MCP currently uses changeDebugValuesDefReg / collectDebugValues to find
debug users of a register, however those functions assume that all
DBG_VALUEs immediately follow the specified instruction, which isn't
necessarily true. This is going to become very often untrue when we turn
off CodeGenPrepare::placeDbgValues.
Instead of calling changeDebugValuesDefReg on an instruction to change its
debug users, in this patch we instead collect DBG_VALUEs of copies as we
iterate over insns, and update the debug users of copies that are made
dead. This isn't a non-functional change, because MCP will now update
DBG_VALUEs that aren't immediately after a copy, but refer to the same
register. I've hijacked the regression test for PR38773 to test for this
new behaviour, an entirely new test seemed overkill.
Differential Revision: https://reviews.llvm.org/D56265
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368835 91177308-0d34-0410-b5e6-96231b3b80d8
In MCAsmStreamer:
.type foo,@function # <--- this is redundant
.type foo,@gnu_indirect_function
In MCELFStreamer, the latter STT_GNU_IFUNC overrides STT_FUNC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368823 91177308-0d34-0410-b5e6-96231b3b80d8
Currently shufflemasks get emitted as any other constant, and you end
up with a bunch of virtual registers of G_CONSTANT with a
G_BUILD_VECTOR. The AArch64 selector then asserts on anything that
doesn't fit this pattern. This isn't an ideal representation, and
should avoid legalization and have fewer opportunities for a
representational error.
Rather than invent a new shuffle mask operand type, similar to what
ShuffleVectorSDNode does, just track the original IR Constant mask
operand. I don't completely like the idea of adding another link to
the IR, but MIR is already quite dependent on IR constants already,
and this will allow sharing the shuffle mask utility functions with
the IR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368704 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This implements an optimization described in Hacker's Delight 10-17:
when `C` is constant, the result of `X % C == 0` can be computed
more cheaply without actually calculating the remainder.
The motivation is discussed here: https://bugs.llvm.org/show_bug.cgi?id=35479.
One huge caveat: this signed case is only valid for positive divisors.
While we can freely negate negative divisors, we can't negate `INT_MIN`,
so for now if `INT_MIN` is encountered, we bailout.
As a follow-up, it should be possible to handle that more gracefully
via extra `and`+`setcc`+`select`.
This passes llvm's test-suite, and from cursory(!) cross-examination
the folds (the assembly) match those of GCC, and manual checking via alive
did not reveal any issues (other than the `INT_MIN` case)
Reviewers: RKSimon, spatel, hermord, craig.topper, xbolva00
Reviewed By: RKSimon, xbolva00
Subscribers: xbolva00, thakis, javed.absar, hiraditya, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65366
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368702 91177308-0d34-0410-b5e6-96231b3b80d8
The comment initially matched the code, but the code was incorrect
and was fixed after the initial revert back back when it was introduced,
but the comment was never updated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368701 91177308-0d34-0410-b5e6-96231b3b80d8
This introduced a false positive MemorySanitizer warning about use of
uninitialized memory in a vectorized crc function in Chromium. That suggests
maybe something is not right with this transformation. See
https://crbug.com/992853#c7 for a reproducer.
This also reverts the follow-up commits r368307 and r368308 which
depended on this.
> This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
>
> In particular this helps remove some unnecessary scalar->vector->scalar patterns.
>
> The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
>
> Differential Revision: https://reviews.llvm.org/D65887
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368660 91177308-0d34-0410-b5e6-96231b3b80d8
Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.
AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.
Differential Revision: https://reviews.llvm.org/D65984
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368652 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This was mostly an experiment to assess the feasibility of completely
eliminating a problematic implicit conversion case in D61321 in advance of
landing that* but it also happens to align with the goal of propagating the
use of Register/MCRegister instead of unsigned so I believe it makes sense
to commit it.
The overall process for eliminating the implicit conversions from
Register/MCRegister -> unsigned was to:
1. Add an explicit conversion to support genuinely required conversions to
unsigned. For example, using them as an index for IndexedMap. Sadly it's
not possible to have an explicit and implicit conversion to the same
type and only deprecate the implicit one so I called the explicit
conversion get().
2. Temporarily annotate the implicit conversion to unsigned with
LLVM_ATTRIBUTE_DEPRECATED to make them visible
3. Eliminate implicit conversions by propagating Register/MCRegister/
explicit-conversions appropriately
4. Remove the deprecation added in 2.
* My conclusion is that it isn't feasible as there's too much code to
update in one go.
Depends on D65678
Reviewers: arsenm
Subscribers: MatzeB, wdng, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65685
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368643 91177308-0d34-0410-b5e6-96231b3b80d8
It caused assertions to fire when building Chromium:
lib/CodeGen/LiveDebugValues.cpp:331: bool
{anonymous}::LiveDebugValues::OpenRangesSet::empty() const: Assertion
`Vars.empty() == VarLocs.empty() && "open ranges are inconsistent"' failed.
See https://crbug.com/992871#c3 for how to reproduce.
> Patch https://reviews.llvm.org/D43256 introduced more aggressive loop layout optimization which depends on profile information. If profile information is not available, the statically estimated profile information(generated by BranchProbabilityInfo.cpp) is used. If user program doesn't behave as BranchProbabilityInfo.cpp expected, the layout may be worse.
>
> To be conservative this patch restores the original layout algorithm in plain mode. But user can still try the aggressive layout optimization with -force-precise-rotation-cost=true.
>
> Differential Revision: https://reviews.llvm.org/D65673
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368579 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When eliminating an unreachable block we must remove any call site
information for calls residing in the block.
This was originally found on a downstream target, and the attached x86
test case was produced by hand-modifying some MIR.
Reviewers: aprantl, asowda, NikolaPrica, djtodoro, ivanbaev, vsk
Reviewed By: NikolaPrica, vsk
Subscribers: vsk, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D64500
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368566 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In `block-placement` pass, it will create some patterns for unconditional we can do the simple early retrun.
But the `early-ret` pass is before `block-placement`, we don't want to run it again.
This patch is to do the simple early return to optimize the blocks at the last of `block-placement`.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D63972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368565 91177308-0d34-0410-b5e6-96231b3b80d8
> In `block-placement` pass, it will create some patterns for unconditional we can do the simple early retrun.
> But the `early-ret` pass is before `block-placement`, we don't want to run it again.
> This patch is to do the simple early return to optimize the blocks at the last of `block-placement`.
>
> Reviewed By: efriedma
>
> Differential Revision: https://reviews.llvm.org/D63972
This also revertes follow-ups r368514 and r368532.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368560 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
After the commits that changed x86 backend to widen vectors
instead of using promotion some of our downstream tests
started to fail. It was noticed that WidenVectorResult has
been missing support for SMULFIX/UMULFIX/SMULFIXSAT. This
patch adds the missing functionality.
Reviewers: craig.topper, RKSimon
Reviewed By: craig.topper
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66051
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368540 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In `block-placement` pass, it will create some patterns for unconditional we can do the simple early retrun.
But the `early-ret` pass is before `block-placement`, we don't want to run it again.
This patch is to do the simple early return to optimize the blocks at the last of `block-placement`.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D63972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368509 91177308-0d34-0410-b5e6-96231b3b80d8
This is the codegen part of fixing:
https://bugs.llvm.org/show_bug.cgi?id=32939
Even with the optimal/canonical IR that is ideally created by D65954,
we would reverse that transform in DAGCombiner and end up with the same
asm on AArch64 or x86.
I see 2 options for trying to correct this:
1. Limit isNegatibleForFree() by special-casing the fmul pattern (this patch).
2. Avoid creating (fmul X, 2.0) in the 1st place by adding a special-case
transform to SelectionDAG::getNode() and/or SelectionDAGBuilder::visitFMul()
that matches the transform done by DAGCombiner.
This seems like the less intrusive patch, but if there's some other reason to
prefer 1 option over the other, we can change to the other option.
Differential Revision: https://reviews.llvm.org/D66016
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368490 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Targets often have instructions that can sign-extend certain cases faster
than the equivalent shift-left/arithmetic-shift-right. Such cases can be
identified by matching a shift-left/shift-right pair but there are some
issues with this in the context of combines. For example, suppose you can
sign-extend 8-bit up to 32-bit with a target extend instruction.
%1:_(s32) = G_SHL %0:_(s32), i32 24 # (I've inlined the G_CONSTANT for brevity)
%2:_(s32) = G_ASHR %1:_(s32), i32 24
%3:_(s32) = G_ASHR %2:_(s32), i32 1
would reasonably combine to:
%1:_(s32) = G_SHL %0:_(s32), i32 24
%2:_(s32) = G_ASHR %1:_(s32), i32 25
which no longer matches the special case. If your shifts and extend are
equal cost, this would break even as a pair of shifts but if your shift is
more expensive than the extend then it's cheaper as:
%2:_(s32) = G_SEXT_INREG %0:_(s32), i32 8
%3:_(s32) = G_ASHR %2:_(s32), i32 1
It's possible to match the shift-pair in ISel and emit an extend and ashr.
However, this is far from the only way to break this shift pair and make
it hard to match the extends. Another example is that with the right
known-zeros, this:
%1:_(s32) = G_SHL %0:_(s32), i32 24
%2:_(s32) = G_ASHR %1:_(s32), i32 24
%3:_(s32) = G_MUL %2:_(s32), i32 2
can become:
%1:_(s32) = G_SHL %0:_(s32), i32 24
%2:_(s32) = G_ASHR %1:_(s32), i32 23
All upstream targets have been configured to lower it to the current
G_SHL,G_ASHR pair but will likely want to make it legal in some cases to
handle their faster cases.
To follow-up: Provide a way to legalize based on the constant. At the
moment, I'm thinking that the best way to achieve this is to provide the
MI in LegalityQuery but that opens the door to breaking core principles
of the legalizer (legality is not context sensitive). That said, it's
worth noting that looking at other instructions and acting on that
information doesn't violate this principle in itself. It's only a
violation if, at the end of legalization, a pass that checks legality
without being able to see the context would say an instruction might not be
legal. That's a fairly subtle distinction so to give a concrete example,
saying %2 in:
%1 = G_CONSTANT 16
%2 = G_SEXT_INREG %0, %1
is legal is in violation of that principle if the legality of %2 depends
on %1 being constant and/or being 16. However, legalizing to either:
%2 = G_SEXT_INREG %0, 16
or:
%1 = G_CONSTANT 16
%2:_(s32) = G_SHL %0, %1
%3:_(s32) = G_ASHR %2, %1
depending on whether %1 is constant and 16 does not violate that principle
since both outputs are genuinely legal.
Reviewers: bogner, aditya_nandakumar, volkan, aemerson, paquette, arsenm
Subscribers: sdardis, jvesely, wdng, nhaehnle, rovka, kristof.beyls, javed.absar, hiraditya, jrtc27, atanasyan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61289
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368487 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A block address may be used in inline assembly. In which case it
requires a name so that the asm parser has something to parse. Creating
a name for every block address is a large hammer, but is necessary
because at the point when a temp symbol is created we don't necessarily
know if it's used in inline asm. This ensures that it exists regardless.
Reviewers: nickdesaulniers, craig.topper
Subscribers: nathanchance, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65352
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368478 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch keeps track of MCSymbols created for blocks that were
referenced in inline asm. It prevents creating a new symbol which
doesn't refer to the block.
Inline asm may have a reference to a label. The asm parser however
doesn't recognize it as a label and tries to create a new symbol. The
result being that instead of the original symbol (e.g. ".Ltmp0") the
parser replaces it in the inline asm with the new one (e.g. ".Ltmp00")
without updating it in the symbol table. So the machine basic block
retains the "old" symbol (".Ltmp0"), but the inline asm uses the new one
(".Ltmp00").
Reviewers: nickdesaulniers, craig.topper
Subscribers: nathanchance, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65304
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368477 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is exposed by adding a new testcase in PowerPC in
https://reviews.llvm.org/rL367732
The testcase got different output on different platform, hence breaking
buildbots.
The problem is that we get differnt FuncUnitOrder when calculateResMII.
The root cause is:
1. Two MachineInstr might get SAME priority(MFUsx) from minFuncUnits.
2. Current comparison operator() will return `MFUs1 > MFUs2`.
3. We use iterators for MachineInstr, so the input to FuncUnitSorter
might be different on differnt platform due to the iterator nature.
So for two MI with same MFU, their order is actually depends on the
iterator order, which is platform (implemtation) dependent.
This is risky, and may cause cross-compiling problems.
The fix is to check make sure we assign a determine order when they are
equal.
Reviewers: bcahoon, hfinkel, jmolloy
Subscribers: nemanjai, hiraditya, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65992
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368441 91177308-0d34-0410-b5e6-96231b3b80d8
I've now needed to add an extra parameter to this call twice recently. Not only
is the signature getting extremely unwieldy, but just updating all of the
callsites and implementations is a pain. Putting the parameters in a struct
sidesteps both issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368408 91177308-0d34-0410-b5e6-96231b3b80d8
We may be able to look to how VSELECT is handled to further
improve this, but this appears to be neutral or an improvement
on the test cases we have.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368344 91177308-0d34-0410-b5e6-96231b3b80d8
Patch https://reviews.llvm.org/D43256 introduced more aggressive loop layout optimization which depends on profile information. If profile information is not available, the statically estimated profile information(generated by BranchProbabilityInfo.cpp) is used. If user program doesn't behave as BranchProbabilityInfo.cpp expected, the layout may be worse.
To be conservative this patch restores the original layout algorithm in plain mode. But user can still try the aggressive layout optimization with -force-precise-rotation-cost=true.
Differential Revision: https://reviews.llvm.org/D65673
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368339 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch enable assembly output of local commons for AIX using .lcomm
directives. Adds a EmitXCOFFLocalCommonSymbol to MCStreamer so we can emit the
AIX version of .lcomm assembly directives which include a csect name. Handle the
case of BSS locals in PPCAIXAsmPrinter by using EmitXCOFFLocalCommonSymbol. Adds
a test for generating .lcomm on AIX Targets.
Reviewers: cebowleratibm, hubert.reinterpretcast, Xiangling_L, jasonliu, sfertile
Reviewed By: sfertile
Subscribers: wuzish, nemanjai, hiraditya, kbarton, MaskRay, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64825
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368306 91177308-0d34-0410-b5e6-96231b3b80d8
This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
In particular this helps remove some unnecessary scalar->vector->scalar patterns.
The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
Differential Revision: https://reviews.llvm.org/D65887
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368276 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit fbc563e2cb6c5f1d0200b390513506b6aca4d2e9 "Create
unique, but identically-named ELF sections for explicitly-sectioned
functions and globals when using -function-sections and
-data-sections."
Reason for revert: sections are created with potentially wrong
attributes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368204 91177308-0d34-0410-b5e6-96231b3b80d8
In particular this helps the SSE vector shift cvttps2dq+add+shl pattern by avoiding the need for zeros in shuffle style extensions to vXi32 types as we'll be shifting out those bits anyway
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368155 91177308-0d34-0410-b5e6-96231b3b80d8
https://reviews.llvm.org/D65698
This adds a KnownBits analysis pass for GISel. This was done as a
pass (compared to static functions) so that we can add other features
such as caching queries(within a pass and across passes) in the future.
This patch only adds the basic pass boiler plate, and implements a lazy
non caching knownbits implementation (ported from SelectionDAG). I've
also hooked up the AArch64PreLegalizerCombiner pass to use this - there
should be no compile time regression as the analysis is lazy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368065 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes the DAG legalizer to respect the operation actions
set by the target for strict floating-point operations. (Currently, the
legalizer will usually fall back to mutate to the non-strict action
(which is assumed to be legal), and only skip mutation if the strict
operation is marked legal.)
With this patch, if whenever a strict operation is marked as Legal or
Custom, it is passed to the target as usual. Only if it is marked as
Expand will the legalizer attempt to mutate to the non-strict operation.
Note that this will now fail if the non-strict operation is itself
marked as Custom -- the target will have to provide a Custom definition
for the strict operation then as well.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D65226
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368012 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Before this patch MGATHER/MSCATTER is capable of representing all
common addressing modes, but only when illegal types are used.
This patch adds an IndexType property so more representations
are available when using legal types only.
Original modes:
vector of bases
base + vector of signed scaled offsets
New modes:
base + vector of signed unscaled offsets
base + vector of unsigned scaled offsets
base + vector of unsigned unscaled offsets
The current behaviour of addressing modes for gather/scatter remains
unchanged.
Patch by Paul Walker.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D65636
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368008 91177308-0d34-0410-b5e6-96231b3b80d8
Jeremy Morse