it's a bit more plausible to use this instead of CodePlacementOpt. The
code for this was shamelessly stolen from CodePlacementOpt, and then
trimmed down a bit. There doesn't seem to be much utility in returning
true/false from this pass as we may or may not have rewritten all of the
blocks. Also, the statistic of counting how many loops were aligned
doesn't seem terribly important so I removed it. If folks would like it
to be included, I'm happy to add it back.
This was probably the most egregious of the missing features, and now
I'm going to start gathering some performance numbers and looking at
specific loop structures that have different layout between the two.
Test is updated to include both basic loop alignment and nested loop
alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142645 91177308-0d34-0410-b5e6-96231b3b80d8
block frequency analyses. This differs substantially from the existing
block-placement pass in LLVM:
1) It operates on the Machine-IR in the CodeGen layer. This exposes much
more (and more precise) information and opportunities. Also, the
results are more stable due to fewer transforms ocurring after the
pass runs.
2) It uses the generalized probability and frequency analyses. These can
model static heuristics, code annotation derived heuristics as well
as eventual profile loading. By basing the optimization on the
analysis interface it can work from any (or a combination) of these
inputs.
3) It uses a more aggressive algorithm, both building chains from tho
bottom up to maximize benefit, and using an SCC-based walk to layout
chains of blocks in a profitable ordering without O(N^2) iterations
which the old pass involves.
The pass is currently gated behind a flag, and not enabled by default
because it still needs to grow some important features. Most notably, it
needs to support loop aligning and careful layout of loop structures
much as done by hand currently in CodePlacementOpt. Once it supports
these, and has sufficient testing and quality tuning, it should replace
both of these passes.
Thanks to Nick Lewycky and Richard Smith for help authoring & debugging
this, and to Jakob, Andy, Eric, Jim, and probably a few others I'm
forgetting for reviewing and answering all my questions. Writing
a backend pass is *sooo* much better now than it used to be. =D
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142641 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser. This patch adds validation for target data layout strings upon
construction of TargetData objects. An attempt to construct a TargetData object
from a malformed string will trigger an assertion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142605 91177308-0d34-0410-b5e6-96231b3b80d8
When checking the availability of instructions using the TLI, a 'promoted'
instruction IS available. It means that the value is bitcasted to another type
for which there is an operation. The correct check for the availablity of an
instruction is to check if it should be expanded.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142542 91177308-0d34-0410-b5e6-96231b3b80d8
On spec/gcc, this caused a codesize improvement of ~1.9% for ARM mode and ~4.9% for Thumb(2) mode. This is
codesize including literal pools.
The pools themselves doubled in size for ARM mode and quintupled for Thumb mode, leaving suggestion that there
is still perhaps redundancy in LLVM's use of constant pools that could be decreased by sharing entries.
Fixes PR11087.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142530 91177308-0d34-0410-b5e6-96231b3b80d8
Add a paste operator '#' to take two identifier-like strings and joint
them. Internally paste gets represented as a !strconcat() with any
necessary casts to string added.
This will be used to implement basic for loop functionality as in:
for i = [0, 1, 2, 3, 4, 5, 6, 7] {
def R#i : Register<...>
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142525 91177308-0d34-0410-b5e6-96231b3b80d8
During multiclass def instantiation, replace NAME in any expressions
with the value of the def or defm ID.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142524 91177308-0d34-0410-b5e6-96231b3b80d8
Parse and process a defm prefix as an Init expression. This allows
paste operations to create defm prefixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142523 91177308-0d34-0410-b5e6-96231b3b80d8
Stop parsing a value if we are in name parsing mode and we see a left
brace. A left brace indicates the start of an object body when we are
parsing a name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142521 91177308-0d34-0410-b5e6-96231b3b80d8
Augment the value parser to respect the parse mode and not error if an
ID doesn't map to an object and we are in name parsing mode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142520 91177308-0d34-0410-b5e6-96231b3b80d8
Add a mode control to value and ID parsers. The two modes are:
- Parse a value. Expect the parsed ID to map to an existing object.
- Parse a name. Expect the parsed ID to not map to any existing object.
The first is used when parsing an identifier to be looked up, for
example a record field or template argument. The second is used for
parsing declarations. Paste functionality implies that declarations
can contain arbitrary expressions so we need to be able to call into
the general value parser to parse declarations with paste operators.
So we need a way to parse a value-like thing without expecting that
the result will map to some existing object. This parse mode provides
that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142519 91177308-0d34-0410-b5e6-96231b3b80d8
Add a Value named "NAME" to each Record. This will be set to the def or defm
name when instantiating multiclasses. This will replace the #NAME# processing
hack once paste functionality is in place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142518 91177308-0d34-0410-b5e6-96231b3b80d8
Use lookahead to determine whether a number is really a number or is
part of something forming an identifier. This won't come into play
until the paste operator is recognized as a unique token.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142513 91177308-0d34-0410-b5e6-96231b3b80d8
Add a peek function to let the Lexer look at a character arbitrarily
far ahead in the stream without consuming anything. We need this to
disambiguate numbers and operands of a paste operation. For example:
def foo#8i
Without lookahead the lexer will treat '8' as a number rather than as
part of a string to be pasted to form an identifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142512 91177308-0d34-0410-b5e6-96231b3b80d8
When resolving Record values, be sure to update the Record name as it
may contain references to the value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142511 91177308-0d34-0410-b5e6-96231b3b80d8
Add Record names to be changed even on Records that aren't yet
registered. We need to be able to do this for paste functionality
because we do not want to register def names before they are unique
and that can only happen once all paste operations are done. This
change lets us update Record names formed by paste operations and
register the result later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142510 91177308-0d34-0410-b5e6-96231b3b80d8
