments to the linker.
Some tests were failing to account for this in their usage of *-NOT: lines
and would fail if compiled with
-DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-unknown
llvm-svn: 228902
Looks like llvm::sys::path::filename() was canonicalizing my paths
before emitting them for FileCheck to stumble over.
Fix a style nit with r219460 while I'm at it.
llvm-svn: 219464
When building with coverage, -no-integrated-as, and -c, the driver was
emitting -cc1 -coverage-file pointing at a file in /tmp. Ensure the
coverage file is emitted in the same directory as the output file.
llvm-svn: 219460
Several options were moved to the clang_ignored_gcc_optimization group
in r213365, but -fkeep-inline-functions was accidentally dropped. This
restores the flag.
Patch by Steven Wu. Thanks!
llvm-svn: 216522
Summary:
Just like with -finput-charset=UTF-8 in review http://reviews.llvm.org/D4347, I think we should just ignore it when UTF-8 is provided.
Reviewers: rnk, rafael
Reviewed By: rafael
Subscribers: rafael, cfe-commits
Differential Revision: http://reviews.llvm.org/D4841
llvm-svn: 215368
We don't have a style guide for diagnostic messages, but convention strongly
favours the forms:
'attribute is not supported', 'unsupported attribute'
We generally avoid:
'attribute is unsupported', 'non-supported attribute'
llvm-svn: 212972
Use -Winvalid-command-line-argument here to align with existing gcc opt
diagnostics. Meanwhile -Wunused-command-line-argument is for flags that we
support but were, say, fed into the wrong invocation.
Also tweak wording to make sense with -Werror.
llvm-svn: 212964
Summary:
Added some tests to see if the new warning would be silenced with a flag.
Patch by Arthur Marble <arthur@info9.net> in the context of Debian Google Summer of code 2014.
Reviewers: sylvestre.ledru
Reviewed By: sylvestre.ledru
Differential Revision: http://reviews.llvm.org/D4475
llvm-svn: 212833
Returns a warning when using an unknown optimization flag.
This patch includes -finline-limit as one of those ignored flags.
More options will be moved in this group
Patch by Arthur Marble <arthur@info9.net> in the context of
Debian Google Summer of code 2014.
Reviewers: rnk, Sylvestre
llvm-svn: 212805
Currently, we fail with an error.
Reviewers: rafael
Reviewed By: rafael
Subscribers: rnk, cfe-commits
Differential Revision: http://reviews.llvm.org/D4347
llvm-svn: 212110
hack of passing -fconst-strings to -cc1"
Passing or not a language option based on diagnostic settings is a bad idea, it breaks
using a PCH that was compiled with different diagnostic settings.
Also add a test case to make sure we don't regress.
llvm-svn: 200964
Summary:
GCC uses -fauto-profile to enable sample-based PGO. This patch
adds it to Clang as an alias for -fprofile-sample-use.
Differential Revision: http://llvm-reviews.chandlerc.com/D2353
llvm-svn: 196589
After r195009, the test would write a .o file to the test dir. Send that to
/dev/null instead. Also fix the typo in test/Frontend/invalid-o-level.c.
llvm-svn: 195047
Summary:
Currently with clang:
$ clang -O20 foo.c
error: invalid value '20' in '-O20'
With the patch:
$ clang -O20 foo.c
warning: optimization level '-O20' is unsupported; using '-O3' instead.
1 warning generated.
This matches the gcc behavior (with a warning added)
Pass all tests:
Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
Testing Time: 94.14s
Expected Passes : 6721
Expected Failures : 20
Unsupported Tests : 17
(which was not the case of http://llvm-reviews.chandlerc.com/D2125)
Differential Revision: http://llvm-reviews.chandlerc.com/D2212
llvm-svn: 195009
This adds -freroll-loops (and -fno-reroll-loops in the usual way) to enable
loop rerolling as part of the optimization pass manager. This transformation
can enable vectorization, reduce code size (or both).
Briefly, loop rerolling can transform a loop like this:
for (int i = 0; i < 3200; i += 5) {
a[i] += alpha * b[i];
a[i + 1] += alpha * b[i + 1];
a[i + 2] += alpha * b[i + 2];
a[i + 3] += alpha * b[i + 3];
a[i + 4] += alpha * b[i + 4];
}
into this:
for (int i = 0; i < 3200; ++i) {
a[i] += alpha * b[i];
}
Loop rerolling is currently disabled by default at all optimization levels.
llvm-svn: 194967
Trying to fix test failures since earlier today.
One of the tests added in this commit is outputting test/Driver/clang_f_opts.s
which the builders that build in-tree (eg. clang-native-arm-cortex-a9) are
trying to run as a test case, causing failures.
clang_f_opts.c:
If -### doesn't emit the warning then this test probably shouldn't be in
here in the first place. Frontend maybe?
invalid-o-level.c:
Running %clang_cc1 in the Driver tests doesn't make sense because -cc1
bypasses the driver. (I'm not reverting the commit that introduced this but
please fix instead of keeping it this way.)
Reverting to fix the build failures and also so that the tests can be thought
out more thoroughly.
This reverts commit r194817.
llvm-svn: 194845
This adds a new option -fprofile-sample-use=filename to Clang. It
tells the driver to schedule the SampleProfileLoader pass and passes
on the name of the profile file to use.
llvm-svn: 194567
Summary:
Currently with clang:
$ clang -O20 foo.c
error: invalid value '20' in '-O20'
With the patch:
$ clang -O20 foo.c
warning: invalid value '20' in '-O20'. Fall back on value '3'
Reviewers: rengolin, hfinkel
Reviewed By: rengolin
CC: cfe-commits, hfinkel, rengolin
Differential Revision: http://llvm-reviews.chandlerc.com/D2125
llvm-svn: 194403
hack of passing -fconst-strings to -cc1, but at least the driver uses
the regular warning checking code path.
Since we don't support a warning that is DefaultIgnore in one language
but not in another, this patch creates a dummy C only warning in the same
group as the existing one to get the desired effect.
llvm-svn: 194097
This GCC flag is useful when you want to control whether implicit
template instantiation occurs at the commandline level. Clang doesn't
currently support such controls, but technically *always* implicitly
instantiating (what Clang does, and what every other compiler still in
use does by default) is valid behavior even under
-fno-implicit-templates, it just may be slow and very wasteful. If
people really want this, we can try to implement it, but I don't have an
actual use.
This should help fix the build of libstdc++ with Clang, its build system
uses this flag.
llvm-svn: 193319
flag. We should probably wire at least some variants of this up to our
actual diagnostics engine, but I'm leaving that for someone else. This
fixes the builds of packages which hard code something here, at least
including libstdc++ itself.
llvm-svn: 193318
It is possible that we should say some of these are unsupported, but this is
not any worse than the old behavior of ignoring all unknown -f options.
llvm-svn: 191429
* In C, as before, if the "warning flag" is enabled, warnings are produced by
forcing string literals to have const-qualified types (the produced warnings
are *not* -Wwrite-strings warnings). However, more recent GCCs (at least 4.4
onwards) now take -w into account here, so we now do the same.
* In C++, this flag is entirely sane: it behaves just like any other warning
flag. Stop triggering -fconst-strings here. This is a bit cleaner, but there's
no real functionality change except in the case where -Xclang -fno-const-strings
is also specified.
llvm-svn: 190006
As Chandler pointed out, we should not be using -backend-option because this
will cause crashes for users of the tooling interface, etc. A better way to fix
this will be to provide the unrolling pass-manager flag to the loop vectorizer
directly.
Original commit message:
Disable loop vectorizer unrolling when no unrolling requested
In addition to the regular loop unrolling transformation, the loop vectorizer
can also unroll loops. If no unrolling has specifically been requested (by
-fno-unroll-loops), and the loop vectorizer will be used, then add the backend
option to (also) prevent the loop vectorizer from unrolling loops.
I confirmed with Nadav (off list) that disabling vectorizer loop unrolling when
-fno-unroll-loops is provided is the desired behavior.
llvm-svn: 189441
In addition to the regular loop unrolling transformation, the loop vectorizer
can also unroll loops. If no unrolling has specifically been requested (by
-fno-unroll-loops), and the loop vectorizer will be used, then add the backend
option to (also) prevent the loop vectorizer from unrolling loops.
I confirmed with Nadav (off list) that disabling vectorizer loop unrolling when
-fno-unroll-loops is provided is the desired behavior.
llvm-svn: 189440
We error on -O5 and higher. While it is tempting to do the same for -O4, I
agree with Jordan Rose: we should warn for a release at least first.
llvm-svn: 189369
We used to decide whether to really vectorize depending on the optimization
level in PassManagerBuilder.
This patch moves this decision to the clang driver. We look at the optimization
level and whether the f(no-)vectorize is set and decide whether to vectorize.
This allows us to simplify the logic in PassManagerBuilder to just a check for
whether the vectorizer should run or not.
We now do the right thing for:
$ clang -O1 -fvectorize
$ clang -fno-vectorize -O3
llvm-svn: 188280
'-fno-unroll-loops'. The option to the backend is even called
'DisableUnrollLoops'. This is precisely the form that Clang *didn't*
support. We didn't recognize the flag, we didn't pass it to the CC1
layer, and even if we did we wouldn't use it. Clang only inspected the
positive form of the flag, and only did so to enable loop unrolling when
the optimization level wasn't high enough. This only occurs for an
optimization level that even has a chance of running the loop unroller
when optimizing for size.
This commit wires up the 'no' variant, and switches the code to actually
follow the standard flag pattern of using the last flag and allowing
a flag in either direction to override the default.
I think this is still wrong. I don't know why we disable the loop
unroller entirely *from Clang* when optimizing for size, as the loop
unrolling pass *already has special logic* for the case where the
function is attributed as optimized for size! We should really be
trusting that. Maybe in a follow-up patch, I don't really want to change
behavior here.
llvm-svn: 187969
This was GCC's option to turn on UCN support, which we always have on now
in C99 and C++ modes.
Additionally, mark the -fno-extended-identifiers option as unsupported,
since we don't support disabling UCNs in C99 and C++ modes.
PR11538
llvm-svn: 174530
Add -fslp-vectorize (with -ftree-slp-vectorize as an alias for gcc compatibility)
to provide a way to enable the basic-block vectorization pass. This uses the same
acronym as gcc, superword-level parallelism (SLP), also common in the literature,
to refer to basic-block vectorization.
Nadav suggested this as a follow-up to the adding of -fvectorize.
llvm-svn: 169909
assembly.
By default, we don't emit IR for MS-style inline assembly (see r158833 as to
why). This is strictly for testing purposes and should not be enabled with the
expectation that things will work. This is a temporary flag and will be removed
once MS-style inline assembly is fully supported.
llvm-svn: 160573
This flag sets the 'fp-contract' mode, which controls the formation of fused
floating point operations. Available modes are:
- Fast: Form fused operations anywhere.
- On: Form fused operations where allowed by FP_CONTRACT. This is the default
mode.
- Off: Don't form fused operations (in future this may be relaxed to forming
fused operations where it can be proved that the result won't be
affected).
Currently clang doesn't support the FP_CONTRACT pragma, so the 'On' and 'Off'
modes are equivalent.
llvm-svn: 159794
matches GCC behavior which libstdc++ uses to limit #warning-based
messages about deprecation.
The machinery involves threading this through a new '-fdeprecated-macro'
flag for CC1. The flag defaults to "on", similarly to -Wdeprecated. We
turn the flag off in the driver when the warning is turned off (modulo
matching some GCC bugs). We record this as a language option, and key
the preprocessor on the option when introducing the define.
A separate flag rather than a '-D' flag allows us to properly represent
the difference between C and C++ builds (only C++ receives the define),
and it allows the specific behavior of following -Wdeprecated without
potentially impacting the set of user-provided macro flags.
llvm-svn: 130055
-Wwrite-strings. First and foremost, once the positive form of the flag
was passed, it could never be disabled by passing -Wno-write-strings.
Also, the diagnostic engine couldn't in turn use -Wwrite-strings to
control diagnostics (as GCC does) because it was essentially hijacked to
drive the language semantics.
Fix this by giving CC1 a clean '-fconst-strings' flag to enable
const-qualified strings in C and ObjC compilations. Corresponding
'-fno-const-strings' is also added. Then the driver is taught to
introduce '-fconst-strings' in the CC1 command when '-Wwrite-strings'
dominates.
This entire flag is basically GCC-bug-compatibility driven, so we also
match GCC's bug where '-w' doesn't actually disable -Wwrite-strings. I'm
open to changing this though as it seems insane.
llvm-svn: 130051
'-fasm' and explicitly map from that flag to -fgnu-keywords in the driver. Turn
off the driver in the lexer test for this madness and add a test to the driver
that the translation actually works.
llvm-svn: 104428
Mike Edwards