[x86] Based on a long conversation between myself, Jim Grosbach, Hal
Finkel, Eric Christopher, and a bunch of other people I'm probably
forgetting (sorry), add an option to the x86 backend to widen vectors
during type legalization rather than promote them.
This still would promote vNi1 vectors to get the masks right, but would
widen other vectors. A lot of experiments are piling up right now
showing that widening should probably be the default legalization
strategy outside of vNi1 cases, but it is very hard to test the
rammifications of that and fix bugs in widening-based legalization
without an option that enables it. I'll be checking in tests shortly
that use this option to exercise cases where widening doesn't work well
and hopefully we'll be able to switch fully to this soon.
[codegen,aarch64] Add a target hook to the code generator to control
vector type legalization strategies in a more fine grained manner, and
change the legalization of several v1iN types and v1f32 to be widening
rather than scalarization on AArch64.
This fixes an assertion failure caused by scalarizing nodes like "v1i32
trunc v1i64". As v1i64 is legal it will fail to scalarize v1i32.
This also provides a foundation for other targets to have more granular
control over how vector types are legalized.
Patch by Hao Liu, reviewed by Tim Northover. I'm committing it to allow
some work to start taking place on top of this patch as it adds some
really important hooks to the backend that I'd like to immediately start
using. =]
Move subtarget dependent features into the subtarget from the target
machine. Includes a fix for a subtarget initialization for
hard floating point on mips16.
So that we can include frame lowering in the subtarget, remove include
circular dependency with the subtarget by inlining accessor methods and
outlining a routine.
So that we can include target lowering in the subtarget, remove include
circular dependency with the subtarget by inlining accessor methods and
outlining a routine.
David Blaikie [Wed, 2 Jul 2014 21:42:28 +0000 (21:42 +0000)]
Revert "DebugInfo: Ensure that all debug location scope chains from instructions within a function, lead to the function itself."
This reverts commit r212205.
Reverting this again, still seeing crashes when building compiler-rt...
Sorry for the continued noise, not sure why I'm failing to reproduce
this locally.
Adam Nemet [Wed, 2 Jul 2014 21:25:58 +0000 (21:25 +0000)]
[X86] AVX512: Generate Pat<>'s for the vpermt2* intrinsics via multiclass
This new multiclass, avx512_perm_table_3src derives from the current one and
provides the Pat<>. The next patch will add another Pat<> that uses the
writemask.
Note that I dropped the type annotation from the intrinsic call, i.e.: (v16f32
VR512:$src1) -> R512:$src1. I think that this should be fine (at least many
intrinsic calls don't provide them) and it greatly reduces the number of
template arguments.
The value of SGPR0 will 1 no matter what the condition is.
In order to deal with this situation correctly, we need to view the
program as if it were a single basic block when we calculate the
live ranges for the SGPRs. They way we actually update the live
range is by iterating over all of the segments in each LiveRange
object and setting the end of each segment equal to the start of
the next segment. So a live range like:
[3888r,9312r:0)[10032B,10384B:0) 0@3888r
will become:
[3888r,10032B:0)[10032B,10384B:0) 0@3888r
This change will allow us to use SALU instructions within branches.
David Blaikie [Wed, 2 Jul 2014 18:32:05 +0000 (18:32 +0000)]
DebugInfo: Ensure that all debug location scope chains from instructions within a function, lead to the function itself.
Originally committed in r211723, reverted in r211724 due to failure
cases found and fixed (ArgumentPromotion: r211872, Inlining: r212065),
committed again in r212085 and reverted again in r212089 after fixing
some other cases, such as debug info subprogram lists not keeping track
of the function they represent (r212128) and then short-circuiting
things like LiveDebugVariables that build LexicalScopes for functions
that might not have full debug info.
And again, I believe the invariant actually holds for some reasonable
amount of code (but I'll keep an eye on the buildbots and see what
happens... ).
Original commit message:
PR20038: DebugInfo: Inlined call sites where the caller has debug info
but the call itself has no debug location.
This situation does bad things when inlined, so I've fixed Clang not to
produce inlinable call sites without locations when the caller has debug
info (in the one case where I could find that this occurred). This
updates the PR20038 test case to be what clang now produces, and readds
the assertion that had to be removed due to this bug.
I've also beefed up the debug info verifier to help diagnose these
issues in the future, and I hope to add checks to the inliner to just
assert-fail if it encounters this situation. If, in the future, we
decide we have to cope with this situation, the right thing to do is
probably to just remove all the DebugLocs from the inlined instructions.
[RegAllocGreedy] Provide a subtarget hook to disable the local reassignment
heuristic.
By default, no functionality change.
This is a follow-up of r212099.
This hook provides a finer grain to control the optimization.
David Blaikie [Wed, 2 Jul 2014 18:31:35 +0000 (18:31 +0000)]
Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information.
If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.
While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.
Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.
Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).
[ASan] Print exact source location of global variables in error reports.
See https://code.google.com/p/address-sanitizer/issues/detail?id=299 for the
original feature request.
Introduce llvm.asan.globals metadata, which Clang (or any other frontend)
may use to report extra information about global variables to ASan
instrumentation pass in the backend. This metadata replaces
llvm.asan.dynamically_initialized_globals that was used to detect init-order
bugs. llvm.asan.globals contains the following data for each global:
1) source location (file/line/column info);
2) whether it is dynamically initialized;
3) whether it is blacklisted (shouldn't be instrumented).
Source location data is then emitted in the binary and can be picked up
by ASan runtime in case it needs to print error report involving some global.
For example:
0x... is located 4 bytes to the right of global variable 'C::array' defined in '/path/to/file:17:8' (0x...) of size 40
These source locations are printed even if the binary doesn't have any
debug info.
This is an ABI-breaking change. ASan initialization is renamed to
__asan_init_v4(). Pre-built libraries compiled with older Clang will not work
with the fresh runtime.
Chad Rosier [Wed, 2 Jul 2014 16:46:08 +0000 (16:46 +0000)]
Revert "Revert "MachineScheduler: better book-keeping for asserts.""
This reverts commit r212109, which reverted r212088.
However, disable the assert as it's not necessary for correctness. There are
several corner cases that the assert needed to handle better for in-order
scheduling, but none of them are incorrect scheduler behavior. The assert is
mainly there to collect good unit tests like this and ensure that the
target-independent scheduler is working as expected with the various machine
models.
AVX-512: dec/inc instructions are slow on KNL
After Alexey Volkov, I'm adding the same property for KNL, that prefers ADD/SUB instead of INC/DEC.
Added a test.
[cleanup] Hoist an if-else chain on ISD opcodes (really designed for
switches) into a switch, and sink them into a dispatch function that can
return the result rather than awkward variable setting with breaks.
aarch64: support target-specific .req assembler directive
Based on the support for .req on ARM. The aarch64 variant has to keep track if
the alias register was a vector register (v0-31) or a general purpose or
VFP/Advanced SIMD ([bhsdq]0-31) register.
[cleanup] Hoist the promotion dispatch logic into the promote function
so that we can use return to express it more cleanly and avoid so many
nested switch statements.
Remove the recommendation against using std::function
Clang-cl supports MSVC-style RTTI now, and we can even compile
typeid(...) with /GR-. Just don't instantiate std::function with a
polymorphic type, or bad things will happen.
[DAG] Pass the argument list to the CallLoweringInfo via move semantics. NFCI.
The argument list vector is never used after it has been passed to the
CallLoweringInfo and moving it to the CallLoweringInfo is cleaner and
pretty much as cheap as keeping a pointer to it.
Tim Northover [Tue, 1 Jul 2014 21:44:59 +0000 (21:44 +0000)]
X86: delegate expanding atomic libcalls to generic code.
On targets without cmpxchg16b or cmpxchg8b, the borderline atomic
operations were slipping through the gaps.
X86AtomicExpand.cpp was delegating to ISelLowering. Generic
ISelLowering was delegating to X86ISelLowering and X86ISelLowering was
asserting. The correct behaviour is to expand to a libcall, preferably
in generic ISelLowering.
This can be achieved by X86ISelLowering deciding it doesn't want the
faff after all.
This patch reduces the stack memory consumption of the InstCombine
function "isOnlyCopiedFromConstantGlobal() ", that in certain conditions
could overflow the stack because of excessive recursiveness.
This piece of code crashes llvm when trying to apply instcombine on
desktop. On embedded devices this could happen with a much lower limit
of recursiveness. Some instructions (getelementptr and bitcasts) make
the function recursively call itself on their uses, which is what makes
the example above consume so much stack (it becomes a recursive
depth-first tree visit with a very big depth).
The patch changes the algorithm to be semantically equivalent, but
iterative instead of recursive and the visiting order to be from a
depth-first visit to a breadth-first visit (visit all the instructions
of the current level before the ones of the next one).
Now if a lot of memory is required a heap allocation is done instead of
the the stack allocation, avoiding the possible crash.
Patch by Marcello Maggioni! We don't generally commit large stress test
that look for out of memory conditions, so I didn't request that one be
added to the patch.
David Blaikie [Tue, 1 Jul 2014 21:13:37 +0000 (21:13 +0000)]
DebugInfo: Keep track of subprograms who's arguments have been promoted.
Matching behavior with DeadArgumentElimination (and leveraging some
now-common infrastructure), keep track of the function from debug info
metadata if arguments are promoted.
This may produce interesting debug info - since the arguments may be
missing or of different types... but at least backtraces, inlining, etc,
will be correct.
Tim Northover [Tue, 1 Jul 2014 18:53:31 +0000 (18:53 +0000)]
X86: expand atomics in IR instead of as MachineInstrs.
The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..
Kevin Enderby [Tue, 1 Jul 2014 17:19:10 +0000 (17:19 +0000)]
Add the -arch flag support to llvm-size like what was done to llvm-nm
to select the slice out of a Mach-O universal file. This also includes
support for -arch all, selecting the host architecture by default from
a universal file and checking if -arch is used with a standard Mach-O
it matches that architecture.
This is a small targeted fix for pr20119. The code needs quiet a bit of
refactoring and I added some FIXMEs about it, but I want to get the testcase
passing first.
[PeepholeOptimizer] Advanced rewriting of copies to avoid cross register banks
copies.
This patch extends the peephole optimization introduced in r190713 to produce
register-coalescer friendly copies when possible.
This extension taught the existing cross-bank copy optimization how to deal
with the instructions that generate cross-bank copies, i.e., insert_subreg,
extract_subreg, reg_sequence, and subreg_to_reg.
E.g.
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy b.sub0 <-- cross-bank copy
Would produce the following code:
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy A <-- same-bank copy
This patch also introduces a new helper class for that: ValueTracker.
This class implements the logic to look through the copy related instructions
and get the related source.
For now, the advanced rewriting is disabled by default as we are lacking the
semantic on target specific instructions to catch the motivating examples.
[RegAllocGreedy] Provide a flag to disable the local reassignment heuristic.
By default, no functionality change.
Before evicting a local variable, this heuristic tries to find another (set of)
local(s) that can be reassigned to a free color.
In some extreme cases (large basic blocks with tons of local variables), the
compilation time is dominated by the local interference checks that this
heuristic must perform, with no code gen gain.
E.g., the motivating example takes 4 minutes to compile with this heuristic, 12
seconds without.
Improving the situation will likely require to make drastic changes to the
register allocator and/or the interference check framework.
For now, provide this flag to better understand the impact of that heuristic.
Alp Toker [Tue, 1 Jul 2014 03:18:49 +0000 (03:18 +0000)]
ExecutionEngine::create(): fix interpreter fallback when JIT is unavailable
ForceInterpreter=false shouldn't disable the interpreter completely because it
can still be necessary to interpret if the target doesn't support JIT.
No obvious way to test this in LLVM, but this matches what
LLVMCreateExecutionEngineForModule() does and fixes the clang-interpreter
example in the clang source tree which uses the ExecutionEngine.
David Blaikie [Tue, 1 Jul 2014 03:11:59 +0000 (03:11 +0000)]
DebugInfo: Ensure that all debug location scope chains from instructions within a function, lead to the function itself.
Originally committed in r211723, reverted in r211724 due to failure
cases found and fixed (ArgumentPromotion: r211872, Inlining: r212065),
and I now believe the invariant actually holds for some reasonable
amount of code (but I'll keep an eye on the buildbots and see what
happens... ).
Original commit message:
PR20038: DebugInfo: Inlined call sites where the caller has debug info
but the call itself has no debug location.
This situation does bad things when inlined, so I've fixed Clang not to
produce inlinable call sites without locations when the caller has debug
info (in the one case where I could find that this occurred). This
updates the PR20038 test case to be what clang now produces, and readds
the assertion that had to be removed due to this bug.
I've also beefed up the debug info verifier to help diagnose these
issues in the future, and I hope to add checks to the inliner to just
assert-fail if it encounters this situation. If, in the future, we
decide we have to cope with this situation, the right thing to do is
probably to just remove all the DebugLocs from the inlined instructions.
projects / llvm / log