When instcombine sinks an instruction between two basic blocks, it sinks any
dbg.value users in the source block with it, to prevent debug use-before-free.
However we can do better by attempting to salvage the debug users, which would
avoid moving where the variable location changes. If we successfully salvage,
still sink a (cloned) dbg.value with the sunk instruction, as the sunk
instruction is more likely to be "live" later in the compilation process.
If we can't salvage dbg.value users of a sunk instruction, mark the dbg.values
in the original block as being undef. This terminates any earlier variable
location range, and represents the fact that we've optimized out the variable
location for a portion of the program.
Differential Revision: https://reviews.llvm.org/D56788
llvm-svn: 353936
This patch adds support of guards expressed in explicit form via
`widenable_condition` in Guard Widening pass.
Differential Revision: https://reviews.llvm.org/D56075
Reviewed By: reames
llvm-svn: 353932
Summary:
This is a follow-up to D57510. This patch stops DebugHandlerBase from
changing the starting label for the first non-overlapping,
register-described parameter DBG_VALUEs to the beginning of the
function. That code did not consider what defined the registers, which
could result in the ranges for the debug values starting before their
defining instructions. We currently do not emit debug values for
constant values directly at the start of the function, so this code is
still useful for such values, but my intention is to remove the code
from DebugHandlerBase completely when we get there. One reason for
removing it is that the code violates the history map's ranges, which I
think can make it quite confusing when troubleshooting.
In D57510, PrologEpilogInserter was amended so that parameter DBG_VALUEs
now are kept at the start of the entry block, even after emission of
prologue code. That was done to reduce the degradation of debug
completeness from this patch. PR40638 is another example, where the
lexical-scope trimming that LDV does, in combination with scheduling,
results in instructions after the prologue being left without locations.
There might be other cases where the DBG_VALUEs are pushed further down,
for which the DebugHandlerBase code may be helpful, but as it now quite
often result in incorrect locations, even after the prologue, it seems
better to remove that code, and try to work our way up with accurate
locations.
In the long run we should maybe not aim to provide accurate locations
inside the prologue. Some single location descriptions, at least those
referring to stack values, generate inaccurate values inside the
epilogue, so we maybe should not aim to achieve accuracy for location
lists. However, it seems that we now emit line number programs that can
result in GDB and LLDB stopping inside the prologue when doing line
number stepping into functions. See PR40188 for more information.
A summary of some of the changed test cases is available in PR40188#c2.
Reviewers: aprantl, dblaikie, rnk, jmorse
Reviewed By: aprantl
Subscribers: jdoerfert, jholewinski, jvesely, javed.absar, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D57511
llvm-svn: 353928
Try to use 64-bit SLP vectorization. In addition to horizontal instrs
this change triggers optimizations for partial vector operations (for instance,
using low halfs of 128-bit registers xmm0 and xmm1 to multiply <2 x float> by
<2 x float>).
Fixes llvm.org/PR32433
llvm-svn: 353923
In 64-bit mode prior to avx512 we use Expand, but with avx512 we need to make f32/f64 conversions Legal so we use Custom and then do our own expansion for f80. But this seems to produce codegen differences relative to avx2. This patch corrects this.
llvm-svn: 353921
We stil don't have a source location, which is pretty lame, but at least
we won't tell the user to file a clang bug report anymore.
Fixes PR40712
llvm-svn: 353907
The DWARF standard says that an empty compile unit is not valid:
> Each such contribution consists of a compilation unit header (see
> Section 7.5.1.1 on page 200) followed by a single DW_TAG_compile_unit or
> DW_TAG_partial_unit debugging information entry, together with its
> children.
Therefore we shouldn't clone them in dsymutil.
Differential revision: https://reviews.llvm.org/D57979
llvm-svn: 353903
This was inhibiting inlining of library functions when clang was
invoking the inliner directly. This is covering a bit of a mess with
subtarget feature handling, and this shouldn't be a subtarget
feature. The behavior is different depending on whether you are using
a -mattr flag in clang, or llc, opt.
llvm-svn: 353899
r352664 added a 'dynamic' parameter to objectsize, but the AutoUpgrade
changes were incomplete. Also, fix an off-by-one error I made in the
upgrade logic that is now no longer unreachable.
Differential revision: https://reviews.llvm.org/D58071
llvm-svn: 353884
This is a recommit of r335091 Add more test cases for deopt-operands via regalloc, and r335077 [InlineSpiller] Fix a crash due to lack of forward progress from remat specifically for STATEPOINT. They were reverted due to a crash.
This change includes the text of both original changes, but also includes three aditional pieces:
1) A bug fix for the observed crash. I had failed to record the failed remat value as live which resulted in an instruction being deleted which still had uses. With the machine verifier, this is caught quickly. Without it, we fail in StackSlotColoring due to an empty live interval from LiveStack.
2) A test case which demonstrates the fix for (1). See @test11.
3) A control flag which defaults to disabling this for the moment. Once I've run more extensive validaton, I will switch the default and then remove this flag.
llvm-svn: 353871
isFPImmLegal() has been extended to recognize certain FP immediates that can
be built with VGM (Vector Generate Mask).
These scalar FP immediates (that were previously loaded from the constant
pool) are now selected as VGMF/VGMG in Select().
Review: Ulrich Weigand
https://reviews.llvm.org/D58003
llvm-svn: 353867
This teaches the IRTranslator to emit G_BSWAP when it runs into
Intrinsic::bswap. This allows us to select G_BSWAP for non-vector types in
AArch64.
Add a select-bswap.mir test, and add global isel checks to a couple existing
tests in test/CodeGen/AArch64.
This doesn't handle every bswap case, since some of these rely on known bits
stuff. This just lets us handle the naive case.
Differential Revision: https://reviews.llvm.org/D58081
llvm-svn: 353861
A more limited version of rL352997 that had to be disabled in rL353198 - allow extension of any 128/256/512 bit vector that at least uses byte sized scalars.
llvm-svn: 353860
If we're comparing some value for equality against 2 constants
and those constants have an absolute difference of just 1 bit,
then we can offset and mask off that 1 bit and reduce to a single
compare against zero:
and/or (setcc X, C0, ne), (setcc X, C1, ne/eq) -->
setcc ((add X, -C1), ~(C0 - C1)), 0, ne/eq
https://rise4fun.com/Alive/XslKj
This transform is disabled by default using a TLI hook
("convertSetCCLogicToBitwiseLogic()").
That should be overridden for AArch64, MIPS, Sparc and possibly
others based on the asm shown in:
https://bugs.llvm.org/show_bug.cgi?id=40611
llvm-svn: 353859
Summary:
The SMULO/UMULO DAG nodes, when not directly supported by the target,
expand to a multiplication twice as wide. In case that the resulting
type is not legal, the legalizer cannot directly call the intrinsic
with the wide arguments; instead, it "pre-lowers" them by splitting
them in halves.
rL283203 made sure that on big endian targets, the legalizer passes
the argument halves in the correct order. It did not do the same
for the return value halves because the existing code used a hack;
it put an illegal type into DAG and hoped that nothing would break
and it would be correctly lowered elsewhere.
rL307207 fixed this, handling return value halves similar to how
argument handles are handled, but did not take big-endian targets
into account.
This commit fixes the expansion on big-endian targets, such as
the out-of-tree OR1K target.
Reviewers: eli.friedman, vadimcn
Subscribers: george-hopkins, efriedma, llvm-commits
Differential Revision: https://reviews.llvm.org/D45355
llvm-svn: 353854
We need to clear the kill flags on both SingleValReg and OldReg, to ensure they remain
conservatively correct.
Differential Revision: https://reviews.llvm.org/D58114
llvm-svn: 353847
Summary:
An empty dwo_id indicates a degenerate .dwo file that should not have been generated in the first place. Instead of discovering this error later when merging with another degenerate .dwo file, print an error immediately when noticing an unset dwo_id, including the filename of the offending file.
Test case created by compiling a trivial file w/ `-fno-split-dwarf-inlining -gmlt -gsplit-dwarf -c` prior to r353771
Reviewers: dblaikie
Reviewed By: dblaikie
Subscribers: jdoerfert, aprantl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58085
llvm-svn: 353846
Salvaging a redundant load instruction into a debug expression hides a
memory read from optimisation passes. Passes that alter memory behaviour
(such as LICM promoting memory to a register) aren't aware of these debug
memory reads and leave them unaltered, making the debug variable location
point somewhere unsafe.
Teaching passes to know about these debug memory reads would be challenging
and probably incomplete. Finding dbg.value instructions that need to be fixed
would likely be computationally expensive too, as more analysis would be
required. It's better to not generate debug-memory-reads instead, alas.
Changed tests:
* DeadStoreElim: test for salvaging of intermediate operations contributing
to the dead store, instead of salvaging of the redundant load,
* GVN: remove debuginfo behaviour checks completely, this behaviour is still
covered by other tests,
* InstCombine: don't test for salvaged loads, we're removing that behaviour.
Differential Revision: https://reviews.llvm.org/D57962
llvm-svn: 353824
Summary:
This is a preparatory change for removing the code from
DebugHandlerBase::beginFunction() which changes the starting label for
the first non-overlapping DBG_VALUEs of parameters to the beginning of
the function. It does that to be able to show parameters when entering a
function. However, that code does not consider what defines the values,
which can result in the ranges for the debug values starting before
their defining instructions. That code is removed in a follow-up patch.
When prologue code is inserted, it leads to DBG_VALUEs that start
directly in the entry block being moved down after the prologue
instructions. This patch fixes that by stashing away DBG_VALUEs for
parameters before emitting the prologue, and then reinserts them at the
start of the block. This assumes that there is no target that somehow
clobbers parameter registers in the frame setup; there is no such case
in the lit tests at least.
See PR40188 for more information.
Reviewers: aprantl, dblaikie, rnk, jmorse
Reviewed By: aprantl
Subscribers: bjope, llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D57510
llvm-svn: 353823
Logic in `getInsertPointForUses` doesn't account for a corner case when `Def`
only comes to a Phi user from unreachable blocks. In this case, the incoming
value may be arbitrary (and not even available in the input block) and break
the loop-related invariants that are asserted below.
In fact, if we encounter this situation, no IR modification is needed. This
Phi will be simplified away with nearest cleanup.
Differential Revision: https://reviews.llvm.org/D58045
Reviewed By: spatel
llvm-svn: 353816
The function `LI.erase` has some invariants that need to be preserved when it
tries to remove a loop which is not the top-level loop. In particular, it
requires loop's preheader to be strictly in loop's parent. Our current logic
of deletion of dead blocks may erase the information about preheader before we
handle the loop, and therefore we may hit this assertion.
This patch changes the logic of loop deletion: we make them top-level loops
before we actually erase them. This allows us to trigger the simple branch of
`erase` logic which just detatches blocks from the loop and does not try to do
some complex stuff that need this invariant.
Thanks to @uabelho for reporting this!
Differential Revision: https://reviews.llvm.org/D57221
Reviewed By: fedor.sergeev
llvm-svn: 353813
ELFYAML.h contains a `Section` class which is a base for a few other
sections classes that are used for mapping different section types.
`Section` has a `StringRef Info` field used for storing sh_info.
At the same time, sh_info has very different meanings for sections and
cannot be processed in a similar way generally,
for example ELFDumper does not handle it in `dumpCommonSection`
but do that in `dumpGroup` and `dumpCommonRelocationSection` respectively.
At this moment, we have and handle it as a string, because that was possible for
the current use case. But also it can simply be a number:
For SHT_GNU_verdef is "The number of version definitions within the section."
The patch moves `Info` field out to be able to have it as a number.
With that change, each class will be able to decide what type and purpose
of the sh_info field it wants to use.
I also had to edit 2 test cases. This is because patch fixes a bug. Previously we
accepted yaml files with Info fields for all sections (for example, for SHT_DYNSYM too).
But we do not handle it and the resulting objects had zero sh_info fields set for
such sections. Now it is accepted only for sections that supports it.
Differential revision: https://reviews.llvm.org/D58054
llvm-svn: 353810
Utility function that we use for blocks deletion always unconditionally removes
one-input Phis. In LoopSimplifyCFG, it can lead to breach of LCSSA form.
This patch alters this function to keep them if needed.
Differential Revision: https://reviews.llvm.org/D57231
Reviewed By: fedor.sergeev
llvm-svn: 353803
The code checked that the first root was an appropriate distance from
the base value, but skipped checking the other roots. This could lead to
rerolling a loop that can't be legally rerolled (at least, not without
rewriting the loop in a non-trivial way).
Differential Revision: https://reviews.llvm.org/D56812
llvm-svn: 353779
This configuration (due to r349207) was intended not to emit any DWO CU,
but a degenerate CU was still being emitted - containing a header and a
DW_TAG_compile_unit with no attributes.
Under that situation, emit nothing to the .dwo file. (since this is a
dynamic property of the input the .dwo file is still emitted, just with
nothing in it (so a valid, but empty, ELF file) - if some other CU
didn't satisfy this criteria, its DWO CU would still go there, etc)
llvm-svn: 353771
It seems that, since VC19, the `float` C99 math functions are supported for all
targets, unlike the C89 ones.
According to the discussion at https://reviews.llvm.org/D57625.
llvm-svn: 353758
Diana Picus