Commit Graph

16 Commits

Author SHA1 Message Date
Manman Ren
aa6627016f PGO branch weight: keep halving the weights until they can fit into
uint32.

When folding branches to common destination, the updated branch weights
can exceed uint32 by more than factor of 2. We should keep halving the
weights until they can fit into uint32.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200262 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-27 23:39:03 +00:00
Justin Bogner
bcb726dc8a Transforms: Don't create bad weights when eliminating dead cases
If we happen to eliminate every case in a switch that has branch
weights, we currently try to create metadata for the one remaining
branch, triggering an assert. Instead, we need to check that the
metadata we're trying to create is sensible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197791 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-20 08:21:30 +00:00
Justin Bogner
35c913b5b1 test: Make a branchweight test more specific
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197790 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-20 08:21:27 +00:00
Justin Bogner
a2323825cb test: Prefer CHECK-LABEL to CHECK in branchweight tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197789 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-20 08:21:24 +00:00
Justin Bogner
31eaed9c6d Transforms: Don't create bad branch weights when folding a switch
This avoids creating branch weight metadata of length one when we fold
cases into the default of a switch instruction, which was triggering
an assert.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196845 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-10 00:13:41 +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
222d6192ad PGO: preserve branch-weight metadata when simplifying Switch to a sub, an icmp
and a conditional branch; also when removing dead cases from a switch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164084 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18 00:47:33 +00:00
Manman Ren
b010277b59 PGO: preserve branch-weight metadata when simplifying Switch
Hanlde the case when we split the default edge if the default target has "icmp"
and unconditinal branch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164076 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17 23:07:43 +00:00
Manman Ren
b11cbe6b23 PGO: preserve branch-weight metadata when simplifying SwitchOnSelect.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164068 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17 22:28:55 +00:00
Manman Ren
566540332f PGO: preserve branch-weight metadata when simplifying two branches with a common
destination in SimplifyCondBranchToCondBranch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164054 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17 21:30:40 +00:00
Manman Ren
062986c2f0 PGO: preserve branch-weight metadata when simplifying two branches with a common
destination.

Updated previous implementation to fix a case not covered:
// PBI: br i1 %x, TrueDest, BB
// BI:  br i1 %y, TrueDest, FalseDest
The other case was handled correctly.
// PBI: br i1 %x, BB, FalseDest
// BI:  br i1 %y, TrueDest, FalseDest

Also tried to use 64-bit arithmetic instead of APInt with scale to simplify the
computation. Let me know if you have other opinions about this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163954 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-15 00:39:57 +00:00
Manman Ren
ad2890760f PGO: preserve branch-weight metadata when simplifying a switch with a single
case to a conditional branch and when removing dead cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163942 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14 21:53:06 +00:00
Manman Ren
ee99c7f1bf PGO: preserve branch-weight metadata when removing a case which jumps
to the default target.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163724 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12 17:04:11 +00:00
Benjamin Kramer
44aac553f6 FileCheck hygiene.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147580 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05 00:43:34 +00:00
Nick Lewycky
06cc66f65a Teach simplifycfg to recompute branch weights when merging some branches, and
to discard weights when appropriate. Still more to do (and a new TODO), but
it's a start!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-27 04:31:52 +00:00
Nick Lewycky
c9a1aed7fe Update the branch weight metadata when reversing the order of a branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147280 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-26 20:54:14 +00:00