Commit Graph

11 Commits

Author SHA1 Message Date
Chandler Carruth
13086a658a Begin fleshing out an interface in TTI for modelling the costs of
generic function calls and intrinsics. This is somewhat overlapping with
an existing intrinsic cost method, but that one seems targetted at
vector intrinsics. I'll merge them or separate their names and use cases
in a separate commit.

This sinks the test of 'callIsSmall' down into TTI where targets can
control it. The whole thing feels very hack-ish to me though. I've left
a FIXME comment about the fundamental design problem this presents. It
isn't yet clear to me what the users of this function *really* care
about. I'll have to do more analysis to figure that out. Putting this
here at least provides it access to proper analysis pass tools and other
such. It also allows us to more cleanly implement the baseline cost
interfaces in TTI.

With this commit, it is now theoretically possible to simplify much of
the inline cost analysis's handling of calls by calling through to this
interface. That conversion will have to happen in subsequent commits as
it requires more extensive restructuring of the inline cost analysis.

The CodeMetrics class is now really only in the business of running over
a block of code and aggregating the metrics on that block of code, with
the actual cost evaluation done entirely in terms of TTI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173148 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-22 11:26:02 +00:00
Chandler Carruth
a5157e68d1 Switch CodeMetrics itself over to use TTI to determine if an instruction
is free. The whole CodeMetrics API should probably be reworked more, but
this is enough to allow deleting the duplicate code there for computing
whether an instruction is free.

All of the passes using this have been updated to pull in TTI and hand
it to the CodeMetrics stuff. Further, a dead CodeMetrics API
(analyzeFunction) is nuked for lack of users.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173036 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-21 13:04:33 +00:00
Chandler Carruth
1e05bd9e71 Introduce a generic interface for querying an operation's expected
lowered cost.

Currently, this is a direct port of the logic implementing
isInstructionFree in CodeMetrics. The hope is that the interface can be
improved (f.ex. supporting un-formed instruction queries) and the
implementation abstracted so that as we have test cases and target
knowledge we can expose increasingly accurate heuristics to clients.

I'll start switching existing consumers over and kill off the routine in
CodeMetrics in subsequent commits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172998 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-21 01:27:39 +00:00
Renato Golin
053a211983 Revert CostTable algorithm, will re-write
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172992 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 20:57:20 +00:00
Renato Golin
065db2347f Fix 80-col and early exit in cost model
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172877 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-19 00:42:16 +00:00
Renato Golin
d3c965d625 Change CostTable model to be global to all targets
Moving the X86CostTable to a common place, so that other back-ends
can share the code. Also simplifying it a bit and commoning up
tables with one and two types on operations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172658 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-16 21:29:55 +00:00
Nadav Rotem
14925e6b88 ARM Cost model: Use the size of vector registers and widest vectorizable instruction to determine the max vectorization factor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172010 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 22:29:00 +00:00
Nadav Rotem
83be7b0dd3 Cost Model: Move the 'max unroll factor' variable to the TTI and add initial Cost Model support on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 01:15:42 +00:00
Chandler Carruth
e4ba75f43e Switch the SCEV expander and LoopStrengthReduce to use
TargetTransformInfo rather than TargetLowering, removing one of the
primary instances of the layering violation of Transforms depending
directly on Target.

This is a really big deal because LSR used to be a "special" pass that
could only be tested fully using llc and by looking at the full output
of it. It also couldn't run with any other loop passes because it had to
be created by the backend. No longer is this true. LSR is now just
a normal pass and we should probably lift the creation of LSR out of
lib/CodeGen/Passes.cpp and into the PassManagerBuilder. =] I've not done
this, or updated all of the tests to use opt and a triple, because
I suspect someone more familiar with LSR would do a better job. This
change should be essentially without functional impact for normal
compilations, and only change behvaior of targetless compilations.

The conversion required changing all of the LSR code to refer to the TTI
interfaces, which fortunately are very similar to TargetLowering's
interfaces. However, it also allowed us to *always* expect to have some
implementation around. I've pushed that simplification through the pass,
and leveraged it to simplify code somewhat. It required some test
updates for one of two things: either we used to skip some checks
altogether but now we get the default "no" answer for them, or we used
to have no information about the target and now we do have some.

I've also started the process of removing AddrMode, as the TTI interface
doesn't use it any longer. In some cases this simplifies code, and in
others it adds some complexity, but I think it's not a bad tradeoff even
there. Subsequent patches will try to clean this up even further and use
other (more appropriate) abstractions.

Yet again, almost all of the formatting changes brought to you by
clang-format. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171735 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 14:41:08 +00:00
Chandler Carruth
d1b8ef97c4 Make the popcnt support enums and methods have more clear names and
follow the conding conventions regarding enumerating a set of "kinds" of
things.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171687 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 03:16:03 +00:00
Chandler Carruth
be04929f7f Move TargetTransformInfo to live under the Analysis library. This no
longer would violate any dependency layering and it is in fact an
analysis. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171686 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 03:08:10 +00:00