Commit Graph

11 Commits

Author SHA1 Message Date
Craig Topper
b72ae70036 Add rest of BMI/BMI2 instructions to the folding tables as well as popcnt and lzcnt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170304 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-17 05:02:29 +00:00
Chandler Carruth
7782102c70 Use standard promotion for i8 CTTZ nodes and i8 CTLZ nodes when the
LZCNT instructions are available. Force promotion to i32 to get
a smaller encoding since the fix-ups necessary are just as complex for
either promoted type

We can't do standard promotion for CTLZ when lowering through BSR
because it results in poor code surrounding the 'xor' at the end of this
instruction. Essentially, if we promote the entire CTLZ node to i32, we
end up doing the xor on a 32-bit CTLZ implementation, and then
subtracting appropriately to get back to an i8 value. Instead, our
custom logic just uses the knowledge of the incoming size to compute
a perfect xor. I'd love to know of a way to fix this, but so far I'm
drawing a blank. I suspect the legalizer could be more clever and/or it
could collude with the DAG combiner, but how... ;]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147251 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 12:12:34 +00:00
Chandler Carruth
d873a4b89b Expand more when we have a nice 'tzcnt' instruction, to avoid generating
'bsf' instructions here.

This one is actually debatable to my eyes. It's not clear that any chip
implementing 'tzcnt' would have a slow 'bsf' for any reason, and unless
EFLAGS or a zero input matters, 'tzcnt' is just a longer encoding.
Still, this restores the old behavior with 'tzcnt' enabled for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147246 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 11:11:38 +00:00
Chandler Carruth
131f7d3544 Tidy up some of these tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147245 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 11:11:36 +00:00
Chandler Carruth
ddbc274169 Manually upgrade the test suite to specify the flag to cttz and ctlz.
I followed three heuristics for deciding whether to set 'true' or
'false':

- Everything target independent got 'true' as that is the expected
  common output of the GCC builtins.
- If the target arch only has one way of implementing this operation,
  set the flag in the way that exercises the most of codegen. For most
  architectures this is also the likely path from a GCC builtin, with
  'true' being set. It will (eventually) require lowering away that
  difference, and then lowering to the architecture's operation.
- Otherwise, set the flag differently dependending on which target
  operation should be tested.

Let me know if anyone has any issue with this pattern or would like
specific tests of another form. This should allow the x86 codegen to
just iteratively improve as I teach the backend how to differentiate
between the two forms, and everything else should remain exactly the
same.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146370 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-12 11:59:10 +00:00
Craig Topper
b4c945716f Remove intrinsics for X86 BLSI, BLSMSK, and BLSR intrinsics and replace with custom isel lowering code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142642 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-21 06:55:01 +00:00
Craig Topper
717cdb0df8 Rename PEXTR to PEXT. Add intrinsics for BMI instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-19 07:48:35 +00:00
Craig Topper
54a11176f6 Add X86 ANDN instruction. Including instruction selection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141947 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-14 07:06:56 +00:00
Craig Topper
909652f687 Add X86 TZCNT instruction and patterns to select it. Also added core-avx2 processor which is gcc's name for Haswell.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141939 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-14 03:21:46 +00:00
Bill Wendling
1203fe7fc8 Revert r141854 because it was causing failures:
http://lab.llvm.org:8011/builders/llvm-x86_64-linux/builds/101

--- Reverse-merging r141854 into '.':
U    test/MC/Disassembler/X86/x86-32.txt
U    test/MC/Disassembler/X86/simple-tests.txt
D    test/CodeGen/X86/bmi.ll
U    lib/Target/X86/X86InstrInfo.td
U    lib/Target/X86/X86ISelLowering.cpp
U    lib/Target/X86/X86.td
U    lib/Target/X86/X86Subtarget.h



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141857 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-13 07:48:07 +00:00
Craig Topper
8ab1d1e900 Add X86 TZCNT instruction and patterns to select it. Also added core-avx2 processor which is gcc's name for Haswell.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141854 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-13 07:09:14 +00:00