add A, sext(B) --> sub A, zext(B)
We have to choose 1 of these forms, so I'm opting for the
zext because that's easier for value tracking.
The backend should be prepared for this change after:
D57401
rL353433
This is also a preliminary step towards reducing the amount
of bit hackery that we do in IR to optimize icmp/select.
That should be waiting to happen at a later optimization stage.
The seeming regression in the fuzzer test was discussed in:
D58359
We were only managing that fold in instcombine by luck, and
other passes should be able to deal with that better anyway.
llvm-svn: 354748
There's likely a missed IR canonicalization for at least 1 of these
patterns. Otherwise, we wouldn't have needed the pattern-matching
enhancement in D57516.
Note that -- unlike usubo added with D57789 -- the TLI hook for
this transform defaults to 'on'. So if there's any perf fallout
from this, targets should look at how they're lowering the uaddo
node in SDAG and/or override that hook.
The x86 diffs suggest that there's some missing pattern-matching
for forming inc/dec.
This should fix the remaining known problems in:
https://bugs.llvm.org/show_bug.cgi?id=40486https://bugs.llvm.org/show_bug.cgi?id=31754
llvm-svn: 354746
As requested during review of D57601, be equally conservative for atomic MMOs as for volatile MMOs in all in tree backends. At the moment, all atomic MMOs are also volatile, but I'm about to change that.
Reviewed as part of https://reviews.llvm.org/D58490, with other backends still pending review.
llvm-svn: 354740
Thread Twine a little deeper through the VFS to avoid unnecessarily
constructing the same std::string twice in a parameter sequence:
Twine -> std::string -> StringRef -> std::string
Changing a few parameters from StringRef to Twine avoids the early call
to `Twine::str()`.
llvm-svn: 354739
The new instruciton might have less operands than the original instruction. If we don't resample, the next loop iteration might read an operand that doesn't exist.
X86 can commute blends to movss/movsd which reduces from 4 operands to 3. This happened in the test case that caused r354363 & company to be reverted. A reduced version of that has been committed here.
Really this whole checking for more commutable operands is a little fragile. It assumes that the new instructions operands are the same order and positions as the original except for the pair that was swapped. I don't know of anything that breaks this assumption today, but I've left a fixme. Fixing this will likely require an interface change.
llvm-svn: 354738
r354648 was a follow up to fix a regression "[X86] Add a DAG combine for (aext_vector_inreg (aext_vector_inreg X)) -> (aext_vector_inreg X) to fix a regression from my previous commit."
These were reverted in r354713 as their context depended on other patches that were reverted for a bug.
llvm-svn: 354734
Fixes https://bugs.llvm.org/show_bug.cgi?id=40805 introduced by
patterns added in D53676.
I'm removing the patterns entirely here, as they are not correct
in the general case. If necessary something more specific can be
added in the future.
Differential Revision: https://reviews.llvm.org/D58575
llvm-svn: 354733
Even on AVX1 we can pretty cheaply (VPERM2F128+VSHUFPD) permute a single v4f64/v4i64 input (on AVX2 its just a single VPERMPD), followed by a BLENDPD.
llvm-svn: 354729
Summary:
Previously, we'd run some experimental tests even when enable_experimental=False
was used with lit.
Reviewers: EricWF
Subscribers: christof, jkorous, dexonsmith, libcxx-commits, mclow.lists
Differential Revision: https://reviews.llvm.org/D55834
llvm-svn: 354725
Conversion from ConstantSDNode to MachineInstr sign extends immediates from their APInt representation to int64_t.
This commit makes sure we do the same for commuting. The tests changes show how this improves CSE. This issue was made worse by the MachineCSE using commuteInstruction to undo a commute. So we virtually guarantee the sign extend from isel would be lost.
The improved CSE also occurred with r354363, but that was reverted. I'm working to undo the revert, but wanted to get this fix in while it was easy to see the results.
llvm-svn: 354724
Summary:
The objdump Mach-O parser uses MachOObjectFile::checkSymbolTable() to
verify the symbol table is in a legal state before dereferencing the
offsets in the table. This routine missed a test for N_STAB symbols
when validating the two-level name space library ordinal for undefined
symbols. If the binary in question contained a value in the n_desc high
byte that is larger than the list of loaded dylibs, checkSymbolTable()
will flag the library ordinal as being out of range. Most of the time
the n_desc field is set to 0 or to small values, but old final linked
binaries exist with N_STAB symbols bearing non-trivial n_desc fields.
The change here is simply to verify a symbol is not an N_STAB symbol
before consulting the values of n_other or n_desc.
rdar://44977336
Reviewers: lhames, pete, ab
Reviewed By: pete
Subscribers: llvm-commits, rupprecht
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58568
llvm-svn: 354722
r354363 caused https://crbug.com/934963#c1, which has a plain C reduced
test case.
I also had to revert some dependent changes:
- r354648
- r354647
- r354640
- r354511
llvm-svn: 354713
If the the input type will be promoted to 128 bits its better to put a sign_extend_inreg/and in the 128 bit register before the split occurs. Otherwise we end up doing it on each half in the wider register.
Some of the overflow arithmetic tests are regressions, but I think we can make some improvement using getSetccResultType in DAG combine and/or type legalization.
llvm-svn: 354709
If v8i64 isn't a legal type but v4i64 is, these will be split and then each half will get their input promoted and become an any_extend_vector_inreg/punpckhwd + any_extend + and/sign_extend_inreg.
If we instead recognize the input will be promoted we can emit the and/sign_extend_inreg first in a 128 bit register. Then we can sign_extend/zero_extend one half and pshufd+sign_extend/zero_extend the other half.
llvm-svn: 354708
They aren't designed to nest recursively, so this will prevent that.
Also add a --auto-continue flag, putting "continue" in the stop hook makes
the stop hooks fight one another in multi-threaded programs.
Also allow more than one -o options so you can make more complex stop hooks w/o
having to go into the editor.
<rdar://problem/48115661>
Differential Revision: https://reviews.llvm.org/D58394
llvm-svn: 354706
The deserializer was not handling this case. For now we just
accept the absent option, and set it to the breakpoint default.
This will be more important if/when I figure out how to serialize
the options set on breakpont locations.
<rdar://problem/48322664>
llvm-svn: 354702
Kristina Brooks