Commit Graph

28 Commits

Author SHA1 Message Date
Dehao Chen f16376b505 Follow-up patch of http://reviews.llvm.org/D19948 to handle missing profiles when simplifying CFG.
Summary: Set default branch weight to 1:1 if one of the branch has profile missing when simplifying CFG.

Reviewers: spatel, davidxl

Subscribers: danielcdh, llvm-commits

Differential Revision: http://reviews.llvm.org/D20307

llvm-svn: 269995
2016-05-18 22:41:03 +00:00
Dehao Chen b76e5d948a Propagate branch metadata when some branch probability is missing.
Summary: In sample profile, some branches may have profile missing due to profile inaccuracy. We want existing branch probability still valid after propagation.

Reviewers: hfinkel, davidxl, spatel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19948

llvm-svn: 269137
2016-05-10 23:07:19 +00:00
Sanjay Patel 1cb6241a89 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 / r268751 with possible fix)
Retrying r268550/r268751 which were reverted at r268577/r268765 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken another guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268767
2016-05-06 18:07:46 +00:00
Sanjay Patel 84a0bf64a8 revert r268751 - caused same failures on msan bot
llvm-svn: 268765
2016-05-06 17:51:37 +00:00
Sanjay Patel 6609510c32 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 with possible fix)
Retrying r268550 which was reverted at r268577 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken a guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268751
2016-05-06 17:07:47 +00:00
Vitaly Buka fdcea9d78a Revert "[SimplifyCFG] propagate branch metadata when creating select"
MemorySanitizer: use-of-uninitialized-value
0x4910e47 in count /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:159:12
0x4910e47 in countLeadingZeros<unsigned long> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:183
0x4910e47 in FitWeights /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:855
0x4910e47 in SimplifyCondBranchToCondBranch /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2895

This reverts commit 609f4dd4bf3bc735c8c047a4d4b0a8e9e4d202e2.

llvm-svn: 268577
2016-05-04 23:59:33 +00:00
Sanjay Patel 7e8c285814 [SimplifyCFG] propagate branch metadata when creating select
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268550
2016-05-04 20:48:24 +00:00
Sanjay Patel bc6fad0bdf add minimal test to show dropped metadata
llvm-svn: 268141
2016-04-30 00:12:54 +00:00
Sanjay Patel 29dea0d230 [SimplifyCFG] propagate branch metadata when creating select
llvm-svn: 267624
2016-04-26 23:15:48 +00:00
Sanjay Patel 82059090d3 Add check for "branch_weights" with prof metadata
While we're here, fix the comment and variable names to make it
clear that these are raw weights, not percentages.

llvm-svn: 267491
2016-04-25 23:15:16 +00:00
David Blaikie a79ac14fa6 [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

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
Duncan P. N. Exon Smith be7ea19b58 IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

llvm-svn: 224257
2014-12-15 19:07:53 +00:00
Manman Ren f1cb16e481 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.

llvm-svn: 200262
2014-01-27 23:39:03 +00:00
Justin Bogner 0ba3f211c4 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.

llvm-svn: 197791
2013-12-20 08:21:30 +00:00
Justin Bogner 668eb1f746 test: Make a branchweight test more specific
llvm-svn: 197790
2013-12-20 08:21:27 +00:00
Justin Bogner f71b18e972 test: Prefer CHECK-LABEL to CHECK in branchweight tests
llvm-svn: 197789
2013-12-20 08:21:24 +00:00
Justin Bogner a41a7b3ee5 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.

llvm-svn: 196845
2013-12-10 00:13:41 +00:00
Stephen Lin c1c7a1309c 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

llvm-svn: 186268
2013-07-14 01:42:54 +00:00
Manman Ren 5657555357 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.

llvm-svn: 164084
2012-09-18 00:47:33 +00:00
Manman Ren ce48ea7e25 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.

llvm-svn: 164076
2012-09-17 23:07:43 +00:00
Manman Ren 774246a3a9 PGO: preserve branch-weight metadata when simplifying SwitchOnSelect.
llvm-svn: 164068
2012-09-17 22:28:55 +00:00
Manman Ren 2d4c10fc49 PGO: preserve branch-weight metadata when simplifying two branches with a common
destination in SimplifyCondBranchToCondBranch.

llvm-svn: 164054
2012-09-17 21:30:40 +00:00
Manman Ren bfb9d435e4 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.

llvm-svn: 163954
2012-09-15 00:39:57 +00:00
Manman Ren 8691e5220b PGO: preserve branch-weight metadata when simplifying a switch with a single
case to a conditional branch and when removing dead cases.

llvm-svn: 163942
2012-09-14 21:53:06 +00:00
Manman Ren 49dbe255e6 PGO: preserve branch-weight metadata when removing a case which jumps
to the default target.

llvm-svn: 163724
2012-09-12 17:04:11 +00:00
Benjamin Kramer aca1885695 FileCheck hygiene.
llvm-svn: 147580
2012-01-05 00:43:34 +00:00
Nick Lewycky c554a9b58e 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!

llvm-svn: 147286
2011-12-27 04:31:52 +00:00
Nick Lewycky 8d302df4a4 Update the branch weight metadata when reversing the order of a branch.
llvm-svn: 147280
2011-12-26 20:54:14 +00:00