Commit Graph

38 Commits

Author SHA1 Message Date
Haicheng Wu 691ed105b0 [JumpThreading] See through Cast Instructions
To capture more jump-thread opportunity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263618 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-16 04:52:52 +00:00
Haicheng Wu 35d3c7b00e Revert "[JumpThreading] Simplify Instructions first in ComputeValueKnownInPredecessors()"
Not sure it handles undef properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263605 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-15 23:38:47 +00:00
Haicheng Wu 27a460f328 [JumpThreading] Simplify Instructions first in ComputeValueKnownInPredecessors()
This change tries to find more opportunities to thread over basic blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261981 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-26 06:06:04 +00:00
Jingyue Wu 0a613536b1 [JumpThreading] make jump threading respect convergent annotation.
Summary:
JumpThreading shouldn't duplicate a convergent call, because that would move a convergent call into a control-inequivalent location. For example,
  if (cond) {
    ...
  } else {
    ...
  }
  convergent_call();
  if (cond) {
    ...
  } else {
    ...
  }
should not be optimized to
  if (cond) {
    ...
    convergent_call();
    ...
  } else {
    ...
    convergent_call();
    ...
  }

Test Plan: test/Transforms/JumpThreading/basic.ll

Patch by Xuetian Weng. 

Reviewers: resistor, arsenm, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12484

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 06:10:27 +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
Bill Wendling 351b7a10e2 Use references to attribute groups on the call/invoke instructions.
Listing all of the attributes for the callee of a call/invoke instruction is way
too much and makes the IR unreadable. Use references to attributes instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175877 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-22 09:09:42 +00:00
Dmitri Gribenko fbfb1b286f Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.

My previous regex was not good enough to find these.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171343 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-01 13:57:25 +00:00
James Molloy 67ae135759 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 16:04:27 +00:00
Owen Anderson 2a0fd011c2 Remove dead option from tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113855 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-14 21:03:40 +00:00
Owen Anderson b95df124b2 Add a test for the duplicated-conditional situation illutrated by PR5652.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112621 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 18:49:12 +00:00
Owen Anderson 421cc4c999 Add a micro-test for the transforms I added to JumpThreading.
I have not been able to find a way to test each in isolation, for a few reasons:
1) The ability to look-through non-i1 BinaryOperator's requires the ability to look through non-constant
   ICmps in order for it to ever trigger.
2) The ability to do LVI-powered PHI value determination only matters in cases that ProcessBranchOnPHI
   can't handle.  Since it already handles all the cases without other instructions in the def-use chain
   between the PHI and the branch, it requires the ability to look through ICmps and/or BinaryOperators
   as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112611 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 17:59:07 +00:00
Owen Anderson 660cab32fe Use LVI to eliminate conditional branches where we've tested a related condition previously. Update tests for this change.
This fixes PR5652.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112270 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27 17:12:29 +00:00
Chris Lattner 972a46c96a 1) Use the new SimplifyInstructionsInBlock routine instead of the copy
in JT.

2) When cloning blocks for PHI or xor conditions, use
instsimplify to simplify the code as we go.  This allows us to 
squish common cases early in JT which opens up opportunities for
subsequent iterations, and allows it to completely simplify the
testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93253 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 20:41:47 +00:00
Chris Lattner 2249a0b1bd Teach jump threading to duplicate small blocks when the branch
condition is a xor with a phi node.  This eliminates nonsense
like this from 176.gcc in several places:

 LBB166_84:
        testl   %eax, %eax
-       setne   %al
-       xorb    %cl, %al
-       notb    %al
-       testb   $1, %al
-       je      LBB166_85
+       je      LBB166_69
+       jmp     LBB166_85

This is rdar://7391699



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93221 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 02:07:17 +00:00
Gabor Greif 8bedf029f0 typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86980 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 09:44:17 +00:00
Chris Lattner 66c04c48de use getPredicateOnEdge to fold comparisons through PHI nodes,
which implements GCC PR18046.  This also gets us 360 more
jump threads on 176.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86953 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 05:24:05 +00:00
Chris Lattner 3e04a05672 should not commit when distracted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86929 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 02:04:17 +00:00
Chris Lattner a5810add9c We now thread some impossible condition information with LVI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86927 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:55:20 +00:00
Chris Lattner 87e9f59c7a with the new code we can thread non-instruction values. This
allows us to handle the test10 testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86924 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:41:34 +00:00
Chris Lattner b8c124c343 move some stuff into DEBUG's and turn on lazy-value-info for
the basic.ll testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:22:16 +00:00
Chris Lattner 2b9024c877 oops, didn't mean to commit this, no harm, but add a todoops, didn't mean to commit this, no harm, but add a todoo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86768 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 00:27:54 +00:00
Chris Lattner 10f2d13d58 Stub out a new lazy value info pass, which will eventually
vend value constraint information to the optimizer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86767 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 00:22:30 +00:00
Chris Lattner 055d046f48 implement a TODO by teaching jump threading about "xor x, 1".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86739 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 22:39:16 +00:00
Chris Lattner f3183f6da6 Make jump threading eliminate blocks that just contain phi nodes,
debug intrinsics, and an unconditional branch when possible.  This
reuses the TryToSimplifyUncondBranchFromEmptyBlock function split
out of simplifycfg.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86722 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 21:40:01 +00:00
Chris Lattner fddcf47a24 make jump threading recursively simplify expressions instead of doing it
just one level deep.  On the testcase we go from getting this:

F1:                                               ; preds = %T2
  %F = and i1 true, %cond                         ; <i1> [#uses=1]
  br i1 %F, label %X, label %Y

to a fully threaded:

F1:                                               ; preds = %T2
  br label %Y


This changes gets us to the point where we're forming (too many) switch 
instructions on doug's strswitch testcase.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86646 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:57:31 +00:00