Commit Graph

12 Commits

Author SHA1 Message Date
David Blaikie
7c9c6ed761 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
Reid Kleckner
9d18e626cc Revert "Transforms: reapply SVN r219899"
This reverts commit r220811 and r220839. It made an incorrect change to
musttail handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221226 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-04 02:02:14 +00:00
Saleem Abdulrasool
586cf3d88d Transforms: reapply SVN r219899
This restores the commit from SVN r219899 with an additional change to ensure
that the CodeGen is correct for the case that was identified as being incorrect
(originally PR7272).

In the case that during inlining we need to synthesize a value on the stack
(i.e. for passing a value byval), then any function involving that alloca must
be stripped of its tailness as the restriction that it does not access the
parent's stack no longer holds.  Unfortunately, a single alloca can cause a
rippling effect through out the inlining as the value may be aliased or may be
mutated through an escaped external call.  As such, we simply track if an alloca
has been introduced in the frame during inlining, and strip any tail calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 18:27:37 +00:00
Rafael Espindola
ec51f45338 Revert "TRE: make TRE a bit more aggressive"
This reverts commit r219899.

This also updates byval-tail-call.ll to make it clear what was breaking.
Adding r219899 again will cause the load/store to disappear.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220093 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 21:25:48 +00:00
Saleem Abdulrasool
ebe6584c32 TRE: make TRE a bit more aggressive
Make tail recursion elimination a bit more aggressive.  This allows us to get
tail recursion on functions that are just branches to a different function.  The
fact that the function takes a byval argument does not restrict it from being
optimised into just a tail call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219899 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-16 03:27:30 +00:00
Nick Lewycky
1bda2d9386 We may visit a call that uses an alloca multiple times in callUsesLocalStack, sometimes with IsNocapture true and sometimes with IsNocapture false. We accidentally skipped work we needed to do in the IsNocapture=false case if we were called with IsNocapture=true the first time. Fixes PR20405!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213726 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 06:24:49 +00:00
Nick Lewycky
05da4dd998 Improve 'tail' call marking in TRE. A bootstrap of clang goes from 375k calls marked tail in the IR to 470k, however this improvement does not carry into an improvement of the call/jmp ratio on x86. The most common pattern is a tail call + br to a block with nothing but a 'ret'.
The number of tail call to loop conversions remains the same (1618 by my count).

The new algorithm does a local scan over the use-def chains to identify local "alloca-derived" values, as well as points where the alloca could escape. Then, a visit over the CFG marks blocks as being before or after the allocas have escaped, and annotates the calls accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208017 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-05 23:59:03 +00:00
Reid Kleckner
0df9abbd63 Fix PR7272 in -tailcallelim instead of the inliner
The -tailcallelim pass should be checking if byval or inalloca args can
be captured before marking calls as tail calls.  This was the real root
cause of PR7272.

With a better fix in place, revert the inliner change from r105255.  The
test case it introduced still passes and has been moved to
test/Transforms/Inline/byval-tail-call.ll.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3403

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206789 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 20:48:47 +00:00
Stephen Lin
39f4e8d9cc Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $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
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186268 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:42:54 +00:00
Michael Gottesman
03fddb710e Teach TailRecursionElimination to handle certain cases of nocapture escaping allocas.
Without the changes introduced into this patch, if TRE saw any allocas at all,
TRE would not perform TRE *or* mark callsites with the tail marker.

Because TRE runs after mem2reg, this inadequacy is not a death sentence. But
given a callsite A without escaping alloca argument, A may not be able to have
the tail marker placed on it due to a separate callsite B having a write-back
parameter passed in via an argument with the nocapture attribute.

Assume that B is the only other callsite besides A and B only has nocapture
escaping alloca arguments (*NOTE* B may have other arguments that are not passed
allocas). In this case not marking A with the tail marker is unnecessarily
conservative since:

  1. By assumption A has no escaping alloca arguments itself so it can not
     access the caller's stack via its arguments.

  2. Since all of B's escaping alloca arguments are passed as parameters with
     the nocapture attribute, we know that B does not stash said escaping
     allocas in a manner that outlives B itself and thus could be accessed
     indirectly by A.

With the changes introduced by this patch:

  1. If we see any escaping allocas passed as a capturing argument, we do
     nothing and bail early.

  2. If we do not see any escaping allocas passed as captured arguments but we
     do see escaping allocas passed as nocapture arguments:

       i. We do not perform TRE to avoid PR962 since the code generator produces
          significantly worse code for the dynamic allocas that would be created
          by the TRE algorithm.

       ii. If we do not return twice, mark call sites without escaping allocas
           with the tail marker. *NOTE* This excludes functions with escaping
           nocapture allocas.

  3. If we do not see any escaping allocas at all (whether captured or not):

       i. If we do not have usage of setjmp, mark all callsites with the tail
          marker.

       ii. If there are no dynamic/variable sized allocas in the function,
           attempt to perform TRE on all callsites in the function.

Based off of a patch by Nick Lewycky.

rdar://14324281.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186057 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 04:40:01 +00:00
Michael Gottesman
23fabedce5 [TRE] Combined another test into basic.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185729 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 22:24:06 +00:00
Michael Gottesman
cd56727b55 [TRE] Merged several tests into the the test basic.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 20:45:13 +00:00