VSX has instructions lxsiwax/lxsdx that can load 32/64 bit value into VSX register cheaply. That patch makes it known to memory cost model, so the vectorization of the test case in pr30990 is beneficial.
Differential Revision: https://reviews.llvm.org/D26713
llvm-svn: 288560
Currently when cost of scalar operations is evaluated the vector type is
used for scalar operations. Patch fixes this issue and fixes evaluation
of the vector operations cost.
Several test showed that vector cost model is too optimistic. It
allowed vectorization of 8 or less add/fadd operations, though scalar
code is faster. Actually, only for 16 or more operations vector code
provides better performance.
Differential Revision: https://reviews.llvm.org/D26277
llvm-svn: 288398
Note that the non-splat lshr+lshr test folded, but that does not
work in general. Something is missing or wrong in computeKnownBits
as the non-splat shl+shl test still shows.
llvm-svn: 288005
Currently LLVM assumes that a pointer addrspacecasted to a different addr space is equivalent to trunc or zext bitwise, which is not true. For example, in amdgcn target, when a null pointer is addrspacecasted from addr space 4 to 0, its value is changed from i64 0 to i32 -1.
This patch teaches LLVM not to assume known bits of addrspacecast instruction to its operand.
Differential Revision: https://reviews.llvm.org/D26803
llvm-svn: 287545
Summary:
This extends FCOPYSIGN support to 512-bit vectors.
I've also added tests to show what the 128-bit and 256-bit cases look like with broadcast loads.
Reviewers: delena, zvi, RKSimon, spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26791
llvm-svn: 287298
Add explicit v16i16/v32i8 ADD/SUB costs, matching the costs of v4i64/v8i32 - they were missing for some reason.
This has side effects on the LV max bandwidth tests (AVX1 now prefers 128-bit vectors vs AVX2 which still prefers 256-bit)
llvm-svn: 286832
If the inrange keyword is present before any index, loading from or
storing to any pointer derived from the getelementptr has undefined
behavior if the load or store would access memory outside of the bounds of
the element selected by the index marked as inrange.
This can be used, e.g. for alias analysis or to split globals at element
boundaries where beneficial.
As previously proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-July/102472.html
Differential Revision: https://reviews.llvm.org/D22793
llvm-svn: 286514
These examples are variations that were inspired from a small subgraph taken
from paper.ll which are interesting as they show certain issues with infinite
loops.
llvm-svn: 286450
This patch avoids scalarization of CTLZ by instead expanding to use CTPOP (ref: "Hacker's Delight") when the necessary operations are available.
This also adds the necessary cost models for X86 SSE2 targets (the main beneficiary) to ensure vectorization only happens when its useful.
Differential Revision: https://reviews.llvm.org/D25910
llvm-svn: 286233
There is a bug describing poor cost model for floating point operations:
Bug 29083 - [X86][SSE] Improve costs for floating point operations. This
patch is the second one in series of patches dealing with cost model.
Differential Revision: https://reviews.llvm.org/D25722
llvm-svn: 285564
Summary:
We were trying to add APInt values with different bit sizes after
visiting an addrspacecast instruction which changed the bit width
of the pointer.
Reviewers: majnemer, hfinkel
Subscribers: hfinkel, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D24774
llvm-svn: 285407
With DQI but without VLX, lower v2i64 and v4i64 MUL operations with v8i64 MUL (vpmullq).
Updated cost table accordingly.
Differential Revision: https://reviews.llvm.org/D26011
llvm-svn: 285304
This reverts commit r285191.
LICM appears to rely on the Alias Set Tracker hitting lifetime markers to prevent
code from being moved outside of the original scope.
llvm-svn: 285227
There are two fixes here: one, AnalyzeUsesOfPointer can't return
false until it has checked all the uses of the pointer. Two, if a
global uses another global, we have to assume the address of the
first global escapes.
Fixes https://llvm.org/bugs/show_bug.cgi?id=30707 .
Differential Revision: https://reviews.llvm.org/D25798
llvm-svn: 285034
We were defaulting to SSE2 costs which weren't taking into account the availability of PBLENDW/PBLENDVB to improve merging of per-element shift results.
llvm-svn: 284939
In BasicAA GEP operand values get adjusted ("wrap-around") based on the
pointersize. Otherwise, in non-64b modes, AA could report false negatives.
However, a wrap-around is valid only for a fully evaluated expression.
It had been introduced to fix an alias problem in
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160118/326163.html.
This commit restricts the wrap-around to constant gep operands only where the
value is known at compile-time.
llvm-svn: 284908
Summary:
When SCEVRewriteVisitor traverses the SCEV DAG, it may visit the same SCEV
multiple times if this SCEV is referenced by multiple other SCEVs. This has
exponential time complexity in the worst case. Memoizing the results will
avoid re-visiting the same SCEV. Add a map to save the results, and override
the visit function of SCEVVisitor. Now SCEVRewriteVisitor only visit each
SCEV once and thus returns the same result for the same input SCEV.
This patch fixes PR18606, PR18607.
Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin
Differential Revision: https://reviews.llvm.org/D25810
llvm-svn: 284868
When we have a loop with a known upper bound on the number of iterations, and
furthermore know that either the number of iterations will be either exactly
that upper bound or zero, then we can fully unroll up to that upper bound
keeping only the first loop test to check for the zero iteration case.
Most of the work here is in plumbing this 'max-or-zero' information from the
part of scalar evolution where it's detected through to loop unrolling. I've
also gone for the safe default of 'false' everywhere but howManyLessThans which
could probably be improved.
Differential Revision: https://reviews.llvm.org/D25682
llvm-svn: 284818
This is to avoid inlining too many multiplication operands into a SCEV, which could
take exponential time in the worst case.
Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin
Differential Revision: https://reviews.llvm.org/D25794
llvm-svn: 284784
We weren't accounting for legal types on every subtarget, meaning that many of the costs were using defaults.
We still don't correctly cost (or test) the 512-bit sdiv/udiv by uniform const cases, nor the power-of-2 cases.
llvm-svn: 284744
In loops that look something like
i = n;
do {
...
} while(i++ < n+k);
where k is a constant, the maximum backedge count is k (in fact the backedge
count will be either 0 or k, depending on whether n+k wraps). More generally
for LHS < RHS if RHS-(LHS of first comparison) is a constant then the loop will
iterate either 0 or that constant number of times.
This allows for more loop unrolling with the recent upper bound loop unrolling
changes, and I'm working on a patch that will let loop unrolling additionally
make use of the loop being executed either 0 or k times (we need to retain the
loop comparison only on the first unrolled iteration).
Differential Revision: https://reviews.llvm.org/D25607
llvm-svn: 284465
As discussed on PR28461 we currently miss the chance to lower "fptosi <2 x double> %arg to <2 x i32>" to cvttpd2dq due to its use of illegal types.
This patch adds support for fptosi to 2i32 from both 2f64 and 2f32.
It also recognises that cvttpd2dq zeroes the upper 64-bits of the xmm result (similar to D23797) - we still don't do this for the cvttpd2dq/cvttps2dq intrinsics - this can be done in a future patch.
Differential Revision: https://reviews.llvm.org/D23808
llvm-svn: 284459
Summary: The delinearization algorithm did not consider terms which had an extension without a multiply factor, i.e. a identify factor. We lose cases where size is char type where there will no multiply factor.
Reviewers: sanjoy, grosser
Subscribers: mzolotukhin, Eugene.Zelenko, llvm-commits, mssimpso, sanjoy, grosser
Differential Revision: https://reviews.llvm.org/D16492
llvm-svn: 284378
Summary:
While walking defs of pointer operands we were assuming that the pointer
size would remain constant. This is not true, because addresspacecast
instructions may cast the pointer to an address space with a different
pointer width.
This partial reverts r282612, which was a more conservative solution
to this problem.
Reviewers: reames, sanjoy, apilipenko
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D24772
llvm-svn: 283557
Summary:
The computeKnownBits and ComputeNumSignBits functions in ValueTracking can now do a simple look-through of ExtractElement.
Reviewers: majnemer, spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24955
llvm-svn: 283434
Slightly improves the precision of GlobalsAA in certain situations, and
makes the behavior of optimization passes more predictable.
Differential Revision: https://reviews.llvm.org/D24104
llvm-svn: 283165
This should fix:
https://llvm.org/bugs/show_bug.cgi?id=30433
There are a couple of open questions about the codegen:
1. Should we let scalar ops be scalars and avoid vector constant loads/splats?
2. Should we have a pass to combine constants such as the inverted pair that we have here?
Differential Revision: https://reviews.llvm.org/D25165
llvm-svn: 283119
