The normal dataflow sequence in the ARC optimizer consists of the following
states:
Retain -> CanRelease -> Use -> Release
The optimizer before this patch stored the uses that determine the lifetime of
the retainable object pointer when it bottom up hits a retain or when top down
it hits a release. This is correct for an imprecise lifetime scenario since what
we are trying to do is remove retains/releases while making sure that no
``CanRelease'' (which is usually a call) deallocates the given pointer before we
get to the ``Use'' (since that would cause a segfault).
If we are considering the precise lifetime scenario though, this is not
correct. In such a situation, we *DO* care about the previous sequence, but
additionally, we wish to track the uses resulting from the following incomplete
sequences:
Retain -> CanRelease -> Release (TopDown)
Retain <- Use <- Release (BottomUp)
*NOTE* This patch looks large but the most of it consists of updating
test cases. Additionally this fix exposed an additional bug. I removed
the test case that expressed said bug and will recommit it with the fix
in a little bit.
llvm-svn: 178921
This fixes PEI as previously described, but correctly handles the case where
the instruction defining the virtual register to be scavenged is the first in
the block. Arnold provided me with a bugpoint-reduced test case, but even that
seems too large to use as a regression test. If I'm successful in cleaning it
up then I'll commit that as well.
Original commit message:
This change fixes a bug that I introduced in r178058. After a register is
scavenged using one of the available spills slots the instruction defining the
virtual register needs to be moved to after the spill code. The scavenger has
already processed the defining instruction so that registers killed by that
instruction are available for definition in that same instruction. Unfortunately,
after this, the scavenger needs to iterate through the spill code and then
visit, again, the instruction that defines the now-scavenged register. In order
to avoid confusion, the register scavenger needs the ability to 'back up'
through the spill code so that it can again process the instructions in the
appropriate order. Prior to this fix, once the scavenger reached the
just-moved instruction, it would assert if it killed any registers because,
having already processed the instruction, it believed they were undefined.
Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
for diagnosing the problem and testing this fix.
llvm-svn: 178919
During LTO, the target options on functions within the same Module may
change. This would necessitate resetting some of the back-end. Do this for X86,
because it's a Friday afternoon.
llvm-svn: 178917
Reverting because this breaks one of the LTO builders. Original commit message:
This change fixes a bug that I introduced in r178058. After a register is
scavenged using one of the available spills slots the instruction defining the
virtual register needs to be moved to after the spill code. The scavenger has
already processed the defining instruction so that registers killed by that
instruction are available for definition in that same instruction. Unfortunately,
after this, the scavenger needs to iterate through the spill code and then
visit, again, the instruction that defines the now-scavenged register. In order
to avoid confusion, the register scavenger needs the ability to 'back up'
through the spill code so that it can again process the instructions in the
appropriate order. Prior to this fix, once the scavenger reached the
just-moved instruction, it would assert if it killed any registers because,
having already processed the instruction, it believed they were undefined.
Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
for diagnosing the problem and testing this fix.
llvm-svn: 178916
This optimization is unstable at this moment; it
1) block us on a very important application
2) PR15200
3) test6 and test7 in test/Transforms/ScalarRepl/dynamic-vector-gep.ll
(the CHECK command compare the output against wrong result)
I personally believe this optimization should not have any impact on the
autovectorized code, as auto-vectorizer is supposed to put gather/scatter
in a "right" way. Although in theory downstream optimizaters might reveal
some gather/scatter optimization opportunities, the chance is quite slim.
For the hand-crafted vectorizing code, in term of redundancy elimination,
load-CSE, copy-propagation and DSE can collectively achieve the same result,
but in much simpler way. On the other hand, these optimizers are able to
improve the code in a incremental way; in contrast, SROA is sort of all-or-none
approach. However, SROA might slighly win in stack size, as it tries to figure
out a stretch of memory tightenly cover the area accessed by the dynamic index.
rdar://13174884
PR15200
llvm-svn: 178912
It's possible for the lock file to disappear and the owning process to
return before we're able to see the generated file. Spin for a little
while to see if it shows up before failing.
llvm-svn: 178909
If the directory that will contain the unique file doesn't exist when
we tried to create the file, but another process creates it before we
get a chance to try creating it, we would bail out rather than try to
create the unique file.
llvm-svn: 178908
memory operands.
Essentially, this layers an infix calculator on top of the parsing state
machine. The scale on the index register is still expected to be an immediate
__asm mov eax, [eax + ebx*4]
and will not work with more complex expressions. For example,
__asm mov eax, [eax + ebx*(2*2)]
The plus and minus binary operators assume the numeric value of a register is
zero so as to not change the displacement. Register operands should never
be an operand for a multiply or divide operation; the scale*indexreg
expression is always replaced with a zero on the operand stack to prevent
such a case.
rdar://13521380
llvm-svn: 178881
Summary:
Sets a report hook that emulates pressing "retry" in the "abort, retry,
ignore" dialog box that _CrtDbgReport normally raises. There are many
other ways to disable assertion reports, but this was the only way I
could find that still calls our exception handler.
Reviewers: Bigcheese
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D625
llvm-svn: 178880
InMemoryStruct is extremely dangerous as it returns data from an internal
buffer when the endiannes doesn't match. This should fix the tests on big
endian hosts.
llvm-svn: 178875
When the RuntimeDyldELF::processRelocationRef routine finds the target
symbol of a relocation in the local or global symbol table, it performs
a section-relative relocation:
Value.SectionID = lsi->second.first;
Value.Addend = lsi->second.second;
At this point, however, any Addend that might have been specified in
the original relocation record is lost. This is somewhat difficult to
trigger for relocations within the code section since they usually
do not contain non-zero Addends (when built with the default JIT code
model, in any case). However, the problem can be reliably triggered
by a relocation within the data section caused by code like:
int test[2] = { -1, 0 };
int *p = &test[1];
The initializer of "p" will need a relocation to "test + 4". On
platforms using RelA relocations this means an Addend of 4 is required.
Current code ignores this addend when processing the relocation,
resulting in incorrect execution.
Fixed by taking the Addend into account when processing relocations
to symbols found in the local or global symbol table.
Tested on x86_64-linux and powerpc64-linux.
llvm-svn: 178869
This change fixes a bug that I introduced in r178058. After a register is
scavenged using one of the available spills slots the instruction defining the
virtual register needs to be moved to after the spill code. The scavenger has
already processed the defining instruction so that registers killed by that
instruction are available for definition in that same instruction. Unfortunately,
after this, the scavenger needs to iterate through the spill code and then
visit, again, the instruction that defines the now-scavenged register. In order
to avoid confusion, the register scavenger needs the ability to 'back up'
through the spill code so that it can again process the instructions in the
appropriate order. Prior to this fix, once the scavenger reached the
just-moved instruction, it would assert if it killed any registers because,
having already processed the instruction, it believed they were undefined.
Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
for diagnosing the problem and testing this fix.
llvm-svn: 178845
For now, just save the compile time since the ConvergingScheduler
heuristics don't use this analysis. We'll probably enable it later
after compile-time investigation.
llvm-svn: 178822
Pass down the fact that an operand is going to be a vector of constants.
This should bring the performance of MultiSource/Benchmarks/PAQ8p/paq8p on x86
back. It had degraded to scalar performance due to my pervious shift cost change
that made all shifts expensive on x86.
radar://13576547
llvm-svn: 178809
SSE2 has efficient support for shifts by a scalar. My previous change of making
shifts expensive did not take this into account marking all shifts as expensive.
This would prevent vectorization from happening where it is actually beneficial.
With this change we differentiate between shifts of constants and other shifts.
radar://13576547
llvm-svn: 178808
On certain architectures we can support efficient vectorized version of
instructions if the operand value is uniform (splat) or a constant scalar.
An example of this is a vector shift on x86.
We can efficiently support
for (i = 0 ; i < ; i += 4)
w[0:3] = v[0:3] << <2, 2, 2, 2>
but not
for (i = 0; i < ; i += 4)
w[0:3] = v[0:3] << x[0:3]
This patch adds a parameter to getArithmeticInstrCost to further qualify operand
values as uniform or uniform constant.
Targets can then choose to return a different cost for instructions with such
operand values.
A follow-up commit will test this feature on x86.
radar://13576547
llvm-svn: 178807
There is a difference for FORM_ref_addr between DWARF 2 and DWARF 3+.
Since Eric is against guarding DWARF 2 ref_addr with DarwinGDBCompat, we are
still in discussion on how to handle this.
The correct solution is to update our header to say version 4 instead of version
2 and update tool chains as well.
rdar://problem/13559431
llvm-svn: 178806
BCL is normally a conditional branch-and-link instruction, but has
an unconditional form (which is used in the SjLj code, for example).
To make clear that this BCL instruction definition is specifically
the special unconditional form (which does not meaningfully take
a condition-register input), rename it to BCLalways.
No functionality change intended.
llvm-svn: 178803
The DAGCombine logic that recognized a/sqrt(b) and transformed it into
a multiplication by the reciprocal sqrt did not handle cases where the
sqrt and the division were separated by an fpext or fptrunc.
llvm-svn: 178801
It fixes following tests for Hexagon:
CodeGen/Generic/2003-07-29-BadConstSbyte.ll
CodeGen/Generic/2005-10-21-longlonggtu.ll
CodeGen/Generic/2009-04-28-i128-cmp-crash.ll
CodeGen/Generic/MachineBranchProb.ll
CodeGen/Generic/builtin-expect.ll
CodeGen/Generic/pr12507.ll
llvm-svn: 178794
OpndPtrs stored pointers into the Opnd vector that became invalid when the
vector grows. Store indices instead. Sadly I only have a large testcase that
only triggers under valgrind, so I didn't include it.
llvm-svn: 178793
At the time when the XCore backend was added there were some issues with
with overlapping register classes but these all seem to be fixed now.
Describing the register classes correctly allow us to get rid of a
codegen only instruction (LDAWSP_lru6_RRegs) and it means we can
disassemble ru6 instructions that use registers above r11.
llvm-svn: 178782
The Thumb2SizeReduction pass avoids false CPSR dependencies, except it
still aggressively creates tMOVi8 instructions because they are so
common.
Avoid creating false CPSR dependencies even for tMOVi8 instructions when
the the CPSR flags are known to have high latency. This allows integer
computation to overlap floating point computations.
Also process blocks in a reverse post-order and propagate high-latency
flags to successors.
<rdar://problem/13468102>
llvm-svn: 178773
This requires v9 cmov instructions using the %xcc flags instead of the
%icc flags.
Still missing:
- Select floats on %xcc flags.
- Select i64 on %fcc flags.
llvm-svn: 178737
the target system.
It was hard-coded to 4 bytes before. I can't get llvm to generate a
ref_addr on a reasonably sized testing case.
rdar://problem/13559431
llvm-svn: 178722
Cleaned up trailing whitespace and added extra slashes in front of a
function level comment so that it follow the convention of having 3
slashes.
llvm-svn: 178712
