Commit Graph

35 Commits

Author SHA1 Message Date
Kyle Butt b15c06677c CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well, subject to some simple frequency calculations.

Differential Revision: https://reviews.llvm.org/D28583

llvm-svn: 293716
2017-01-31 23:48:32 +00:00
Kyle Butt efe56fed12 Revert "CodeGen: Allow small copyable blocks to "break" the CFG."
This reverts commit ada6595a526d71df04988eb0a4b4fe84df398ded.

This needs a simple probability check because there are some cases where it is
not profitable.

llvm-svn: 291695
2017-01-11 19:55:19 +00:00
Kyle Butt df27aa8c89 CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well.

Differential revision: https://reviews.llvm.org/D27742

llvm-svn: 291609
2017-01-10 23:04:30 +00:00
David Blaikie 23af64846f [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction
See r230786 and r230794 for similar changes to gep and load
respectively.

Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.

When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.

This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.

This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).

No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.

This leaves /only/ the varargs case where the explicit type is required.

Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.

About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.

import fileinput
import sys
import re

pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")

def conv(match, line):
  if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
    return line
  return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]

for line in sys.stdin:
  sys.stdout.write(conv(re.search(pat, line), line))

llvm-svn: 235145
2015-04-16 23:24:18 +00:00
Matthias Braun 898d11e864 DAGCombiner: Canonicalize select(and/or,x,y) depending on target.
This is based on the following equivalences:
select(C0 & C1, X, Y) <=> select(C0, select(C1, X, Y), Y)
select(C0 | C1, X, Y) <=> select(C0, X, select(C1, X, Y))

Many target cannot perform and/or on the CPU flags and therefore the
right side should be choosen to avoid materializign the i1 flags in an
integer register. If the target can perform this operation efficiently
we normalize to the left form.

Differential Revision: http://reviews.llvm.org/D7622

llvm-svn: 231507
2015-03-06 19:49:10 +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
David Blaikie 79e6c74981 [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

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Chandler Carruth 9f4530b95d [SDAG] Introduce a combined set to the DAG combiner which tracks nodes
which have successfully round-tripped through the combine phase, and use
this to ensure all operands to DAG nodes are visited by the combiner,
even if they are only added during the combine phase.

This is critical to have the combiner reach nodes that are *introduced*
during combining. Previously these would sometimes be visited and
sometimes not be visited based on whether they happened to end up on the
worklist or not. Now we always run them through the combiner.

This fixes quite a few bad codegen test cases lurking in the suite while
also being more principled. Among these, the TLS codegeneration is
particularly exciting for programs that have this in the critical path
like TSan-instrumented binaries (although I think they engineer to use
a different TLS that is faster anyways).

I've tried to check for compile-time regressions here by running llc
over a merged (but not LTO-ed) clang bitcode file and observed at most
a 3% slowdown in llc. Given that this is essentially a worst case (none
of opt or clang are running at this phase) I think this is tolerable.
The actual LTO case should be even less costly, and the cost in normal
compilation should be negligible.

With this combining logic, it is possible to re-legalize as we combine
which is necessary to implement PSHUFB formation on x86 as
a post-legalize DAG combine (my ultimate goal).

Differential Revision: http://reviews.llvm.org/D4638

llvm-svn: 213898
2014-07-24 22:15:28 +00:00
Stephen Lin 98cbca2e4d Disambiguate function names in some CodeGen tests. (Some tests were using function names that also were names of instructions and/or doing other unusual things that were making the test not amenable to otherwise scriptable pattern matching.) No functionality change.
llvm-svn: 186621
2013-07-18 22:29:15 +00:00
Stephen Lin d24ab20e9b Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.
This update was done with the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc.*debug" $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
      sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
      sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
      sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
      sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
      mv $TEMP $NAME
    fi
  done

llvm-svn: 186280
2013-07-14 06:24:09 +00:00
Stephen Lin f799e3f944 Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion.
This was done with the following sed invocation to catch label lines demarking function boundaries:
    sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.

llvm-svn: 186258
2013-07-13 20:38:47 +00:00
Shuxin Yang 01efdd6c28 (For X86) Enhancement to add-carray/sub-borrow (adc/sbb) optimization.
The adc/sbb optimization is to able to convert following expression
into a single adc/sbb instruction:
  (ult) ... = x + 1 // where the ult is unsigned-less-than comparison
  (ult) ... = x - 1

  This change is to flip the "x >u y" (i.e. ugt comparison) in order 
to expose the adc/sbb opportunity.

llvm-svn: 167180
2012-10-31 23:11:48 +00:00
Manman Ren 009cd82c59 Testcase for r164835
llvm-svn: 164842
2012-09-28 20:26:33 +00:00
Jan Wen Voung 4ce1d7b4f1 Add some cases to x86 OptimizeCompare to handle DEC and INC, too.
While we are setting the earlier def to true, also make it live.

llvm-svn: 164056
2012-09-17 22:04:23 +00:00
Manman Ren 1be131ba27 X86: enable CSE between CMP and SUB
We perform the following:
1> Use SUB instead of CMP for i8,i16,i32 and i64 in ISel lowering.
2> Modify MachineCSE to correctly handle implicit defs.
3> Convert SUB back to CMP if possible at peephole.

Removed pattern matching of (a>b) ? (a-b):0 and like, since they are handled
by peephole now.

rdar://11873276

llvm-svn: 161462
2012-08-08 00:51:41 +00:00
Manman Ren 32367c063b X86 Peephole: fix PR13475 in optimizeCompare.
It is possible that an instruction can use and update EFLAGS.
When checking the safety, we should check the usage of EFLAGS first before
declaring it is safe to optimize due to the update.

llvm-svn: 160912
2012-07-28 03:15:46 +00:00
Manman Ren cc1dc6dc11 Disable rematerialization in TwoAddressInstructionPass.
It is redundant; RegisterCoalescer will do the remat if it can't eliminate
the copy. Collected instruction counts before and after this. A few extra
instructions are generated due to spilling but it is normal to see these kinds
of changes with almost any small codegen change, according to Jakob.

This also fixed rdar://11830760 where xor is expected instead of movi0.

llvm-svn: 160749
2012-07-25 18:28:13 +00:00
Manman Ren d0a4ee8427 X86: remove redundant cmp against zero.
Updated OptimizeCompare in peephole to remove redundant cmp against zero.
We only remove Compare if CF and OF are not used.

rdar://11855129

llvm-svn: 160454
2012-07-18 21:40:01 +00:00
Manman Ren 1553ce0e81 X86: Update to peephole optimization to move Movr0 before (Sub, Cmp) pair.
When Movr0 is between sub and cmp, we move Movr0 before sub if it enables
removal of Cmp.

llvm-svn: 160066
2012-07-11 19:35:12 +00:00
Manman Ren 5f6fa428fa X86: implement functions to analyze & synthesize CMOV|SET|Jcc
getCondFromSETOpc, getCondFromCMovOpc, getSETFromCond, getCMovFromCond

No functional change intended.
If we want to update the condition code of CMOV|SET|Jcc, we first analyze the
opcode to get the condition code, then update the condition code, finally
synthesize the new opcode form the new condition code.

llvm-svn: 159955
2012-07-09 18:57:12 +00:00
Manman Ren bb36074047 X86: Fix optimizeCompare to correctly check safe condition.
It is safe if EFLAGS is killed or re-defined.
When we are done with the basic block, check whether EFLAGS is live-out.
Do not optimize away cmp if EFLAGS is live-out.

llvm-svn: 159888
2012-07-07 03:34:46 +00:00
Manman Ren c965673707 X86: peephole optimization to remove cmp instruction
For each Cmp, we check whether there is an earlier Sub which make Cmp
redundant. We handle the case where SUB operates on the same source operands as
Cmp, including the case where the two source operands are swapped.

llvm-svn: 159838
2012-07-06 17:36:20 +00:00
Manman Ren bf86b295bb Test case for r158160
llvm-svn: 158218
2012-06-08 18:42:37 +00:00
Manman Ren ae02c5a93e X86: replace SUB with CMP if possible
This patch will optimize the following
    movq    %rdi, %rax
    subq    %rsi, %rax
    cmovsq  %rsi, %rdi
    movq    %rdi, %rax
to
    cmpq    %rsi, %rdi
    cmovsq  %rsi, %rdi
    movq    %rdi, %rax

Perform this optimization if the actual result of SUB is not used.

rdar: 11540023
llvm-svn: 158126
2012-06-07 00:42:47 +00:00
Manman Ren 9c9641812c Revert r157755.
The commit is intended to fix rdar://11540023.
It is implemented as part of peephole optimization. We can actually implement
this in the SelectionDAG lowering phase.

llvm-svn: 158122
2012-06-06 23:53:03 +00:00
Manman Ren 5097e4f38a Revert r157831
llvm-svn: 157896
2012-06-03 03:14:24 +00:00
Manman Ren 879ca9d47d X86: peephole optimization to remove cmp instruction
This patch will optimize the following:
  sub r1, r3
  cmp r3, r1 or cmp r1, r3
  bge L1
TO
  sub r1, r3
  bge L1 or ble L1

If the branch instruction can use flag from "sub", then we can eliminate
the "cmp" instruction.

llvm-svn: 157831
2012-06-01 19:49:33 +00:00
Manman Ren 9bccb64e56 X86: replace SUB with CMP if possible
This patch will optimize the following
        movq    %rdi, %rax
        subq    %rsi, %rax
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax
to
        cmpq    %rsi, %rdi
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax

Perform this optimization if the actual result of SUB is not used.

rdar: 11540023
llvm-svn: 157755
2012-05-31 17:20:29 +00:00
Evan Cheng b64e7b778b Fix two-address pass's aggressive instruction commuting heuristics. It's meant
to catch cases like:
 %reg1024<def> = MOV r1
 %reg1025<def> = MOV r0
 %reg1026<def> = ADD %reg1024, %reg1025
 r0            = MOV %reg1026

By commuting ADD, it let coalescer eliminate all of the copies. However, there
was a bug in the heuristics where it ended up commuting the ADD in:

 %reg1024<def> = MOV r0
 %reg1025<def> = MOV 0
 %reg1026<def> = ADD %reg1024, %reg1025
 r0            = MOV %reg1026

That did no benefit but rather ensure the last MOV would not be coalesced.

rdar://11355268

llvm-svn: 156048
2012-05-03 01:45:13 +00:00
Manman Ren 425a55c1ce X86: optimization for max-like struct
This patch will optimize the following cases on X86
(a > b) ? (a-b) : 0
(a >= b) ? (a-b) : 0
(b < a) ? (a-b) : 0
(b <= a) ? (a-b) : 0

FROM
movl    %edi, %ecx
subl    %esi, %ecx
cmpl    %edi, %esi
movl    $0, %eax
cmovll  %ecx, %eax
TO
xorl    %eax, %eax
subl    %esi, %edi
cmovll  %eax, %edi
movl    %edi, %eax

rdar: 10734411
llvm-svn: 155919
2012-05-01 17:16:15 +00:00
NAKAMURA Takumi 91a3f886ef test/CodeGen/X86/jump_sign.ll: Add -mcpu=pentiumpro for non-x86 hosts. It uses "cmov".
llvm-svn: 147521
2012-01-04 03:52:23 +00:00
Evan Cheng 104dbb0fd1 For x86, canonicalize max
(x > y) ? x : y
=>
(x >= y) ? x : y

So for something like
(x - y) > 0 : (x - y) ? 0
It will be
(x - y) >= 0 : (x - y) ? 0

This makes is possible to test sign-bit and eliminate a comparison against
zero. e.g.
subl   %esi, %edi
testl  %edi, %edi
movl   $0, %eax
cmovgl %edi, %eax
=>
xorl   %eax, %eax
subl   %esi, $edi
cmovsl %eax, %edi

rdar://10633221

llvm-svn: 147512
2012-01-04 01:41:39 +00:00
Dan Gohman 40503396da Eliminate more uses of llvm-as and llvm-dis.
llvm-svn: 81290
2009-09-08 23:54:48 +00:00
Tanya Lattner 3cdf542f5a Remove llvm-upgrade and update tests.
llvm-svn: 47432
2008-02-21 07:42:26 +00:00
Reid Spencer 83b3d82672 Regression is gone, don't try to find it on clean target.
llvm-svn: 33296
2007-01-17 07:59:14 +00:00