Commit Graph

5 Commits

Author SHA1 Message Date
Adam Nemet
6a56c37b95 [LSR] Add llc testcase for r207271/r207569.
See PR19608 for the details but to summarize it was easy to modify the .ll
file to get the desired def-use ordering.

llvm-svn: 207887
2014-05-02 23:49:01 +00:00
Chandler Carruth
c71b2c3c7f Revert r207271 for now. This commit introduced a test case that ran
clang directly from the LLVM test suite! That doesn't work. I've
followed up on the review thread to try and get a viable solution sorted
out, but trying to get the tree clean here.

llvm-svn: 207462
2014-04-28 23:07:49 +00:00
Adam Nemet
03d91c51e4 [LoopStrengthReduce] Don't trim formula that uses a subset of required registers
Consider this use from the new testcase:

  LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i32
    reg({1000,+,-1}<nw><%for.body>)
    -3003 + reg({3,+,3}<nw><%for.body>)
    -1001 + reg({1,+,1}<nuw><nsw><%for.body>)
    -1000 + reg({0,+,1}<nw><%for.body>)
    -3000 + reg({0,+,3}<nuw><%for.body>)
    reg({-1000,+,1}<nw><%for.body>)
    reg({-3000,+,3}<nsw><%for.body>)

This is the last use we consider for a solution in SolveRecurse, so CurRegs is
a large set.  (CurRegs is the set of registers that are needed by the
previously visited uses in the in-progress solution.)

ReqRegs is {
  {3,+,3}<nw><%for.body>,
  {1,+,1}<nuw><nsw><%for.body>
}

This is the intersection of the regs used by any of the formulas for the
current use and CurRegs.

Now, the code requires a formula to contain *all* these regs (the comment is
simply wrong), otherwise the formula is immediately disqualified.  Obviously,
no formula for this use contains two regs so they will all get disqualified.

The fix modifies the check to allow the formula in this case.  The idea is
that neither of these formulae is introducing any new registers which is the
point of this early pruning as far as I understand.

In terms of set arithmetic, we now allow formulas whose used regs are a subset
of the required regs not just the other way around.

There are few more loops in the test-suite that are now successfully LSRed.  I
have benchmarked those and found very minimal change.

Fixes <rdar://problem/13965777>

llvm-svn: 207271
2014-04-25 21:02:21 +00:00
NAKAMURA Takumi
4cf1a3be82 llvm/test/Transforms/LoopStrengthReduce/ARM64/lsr-*.ll: Add explicit triple arm64-unknown for targeting pecoff.
llvm-svn: 205125
2014-03-30 05:01:04 +00:00
Tim Northover
00ed9964c6 ARM64: initial backend import
This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.

Everything will be easier with the target in-tree though, hence this
commit.

llvm-svn: 205090
2014-03-29 10:18:08 +00:00