The Swift Machine Scheduler Model is incomplete. There are instructions
missing which can trigger the "incomplete machine model" abort. This was
observed when a downstream SchedMachineModel was added to the ARM
target.
Patch by Christof Douma!
llvm-svn: 250033
C semantics force sub-int-sized values (e.g. i8, i16) to be promoted to int
type (e.g. i32) whenever arithmetic is performed on them.
For targets with native i8 or i16 operations, usually InstCombine can shrink
the arithmetic type down again. However InstCombine refuses to create illegal
types, so for targets without i8 or i16 registers, the lengthening and
shrinking remains.
Most SIMD ISAs (e.g. NEON) however support vectors of i8 or i16 even when
their scalar equivalents do not, so during vectorization it is important to
remove these lengthens and truncates when deciding the profitability of
vectorization.
The algorithm this uses starts at truncs and icmps, trawling their use-def
chains until they terminate or instructions outside the loop are found (or
unsafe instructions like inttoptr casts are found). If the use-def chains
starting from different root instructions (truncs/icmps) meet, they are
unioned. The demanded bits of each node in the graph are ORed together to form
an overall mask of the demanded bits in the entire graph. The minimum bitwidth
that graph can be truncated to is the bitwidth minus the number of leading
zeroes in the overall mask.
The intention is that this algorithm should "first do no harm", so it will
never insert extra cast instructions. This is why the use-def graphs are
unioned, so that subgraphs with different minimum bitwidths do not need casts
inserted between them.
This algorithm works hard to reduce compile time impact. DemandedBits are only
queried if there are extends of illegal types and if a truncate to an illegal
type is seen. In the general case, this results in a simple linear scan of the
instructions in the loop.
No non-noise compile time impact was seen on a clang bootstrap build.
llvm-svn: 250032
This patch fixes a problem in function 'combineX86ShuffleChain' that causes a
chain of shuffles to be wrongly folded away when the combined shuffle mask has
only one element.
We may end up with a combined shuffle mask of one element as a result of
multiple calls to function 'canWidenShuffleElements()'.
Function canWidenShuffleElements attempts to simplify a shuffle mask by widening
the size of the elements being shuffled.
For every pair of shuffle indices, function canWidenShuffleElements checks if
indices refer to adjacent elements. If all pairs refer to "adjacent" elements
then the shuffle mask is safely widened. As a consequence of widening, we end up
with a new shuffle mask which is half the size of the original shuffle mask.
The byte shuffle (pshufb) from test pr24562.ll has a mask of all SM_SentinelZero
indices. Function canWidenShuffleElements would combine each pair of
SM_SentinelZero indices into a single SM_SentinelZero index. So, in a
logarithmic number of steps (4 in this case), the pshufb mask is simplified to
a mask with only one index which is equal to SM_SentinelZero.
Before this patch, function combineX86ShuffleChain wrongly assumed that a mask
of size one is always equivalent to an identity mask. So, the entire shuffle
chain was just folded away as the combined shuffle mask was treated as a no-op
mask.
With this patch we know check if the only element of a combined shuffle mask is
SM_SentinelZero. In case, we propagate a zero vector.
Differential Revision: http://reviews.llvm.org/D13364
llvm-svn: 250027
Summary: Unnecessary space at the beginning of LLVM_DEFINITIONS in cmake shared files can break projects that use the variable.
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13432
llvm-svn: 250025
New instructions using floating point registers have been added, to check
that AsmParser can deal with fp regs in vector instructions.
This tests r249810.
llvm-svn: 250023
This script prints a CSV of all misched models of a target when given the output of the debug output of subtarget using:
llvm-tblgen --gen-subtarget --debug-only=subtarget-emitter ...
With thanks to Dave Estes for mentioning the idea at the 2014 LLVM Developers' Meeting.
Patch by Christof Douma!
llvm-svn: 250020
This patch also allows the -delinearize pass to delinearize expressions that do
not have an outermost SCEVAddRec expression. The SCEV::delinearize
infrastructure allowed this since r240952, but the -delinearize pass was not
updated yet.
llvm-svn: 250018
The XOP vector integer comparisons can deal with all signed/unsigned comparison cases directly and can be easily commuted as well (D7646).
llvm-svn: 249976
Summary:
The change to use the VST function entries for lazy deserialization did
not handle the case of anonymous functions without aliases. In that case
we must fall back to scanning the function blocks as there is no VST
entry.
Reviewers: dexonsmith, joker.eph, davidxl
Subscribers: tstellarAMD, llvm-commits
Differential Revision: http://reviews.llvm.org/D13596
llvm-svn: 249947
expandPostRAPseudo():
STX -> 2 * STD: The first STD should not have the kill flag set for the address.
SystemZElimCompare:
BRC -> BRCT conversion: Don't forget to remove the CC<use,kill> operand.
Needed to make SystemZ/asm-17.ll pass with -verify-machineinstrs, which
now runs with this flag.
Reviewed by Ulrich Weigand.
llvm-svn: 249945
Summary:
Rather than just iterating over all sections and checking whether we have relocations for them, iterate over the relocation map instead. This showed up heavily in an artificial julia benchmark that does lots of compilation. On that particular benchmark, this patch gives
~15% performance improvements. As far as I can tell the primary reason why the original
loop was so expensive is that Relocations[i] actually constructs a relocationList (allocating memory & doing lots of other unnecessary computing) if none is found.
Reviewers: lhames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13545
llvm-svn: 249942
Remove implicit ilist iterator conversions from LLVMAnalysis.
I came across something really scary in `llvm::isKnownNotFullPoison()`
which relied on `Instruction::getNextNode()` being completely broken
(not surprising, but scary nevertheless). This function is documented
(and coded to) return `nullptr` when it gets to the sentinel, but with
an `ilist_half_node` as a sentinel, the sentinel check looks into some
other memory and we don't recognize we've hit the end.
Rooting out these scary cases is the reason I'm removing the implicit
conversions before doing anything else with `ilist`; I'm not at all
surprised that clients rely on badness.
I found another scary case -- this time, not relying on badness, just
bad (but I guess getting lucky so far) -- in
`ObjectSizeOffsetEvaluator::compute_()`. Here, we save out the
insertion point, do some things, and then restore it. Previously, we
let the iterator auto-convert to `Instruction*`, and then set it back
using the `Instruction*` version:
Instruction *PrevInsertPoint = Builder.GetInsertPoint();
/* Logic that may change insert point */
if (PrevInsertPoint)
Builder.SetInsertPoint(PrevInsertPoint);
The check for `PrevInsertPoint` doesn't protect correctly against bad
accesses. If the insertion point has been set to the end of a basic
block (i.e., `SetInsertPoint(SomeBB)`), then `GetInsertPoint()` returns
an iterator pointing at the list sentinel. The version of
`SetInsertPoint()` that's getting called will then call
`PrevInsertPoint->getParent()`, which explodes horribly. The only
reason this hasn't blown up is that it's fairly unlikely the builder is
adding to the end of the block; usually, we're adding instructions
somewhere before the terminator.
llvm-svn: 249925
malformed Mach-O file that caused a crash. This was because of an
assert where the code was incorrectly attempting to parse relocation
entries off of the sections and the filetype was not an MH_OBJECT.
rdar://22983603
llvm-svn: 249921
The new implementation works at least as well as the old implementation
did.
Also delete the associated preparation tests. They don't exercise
interesting corner cases of the new implementation. All the codegen
tests of the EH tables have already been ported.
llvm-svn: 249918
Also Fix a buglet where SEH tables had ranges that spanned funclets.
The remaining tests using the old landingpad IR are preparation tests,
and will be deleted along with the old preparation.
llvm-svn: 249917
