undefined result. This adds new ISD nodes for the new semantics,
selecting them when the LLVM intrinsic indicates that the undef behavior
is desired. The new nodes expand trivially to the old nodes, so targets
don't actually need to do anything to support these new nodes besides
indicating that they should be expanded. I've done this for all the
operand types that I could figure out for all the targets. Owners of
various targets, please review and let me know if any of these are
incorrect.
Note that the expand behavior is *conservatively correct*, and exactly
matches LLVM's current behavior with these operations. Ideally this
patch will not change behavior in any way. For example the regtest suite
finds the exact same instruction sequences coming out of the code
generator. That's why there are no new tests here -- all of this is
being exercised by the existing test suite.
Thanks to Duncan Sands for reviewing the various bits of this patch and
helping me get the wrinkles ironed out with expanding for each target.
Also thanks to Chris for clarifying through all the discussions that
this is indeed the approach he was looking for. That said, there are
likely still rough spots. Further review much appreciated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146466 91177308-0d34-0410-b5e6-96231b3b80d8
Constant pool entries with different alignment may cause more alignment
padding to be inserted. Compute the amount of padding needed, and try to
pick the location that requires the least amount of padding.
Also take the extra padding into account when the water is above the
use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146458 91177308-0d34-0410-b5e6-96231b3b80d8
subdirectories to traverse into.
- Originally I wanted to avoid this and just autoscan, but this has one key
flaw in that new subdirectories can not automatically trigger a rerun of the
llvm-build tool. This is particularly a pain when switching back and forth
between trees where one has added a subdirectory, as the dependencies will
tend to be wrong. This will also eliminates FIXME implicitly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146436 91177308-0d34-0410-b5e6-96231b3b80d8
These modifiers simply select either the low or high D subregister of a Neon
Q register. I've also removed the unimplemented 'p' modifier, which turns out
to be a bit different than the comment here suggests and as far as I can tell
was only intended for internal use in Apple's version of gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146417 91177308-0d34-0410-b5e6-96231b3b80d8
Downgrade the alignment of the initial constant island when constant
pool entries are moved elsewhere.
This is all gated by -arm-align-constant-islands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146391 91177308-0d34-0410-b5e6-96231b3b80d8
Order constant pool entries by descending alignment in the initial
island to ensure packing and correct alignment. When the command line
flag is set, also align the basic block containing the constant pool
entries.
This is only a partial implementation of constant island alignment. More
to come.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146375 91177308-0d34-0410-b5e6-96231b3b80d8
The split point is picked such that the newly created water has the same
alignment as the function. This makes the island suitable for constant
pool entries with potentially higher alignment.
This also fixes an issue where the basic block was split one instruction
too late, causing nonconvergence of the algorithm.
<rdar://problem/10550705>
There is still an issue with correctly packing differently aligned
entries in the island.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146314 91177308-0d34-0410-b5e6-96231b3b80d8
Backwards compatibility with 'gas'. #imm is the preferered and documented
syntax, but lots of existing code uses the '$' prefix, so we should
support it if we can.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146285 91177308-0d34-0410-b5e6-96231b3b80d8
When the immediate operand of an AND or BIC instruction isn't representable
in the immediate field of the instruction, but the bitwise negation of the
immediate is, assemble the instruction as the inverse operation instead
with the inverted immediate as the operand.
rdar://10550057
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146283 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor the instructions into fixed writeback and register-stride
writeback variants to simplify the offset operand (no more optional
register operand using reg0). This is a simpler representation and allows
the assembly parser to more easily handle these instructions.
Add tests for the instruction variants now supported.
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It is not used any more. We are tracking inline assembly misalignments
directly through the BBInfo.Unalign and KnownBits fields.
A simple conservative size estimate is not good enough since it can
cause alignment padding to be underestimated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146124 91177308-0d34-0410-b5e6-96231b3b80d8
Compute alignment padding before and after basic blocks dynamically.
Heed basic block alignment.
This simplifies bookkeeping because we don't have to constantly add and
remove padding from BBInfo.Size. It also makes it possible to track the
extra known alignment bits we get after a tBR_JTr terminator and when
entering an aligned basic block.
This makes the ARMConstantIslandPass aware of aligned basic blocks.
It is tricky to model block alignment correctly when dealing with inline
assembly and tBR_JTr instructions that have variable size. If inline
assembly turns out to be smaller than expected, that may cause following
alignment padding to be larger than expected. This could cause constant
pool entries to move out of range.
To avoid that problem, we use the worst case alignment padding following
inline assembly. This may cause slightly suboptimal constant island
placement in aligned basic blocks following inline assembly. Normal
functions should be unaffected.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146118 91177308-0d34-0410-b5e6-96231b3b80d8
