Commit Graph

7 Commits

Author SHA1 Message Date
Sanjoy Das f7302c8baf [PlaceSafepoints] Clamp NoStatepoints to true
This change permanently clamps -spp-no-statepoints to true (the code
deletion will come later).  Tests that specifically tested
PlaceSafepoint's ability to wrap calls in gc.statepoint have been moved
to RS4GC's test suite.

llvm-svn: 259096
2016-01-28 21:51:14 +00:00
Sanjoy Das 2321a4cd71 [PlaceSafepoints] Clean up tests; NFC
Use `opt < %s` instead of `opt %s` as specified in
http://llvm.org/docs/TestingGuide.html#fragile-tests.

llvm-svn: 259062
2016-01-28 18:01:03 +00:00
Bill Schmidt 34af5e1c76 [PowerPC] Add an MI SSA peephole pass.
This patch adds a pass for doing PowerPC peephole optimizations at the
MI level while the code is still in SSA form.  This allows for easy
modifications to the instructions while depending on a subsequent pass
of DCE.  Both passes are very fast due to the characteristics of SSA.

At this time, the only peepholes added are for cleaning up various
redundancies involving the XXPERMDI instruction.  However, I would
expect this will be a useful place to add more peepholes for
inefficiencies generated during instruction selection.  The pass is
placed after VSX swap optimization, as it is best to let that pass
remove unnecessary swaps before performing any remaining clean-ups.

The utility of these clean-ups are demonstrated by changes to four
existing test cases, all of which now have tighter expected code
generation.  I've also added Eric Schweiz's bugpoint-reduced test from
PR25157, for which we now generate tight code.  One other test started
failing for me, and I've fixed it
(test/Transforms/PlaceSafepoints/finite-loops.ll) as well; this is not
related to my changes, and I'm not sure why it works before and not
after.  The problem is that the CHECK-NOT: of "statepoint" from test1
fails because of the "statepoint" in test2, and so forth.  Adding a
CHECK-LABEL in between keeps the different occurrences of that string
properly scoped.

llvm-svn: 252651
2015-11-10 21:38:26 +00:00
Sanjoy Das f75e15e5ac [PlaceSafepoints] Make the width of a counted loop settable.
Summary:
This change lets a `PlaceSafepoints` client change how wide the trip
count of a loop has to be for the loop to be considerd "counted", via
`CountedLoopTripWidth`.  It also removes the boolean `SkipCounted` flag
and the `upperTripBound` constant -- we can get the old behavior of
`SkipCounted` == `false` by setting `CountedLoopTripWidth` to `13` (2 ^
13 == 8192).

Reviewers: reames

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D12789

llvm-svn: 247656
2015-09-15 01:42:48 +00:00
Sanjoy Das a1d39ba940 [Statepoints] Support for "patchable" statepoints.
Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`.  `id` gets propagated to the ID field
in the generated StackMap section.  If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.

This change brings statepoints one step closer to patchpoints.  With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.

PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`.  This can be made more sophisticated
later.

Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9546

llvm-svn: 237214
2015-05-12 23:52:24 +00:00
Philip Reames 0b1b387441 [PlaceSafepoints] Adjust enablement logic to default to off and be GC configurable per GC
Previously, this pass ran over every function in the Module if added to the pass order.  With this change, it runs only over those with a GC attribute where the GC explicitly opts in.  A GC can also choose which of entry safepoint polls, backedge safepoint polls, and call safepoints it wants.  I hope to get these exposed as checks on the GCStrategy at some point, but for now, the checks are manual string comparisons.

llvm-svn: 230097
2015-02-21 00:09:09 +00:00
Philip Reames 0edbf2e407 Introduce more tests for PlaceSafepoints
These tests the two optimizations for backedge insertion currently implemented and the split backedge flag which is currently off by default.

llvm-svn: 228617
2015-02-09 22:10:15 +00:00