This partially fixes PR13007 (ARM CodeGen fails with large stack
alignment): for ARM and Thumb2 targets, but not for Thumb1, as it
seems stack alignment for Thumb1 targets hasn't been supported at
all.
Producing an aligned stack pointer is done by zero-ing out the lower
bits of the stack pointer. The BIC instruction was used for this.
However, the immediate field of the BIC instruction only allows to
encode an immediate that can zero out up to a maximum of the 8 lower
bits. When a larger alignment is requested, a BIC instruction cannot
be used; llvm was silently producing incorrect code in this case.
This commit fixes code generation for large stack aligments by
using the BFC instruction instead, when the BFC instruction is
available. When not, it uses 2 instructions: a right shift,
followed by a left shift to zero out the lower bits.
The lowering of ARM::Int_eh_sjlj_dispatchsetup still has code
that unconditionally uses BIC to realign the stack pointer, so it
very likely has the same problem. However, I wasn't able to
produce a test case for that. This commit adds an assert so that
the compiler will fail the assert instead of silently generating
wrong code if this is ever reached.
llvm-svn: 225446
Its functionality has been replaced by calling
SIInstrInfo::legalizeOperands() from
SIISelLowering::AdjstInstrPostInstrSelection() and running the
SIFoldOperands and SIShrinkInstructions passes.
llvm-svn: 225445
This makes piped output easier to read in many instances.
Before:
llvm::errs() << aaaa << std::endl << bbbb << std::endl;
After:
llvm::errs() << aaaa << std::endl
<< bbbb << std::endl;
Also fix a few instance of "don't use else after return" as per the
coding standards.
llvm-svn: 225444
If there are some non-ascii character in the input source code, the
column index might be smallar than the byte index. This will result
in two possible assertion failures. This CL fixes the computation of
the column index and byte index.
1. The assertion in startOfNextColumn() and startOfPreviousColumn()
should not be raised when the byte index is greater than the column
index since the non-ascii characters may use more than one bytes to
store a character in a column.
2. The length of the caret line should be equal to the number of columns
of source line, instead of the length of the source line. Otherwise,
the assertion in selectInterestingSourceRegion will be raised because
the removed columns plus the kept columns are not greater than the max
column, which means that we should not remove any column at all.
llvm-svn: 225442
The call lowering assumes that if the callee is a global, we want to emit a direct call.
This is correct for regular globals, but not for TLS ones.
Differential Revision: http://reviews.llvm.org/D6862
llvm-svn: 225438
PEI tries to keep track of how much starting or ending a call sequence adjusts the stack pointer by, so that it can resolve frame-index references. Currently, it takes a very simplistic view of how SP adjustments are done - both FrameStartOpcode and FrameDestroyOpcode adjust it exactly by the amount written in its first argument.
This view is in fact incorrect for some targets (e.g. due to stack re-alignment, or because it may want to adjust the stack pointer in multiple steps). However, that doesn't cause breakage, because most targets (the only in-tree exception appears to be 32-bit ARM) rely on being able to simplify the call frame pseudo-instructions earlier, so this code is never hit.
Moving the computation into TargetInstrInfo allows targets to override the way the adjustment is computed if they need to have a non-zero SPAdj.
Differential Revision: http://reviews.llvm.org/D6863
llvm-svn: 225437
Summary:
With this patch, llgo uses ssautil.Switches
to reconstitute (and synthesise) switches,
which can then be lowered to lookup tables,
trees, etc.
We currently only handle integer const case
switches. We erase the comparison blocks (other
than the initial block), and generate a switch
instruction at the end of the block starting
the if-else-if chain. ssautil.Switches does
not remove duplicate const cases (e.g. same
operands for "||"), so we do this in llgo for
now.
Test Plan: lit test added
Reviewers: pcc
Reviewed By: pcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6831
llvm-svn: 225433
which registers have been spilled (saved to the stack) - and
if we see that same register being saved to the stack again,
don't record that, it's something specific to this stack frame.
I found a code sequence for i386 where clang did a push %esi
and then later in the function it did movl %esi, -0x7c(%ebp)
and that second save of a scratch value overrode the original
push location.
<rdar://problem/19171178>
llvm-svn: 225431
This is necessary to support linking a basic program which references symbols
outside of the module itself. Add the import thunk for ARM NT style imports.
This allows us to create the reference. However, it is still insufficient to
generate executables that will run due to base relocations not being emitted for
the import.
llvm-svn: 225428
so that we will use the UnwindPlan's rule for providing the stack
pointer BEFORE we use the trick of using the callee's CFA address
as the stack pointer. When we're in a _sigtramp frame, the CFA of
the _sigtramp stack frame is not the same as the stack pointer value
when the async interrupt occurred -- we need to use the eh_frame
rules for retrieving the correct value.
<rdar://problem/18913548>
llvm-svn: 225427
A broken hint is a copy where both ends are assigned different colors. When a
variable gets evicted in the neighborhood of such copies, it is likely we can
reconcile some of them.
** Context **
Copies are inserted during the register allocation via splitting. These split
points are required to relax the constraints on the allocation problem. When
such a point is inserted, both ends of the copy would not share the same color
with respect to the current allocation problem. When variables get evicted,
the allocation problem becomes different and some split point may not be
required anymore. However, the related variables may already have been colored.
This usually shows up in the assembly with pattern like this:
def A
...
save A to B
def A
use A
restore A from B
...
use B
Whereas we could simply have done:
def B
...
def A
use A
...
use B
** Proposed Solution **
A variable having a broken hint is marked for late recoloring if and only if
selecting a register for it evict another variable. Indeed, if no eviction
happens this is pointless to look for recoloring opportunities as it means the
situation was the same as the initial allocation problem where we had to break
the hint.
Finally, when everything has been allocated, we look for recoloring
opportunities for all the identified candidates.
The recoloring is performed very late to rely on accurate copy cost (all
involved variables are allocated).
The recoloring is simple unlike the last change recoloring. It propagates the
color of the broken hint to all its copy-related variables. If the color is
available for them, the recoloring uses it, otherwise it gives up on that hint
even if a more complex coloring would have worked.
The recoloring happens only if it is profitable. The profitability is evaluated
using the expected frequency of the copies of the currently recolored variable
with a) its current color and b) with the target color. If a) is greater or
equal than b), then it is profitable and the recoloring happen.
** Example **
Consider the following example:
BB1:
a =
b =
BB2:
...
= b
= a
Let us assume b gets split:
BB1:
a =
b =
BB2:
c = b
...
d = c
= d
= a
Because of how the allocation work, b, c, and d may be assigned different
colors. Now, if a gets evicted to make room for c, assuming b and d were
assigned to something different than a.
We end up with:
BB1:
a =
st a, SpillSlot
b =
BB2:
c = b
...
d = c
= d
e = ld SpillSlot
= e
This is likely that we can assign the same register for b, c, and d,
getting rid of 2 copies.
** Performances **
Both ARM64 and x86_64 show performance improvements of up to 3% for the
llvm-testsuite + externals with Os and O3. There are a few regressions too that
comes from the (in)accuracy of the block frequency estimate.
<rdar://problem/18312047>
llvm-svn: 225422
type (in addition to the memory type).
The *LoadExt* legalization handling used to only have one type, the
memory type. This forced users to assume that as long as the extload
for the memory type was declared legal, and the result type was legal,
the whole extload was legal.
However, this isn't always the case. For instance, on X86, with AVX,
this is legal:
v4i32 load, zext from v4i8
but this isn't:
v4i64 load, zext from v4i8
Whereas v4i64 is (arguably) legal, even without AVX2.
Note that the same thing was done a while ago for truncstores (r46140),
but I assume no one needed it yet for extloads, so here we go.
Calls to getLoadExtAction were changed to add the value type, found
manually in the surrounding code.
Calls to setLoadExtAction were mechanically changed, by wrapping the
call in a loop, to match previous behavior. The loop iterates over
the MVT subrange corresponding to the memory type (FP vectors, etc...).
I also pulled neighboring setTruncStoreActions into some of the loops;
those shouldn't make a difference, as the additional types are illegal.
(e.g., i128->i1 truncstores on PPC.)
No functional change intended.
Differential Revision: http://reviews.llvm.org/D6532
llvm-svn: 225421
The register coalescer used to remove implicit_defs when they are
covered by the main range anyway. With subreg liveness tracking we can't
do that anymore in places where the IMPLICIT_DEF is required as begin of
a subregister liverange.
llvm-svn: 225416
I got confused and assumed SrcIdx/DstIdx of the CoalescerPair is a
subregister index in SrcReg/DstReg, but they are actually subregister
indices of the coalesced register that get you back to SrcReg/DstReg
when applied.
Fixed the bug, improved comments and simplified code accordingly.
Testcase by Tom Stellard!
llvm-svn: 225415
Patch by: Ramkumar Ramachandra <artagnon@gmail.com>
"This patch started out as an exploration of gc.relocate, and an attempt
to write a simple test in call-lowering. I then noticed that the
arguments of gc.relocate were not checked fully, so I went in and fixed
a few things. Finally, the most important outcome of this patch is that
my new error handling code caught a bug in a callsite in
stackmap-format."
Differential Revision: http://reviews.llvm.org/D6824
llvm-svn: 225412
Now that we have MVT::FIRST_VALUETYPE (r225362), we can provide a method
checking that the MVT is valid, that is, it's in
[FIRST_VALUETYPE, LAST_VALUETYPE[.
This commit also uses it in a few asserts, that would previously accept
invalid MVTs, such as the default constructed -1. In that case,
the code following those asserts would do an out-of-bounds array access.
Using MVT::isValid, those assertions fail as expected when passed
invalid MVTs.
It feels clunky to have such a validity checking function, but it's
at least better than the alternative of broken manual checks.
llvm-svn: 225411
I keep forgetting the exact spelling of -macosx-version-min=, and now I can
run `bin/clang --help | grep version -A 2` to remind myself. While here,
also document -mios-version-min=. Don't document -mios-simulator-version-min=
as it's just an alias for -mios-version-min= these days.
llvm-svn: 225409
To fix this I added a new method to TestBase:
def getRerunArgs(self):
return " -f %s.%s" % (self.__class__.__name__, self._testMethodName)
The InlineTest which inherits from TestBase then overrides this function with a custom version which does the right thing.
llvm-svn: 225407
Allow distinct `MDNode`s to be explicitly created. There's no way (yet)
of representing their distinctness in assembly/bitcode, however, so this
still isn't first-class.
Part of PR22111.
llvm-svn: 225406
Add API to indicate whether an `MDNode` is distinct. A distinct node is
not stored in the MDNode uniquing tables, and will never be returned by
`MDNode::get()`.
Although distinct nodes are only currently created by uniquing
collisions (when operands change), PR22111 will allow these nodes to be
explicitly created.
llvm-svn: 225401
Differential Revision: http://reviews.llvm.org/D6797
lldb-gdbserver statically links all llvm dependencies. This allows
dead stripping code and reduces total binary size.
This change modifies lldb-plaform to static link llvm dependencies
like lldb-gdbserver.
llvm-svn: 225398
`MDNode::replaceOperandWith()` changes all instances of metadata. Stop
using it when linking module flags, since (due to uniquing) the flag
values could be used by other metadata.
Instead, use new API `NamedMDNode::setOperand()` to update the reference
directly.
llvm-svn: 225397
Kristof Beyls