8 Commits

Author SHA1 Message Date
Haicheng Wu
1d3fb4f736 [JumpThreading] Split select that has constant conditions coming from the PHI node
Look for PHI/Select in the same BB of the form

bb:
  %p = phi [false, %bb1], [true, %bb2], [false, %bb3], [true, %bb4], ...
  %s = select p, trueval, falseval

And expand the select into a branch structure. This later enables
jump-threading over bb in this pass.

Using the similar approach of SimplifyCFG::FoldCondBranchOnPHI(), unfold
select if the associated PHI has at least one constant.  If the unfolded
select is not jump-threaded, it will be folded again in the later
optimizations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257198 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-08 19:39:39 +00:00
Geoff Berry
7a39479674 [JumpThreading] Fix opcode bonus in getJumpThreadDuplicationCost()
The code that was meant to adjust the duplication cost based on the
terminator opcode was not being executed in cases where the initial
threshold was hit inside the loop.

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D15536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256568 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-29 18:10:16 +00:00
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
Dinesh Dwivedi
199da600f3 Fixed jump threading going to infinite loop.
This patch add code to remove unreachable blocks from function
as they may cause jump threading to stuck in infinite loop.

Differential Revision: http://reviews.llvm.org/D3991



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211103 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 14:34:19 +00:00
Benjamin Kramer
c11b107f21 JumpThreading: Turn a select instruction into branching if it allows to thread one half of the select.
This is a common pattern coming out of simplifycfg generating gross code.

a:                                       ; preds = %entry
  %sel = select i1 %cmp1, double %add, double 0.000000e+00
  br label %b

b:
  %cond5 = phi double [ %sel, %a ], [ %sub, %entry ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

becomes

a:
  br i1 %cmp1, label %b, label %if.then

b:
  %cond5 = phi double [ %sub, %entry ], [ %add, %a ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

Skipping block b completely if possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187880 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 10:29:38 +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
Manman Ren
408853ea16 JumpThreading: when default destination is the destination of some cases in a
switch, make sure we include the value for the cases when calculating edge
value from switch to the default destination.

rdar://12241132


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163270 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05 23:45:58 +00:00
Frits van Bommel
26e097ca4b Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121859 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 09:51:20 +00:00