Commit Graph

238 Commits

Author SHA1 Message Date
Daniel Dunbar 9efbedfd35 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

llvm-svn: 188513
2013-08-16 00:37:11 +00:00
Daniel Dunbar b44e1b81ab [tests] Fix refacto in r187764 that effectively disabled SimplifyCFG tests. :(
llvm-svn: 188503
2013-08-15 22:52:27 +00:00
Tom Stellard aa664d9b92 Factor FlattenCFG out from SimplifyCFG
Patch by: Mei Ye

llvm-svn: 187764
2013-08-06 02:43:45 +00:00
Bill Wendling a5c536e1ee Use function attributes to indicate that we don't want to realign the stack.
Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.

llvm-svn: 187618
2013-08-01 21:42:05 +00:00
Manman Ren 620e978f69 Debug Info: enable verifier for testing cases.
llvm-svn: 187375
2013-07-29 20:18:19 +00:00
Tom Stellard 9ba44da833 SimplifyCFG: Add missing tests from r187278
llvm-svn: 187291
2013-07-27 02:54:44 +00:00
Manman Ren 921382ed78 Debug Info Verifier: verify SPs in llvm.dbg.sp.
Also always add DIType, DISubprogram and DIGlobalVariable to the list
in DebugInfoFinder without checking them, so we can verify them later
on.

llvm-svn: 187285
2013-07-27 01:26:08 +00:00
Rafael Espindola 2012b82625 Next batch of -disable-debug-info-verifier.
These tests fail without it if pipefail is enabled.

llvm-svn: 187205
2013-07-26 14:16:30 +00:00
Rafael Espindola b552086fcb add -disable-debug-info-verifier to 3 test to fix tests with pipefail.
llvm-svn: 187064
2013-07-24 18:44:10 +00:00
Stephen Lin a76289aa1b 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

llvm-svn: 186269
2013-07-14 01:50:49 +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
Duncan Sands e773c08021 TryToSimplifyUncondBranchFromEmptyBlock was checking that any common
predecessors of the two blocks it is attempting to merge supply the
same incoming values to any phi in the successor block.  This change
allows merging in the case where there is one or more incoming values
that are undef.  The undef values are rewritten to match the non-undef
value that flows from the other edge.  Patch by Mark Lacey.

llvm-svn: 186069
2013-07-11 08:28:20 +00:00
Benjamin Kramer 371722288c SimplifyCFG: Teach switch generation some patterns that instcombine forms.
This allows us to create switches even if instcombine has munged two of the
incombing compares into one and some bit twiddling. This was motivated by enum
compares that are common in clang.

llvm-svn: 185632
2013-07-04 14:22:02 +00:00
Rafael Espindola a5e536ab0e Second part of pr16069
The problem this time seems to be a thinko. We were assuming that in the CFG

A
| \
|  B
| /
C

speculating the basic block B would cause only the phi value for the B->C edge
to be speculated. That is not true, the phi's are semantically in the edges, so
if the A->B->C path is taken, any code needed for A->C is not executed and we
have to consider it too when deciding to speculate B.

llvm-svn: 183226
2013-06-04 14:11:59 +00:00
David Majnemer c82f27af2a SimplifyCFG: Do not transform PHI to select if doing so would be unsafe
PR16069 is an interesting case where an incoming value to a PHI is a
trap value while also being a 'ConstantExpr'.

We do not consider this case when performing the 'HoistThenElseCodeToIf'
optimization.

Instead, make our modifications more conservative if we detect that we
cannot transform the PHI to a select.

llvm-svn: 183152
2013-06-03 20:43:12 +00:00
Arnold Schwaighofer 474df6d3ed SimplifyCFG: If convert single conditional stores
This resurrects r179957, but adds code that makes sure we don't touch
atomic/volatile stores:

This transformation will transform a conditional store with a preceeding
uncondtional store to the same location:

 a[i] =
 may-alias with a[i] load
 if (cond)
   a[i] = Y

into an unconditional store.

 a[i] = X
 may-alias with a[i] load
 tmp = cond ? Y : X;
 a[i] = tmp

We assume that on average the cost of a mispredicted branch is going to be
higher than the cost of a second store to the same location, and that the
secondary benefits of creating a bigger basic block for other optimizations to
work on outway the potential case where the branch would be correctly predicted
and the cost of the executing the second store would be noticably reflected in
performance.

hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With
this change we are on par with gcc's performance (gcc also performs this
transformation). There was a 1.2 % performance improvement on a ARM swift chip.
Other tests in the test-suite+external seem to be mostly uninfluenced in my
experiments:
This optimization was triggered on 41 tests such that the executable was
different before/after the patch. Only 1 out of the 40 tests (dealII) was
reproducable below 100% (by about .4%). Given that hmmer benefits so much I
believe this to be a fair trade off.

llvm-svn: 180731
2013-04-29 21:28:24 +00:00
Arnold Schwaighofer 6eb32b31bd Revert "SimplifyCFG: If convert single conditional stores"
There is the temptation to make this tranform dependent on target information as
it is not going to be beneficial on all (sub)targets. Therefore, we should
probably do this in MI Early-Ifconversion.

This reverts commit r179957. Original commit message:

"SimplifyCFG: If convert single conditional stores

This transformation will transform a conditional store with a preceeding
uncondtional store to the same location:

a[i] =
may-alias with a[i] load
if (cond)
    a[i] = Y
into an unconditional store.

a[i] = X
may-alias with a[i] load
tmp = cond ? Y : X;
a[i] = tmp

We assume that on average the cost of a mispredicted branch is going to be
higher than the cost of a second store to the same location, and that the
secondary benefits of creating a bigger basic block for other optimizations to
work on outway the potential case were the branch would be correctly predicted
and the cost of the executing the second store would be noticably reflected in
performance.

hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With
this change we are on par with gcc's performance (gcc also performs this
transformation). There was a 1.2 % performance improvement on a ARM swift chip.
Other tests in the test-suite+external seem to be mostly uninfluenced in my
experiments:
This optimization was triggered on 41 tests such that the executable was
different before/after the patch. Only 1 out of the 40 tests (dealII) was
reproducable below 100% (by about .4%). Given that hmmer benefits so much I
believe this to be a fair trade off.

I am going to watch performance numbers across the builtbots and will revert
this if anything unexpected comes up."

llvm-svn: 179980
2013-04-21 13:09:04 +00:00
Arnold Schwaighofer 3546ccf465 SimplifyCFG: If convert single conditional stores
This transformation will transform a conditional store with a preceeding
uncondtional store to the same location:

 a[i] =
 may-alias with a[i] load
 if (cond)
   a[i] = Y

into an unconditional store.

 a[i] = X
 may-alias with a[i] load
 tmp = cond ? Y : X;
 a[i] = tmp

We assume that on average the cost of a mispredicted branch is going to be
higher than the cost of a second store to the same location, and that the
secondary benefits of creating a bigger basic block for other optimizations to
work on outway the potential case were the branch would be correctly predicted
and the cost of the executing the second store would be noticably reflected in
performance.

hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With
this change we are on par with gcc's performance (gcc also performs this
transformation). There was a 1.2 % performance improvement on a ARM swift chip.
Other tests in the test-suite+external seem to be mostly uninfluenced in my
experiments:
This optimization was triggered on 41 tests such that the executable was
different before/after the patch. Only 1 out of the 40 tests (dealII) was
reproducable below 100% (by about .4%). Given that hmmer benefits so much I
believe this to be a fair trade off.

I am going to watch performance numbers across the builtbots and will revert
this if anything unexpected comes up.

llvm-svn: 179957
2013-04-20 21:42:09 +00:00
Hans Wennborg c9e1d99279 simplifycfg: Fix integer overflow converting switch into icmp.
If a switch instruction has a case for every possible value of its type,
with the same successor, SimplifyCFG would replace it with an icmp ult,
but the computation of the bound overflows in that case, which inverts
the test.

Patch by Jed Davis!

llvm-svn: 179587
2013-04-16 08:35:36 +00:00
Michael Gottesman ccc93e72e1 Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.
llvm-svn: 179087
2013-04-09 05:18:53 +00:00
Bill Wendling 9534d8885f Don't remove a landing pad if the invoke requires a table entry.
An invoke may require a table entry. For instance, when the function it calls
is expected to throw.
<rdar://problem/13360379>

llvm-svn: 176827
2013-03-11 20:53:00 +00:00
Andrew Trick a0a5ca06b9 SimplifyCFG fix for volatile load/store.
Fixes rdar:13349374.

Volatile loads and stores need to be preserved even if the language
standard says they are undefined. "volatile" in this context means "get
out of the way compiler, let my platform handle it".

Additionally, this is the only way I know of with llvm to write to the
first page (when hardware allows) without dropping to assembly.

llvm-svn: 176599
2013-03-07 01:03:35 +00:00
Bill Wendling a032374ea0 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.

llvm-svn: 175877
2013-02-22 09:09:42 +00:00
Michael Gottesman 41e4ac4224 Filecheckized 2x tests in SimplifyCFG and removed their date prefix to fit with current llvm style for test names.
llvm-svn: 174011
2013-01-31 01:04:23 +00:00
Chandler Carruth 329b590e6e Re-revert r173342, without losing the compile time improvements, flat
out bug fixes, or functionality preserving refactorings.

llvm-svn: 173610
2013-01-27 06:42:03 +00:00
Chandler Carruth ceff222dea Switch this code away from Value::isUsedInBasicBlock. That code either
loops over instructions in the basic block or the use-def list of the
value, neither of which are really efficient when repeatedly querying
about values in the same basic block.

What's more, we already know that the CondBB is small, and so we can do
a much more efficient test by counting the uses in CondBB, and seeing if
those account for all of the uses.

Finally, we shouldn't blanket fail on any such instruction, instead we
should conservatively assume that those instructions are part of the
cost.

Note that this actually fixes a bug in the pass because
isUsedInBasicBlock has a really terrible bug in it. I'll fix that in my
next commit, but the fix for it would make this code suddenly take the
compile time hit I thought it already was taking, so I wanted to go
ahead and migrate this code to a faster & better pattern.

The bug in isUsedInBasicBlock was also causing other tests to test the
wrong thing entirely: for example we weren't actually disabling
speculation for floating point operations as intended (and tested), but
the test passed because we failed to speculate them due to the
isUsedInBasicBlock failure.

llvm-svn: 173417
2013-01-25 05:40:09 +00:00
Benjamin Kramer 1c4e323fdd Reapply chandlerc's r173342 now that the miscompile it was triggering is fixed.
Original commit message:
Plug TTI into the speculation logic, giving it a real cost interface
that can be specialized by targets.

The goal here is not to be more aggressive, but to just be more accurate
with very obvious cases. There are instructions which are known to be
truly free and which were not being modeled as such in this code -- see
the regression test which is distilled from an inner loop of zlib.

Everywhere the TTI cost model is insufficiently conservative I've added
explicit checks with FIXME comments to go add proper modelling of these
cost factors.

If this causes regressions, the likely solution is to make TTI even more
conservative in its cost estimates, but test cases will help here.

llvm-svn: 173357
2013-01-24 16:44:25 +00:00
Chandler Carruth 321c6a7c50 Revert r173342 temporarily. It appears to cause a very late miscompile
of stage2 in a bootstrap. Still investigating....

llvm-svn: 173343
2013-01-24 13:24:24 +00:00
Chandler Carruth 5f4519309f Plug TTI into the speculation logic, giving it a real cost interface
that can be specialized by targets.

The goal here is not to be more aggressive, but to just be more accurate
with very obvious cases. There are instructions which are known to be
truly free and which were not being modeled as such in this code -- see
the regression test which is distilled from an inner loop of zlib.

Everywhere the TTI cost model is insufficiently conservative I've added
explicit checks with FIXME comments to go add proper modelling of these
cost factors.

If this causes regressions, the likely solution is to make TTI even more
conservative in its cost estimates, but test cases will help here.

llvm-svn: 173342
2013-01-24 12:39:29 +00:00
Chandler Carruth 01bffaad03 Address a large chunk of this FIXME by accumulating the cost for
unfolded constant expressions rather than checking each one
independently.

llvm-svn: 173341
2013-01-24 12:05:17 +00:00
Chandler Carruth 8a21005cca Switch the constant expression speculation cost evaluation away from
a cost fuction that seems both a bit ad-hoc and also poorly suited to
evaluating constant expressions.

Notably, it is missing any support for trivial expressions such as
'inttoptr'. I could fix this routine, but it isn't clear to me all of
the constraints its other users are operating under.

The core protection that seems relevant here is avoiding the formation
of a select instruction wich a further chain of select operations in
a constant expression operand. Just explicitly encode that constraint.

Also, update the comments and organization here to make it clear where
this needs to go -- this should be driven off of real cost measurements
which take into account the number of constants expressions and the
depth of the constant expression tree.

llvm-svn: 173340
2013-01-24 11:53:01 +00:00
Dmitri Gribenko d7beca87f5 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.

llvm-svn: 171343
2013-01-01 13:57:25 +00:00
Dmitri Gribenko b137c9e551 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.

llvm-svn: 171246
2012-12-30 01:28:40 +00:00
Evan Cheng 65df808f62 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

llvm-svn: 168970
2012-11-30 02:02:42 +00:00
Hans Wennborg c3c8d95c51 Only do switch-to-lookup table transformation when TargetTransformInfo
is available.

llvm-svn: 167552
2012-11-07 21:35:12 +00:00
Hans Wennborg 11d4ebe224 Fix bad test IR in switch_to_lookup_table.ll
llvm-svn: 167543
2012-11-07 18:38:24 +00:00
Hans Wennborg b71f72aa82 Remove fixme about unreachable cases from SwitchToLookupTable
SimplifyCFG will have removed those cases for us.

llvm-svn: 167132
2012-10-31 16:15:25 +00:00
Hans Wennborg 9e74dd97b8 Do simple constant propagation in lookup table formation for switches
By propagating the value for the switch condition, LLVM can now build
lookup tables for code such as:

  switch (x) {
    case 1: return 5;
    case 2: return 42;
    case 3: case 4: case 5:
      return x - 123;
    default:
      return 123;
  }

Given that x is known for each case, "x - 123" becomes a constant for
cases 3, 4, and 5.

llvm-svn: 167115
2012-10-31 13:42:45 +00:00
Hans Wennborg e0cf14fa9d switch_to_lookup_table.ll: Remove some unnecessary lines, comments,
function attributes, etc.

llvm-svn: 167016
2012-10-30 15:11:52 +00:00
Hans Wennborg f3254838e4 Use TargetTransformInfo to control switch-to-lookup table transformation
When the switch-to-lookup tables transform landed in SimplifyCFG, it
was pointed out that this could be inappropriate for some targets.
Since there was no way at the time for the pass to know anything about
the target, an awkward reverse-transform was added in CodeGenPrepare
that turned lookup tables back into switches for some targets.

This patch uses the new TargetTransformInfo to determine if a
switch should be transformed, and removes
CodeGenPrepare::ConvertLoadToSwitch.

llvm-svn: 167011
2012-10-30 11:23:25 +00:00
Jakob Stoklund Olesen 977f41a1fa Also optimize large switch statements.
The isValueEqualityComparison() guard at the top of SimplifySwitch()
only applies to some of the possible transformations.

The newer transformations work just fine on large switches, and the
check on predecessor count is nonsensical.

llvm-svn: 166710
2012-10-25 18:51:15 +00:00
Benjamin Kramer d12e82e523 SimplifyCFG: Enhance the "remove CFG edge that leads to null pointer dereference" optimization to also handle instructions with multiple uses.
We conservatively only check the first use to avoid walking long use chains.
This catches the common case of having both a load and a store to a pointer
supplied by a PHI node.

llvm-svn: 165232
2012-10-04 16:11:49 +00:00
Benjamin Kramer 9fc3dc7781 SimplifyCFG: Don't crash when forming a switch bitmap with an undef default value.
Fixes PR13985.

llvm-svn: 164934
2012-10-01 11:31:48 +00:00
Benjamin Kramer c2081d1c19 Fix a integer overflow in SimplifyCFG's look up table formation logic.
If the width is very large it gets truncated from uint64_t to uint32_t when
passed to TD->fitsInLegalInteger. The truncated value can fit in a register.
This manifested in massive memory usage or crashes (PR13946).

llvm-svn: 164784
2012-09-27 18:29:58 +00:00
Hans Wennborg cd3a11f725 Address Duncan's comments on r164684:
- Put statistics in alphabetical order
- Don't use getZextValue when building TableInt, just use APInts
- Introduce Create{Z,S}ExtOrTrunc in IRBuilder.

llvm-svn: 164696
2012-09-26 14:01:53 +00:00
Hans Wennborg 39583b88a0 SimplifyCFG: Make the switch-to-lookup table transformation store the
tables in bitmaps when they fit in a target-legal register.

This saves some space, and it also allows for building tables that would
otherwise be deemed too sparse.

One interesting case that this hits is example 7 from
http://blog.regehr.org/archives/320. We currently generate good code
for this when lowering the switch to the selection DAG: we build a
bitmask to decide whether to jump to one block or the other. My patch
will result in the same bitmask, but it removes the need for the jump,
as the return value can just be retrieved from the mask.

llvm-svn: 164684
2012-09-26 09:44:49 +00:00
Manman Ren 93ab64916f SimplifyCFG: sink common codes from IF, ELSE blocks down to END block.
We already have HoistThenElseCodeToIf, this patch implements
SinkThenElseCodeToEnd. When END block has only two predecessors and each
predecessor terminates with unconditional branches, we compare instructions in
IF and ELSE blocks backwards and check whether we can sink the common
instructions down.

rdar://12191395

llvm-svn: 164325
2012-09-20 22:37:36 +00:00
Hans Wennborg f744fa917d SimplifyCFG: Don't generate invalid code for switch used to initialize
two variables where the first variable is returned and the second
ignored.

I don't think this occurs in practice (other passes should have cleaned
up the unused phi node), but it should still be handled correctly.

Also make the logic for determining if we should return early less
sketchy.

llvm-svn: 164225
2012-09-19 14:24:21 +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