If multiplication involves zero-extended arguments and the result is
compared as in the patterns:
%mul32 = trunc i64 %mul64 to i32
%zext = zext i32 %mul32 to i64
%overflow = icmp ne i64 %mul64, %zext
or
%overflow = icmp ugt i64 %mul64 , 0xffffffff
then the multiplication may be replaced by call to umul.with.overflow.
This change fixes PR4917 and PR4918.
Differential Revision: http://llvm-reviews.chandlerc.com/D2814
llvm-svn: 206137
We had been using the known-zero values of the operand of the or to construct
the mask for an rlwimi; this is not quite correct, but fine when the mask is
constant. When the mask is constant, then the known zeros of the operand must
be a superset of the zeros in the mask. However, when the mask is not a
constant, then there might be bits in the operand that are not known to be zero
that, at runtime, might be zero in the mask. Therefore, we check that any bits
not known to be zero *are* known to be one in the mask. Otherwise, we can't
fold the mask with the or and shift.
This was revealed as a miscompile of
MultiSource/Benchmarks/BitBench/drop3/drop3 when I started experimenting with
constant hoisting.
llvm-svn: 206136
I found this from a particular GDB test suite case of inlining
(something similar is provided as a test case) but came across a few
other related cases (other callers of the same functions, and one other
instance of the same coding mistake in a separate function).
I'm not sure what the best way to test this is (let alone to cover the
other cases I discovered), so hopefully this sufficies - open to ideas.
llvm-svn: 206130
Add support for file auxiliary symbol entries in COFF symbol tables. A COFF
symbol table with a FILE entry is followed by sizeof(__FILE__) / 18 auxiliary
symbol records which contain the filename. Read them and form the original
filename that the record contains. Then display the name in the output.
llvm-svn: 206126
Originally the cost model would give up for large constants and just return the
maximum cost. This is not what we want for constant hoisting, because some of
these constants are large in bitwidth, but are still cheap to materialize.
This commit fixes the cost model to either return TCC_Free if the cost cannot be
determined, or accurately calculate the cost even for large constants
(bitwidth > 128).
This fixes <rdar://problem/16591573>.
llvm-svn: 206100
Nice to be able to just print out the Tag and have the debugger print
dwarf::DW_TAG_subprogram or whatever, rather than an int.
It's a bit finicky (for example DIDescriptor::getTag still returns
unsigned) because some places still handle real dwarf tags + our fake
tags (one day we'll remove the fake tags, hopefully).
llvm-svn: 206098
therefore, their declaration cannot have one DW_AT_linkage_name.
The specific instances however can and should have that attribute.
This patch reorders the code in DwarfUnit::getOrCreateSubprogramDIE()
to emit linkage names for C/Dtors.
rdar://problem/16362674.
llvm-svn: 206096
This logic is properly in the realm of whatever is creating the
TargetMachine. This makes plain 'llc foo.ll' consistent across
heterogenous machines.
llvm-svn: 206094
We had disabled use of TBAA during CodeGen (even when otherwise using AA)
because the ptrtoint/inttoptr used by CGP for address sinking caused BasicAA to
miss basic type punning that it should catch (and, thus, we'd fail to override
TBAA when we should).
However, when AA is in use during CodeGen, CGP now uses normal GEPs and
bitcasts, instead of ptrtoint/inttoptr, when doing address sinking. As a
result, BasicAA should be able to make us do the right thing in the face of
type-punning, and it seems safe to enable use of TBAA again. self-hosting seems
fine on PPC64/Linux on the P7, with TBAA enabled and -misched=shuffle.
Note: We still don't update TBAA when merging stack slots, although because
BasicAA should now catch all such cases, this is no longer a blocking issue.
Nevertheless, I plan to commit code to deal with this properly in the near
future.
llvm-svn: 206093
The current memory-instruction optimization logic in CGP, which sinks parts of
the address computation that can be adsorbed by the addressing mode, does this
by explicitly converting the relevant part of the address computation into
IR-level integer operations (making use of ptrtoint and inttoptr). For most
targets this is currently not a problem, but for targets wishing to make use of
IR-level aliasing analysis during CodeGen, the use of ptrtoint/inttoptr is a
problem for two reasons:
1. BasicAA becomes less powerful in the face of the ptrtoint/inttoptr
2. In cases where type-punning was used, and BasicAA was used
to override TBAA, BasicAA may no longer do so. (this had forced us to disable
all use of TBAA in CodeGen; something which we can now enable again)
This (use of GEPs instead of ptrtoint/inttoptr) is not currently enabled by
default (except for those targets that use AA during CodeGen), and so aside
from some PowerPC subtargets and SystemZ, there should be no change in
behavior. We may be able to switch completely away from the ptrtoint/inttoptr
sinking on all targets, but further testing is required.
I've doubled-up on a number of existing tests that are sensitive to the
address sinking behavior (including some store-merging tests that are
sensitive to the order of the resulting ADD operations at the SDAG level).
llvm-svn: 206092
Moves redundant template parameters into an implementation detail of
BlockFrequencyInfoImpl.
No functionality change.
<rdar://problem/14292693>
llvm-svn: 206084
This is a shared implementation class for BlockFrequencyInfo and
MachineBlockFrequencyInfo, not for BlockFrequency, a related (but
distinct) class.
No functionality change.
<rdar://problem/14292693>
llvm-svn: 206083
-fexhaustive-register-search option to allow an exhaustive search during last
chance recoloring.
This is related to PR18747
Patch by MAYUR PANDEY <mayur.p@samsung.com>.
llvm-svn: 206072
Through some oddity where truncate (sextload x) isn't folded into
an anyextload for vectors, the sextload remains if the
vector isn't immediately scalarized. This keeps the expected
zextload instructions in the kernel-args test when small type
vectors aren't scalarized.
llvm-svn: 206070
MCDisassembler has an MCSymbolizer member that is meant to take care of
symbolizing during disassembly, but it also has several methods that enable the
disassembler to do symbolization internally (i.e. without an attached symbolizer
object). There is no need for this duplication, but ARM64 had been making use of
it. This patch moves the ARM64 symbolization logic out of ARM64Disassembler and
into an ARM64ExternalSymbolizer class, and removes the duplicated MCSymbolizer
functionality from the MCDisassembler interface. Symbolization will now be
done exclusively through MCSymbolizers.
There should be no impact on disassembly for any platform, but this allows us to
tidy up the MCDisassembler interface and simplify the process of (and invariants
related to) disassembler setup.
llvm-svn: 206063
When rematerializing an instruction that defines a super register that would be
used by a physical subregisters we use the related physical super register for
the definition.
To keep the live-range information accurate, all the defined subregisters must be
marked as dead def, otherwise the register allocation may miss some
interferences.
Working on a reduced test-case!
<rdar://problem/16582185>
llvm-svn: 206060
The TargetLowering::expandMUL() helper contains lowering code extracted
from the DAGTypeLegalizer and allows the SelectionDAGLegalizer to expand more
ISD::MUL patterns without having to use a library call.
llvm-svn: 206037
This code has been moved to a new function in the TargetLowering
class called expandMUL(). The purpose of this is to be able
to share lowering code between the SelectionDAGLegalize and
DAGTypeLegalizer classes.
No functionality changed intended.
llvm-svn: 206036
This was most likely caused by an uninitialized value and the relevant code was re-written in r205292. Reverting to see if it still fails on any of the buildbots.
llvm-svn: 206033
Serge Pavlov