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
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
Also updated as many loops as I could find using df_begin/idf_begin -
strangely I found no uses of idf_begin. Is that just used out of tree?
Also a few places couldn't use df_begin because either they used the
member functions of the depth first iterators or had specific ordering
constraints (I added a comment in the latter case).
Based on a patch by Jim Grosbach. (Jim - you just had iterator_range<T>
where you needed iterator_range<idf_iterator<T>>)
llvm-svn: 206016
GCC 4.8 complains with:
warning: enumeral and non-enumeral type in conditional expression
Although this is silly and harmless in this case, add an explicit cast to
silence the warning.
llvm-svn: 205949
The immediate cost calculation code was hitting an assertion in the included
test case, because APInt was still internally 128-bits. Truncating it to 64-bits
fixed the issue.
Fixes <rdar://problem/16572521>.
llvm-svn: 205947
This implements the target-hooks for ARM64 to enable constant hoisting.
This fixes <rdar://problem/14774662> and <rdar://problem/16381500>.
llvm-svn: 205791
Confusingly, the NEON fmla instructions put the accumulator first but the
scalar versions put it at the end (like the fma lib function & LLVM's
intrinsic).
This should fix PR19345, assuming there's only one issue.
llvm-svn: 205758
There were several overlapping problems here, and this solution is
closely inspired by the one adopted in AArch64 in r201381.
Firstly, scalarisation of v1i1 setcc operations simply fails if the
input types are legal. This is fixed in LegalizeVectorTypes.cpp this
time, and allows AArch64 code to be simplified slightly.
Second, vselect with such a setcc feeding into it ends up in
ScalarizeVectorOperand, where it's not handled. I experimented with an
implementation, but found that whatever DAG came out was rather
horrific. I think Hao's DAG combine approach is a good one for
quality, though there are edge cases it won't catch (to be fixed
separately).
Should fix PR19335.
llvm-svn: 205625
The previous patterns directly inserted FMOV or INS instructions into
the DAG for scalar_to_vector & bitconvert patterns. This is horribly
inefficient and can generated lots more GPR <-> FPR register traffic
than necessary.
It's much better to emit instructions the register allocator
understands so it can coalesce the copies when appropriate.
It led to at least one ISelLowering hack to avoid the problems, which
was incorrect for v1i64 (FPR64 has no dsub). It can now be removed
entirely.
This should also fix PR19331.
llvm-svn: 205616
Without this change, the llvm_unreachable kicked in. The code pattern
being spotted is rather non-canonical for 128-bit MLAs, but it can
happen and there's no point in generating sub-optimal code for it just
because it looks odd.
Should fix PR19332.
llvm-svn: 205615
When rematerializing through truncates, the coalescer may produce instructions
with dead defs, but live implicit-defs of subregs:
E.g.
%X1<def,dead> = MOVi64imm 2, %W1<imp-def>; %X1:GPR64, %W1:GPR32
These instructions are live, and their definitions should not be rewritten.
Fixes <rdar://problem/16492408>
llvm-svn: 205565
Switching between i32 and i64 based on the LHS type is a good idea in
theory, but pre-legalisation uses i64 regardless of our choice,
leading to potential ISel errors.
Should fix PR19294.
llvm-svn: 205519
Just pass a MachineInstr reference rather than an MBB iterator.
Creating a MachineInstr& is the first thing every implementation did
anyway.
llvm-svn: 205453
Weak symbols cannot use the small code model's usual ADRP sequences since the
instruction simply may not be able to encode a value of 0.
This redirects them to use the GOT, which hopefully linkers are able to cope
with even in the static relocation model.
llvm-svn: 205426
Again, coalescing and other optimisations swiftly made the MachineInstrs
consistent again, but when compiled at -O0 a bad INSERT_SUBREGISTER was
produced.
llvm-svn: 205423
The previous attempt was fine with optimisations, but was actually rather
cavalier with its types. When compiled at -O0, it produced invalid COPY
MachineInstrs.
llvm-svn: 205422
A value of 5 means if we have a split or spill option that has a really
low cost (1 << 14 is the entry frequency), we will choose to spill
or split the really cold path before using a callee-saved register.
This gives us the performance benefit on SPECInt2k and is also conservative.
rdar://16162005
llvm-svn: 205248
is not a pattern to lower this with clever instructions that zero the
register, so restrict the zero immediate legality special case to f64
and f32 (the only two sizes which fmov seems to directly support). Fixes
backend errors when building code such as libxml.
llvm-svn: 205161
StringRef::lower() returns a std::string. Better yet, we can now stop
thinking about what it returns and write 'auto'. It does the right
thing. =]
llvm-svn: 205135
It was doing functional but highly suspect operations on bools due to
the more limited shifting operands supported by memory instructions.
Should fix some MSVC warnings.
llvm-svn: 205134
Actually, mostly only those in the top-level directory that already
had a "virtual" attached. But it's the thought that counts and it's
been a long day.
llvm-svn: 205131
The ARM64 backend uses it only as a container to keep an MCLOHType and
Arguments around so give it its own little copy. The other functionality
isn't used and we had a crazy method specialization hack in place to
keep it working. Unfortunately that was incompatible with MSVC.
Also range-ify a couple of loops while at it.
llvm-svn: 205114
no assert at all. ;] Some of these should probably be switched to
llvm_unreachable, but I didn't want to perturb the behavior in this
patch.
Found by -Wstring-conversion, which I'll try to turn on in CMake builds
at least as it is finding useful things.
llvm-svn: 205091
This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.
Everything will be easier with the target in-tree though, hence this
commit.
llvm-svn: 205090
Juergen Ributzka