On Darwin, simple C null-terminated constant strings normally end up in the __TEXT,__cstring section of the resulting Mach-O binary. When instrumented with ASan, these strings are transformed in a way that they cannot be in __cstring (the linker unifies the content of this section and strips extra NUL bytes, which would break instrumentation), and are put into a generic __const section. This breaks some of the tools that we have: Some tools need to scan all C null-terminated strings in Mach-O binaries, and scanning all the contents of __const has a large performance penalty. This patch instead introduces a special section, __asan_cstring which will now hold the instrumented null-terminated strings.
Differential Revision: https://reviews.llvm.org/D25026
llvm-svn: 285619
Fixes Bug 30808.
Note that passing subtarget information to predicates seems too complicated, so gfx8-specific def smrd_offset_20 introduced.
Old gfx6/7-specific def renamed to smrd_offset_8 for clarity.
Lit tests updated.
Differential Revision: https://reviews.llvm.org/D26085
llvm-svn: 285590
with fix: edited invalid-section-index2.elf input to pass the new check and
fail on the same place it was intended to fail.
Original commit message:
Elf.h already has code checking that section table does not go past end of file.
Problem is that this check may not work on values greater than UINT64_MAX / Header->e_shentsize
because of calculation overflow.
Parch fixes the issue.
Differential revision: https://reviews.llvm.org/D25432
llvm-svn: 285586
This patch implements two changes:
- Move processor feature definition into a new file SystemZFeatures.td,
and provide explicit lists of supported and unsupported features for
each level of the z/Architecture. This allows specifying unsupported
features in the scheduler definition files for each processor.
- Add optional aliases for the -mcpu processor names according to the
level of the z/Architecture, for compatibility with other compilers
on the platform. The supported aliases are:
-mcpu=arch8 equals -mcpu=z10
-mcpu=arch9 equals -mcpu=z196
-mcpu=arch10 equals -mcpu=zEC12
-mcpu=arch11 equals -mcpu=z13
llvm-svn: 285577
Currently, when using an instruction that is not supported on the
currently selected architecture, the LLVM assembler is likely to
diagnose an "invalid operand" instead of a "missing feature".
This is because many operands require a custom parser in order to
be processed correctly, and if an instruction is not available
according to the current feature set, the generated parser code
will also not detect the associated custom operand parsers.
Fixed by temporarily enabling all features while parsing operands.
The missing features will then be correctly detected when actually
parsing the instruction itself.
llvm-svn: 285575
LLVM currently treats the first operand of MVCK as if it were a
regular base+index+displacement address. However, it is in fact
a base+displacement combined with a length register field.
While the two might look syntactically similar, there are two
semantic differences:
- %r0 is a valid length register, even though it cannot be used
as an index register.
- In an expression with just a single register like 0(%rX), the
register is treated as base with normal addresses, while it is
treated as the length register (with an empty base) for MVCK.
Fixed by adding a new operand parser class BDRAddr and reworking
the assembler parser to distinguish between address + length
register operands and regular addresses.
llvm-svn: 285574
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
possible pointer-wrap-around concerns, in some cases.
Before this patch, collectConstStridedAccesses (part of interleaved-accesses
analysis) called getPtrStride with [Assume=false, ShouldCheckWrap=true] when
examining all candidate pointers. This is too conservative. Instead, this
patch makes collectConstStridedAccesses use an optimistic approach, calling
getPtrStride with [Assume=true, ShouldCheckWrap=false], and then, once the
candidate interleave groups have been formed, revisits the pointer-wrapping
analysis but only where it matters: namely, in groups that have gaps, and where
the gaps are not at the very end of the group (in which case the loop is
peeled). This second time getPtrStride is called with [Assume=false,
ShouldCheckWrap=true], but this could further be improved to using Assume=true,
once we also add the logic to track that we are not going to meet the scev
runtime checks threshold.
Differential Revision: https://reviews.llvm.org/D25276
llvm-svn: 285517
Summary:
When we have an aliasee that is linkonce, while we can't convert
the non-prevailing copies to available_externally, we still need to
convert the prevailing copy to weak. If a reference to the aliasee
is exported, not converting a copy to weak will result in undefined
references when the linkonce is removed in its original module.
Add a new test and update existing tests.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26076
llvm-svn: 285512
Try harder to detect obfuscated min/max patterns: the initial pattern was added with D9352 / rL236202.
There was a bug fix for PR27137 at rL264996, but I think we can do better by folding the corresponding
smax pattern and commuted variants.
The codegen tests demonstrate the effect of ValueTracking on the backend via SelectionDAGBuilder. We
can't expose these differences minimally in IR because we don't have smin/smax intrinsics for IR.
Differential Revision: https://reviews.llvm.org/D26091
llvm-svn: 285499
Currently computeKnownBits returns the common known zero/one bits for all elements of vector data, when we may only be interested in one/some of the elements.
This patch adds a DemandedElts argument that allows us to specify the elements we actually care about. The original computeKnownBits implementation calls with a DemandedElts demanding all elements to match current behaviour. Scalar types set this to 1.
The approach was found to be easier than trying to add a per-element known bits solution, for a similar usefulness given the combines where computeKnownBits is typically used.
I've only added support for a few opcodes so far (the ones that have proven straightforward to test), all others will default to demanding all elements but can be updated in due course.
DemandedElts support could similarly be added to computeKnownBitsForTargetNode in a future commit.
This looked like this had caused compile time regressions on some buildbots (and was reverted in rL285381), but appears to have just been a harmless bystander!
Differential Revision: https://reviews.llvm.org/D25691
llvm-svn: 285494
Instead of asserting that the shift count is != 0 we just bail out
as it's not profitable trying to optimize a node which will be
removed anyway.
Differential Revision: https://reviews.llvm.org/D26098
llvm-svn: 285480
Summary:
Flat instruction can return out of order, so we need always need to wait
for all the outstanding flat operations.
Reviewers: tony-tye, arsenm
Subscribers: kzhuravl, wdng, nhaehnle, llvm-commits, yaxunl
Differential Revision: https://reviews.llvm.org/D25998
llvm-svn: 285479
Also add glc bit to the scalar loads since they exist on VI
and change the caching behavior.
This currently has an assembler bug where the glc bit is incorrectly
accepted on SI/CI which do not have it.
llvm-svn: 285463
Summary:
In isel, transform
Num % Den
into
Num - (Num / Den) * Den
if the result of Num / Den is already available.
Reviewers: tra
Subscribers: hfinkel, llvm-commits, jholewinski
Differential Revision: https://reviews.llvm.org/D26090
llvm-svn: 285461
Summary:
This "pass" eagerly creates div and rem instructions even when only one
is needed -- it relies on a later pass (machine DCE?) to clean them up.
This is problematic not just from a cleanliness perspective (this pass
is running during CodeGenPrepare, so should leave the IR in a better
state), but it also creates a problem for instruction selection. If we
always have a div+rem, isel will always select a divrem instruction (if
possible), even when a single div or rem would do.
Specifically, in NVPTX, we want to compute rem from the output of div,
if available. But if a div is not available, we want to leave the rem
alone. This transformation is overeager if div is always available.
Because this code runs as part of CodeGenPrepare, it's nontrivial to
write a test for this change. But this will effectively be tested by
a later patch which adds the aforementioned change to NVPTX isel.
Reviewers: tra
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26088
llvm-svn: 285460
Summary:
In BypassSlowDivision's short-dividend path, we would create e.g.
udiv exact i32 %a, %b
"exact" here means that we are asserting that %a is a multiple of %b.
But we have no reason to believe this must be true -- this is just a
bug, as far as I can tell.
Reviewers: tra
Subscribers: jholewinski, llvm-commits
Differential Revision: https://reviews.llvm.org/D26097
llvm-svn: 285459
When LivePhysRegs adds live-in registers, it recognizes ~0 as a special
lane mask indicating the entire register. If the lane mask is not ~0,
it will only add the subregisters that overlap the specified lane mask.
The problem is that if a live-in register does not have subregisters,
and the lane mask is not ~0, it will not be added to the live set.
(The given lane mask may simply be the lane mask of its register class.)
If a register does not have subregisters, add it to the live set if
the lane mask is non-zero.
Differential Revision: https://reviews.llvm.org/D26094
llvm-svn: 285440
It's possible to have a use of the private resource descriptor or
scratch wave offset registers even though there are no allocated
stack objects. This would result in continuing to use the maximum
number reserved registers. This could go over the number of SGPRs
available on VI, or violate the SGPR limit requested by
the function attributes.
llvm-svn: 285435
Do not use LiveIntervals to recalculate kills, because that cannot be
done accurately without implicit uses on predicated instructions.
llvm-svn: 285409
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
Fixes PR 30784. Discussed with Justin, who pointed out that
in the new PassManager infrastructure we can have more fine-grained
control on which analyses we want to preserve, but this is the
best we can do with the current infrastructure.
llvm-svn: 285380
