Commit Graph

9 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
740cd657f3 Don't break the IV update in TLI::SimplifySetCC().
LSR always tries to make the ICmp in the loop latch use the incremented
induction variable. This allows the induction variable to be kept in a
single register.

When the induction variable limit is equal to the stride,
SimplifySetCC() would break LSR's hard work by transforming:

   (icmp (add iv, stride), stride) --> (cmp iv, 0)

This forced us to use lea for the IC update, preventing the simpler
incl+cmp.

<rdar://problem/7643606>
<rdar://problem/11184260>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154119 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-05 20:30:20 +00:00
Jakob Stoklund Olesen
2aa6b4c142 Fix more register allocation sensitive tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134667 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-08 00:24:06 +00:00
Jim Grosbach
e7c1416263 Now that register allocation properly considers reserved regs, simplify the
ARM register class allocation order functions to take advantage of that.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112841 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 18:14:29 +00:00
Rafael Espindola
1e81966626 Remove arm_apcscc from the test files. It is the default and doing this
matches what llvm-gcc and clang now produce.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106221 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-17 15:18:27 +00:00
Dan Gohman
9f23dee08c Start function numbering at 0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101638 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-17 16:29:15 +00:00
Dan Gohman
572645cf84 Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95975 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 10:34:29 +00:00
Dan Gohman
7979b72feb Revert LoopStrengthReduce.cpp to pre-r94061 for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94123 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 00:46:49 +00:00
Dan Gohman
a10756ee65 Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94061 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21 02:09:26 +00:00
Evan Cheng
586f69a118 - Teach LSR to avoid changing cmp iv stride if it will create an immediate that
cannot be folded into target cmp instruction.
- Avoid a phase ordering issue where early cmp optimization would prevent the
  later count-to-zero optimization.
- Add missing checks which could cause LSR to reuse stride that does not have
  users.
- Fix a bug in count-to-zero optimization code which failed to find the pre-inc
  iv's phi node.
- Remove, tighten, loosen some incorrect checks disable valid transformations.
- Quite a bit of code clean up.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86969 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 07:35:05 +00:00