Don't match the UXTW extended reg forms of ADD/ADDS/SUB/SUBS if the
32-bit to 64-bit zero-extend can be done for free by taking advantage
of the 32-bit defining instruction zeroing the upper 32-bits of the X
register destination. This enables better instruction selection in a
few cases, such as:
sub x0, xzr, x8
instead of:
mov x8, xzr
sub x0, x8, w9, uxtw
madd x0, x1, x1, x8
instead of:
mul x9, x1, x1
add x0, x9, w8, uxtw
cmp x2, x8
instead of:
sub x8, x2, w8, uxtw
cmp x8, #0
add x0, x8, x1, lsl #3
instead of:
lsl x9, x1, #3
add x0, x9, w8, uxtw
Reviewers: t.p.northover, jmolloy
Subscribers: mcrosier, aemerson, llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D24747
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282413 91177308-0d34-0410-b5e6-96231b3b80d8
Many high-performance processors have a dedicated branch predictor for
indirect branches, commonly used with jump tables. As sophisticated as such
branch predictors are, they tend to have well defined limits beyond which
their effectiveness is hampered or even nullified. One such limit is the
number of possible destinations for a given indirect branches that such
branch predictors can handle.
This patch considers a limit that a target may set to the number of
destination addresses in a jump table.
Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar
<aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>.
Differential revision: https://reviews.llvm.org/D21940
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282412 91177308-0d34-0410-b5e6-96231b3b80d8
The index of the new insertelement instruction was evaluated in the
wrong way, it was considered as the index of the inserted value instead
of index of the position, where the value should be inserted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282401 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes PR30366.
Function foldUDivShl() worked under the assumption that one of the values
in input to the function was always an instance of llvm::Instruction.
However, function visitUDivOperand() (the only user of foldUDivShl) was
clearly violating that precondition; internally, visitUDivOperand() uses pattern
matches to check the operands of a udiv. Pattern matchers for binary operators
know how to handle both Instruction and ConstantExpr values.
This patch fixes the problem in foldUDivShl(). Now we use pattern matchers
instead of explicit casts to Instruction. The reduced test case from PR30366
has been added to test file InstCombine/udiv-simplify.ll.
Differential Revision: https://reviews.llvm.org/D24565
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282398 91177308-0d34-0410-b5e6-96231b3b80d8
If a constant is unamed_addr and is only used within one function, we can save
on the code size and runtime cost of an indirection by changing the global's storage
to inside the constant pool. For example, instead of:
ldr r0, .CPI0
bl printf
bx lr
.CPI0: &format_string
format_string: .asciz "hello, world!\n"
We can emit:
adr r0, .CPI0
bl printf
bx lr
.CPI0: .asciz "hello, world!\n"
This can cause significant code size savings when many small strings are used in one
function (4 bytes per string).
This recommit contains fixes for a nasty bug related to fast-isel fallback - because
fast-isel doesn't know about this optimization, if it runs and emits references to
a string that we inline (because fast-isel fell back to SDAG) we will end up
with an inlined string and also an out-of-line string, and we won't emit the
out-of-line string, causing backend failures.
It also contains fixes for emitting .text relocations which made the sanitizer
bots unhappy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282387 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Replace a LEA instruction of the form 'lea (%esp), %ebx' --> 'mov %esp, %ebx'
MOV is preferable over LEA because usually there are more issue-slots available to execute MOVs than LEAs. Latest processors also support zero-latency MOVs.
Fixes pr29022.
Reviewers: hfinkel, delena, igorb, myatsina, mkuper
Differential Revision: https://reviews.llvm.org/D24705
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282385 91177308-0d34-0410-b5e6-96231b3b80d8
Noticed due to the warning on this line. Sanjoy is on
a less-than-awesome internet connection, so committing on his behalf.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282380 91177308-0d34-0410-b5e6-96231b3b80d8
In a previous change I collapsed two different caches into one. When
doing that I noticed that ScalarEvolution's move constructor was not
moving those caches.
To keep the previous change simple, I've moved that bugfix into this
separate change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282376 91177308-0d34-0410-b5e6-96231b3b80d8
Both `loopHasNoSideEffects` and `loopHasNoAbnormalExits` involve walking
the loop and maintaining similar sorts of caches. This commit changes
SCEV to compute both the predicates via a single walk, and maintain a
single cache instead of two.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282375 91177308-0d34-0410-b5e6-96231b3b80d8
Specifically, it moves SCEVUnionPredicates from its input into its own
storage. Make this obvious at the type level.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282374 91177308-0d34-0410-b5e6-96231b3b80d8
SCEVUnionPredicate is a "heavyweight" structure, so it is beneficial to
store the (optional) data out of line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282366 91177308-0d34-0410-b5e6-96231b3b80d8
This change simplifies a data structure optimization in the
`BackedgeTakenInfo` class for loops with exactly one computable exit.
I've sanity checked that this does not regress compile time performance,
using sqlite3's amalgamated build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282365 91177308-0d34-0410-b5e6-96231b3b80d8
Stop looking at users of UndefValue and ConstantPointerNull in the
objective C ARC optimizers. The other users aren't actually
interesting, since they're not pointing at a particular object. I
imagine these calls could be optimized through -instcombine... maybe
they already are?
These early returns will be required at some point in the future, with a
WIP patch that asserts when someone accesses a use-list on ConstantData.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282338 91177308-0d34-0410-b5e6-96231b3b80d8
There is no benefit in looking through assumptions on UndefValue to
guess known bits. Return early to avoid walking their use-lists, and
assert that all instances of ConstantData are handled here for similar
reasons (UndefValue was the only integer/pointer holdout).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282337 91177308-0d34-0410-b5e6-96231b3b80d8
Assumptions on UndefValue and ConstantPointerNull aren't relevant to
other users. Ignore them entirely to avoid wasting cycles walking
through their (possibly extremely extensive (cross-module)) use-lists.
It wasn't clear how to add a specific test for this, and it'll be
covered anyway by an eventual patch that asserts when trying to access
the use-list of an instance of ConstantData.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282334 91177308-0d34-0410-b5e6-96231b3b80d8
Check and return early for ConstantPointerNull and UndefValue
specifically in isKnownNonNullAt, and assert that ConstantData never
make it to isKnownNonNullFromDominatingCondition.
This confirms that isKnownNonNullFromDominatingCondition never walks
through the use-list of an instance of ConstantData. Given that such
use-lists cross module boundaries, it never really made sense to do so,
and was potentially very expensive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282333 91177308-0d34-0410-b5e6-96231b3b80d8
Like partial mappings, as we move toward TableGen'ed information, the
number should reach zero eventually.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282325 91177308-0d34-0410-b5e6-96231b3b80d8
This is a step toward statically allocate ValueMapping. Like the
previous few commits, the goal is to move toward a TableGen'ed like
structure with no dynamic allocation at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282324 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we were using the address of the unique instance of a partial
mapping in the related map to access this instance. However, when the
map grows, the whole set of instances may be moved elsewhere and the
previous addresses are not valid anymore.
Instead, keep the address of the unique heap allocated instance of a
partial mapping.
Note: I did not see any actual bugs for that problem as the number of
partial mappings dynamically allocated is small (<= 4).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282323 91177308-0d34-0410-b5e6-96231b3b80d8
Return early from llvm::isSafeToDestroyConstant() whenever the value
`isa<ConstantData>()`. These constants are shared across the
LLVMContext. We never really want to delete them here, and walking
their use-lists can be very expensive.
(This is motivated by an eventual goal of removing use-lists entirely
from ConstantData.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282320 91177308-0d34-0410-b5e6-96231b3b80d8
This is similar to:
https://reviews.llvm.org/rL279958
By not prematurely lowering to loads, we should be able to more easily eliminate
the 'or' with zero instructions seen in copysign-constant-magnitude.ll.
We should also be able to extend this code to handle vectors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282312 91177308-0d34-0410-b5e6-96231b3b80d8
The NativeObjectOutput class has a design problem: it mixes up the caching
policy with the interface for output streams, which makes the client-side
code hard to follow and would for example make it harder to replace the
cache implementation in an arbitrary client.
This change separates the two aspects by moving the caching policy
to a separate field in Config, replacing NativeObjectOutput with a
NativeObjectStream class which only deals with streams and does not need to
be overridden by most clients and introducing an AddFile callback for adding
files (e.g. from the cache) to the link.
Differential Revision: https://reviews.llvm.org/D24622
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282299 91177308-0d34-0410-b5e6-96231b3b80d8
