Commit Graph

20 Commits

Author SHA1 Message Date
Tim Northover
d0dbe02fd2 ARM & AArch64: make use of common cmpxchg idioms after expansion
The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.

When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.

This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.

I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.

rdar://problem/16227836

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209883 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-30 10:09:59 +00:00
Saleem Abdulrasool
2b42ff6fdb ARM: remove ancient -arm-tail-calls option
This option is from 2010, designed to work around a linker issue on Darwin for
ARM.  According to grosbach this is no longer an issue and this option can
safely be removed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203576 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-11 15:09:49 +00:00
Stephen Lin
8b2b8a1835 Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.
This update was done with the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc.*debug" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_-]*\):\( *\)$FUNC: *\$/;\1\2-LABEL:\3$FUNC:/g" $TEMP
      done
      sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
      sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
      sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
      sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186280 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 06:24:09 +00:00
Lang Hames
d26c93d3a8 Correctly preserve the input chain for potential tailcall nodes whose
return values are bitcasts.

The chain had previously been being clobbered with the entry node to
the dag, which sometimes caused other code in the function to be
erroneously deleted when tailcall optimization kicked in.

<rdar://problem/13827621>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181696 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-13 10:21:19 +00:00
Benjamin Kramer
1cb47b9afe Test case hygiene.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176772 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-09 18:25:40 +00:00
Evan Cheng
fa12d0df5a Add proper checks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154379 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-10 03:15:42 +00:00
Evan Cheng
bf010eb911 Fix a long standing tail call optimization bug. When a libcall is emitted
legalizer always use the DAG entry node. This is wrong when the libcall is
emitted as a tail call since it effectively folds the return node. If
the return node's input chain is not the entry (i.e. call, load, or store)
use that as the tail call input chain.

PR12419
rdar://9770785
rdar://11195178


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154370 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-10 01:51:00 +00:00
Evan Cheng
1c80f56268 ARM target should allow codegenprep to duplicate ret instructions to enable tailcall opt. rdar://11140249
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153717 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-30 01:24:39 +00:00
Evan Cheng
afff941211 ARM target code clean up. Check for iOS, not Darwin where it makes sense.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146981 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-20 18:26:50 +00:00
Bob Wilson
6d2f9cec71 Reenable tail calls for iOS 5.0 and later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141370 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-07 17:17:49 +00:00
Jim Grosbach
245f5e8e2a Use ARMPseudoExpand for ARM tail calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134719 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-08 18:50:22 +00:00
Cameron Zwarich
106acd4158 Make tTAILJMPr/tTAILJMPrND emit a tBX without a preceding MOV of PC to LR. This
fixes <rdar://problem/9495913>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132042 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-25 04:45:27 +00:00
Cameron Zwarich
d34d429401 Fix <rdar://problem/9476260> by having tail calls always generate 32-bit branches
in Darwin Thumb2 code. Tail calls are already disabled on Thumb1.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131894 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-23 01:57:17 +00:00
Jim Grosbach
5edf24efac Clean up ARM tail calls a bit. They're pseudo-instructions for normal branches.
Also more cleanly separate the ARM vs. Thumb functionality. Previously, the
encoding would be incorrect for some Thumb instructions (the indirect calls).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127637 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 00:30:40 +00:00
Evan Cheng
7cfa656ad8 Don't merge restore with tail call instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124167 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 01:28:33 +00:00
Evan Cheng
3d2125c9db Enable sibling call optimization of libcalls which are expanded during
legalization time. Since at legalization time there is no mapping from
SDNode back to the corresponding LLVM instruction and the return
SDNode is target specific, this requires a target hook to check for
eligibility. Only x86 and ARM support this form of sibcall optimization
right now.
rdar://8707777


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120501 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 23:55:39 +00:00
Bob Wilson
703af3ab12 Temporarily disable tail calls on ARM to work around some linker problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111050 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-13 22:43:33 +00:00
Dale Johannesen
7835f1fcdb Changes to ARM tail calls, mostly cosmetic.
Add explicit testcases for tail calls within the same module.
Duplicate some code to humor those who think .w doesn't apply on ARM.
Leave this disabled on Thumb1, and add some comments explaining why it's hard
and won't gain much.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107851 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-08 01:18:23 +00:00
Evan Cheng
0110ac66eb Disable sibcall optimization for Thumb1 for now since Thumb1RegisterInfo::emitEpilogue is not expecting them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106368 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-19 01:01:32 +00:00
Dale Johannesen
c66cdf74a9 Enable tail calls on ARM by default, with some
basic tests.

This has been well tested on Darwin but not elsewhere.
It should work provided the linker correctly resolves
  B.W  <label in other function>
which it has not seen before, at least from llvm-based
compilers.  I'm leaving the arm-tail-calls switch in
until I see if there's any problems because of that;
it might need to be disabled for some environments.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106299 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18 19:00:18 +00:00