28 Commits

Author SHA1 Message Date
David Blaikie
5a70dd1d82 [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232184 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-13 18:20:45 +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
David Blaikie
198d8baafb [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230786 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 19:29:02 +00:00
Hans Wennborg
325385a37f SimplifyCFG: Omit range checks for switch lookup tables when default is unreachable
The range check would get optimized away later, but we might as well not emit
them in the first place.

http://reviews.llvm.org/D6471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227126 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:52:34 +00:00
Hans Wennborg
d5c2318adc SimplifyCFG: don't remove unreachable default switch destinations
An unreachable default destination can be exploited by other optimizations and
allows for more efficient lowering. Both the SDag switch lowering and
LowerSwitch can exploit unreachable defaults.

Also make TurnSwitchRangeICmp handle switches with unreachable default.
This is kind of separate change, but it cannot be tested without the change
above, and I don't want to land the change above without this since that would
regress other tests.

Differential Revision: http://reviews.llvm.org/D6471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:52:32 +00:00
Hans Wennborg
ca71be6415 SimplifyCFG: check uses of constant-foldable instrs in switch destinations (PR20210)
The previous code assumed that such instructions could not have any uses
outside CaseDest, with the motivation that the instruction could not
dominate CommonDest because CommonDest has phi nodes in it. That simply
isn't true; e.g., CommonDest could have an edge back to itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225552 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 22:13:31 +00:00
Hans Wennborg
c9605b6067 Revert r223049, r223050 and r223051 while investigating test failures.
I didn't foresee affecting the Clang test suite :/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223054 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:36:43 +00:00
Hans Wennborg
07c6024f48 SimplifyCFG: Omit range checks for switch lookup tables when default is unreachable
They would get optimized away later, but we might as well not emit them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223051 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:08:38 +00:00
Hans Wennborg
b2fd944378 SimplifyCFG: don't remove unreachable default switch destinations
An unreachable default destination can be exploited by other optimizations, and
SDag lowering is now prepared to handle them efficiently.

For example, branches to the unreachable destination will be optimized away,
such as in the case of range checks for switch lookup tables.

On 64-bit Linux, this reduces the size of a clang bootstrap by 80 kB (and
Chromium by 30 kB).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223050 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:08:35 +00:00
Erik Eckstein
6cfbf12d77 reinstate r222872: Peephole optimization in switch table lookup: reuse the guarding table comparison if possible.
Fixed missing dominance check.
Original commit message:

This optimization tries to reuse the generated compare instruction, if there is a comparison against the default value after the switch.
Example:
   if (idx < tablesize)
      r = table[idx]; // table does not contain default_value
   else
      r = default_value;
   if (r != default_value)
      ...
Is optimized to:
   cond = idx < tablesize;
   if (cond)
      r = table[idx];
   else
      r = default_value;
   if (cond)
      ...
Jump threading will then eliminate the second if(cond).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222891 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 15:13:14 +00:00
Erik Eckstein
4646580bc8 Revert "Peephole optimization in switch table lookup: reuse the guarding table comparison if possible."
It is breaking the clang bootstrag.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222877 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 10:59:08 +00:00
Erik Eckstein
c394c42d6d Peephole optimization in switch table lookup: reuse the guarding table comparison if possible.
This optimization tries to reuse the generated compare instruction, if there is a comparison against the default value after the switch.
Example:
    if (idx < tablesize)
       r = table[idx]; // table does not contain default_value
    else
       r = default_value;
    if (r != default_value)
       ...
Is optimized to:
    cond = idx < tablesize;
    if (cond)
       r = table[idx];
    else
       r = default_value;
    if (cond)
       ...
\endcode
Jump threading will then eliminate the second if(cond).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222872 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 08:33:51 +00:00
Hans Wennborg
ca5ffd51d9 Remove useless rdar:// comment from switch_to_lookup_table.ll test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222772 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-25 18:45:23 +00:00
Juergen Ributzka
18db81a0ec [SimplifyCFG] Make the value type of the hole check bitmask a power-of-2.
When converting a switch to a lookup table we might have to generate a bitmaks
to encode and check for holes in the original switch statement.

The type of this mask depends on the number of switch statements, which can
result in illegal types for pretty much all architectures.

To avoid unnecessary type legalization and help FastISel this commit increases
the size of the bitmask to next power-of-2 value when necessary.

This fixes rdar://problem/18984639.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222168 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 19:39:56 +00:00
Erik Eckstein
72a1394991 Optimize switch lookup tables with linear mapping.
This is a simple optimization for switch table lookup:
It computes the output value directly with an (optional) mul and add if there is a linear mapping between index and output.
Example:

int f1(int x) {
  switch (x) {
    case 0: return 10;
    case 1: return 11;
    case 2: return 12;
    case 3: return 13;
  }
  return 0;
}

generates:

define i32 @f1(i32 %x) #0 {
entry:
  %0 = icmp ult i32 %x, 4
  br i1 %0, label %switch.lookup, label %return

switch.lookup:
  %switch.offset = add i32 %x, 10
  ret i32 %switch.offset

return:
  ret i32 0
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222121 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 09:13:57 +00:00
Marcello Maggioni
db9fed93fa Switch to select optimization for two-case switches
This is the same optimization of r219233 with modifications to support PHIs with multiple incoming edges from the same block
and a test to check that this condition is handled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219656 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 01:58:26 +00:00
Joerg Sonnenberger
c6133c17e0 Revert r219223, it creates invalid PHI nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219587 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-12 17:16:04 +00:00
Marcello Maggioni
5c98f14b78 Two case switch to select optimization
This optimization tries to convert switch instructions that are used to select a value with only 2 unique cases + default block
to a select or a couple of selects (depending if the default block is reachable or not).

The typical case this optimization wants to be able to optimize is this one:

Example:
switch (a) {
  case 10:                %0 = icmp eq i32 %a, 10
    return 10;            %1 = select i1 %0, i32 10, i32 4
  case 20:        ---->   %2 = icmp eq i32 %a, 20
    return 2;             %3 = select i1 %2, i32 2, i32 %1
  default:
    return 4;
}

It also sets the base for further optimizations that are planned and being reviewed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219223 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 18:16:44 +00:00
Hans Wennborg
0545f16700 Don't build switch tables for dllimport and TLS variables in GEPs
This is a follow-up to r211331, which failed to notice that we were
returning early from ValidLookupTableConstant for GEPs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211753 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 00:30:52 +00:00
Hans Wennborg
160dcf5b61 Don't build switch lookup tables for dllimport or TLS variables
We would previously put dllimport variables in switch lookup tables, which
doesn't work because the address cannot be used in a constant initializer.
This is basically the same problem that we have in PR19955.

Putting TLS variables in switch tables also desn't work, because the
address of such a variable is not constant.

Differential Revision: http://reviews.llvm.org/D4220

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211331 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-20 00:38:12 +00:00
Hans Wennborg
09a31f3154 Allow switch-to-lookup table for tables with holes by adding bitmask check
This allows us to generate table lookups for code such as:

  unsigned test(unsigned x) {
    switch (x) {
      case 100: return 0;
      case 101: return 1;
      case 103: return 2;
      case 105: return 3;
      case 107: return 4;
      case 109: return 5;
      case 110: return 6;
      default: return f(x);
    }
  }

Since cases 102, 104, etc. are not constants, the lookup table has holes
in those positions. We therefore guard the table lookup with a bitmask check.

Patch by Jasper Neumann!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203694 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-12 18:35:40 +00:00
Hans Wennborg
89fa06ba0f Switch-to-lookup tables: set threshold to 3 cases
There has been an old FIXME to find the right cut-off for when it's worth
analyzing and potentially transforming a switch to a lookup table.

The switches always have two or more cases. I could not measure any speed-up
by transforming a switch with two cases. A switch with three cases gets a nice
speed-up, and I couldn't measure any compile-time regression, so I think this
is the right threshold.

In a Clang self-host, this causes 480 new switches to be transformed,
and reduces the final binary size with 8 KB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-15 05:00:27 +00:00
Hans Wennborg
19236d53eb Switch-to-lookup tables: Don't require a result for the default
case when the lookup table doesn't have any holes.

This means we can build a lookup table for switches like this:

  switch (x) {
    case 0: return 1;
    case 1: return 2;
    case 2: return 3;
    case 3: return 4;
    default: exit(1);
  }

The default case doesn't yield a constant result here, but that doesn't matter,
since a default result is only necessary for filling holes in the lookup table,
and this table doesn't have any holes.

This makes us transform 505 more switches in a clang bootstrap, and shaves 164 KB
off the resulting clang binary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199025 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-12 00:44:41 +00:00
Benjamin Kramer
f681437cb0 SimplifyCFG: Use existing constant folding logic when forming switch tables.
Both simpler and more powerful than the hand-rolled folding logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194475 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-12 12:24:36 +00:00
Stephen Lin
15bfd6d3ad Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.
This conversion 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/;\(.*\)\([A-Za-z0-9_]*\):\( *\)define\([^@]*\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3define\4@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186269 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:50:49 +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
Evan Cheng
40eef5fe36 Fix logic to determine whether to turn a switch into a lookup table. When
the tables cannot fit in registers (i.e. bitmap), do not emit the table
if it's using an illegal type.

rdar://12779436


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168970 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30 02:02:42 +00:00
Hans Wennborg
b0319962cf Only do switch-to-lookup table transformation when TargetTransformInfo
is available.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167552 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-07 21:35:12 +00:00