If we know that the sign bit of a value being sign extended is zero, we can use a zero extension instead. This is motivated by the fact that zero extensions are generally cheaper on x86 (and most other architectures?). We already apply a similar transform in DAGCombine, this just extends that to the IR level.
This comes up when we eagerly canonicalize gep indices to the width of a machine register (i64 on x86_64). To do so, we insert sign extensions (sext) to promote smaller types.
Differential Revision: http://reviews.llvm.org/D7255
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With this commit, llvm-dsymutil learns how to choose which DIEs
it will link in the final output and which ones it won't. This
is based on the 'valid relocation' information that has been
built in the previous commits.
The test only tests that we choose the right 'root DIEs'. The
selection algorithm (and especially the part that walk the
dependencies of a root DIE) lacks a bit test coverage. This
will be much easier to cover when we output actual Dwarf and
thus can use llvm-dwarfdump to verify the structure of the
emitted DIE trees. I'll add more tests then.
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This takes the preposterous number of patterns in this section
that were last added to in r219033 down to just plain obnoxious.
With a little more work, we might get this down to just comical.
I've added more test cases to the existing file that checks these
patterns, but it seems that some of these patterns simply don't
exist with today's shuffle lowering.
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llc would hang trying to write output to a full pipe that FileCheck
wasn't reading. FileCheck wasn't reading from stdin because it needs a
file as a positional argument.
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This patch adds functionality in MIPS delay slot filler such as if delay slot
filler have to put NOP instruction into the delay slot of microMIPS JR
instruction, then instead of emitting NOP this instruction is replaced by
compact jump instruction JRC.
Differential Revision: http://reviews.llvm.org/D7522
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This patch fixes a problem I accidentally introduced in an instruction combine
on select instructions added at r227197. That revision taught the instruction
combiner how to fold a cttz/ctlz followed by a icmp plus select into a single
cttz/ctlz with flag 'is_zero_undef' cleared.
However, the new rule added at r227197 would have produced wrong results in the
case where a cttz/ctlz with flag 'is_zero_undef' cleared was follwed by a
zero-extend or truncate. In that case, the folded instruction would have
been inserted in a wrong location thus leaving the CFG in an inconsistent
state.
This patch fixes the problem and add two reproducible test cases to
existing test 'InstCombine/select-cmp-cttz-ctlz.ll'.
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SimplifyCFG now knows how to speculate calls to intrinsic cttz/ctlz that are
'cheap' for the target. Therefore, some of the logic in CodeGenPrepare
that was originally added at revision 224899 can now be removed.
This patch is basically a no functional change. It removes the duplicated
logic in CodeGenPrepare and converts all the existing target specific tests
for cttz/ctlz into SimplifyCFG tests.
Differential Revision: http://reviews.llvm.org/D7608
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Up the phi node folding threshold from a cheap "1" to a meagre "2".
Update tests for extra added selects and slight code churn.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229099 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Made the following changes:
Added calls to emitDirectiveSetNoAt() and emitDirectiveSetAt().
Added special emit function for .set at=$reg, emitDirectiveSetAtWithArg(unsigned RegNo).
Improved parsing error checks for .set at.
Refactored parser code for .set at.
Improved testing of both directives.
Improved code readability and comments.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7176
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regressions for LLDB on Linux. Rafael indicated on lldb-dev that we
should just go ahead and revert these but that he wasn't at a computer.
The patches backed out are as follows:
r228980: Add support for having multiple sections with the name and ...
r228889: Invert the section relocation map.
r228888: Use the existing SymbolTableIndex intsead of doing a lookup.
r228886: Create the Section -> Rel Section map when it is first needed.
These patches look pretty nice to me, so hoping its not too hard to get
them re-instated. =D
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The issues with the new unroll analyzer are more fundamental than code
cleanup, algorithm, or data structure changes. I've sent an email to the
original commit thread with details and a proposal for how to redesign
things. I'm disabling this for now so that we don't spend time
debugging issues with it in its current state.
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- First, there's a crash when we try to combine that pointers into `icmp`
directly by creating a `bitcast`, which is invalid if that two pointers are
from different address spaces.
- It's not always appropriate to cast one pointer to another if they are from
different address spaces as that is not no-op cast. Instead, we only combine
`icmp` from `ptrtoint` if that two pointers are of the same address space.
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propagating of metadata.
We were propagating !nonnull metadata even when the newly formed load is
no longer of a pointer type. This is clearly broken and results in LLVM
failing the verifier and aborting. This patch just restricts the
propagation of !nonnull metadata to when we actually have a pointer
type.
This bug report and the initial version of this patch was provided by
Charles Davis! Many thanks for finding this!
We still need to add logic to round-trip the metadata correctly if we
combine from pointer types to integer types and then back by using range
metadata for the integer type loads. But this is the minimal and safe
version of the patch, which is important so we can backport it into 3.6.
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This commit makes the following changes:
- Stop issuing a warning when the triples' string representations do not match
exactly if the Triple objects generated from the strings compare equal.
- On Apple platforms, choose the triple that has the larger minimum version
number.
rdar://problem/16743513
Differential Revision: http://reviews.llvm.org/D7591
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Using this in combination with -ffunction-sections allows LLVM to output a .o
file with mulitple sections named .text. This saves space by avoiding long
unique names of the form .text.<C++ mangled name>.
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Constant pool entries are uniqued by their contents regardless of their
type. This means that a pshufb can have a shuffle mask which isn't a
simple array of bytes.
The code path which attempts to decode the mask didn't check for
failure, causing PR22559.
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