Given loops `L1` and `L2` with AddRecs `AR1` and `AR2` varying in them respectively.
When identifying loop disposition of `AR2` w.r.t. `L1`, we only say that it is varying if
`L1` contains `L2`. But there is also a possible situation where `L1` and `L2` are
consecutive sibling loops within the parent loop. In this case, `AR2` is also varying
w.r.t. `L1`, but we don't correctly identify it.
It can lead, for exaple, to attempt of incorrect folding. Consider:
AR1 = {a,+,b}<L1>
AR2 = {c,+,d}<L2>
EXAR2 = sext(AR1)
MUL = mul AR1, EXAR2
If we incorrectly assume that `EXAR2` is invariant w.r.t. `L1`, we can end up trying to
construct something like: `{a * {c,+,d}<L2>,+,b * {c,+,d}<L2>}<L1>`, which is incorrect
because `AR2` is not available on entrance of `L1`.
Both situations "`L1` contains `L2`" and "`L1` preceeds sibling loop `L2`" can be handled
with one check: "header of `L1` dominates header of `L2`". This patch replaces the old
insufficient check with this one.
Differential Revision: https://reviews.llvm.org/D39453
llvm-svn: 318819
After the dataflow algorithm proves that an argument is constant,
it replaces it value with the integer constant and drops the lattice
value associated to the DEF.
e.g. in the example we have @f() that's called twice:
call @f(undef, ...)
call @f(2, ...)
`undef` MEET 2 = 2 so we replace the argument and all its uses with
the constant 2.
Shortly after, tryToReplaceWithConstantRange() tries to get the lattice
value for the argument we just replaced, causing an assertion.
This function is a little peculiar as it runs when we're doing replacement
and not as part of the solver but still queries the solver.
The fix is that of checking whether we replaced the value already and
get a temporary lattice value for the constant.
Thanks to Zhendong Su for the report!
Fixes PR35357.
llvm-svn: 318817
Change the representation of COFF comdats so that a COFF linker
is able to accurately resolve comdats between IR and native object
files. Specifically, apply name mangling to comdat names consistently
with native object files, and do not export comdats with an internal
leader because they do not affect symbol resolution.
Differential Revision: https://reviews.llvm.org/D40278
llvm-svn: 318805
This is based on table 1-1 of the October 2017 revision of Intel® Architecture Instruction Set Extensions and Future Features Programming Reference
llvm-svn: 318799
This partially reverts r298851. The the underlying issue is that we don't
currently model the dependency between mrs (read system register) and
msr (write system register) instructions.
Something like the below should never be reordered:
msr TPIDR_EL0, x0 ;; set thread pointer
mrs x8, TPIDR_EL0 ;; read thread pointer
but was being reordered after r298851. The functional part of the patch
that wasn't reverted needed to remain in place in order to not break
r299462.
PR35317
llvm-svn: 318788
These are pre-UAL syntax, and we don't support any other pre-UAL instructions,
with the exception of FLDMX/FSTMX, which don't have a UAL equivalent. Therefore
there's no reason to keep them or their AsmParser hacks around.
With the AsmParser hacks removed, the FLDMX and FSTMX instructions get the same
operand diagnostics as the UAL instructions.
Differential revision: https://reviews.llvm.org/D39196
llvm-svn: 318777
Summary:
First step in adding MemorySSA as dependency for loop pass manager.
Adding the dependency under a flag.
New pass manager: MSSA pointer in LoopStandardAnalysisResults can be null.
Legacy and new pass manager: Use cl::opt EnableMSSALoopDependency. Disabled by default.
Reviewers: sanjoy, davide, gberry
Subscribers: mehdi_amini, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D40274
llvm-svn: 318772
This was causing the (invalid) predicated versions of the NEON VRINTX and
VRINTZ instructions to be accepted, with the condition code being ignored.
Also, there is no NEON VRINTR instruction, so that part of the check was not
necessary.
Differential revision: https://reviews.llvm.org/D39193
llvm-svn: 318771
- We can still emit this error if the actual instruction has two or more
operands missing compared to the expected one.
- We should only emit this error once per instruction.
Differential revision: https://reviews.llvm.org/D36746
llvm-svn: 318770
As pointed out in post-commit review of r318738, `return ReplaceNode(..)` when
both ReplaceNode and the current function return void is confusing. This patch
moves to using a more obvious early return, and moves to just using an if to
catch the one case we currently care about. A future patch that adds further
custom instruction selection can introduce a switch.
llvm-svn: 318757
properlyDominates() shouldn't be used as sort key. It causes different output between stdlibc++ and libc++.
Instead, I introduced RPOT. In most cases, it works for CSE.
llvm-svn: 318743
The obvious approach of defining a pattern like the one below actually doesn't
work:
`def : Pat<(i32 0), (i32 X0)>;`
As was noted when Lanai made this change (https://reviews.llvm.org/rL288215),
attempting to handle the constant 0 in tablegen leads to assertions due to a
physical register being used where a virtual register is expected.
llvm-svn: 318738
Previous patches primarily ensured that codegen was possible for the standard
RISC-V instructions. However, there are a number of IR inputs that wouldn't be
appropriately lowered. This patch both adds test cases and supports lowering
for a number of these cases:
* Improved sext/zext/trunc support
* Support for setcc variants that don't map directly to RISC-V instructions
* Lowering mul, and hence support for external symbols
* addc, adde, subc, sube
* mulhs, srem, mulhu, urem, udiv, sdiv
* {srl,sra,shl}_parts
* brind
* br_jt
* bswap, ctlz, cttz, ctpop
* rotl, rotr
* BlockAddress operands
Differential Revision: https://reviews.llvm.org/D29938
llvm-svn: 318737
Although ISD::SELECT_CC is a more natural match for RISCVISD::SELECT_CC (and
ultimately the integer RISC-V conditional branch instructions), we choose to
expand ISD::SELECT_CC and lower ISD::SELECT. The appropriate compare+branch
will be created in the case where an ISD::SELECT condition value is created by
an ISD::SETCC node, which operates on XLen types. Other datatypes such as
floating point don't have conditional branch instructions, and lowering
ISD::SELECT allows more flexibility for handling these cases.
Differential Revision: https://reviews.llvm.org/D29937
llvm-svn: 318735
Summary:
Before this change, the FDR mode implementation relied on at thread-exit
handling to return buffers back to the (global) buffer queue. This
introduces issues with the initialisation of the thread_local objects
which, even through the use of pthread_setspecific(...) may eventually
call into an allocation function. Similar to previous changes in this
line, we're finding that there is a huge potential for deadlocks when
initialising these thread-locals when the memory allocation
implementation is also xray-instrumented.
In this change, we limit the call to pthread_setspecific(...) to provide
a non-null value to associate to the key created with
pthread_key_create(...). While this doesn't completely eliminate the
potential for the deadlock(s), it does allow us to still clean up at
thread exit when we need to. The change is that we don't need to do more
work when starting and ending a thread's lifetime. We also have a test
to make sure that we actually can safely recycle the buffers in case we
end up re-using the buffer(s) available from the queue on multiple
thread entry/exits.
This change cuts across both LLVM and compiler-rt to allow us to update
both the XRay runtime implementation as well as the library support for
loading these new versions of the FDR mode logging. Version 2 of the FDR
logging implementation makes the following changes:
* Introduction of a new 'BufferExtents' metadata record that's outside
of the buffer's contents but are written before the actual buffer.
This data is associated to the Buffer handed out by the BufferQueue
rather than a record that occupies bytes in the actual buffer.
* Removal of the "end of buffer" records. This is in-line with the
changes we described above, to allow for optimistic logging without
explicit record writing at thread exit.
The optimistic logging model operates under the following assumptions:
* Threads writing to the buffers will potentially race with the thread
attempting to flush the log. To avoid this situation from occuring,
we make sure that when we've finalized the logging implementation,
that threads will see this finalization state on the next write, and
either choose to not write records the thread would have written or
write the record(s) in two phases -- first write the record(s), then
update the extents metadata.
* We change the buffer queue implementation so that once it's handed
out a buffer to a thread, that we assume that buffer is marked
"used" to be able to capture partial writes. None of this will be
safe to handle if threads are racing to write the extents records
and the reader thread is attempting to flush the log. The optimism
comes from the finalization routine being required to complete
before we attempt to flush the log.
This is a fairly significant semantics change for the FDR
implementation. This is why we've decided to update the version number
for FDR mode logs. The tools, however, still need to be able to support
older versions of the log until we finally deprecate those earlier
versions.
Reviewers: dblaikie, pelikan, kpw
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D39526
llvm-svn: 318733
We don't need separate 32 and 64 node types. We can use SDTCisInt and SDTCisSameSizeAs to ensure the mask size the result type and is integer.
llvm-svn: 318732
DAGTypeLegalizer::SplitInteger uses default pointer size as shift amount constant type,
which causes less performant ISA in amdgcn---amdgiz target since the default pointer
type is i64 whereas the desired shift amount type is i32.
This patch fixes that by using TLI.getScalarShiftAmountTy in DAGTypeLegalizer::SplitInteger.
The X86 change is necessary since splitting i512 requires shifting amount of 256, which
cannot be held by i8.
Differential Revision: https://reviews.llvm.org/D40148
llvm-svn: 318727
Initialize IsVis2 and IsVis3 in SparcSubtarget::initializeSubtargetDependencies.
MSan detected uninitialized read of IsVis3 after r318704. Initializing the
variables to false will prevent undefined behavior.
llvm-svn: 318724
Normally this would be cleaned up by promoting the condition operand next. But in the attached case we promoted the result from v2i48 to v2i64 and the condition from v2i1 to v2i48. Then we tried to "promote" the v2i48 condition back to v2i1 because that's what the SetCC result type for v2i64 is on X86 with VLX. But promote is either a NOP or SIGN_EXTEND and this would need a truncation.
With the change here we now get the SetCC type of v2i1 when we're handling the result promotion and the operand no longer needs to be promoted itself.
Fixes PR35272.
llvm-svn: 318706
Summary:
while investigating performance degradation of imagick benchmark
there were found inefficient pattern for UINT_TO_FP conversion.
That pattern causes RAW hazard in assembly code. Specifically,
uitofp IR operator results in poor assembler :
st %i0, [%fp - 952]
ldd [%fp - 952], %f0
it stores 32-bit integer register into memory location and then
loads 64-bit floating point data from that location.
That is exactly RAW hazard case. To optimize that case it is
possible to use SPISD::ITOF and SPISD::XTOF for conversion from
integer to floating point data type and to use ISD::BITCAST to
copy from integer register into floating point register.
The fix is to write custom UINT_TO_FP pattern using SPISD::ITOF,
SPISD::XTOF, ISD::BITCAST.
Patch by Alexey Lapshin
Reviewers: fedor.sergeev, jyknight, dcederman, lero_chris
Reviewed By: jyknight
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36875
llvm-svn: 318704
Summary:
Add the following heuristics for irreducible loop metadata:
- When an irreducible loop header is missing the loop header weight metadata,
give it the minimum weight seen among other headers.
- Annotate indirectbr targets with the loop header weight metadata (as they are
likely to become irreducible loop headers after indirectbr tail duplication.)
These greatly improve the accuracy of the block frequency info of the Python
interpreter loop (eg. from ~3-16x off down to ~40-55% off) and the Python
performance (eg. unpack_sequence from ~50% slower to ~8% faster than GCC) due to
better register allocation under PGO.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39980
llvm-svn: 318693
