ScalarEvolution in the presence of multiple exits. Previously all
loops exits had to have identical counts for a loop trip count to be
considered computable. This pessimization was implemented by calling
getBackedgeTakenCount(L) rather than getExitCount(L, ExitingBlock)
inside of ScalarEvolution::getSmallConstantTripCount() (see the FIXME
in the comments of that function). The pessimization was added to fix
a corner case involving undefined behavior (pr/16130). This patch more
precisely handles the undefined behavior case allowing the pessimization
to be removed.
ControlsExit replaces IsSubExpr to more precisely track the case where
undefined behavior is expected to occur. Because undefined behavior is
tracked more precisely we can remove MustExit from ExitLimit. MustExit
was used to track the case where the limit was computed potentially
assuming undefined behavior even if undefined behavior didn't necessarily
occur.
llvm-svn: 219517
Fixes a logic error in the MachineScheduler found by Steve Montgomery (and
confirmed by Andy). This has gone unfixed for months because the fix has been
found to introduce some small performance regressions. However, Andy has
recommended that, at this point, we fix this to avoid further dependence on the
incorrect behavior (and then follow-up separately on any regressions), and I
agree.
Fixes PR18883.
llvm-svn: 219512
Summary: Add the ability to convert 64 or 32 bit floating point values to integer in mips fast-isel
Test Plan:
fpintconv.ll
ran 4 flavors of test-suite with no errors, misp32 r1/r2 O0/O2
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits, rfuhler, mcrosier
Differential Revision: http://reviews.llvm.org/D5562
llvm-svn: 219511
This change depends on the ApplePropertyString helper that I sent spearately.
Not sure how you want this tested: as a tool test by adding a binary to dump, or as an llvm test starting from an IR file?
Reviewers: dblaikie, samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5689
llvm-svn: 219507
DW_AT_specification and DW_AT_abstract_origin resolving was only performed
on subroutine DIEs because it used the getSubroutineName method. Introduce
a more generic getName() and use it to dump the reference attributes.
Testcases have been updated to check the printed names instead of the offsets
except when the name could be ambiguous.
Reviewers: dblaikie, samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5625
llvm-svn: 219506
The current VSX feature for PowerPC specifies availability of the VSX
instructions added with the 2.06 architecture version. With 2.07, the
architecture adds new instructions to both the Category:Vector and
Category:VSX instruction sets. Additionally, unaligned vector storage
operations have improved performance.
This patch adds a feature to provide access to the new instructions
and performance capabilities of Power8. For compatibility with GCC,
the feature is controlled via a new -mpower8-vector switch, and the
feature causes the __POWER8_VECTOR__ builtin define to be generated by
the preprocessor.
There is a companion patch for cfe being committed at the same time.
llvm-svn: 219501
This is dangerous for numerous reasons. The primary risk here is with
floating point or double types where if the wrong header files are
included in a strange order this can implicitly convert to integers and
then call the C abs function on the integers. There is a secondary risk
that even impacts integers where if the namespace the code is written in
ever defines an abs overload for types within that namespace the global
abs will be hidden. The correct form is to call std::abs or write 'using
std::abs' for builtin types (and only the latter is correct in any
generic context).
I've also added the requisite header to be a bit more explicit here.
llvm-svn: 219484
We, I suppose naïvely, believed the COFF specification with regard to
auxiliary symbol records which defined sections: they specified that the
symbol value should be zero. However, dumpbin and MinGW's objdump do
not consider the symbol value as a restriction. Relaxing this allows us
to properly dump MinGW linked executables.
llvm-svn: 219479
to what we actually want ilogb implementation. This makes everything
*much* easier to deal with and is actually what we want when using it
anyways.
llvm-svn: 219474
instead
We used to transform this:
define void @test6(i1 %cond, i8* %ptr) {
entry:
br i1 %cond, label %bb1, label %bb2
bb1:
br label %bb2
bb2:
%ptr.2 = phi i8* [ %ptr, %entry ], [ null, %bb1 ]
store i8 2, i8* %ptr.2, align 8
ret void
}
into this:
define void @test6(i1 %cond, i8* %ptr) {
%ptr.2 = select i1 %cond, i8* null, i8* %ptr
store i8 2, i8* %ptr.2, align 8
ret void
}
because the simplifycfg transformation into selects would happen to happen
before the simplifycfg transformation that removes unreachable control flow
(We have 'unreachable control flow' due to the store to null which is undefined
behavior).
The existing transformation that removes unreachable control flow in simplifycfg
is:
/// If BB has an incoming value that will always trigger undefined behavior
/// (eg. null pointer dereference), remove the branch leading here.
static bool removeUndefIntroducingPredecessor(BasicBlock *BB)
Now we generate:
define void @test6(i1 %cond, i8* %ptr) {
store i8 2, i8* %ptr.2, align 8
ret void
}
I did not see any impact on the test-suite + externals.
rdar://18596215
llvm-svn: 219462
Long section names are represented as a slash followed by a numeric
ASCII string. This number is an offset into a string table.
Print the appropriate entry in the string table instead of the less
enlightening /4.
N.B. yaml2obj already does the right thing, this test exercises both
sides of the (de-)serialization.
llvm-svn: 219458
code using it more readable.
Also add a copySign static function that works more like the standard
function by accepting the value and sign-carying value as arguments.
No interesting logic here, but tests added to cover the basic API
additions and make sure they do something plausible.
llvm-svn: 219453
This patch changes the fast-math implementation for calculating sqrt(x) from:
y = 1 / (1 / sqrt(x))
to:
y = x * (1 / sqrt(x))
This has 2 benefits: less code / faster code and one less estimate instruction
that may lose precision.
The only target that will be affected (until http://reviews.llvm.org/D5658 is approved)
is PPC. The difference in codegen for PPC is 2 less flops for a single-precision sqrtf
or vector sqrtf and 4 less flops for a double-precision sqrt.
We also eliminate a constant load and extra register usage.
Differential Revision: http://reviews.llvm.org/D5682
llvm-svn: 219445
The current implementation of GPR->FPR register moves uses a stack slot. This mechanism writes a double word and reads a word. In big-endian the load address must be displaced by 4-bytes in order to get the right value. In little endian this is no longer required. This patch fixes the issue and adds LE regression tests to fast-isel-conversion which currently expose this problem.
llvm-svn: 219441
