This patch addresses two issues with assembly and disassembly for VMRS/VMSR:
1.currently VMRS/VMSR instructions accessing fpsid, mvfr{0-2} and fpexc, are
accepted for non ARMv8-A targets.
2. all VMRS/VMSR instructions accept writing/reading to PC and SP, when only
ARMv7-A and ARMv8-A should be allowed to write/read to SP and none to PC.
This patch addresses those issues and adds tests for these cases.
Differential Revision: https://reviews.llvm.org/D36306
llvm-svn: 310243
The NewNodesMustHaveLegalTypes flag is set to false at the beginning of CodeGenAndEmitDAG, and set to true after legalizing types.
But before calling CodeGenAndEmitDAG we build the DAG for the basic block.
So for the first basic block NewNodesMustHaveLegalTypes would be 'false' during the SDAG building, and for all other basic blocks it would be 'true'.
This patch sets the flag to false before SDAG building each basic block.
Differential Revision:
https://reviews.llvm.org/D33435
llvm-svn: 310239
While here, rename `i` to `Rank` as the latter is more
self-explanatory (and this code also uses `I` two lines below to
identify an Instruction).
llvm-svn: 310238
We can convert any select-of-constants to math ops:
http://rise4fun.com/Alive/d7d
For this patch, I'm enhancing an existing x86 transform that uses fake multiplies
(they always become shl/lea) to avoid cmov or branching. The current code misses
cases where we have a negative constant and a positive constant, so this is just
trying to plug that hole.
The DAGCombiner diff prevents us from hitting a terrible inefficiency: we can start
with a select in IR, create a select DAG node, convert it into a sext, convert it
back into a select, and then lower it to sext machine code.
Some notes about the test diffs:
1. 2010-08-04-MaskedSignedCompare.ll - We were creating control flow that didn't exist in the IR.
2. memcmp.ll - Choose -1 or 1 is the case that got me looking at this again. I
think we could avoid the push/pop in some cases if we used 'movzbl %al' instead of an xor on
a different reg? That's a post-DAG problem though.
3. mul-constant-result.ll - The trade-off between sbb+not vs. setne+neg could be addressed if
that's a regression, but I think those would always be nearly equivalent.
4. pr22338.ll and sext-i1.ll - These tests have undef operands, so I don't think we actually care about these diffs.
5. sbb.ll - This shows a win for what I think is a common case: choose -1 or 0.
6. select.ll - There's another borderline case here: cmp+sbb+or vs. test+set+lea? Also, sbb+not vs. setae+neg shows up again.
7. select_const.ll - These are motivating cases for the enhancement; replace cmov with cheaper ops.
Assembly differences between movzbl and xor to avoid a partial reg stall are caused later by the X86 Fixup SetCC pass.
Differential Revision: https://reviews.llvm.org/D35340
llvm-svn: 310208
The patch from r310028 fixed things to work with the new
`LLVMTargetMachine` constructor that came in on r309911.
However, the fix was partial since an object of type
`CodeModel::Model` must be passed to `LLVMTargetMachine`
(not one of `Optional<CodeModel::Model>`).
This patch fixes the problem in the same fashion that r309911
did for other machines: by checking if the passed optional
code model has a value and using `CodeModel::Small` if not.
llvm-svn: 310200
Test with/without the sandybridge (default) model for SSE2, SSE3 and AVX targets.
pre-SSE3 the issue is the order of the fpsw and fpcw load/stores (with SSE3 trunc-store FIST instructions avoid the sw/cw manipulations).
llvm-svn: 310198
Summary:
On older processors this instruction encoding is treated as a NOP.
MSVC doesn't disable intrinsics based on features the way clang/gcc does. Because the PAUSE instruction encoding doesn't crash older processors, some software out there uses these intrinsics without checking for SSE2.
This change also seems to also be consistent with gcc behavior.
Fixes PR34079
Reviewers: RKSimon, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36361
llvm-svn: 310190
POD-like and we can just splat the empty key across memory.
Sadly we can't optimize the normal loop well enough because we can't
turn the conditional store into an unconditional store according to the
memory model.
This loop actually showed up in a profile of code that was calling clear
as a serious source of time. =[
llvm-svn: 310189
Unfortunately, it looks like there's some other missed optimizations in the generated code for some of these cases. I'll try to look at some of those next.
llvm-svn: 310184
Summary:
MIRParserImpl::computeFunctionProperties uses MRI.getNumVirtRegs() to
set the NoVReg property. By adding a bunch of registers to the MIR test
cases, the NoVReg property is not set when importing the MIR. Otherwise
NoVReg is set after instruction selection while the machine instructions
still contain virtual registers, causing expensive checks to fail.
Reviewers: efriedma, MatzeB, aprantl
Reviewed By: MatzeB, aprantl
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D36152
llvm-svn: 310178
After the previous series of patches, this is now trivial and deletes
a pretty astonishing amount of complexity. This has been a long time
coming, as the move toward a PO sequence of RefSCCs started eroding the
underlying use cases for this half of the data structure.
Among the biggest advantages here is that now there aren't two
independent data structures that need to stay in sync.
Some of my profiling has also indicated that updating the parent sets
was among the most expensive parts of the lazy call graph. Eliminating
it whole sale is likely to be a nice win in terms of compile time.
Last but not least, I had discussed with some folks previously keeping
it around for asserts and other correctness checking, but once the
fundamentals of the parent and child checking were implemented without
the parent sets their value in correctness checking was tiny and no
where near worth the cost of the complexity required to keep everything
up-to-date.
llvm-svn: 310171
isDescendantOf methods on RefSCCs in terms of the forward edges rather
than the parent sets.
This is technically slower, but probably not interestingly slower, and
all of these routines were already so expensive that they're guarded
behind both !NDEBUG and EXPENSIVE_CHECKS.
This removes another non-critical usage of parent sets.
I've also added some comments to try and help clarify to any potential
users the costs of these routines. They're mostly useful for debugging,
asserts, or other queries.
llvm-svn: 310170
walk over the parent set.
When removing a single function from the call graph, we previously would
walk the entire RefSCC's parent set and then walk every outgoing edge
just to find the ones to remove. In addition to this being quite high
complexity in theory, it is also the last fundamental use of the parent
sets.
With this change, when we remove a function we transform the node
containing it to be recognizably "dead" and then teach the edge
iterators to recognize edges to such nodes and skip them the same way
they skip null edges.
We can't move fully to using "dead" nodes -- when disconnecting two live
nodes we need to null out the edge. But the complexity this adds to the
edge sequence isn't too bad and the simplification of lazily handling
this seems like a significant win.
llvm-svn: 310169
Add memory synchronization semantics to LSE Atomics.
The memory semantics feature will be added in a subsequent patch.
In this patch, several corrections were added to the existing LSE Atomics
implementation, based on the ARM Errata D11904 from 05/12/2017.
Patch by: steleman
Differential Revision: https://reviews.llvm.org/D35319
llvm-svn: 310167
The definition of 'false' here was already pretty vague and debatable,
and I'm about to add another potential 'false' that would actually make
much more sense in a bool operator. Especially given how rarely this is
used, a nicely named method seems better.
llvm-svn: 310165
structures, actually null out the graph pointers as well. We won't ever
update these, and we certainly shouldn't be calling any methods on them,
so it seems good to defensively nuke them.
llvm-svn: 310164
pointers in node objects, just walk the map from function to node.
It doesn't have stable ordering, but works just as well and is much
simpler. We don't need ordering when just updating internal pointers.
llvm-svn: 310163
merging RefSCCs.
The logic to directly use the reference edges is simpler and not
substantially slower (despite the comments to the contrary) because this
is not actually an especially hot part of LCG in practice.
llvm-svn: 310161
Previously we were always trying to emit the zext or truncate before any shift. This meant if the 'and' mask was larger than the size of the truncate we would skip the transformation.
Now we shift the result of the and right first leaving the bit within the range of the truncate.
This matches what we are doing in foldSelectICmpAndOr for the same problem.
llvm-svn: 310159
Summary:
Direct calls to dllimport functions are very common Windows. We should
add them to the -O0 fast path.
Reviewers: rafael
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D36197
llvm-svn: 310152
Sometimes LLD will produce a PT_LOAD segment that only covers the
headers (and covers no sections). GNU objcopy does not output the
segment contents for these sections. In particular this is an issue in
building magenta because the final link step for the kernel would
produce just such a PT_LOAD segment. This change is to support this case
and to match what GNU objcopy does in this case.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D36196
llvm-svn: 310149
Dmitry Preobrazhensky