Commit Graph

385 Commits

Author SHA1 Message Date
David Majnemer bd4fef4a89 IR: Do not canonicalize constant GEPs into an out-of-bounds array access
Summary:
Consider a GEP of:
i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c, i32 0, i32 0, i64 0)

If we proceeded to GEP the aforementioned object by 8, would form a GEP of:
i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c, i32 0, i32 0, i64 8)

Note that we would go through the first array member, causing an
out-of-bounds accesses.  This is problematic because we might get fooled
if we are trying to evaluate loads using this GEP, for example, based
off of an object with a constant initializer where the array is zero.

This fixes PR17732.

Reviewers: nicholas, chandlerc, void

Reviewed By: void

CC: llvm-commits, echristo, void, aemerson

Differential Revision: http://llvm-reviews.chandlerc.com/D2093

llvm-svn: 194220
2013-11-07 22:15:53 +00:00
Matt Arsenault 614ea99da7 Fix GVN creating bitcast between address spaces
llvm-svn: 193710
2013-10-30 19:05:41 +00:00
Manman Ren adf4cc171e TBAA: update tbaa format from scalar format to struct-path aware format.
llvm-svn: 191690
2013-09-30 18:17:55 +00:00
Manman Ren 0ed04fc9ab TBAA: handle scalar TBAA format and struct-path aware TBAA format.
Remove the command line argument "struct-path-tbaa" since we should not depend
on command line argument to decide which format the IR file is using. Instead,
we check the first operand of the tbaa tag node, if it is a MDNode, we treat
it as struct-path aware TBAA format, otherwise, we treat it as scalar TBAA
format.

When clang starts to use struct-path aware TBAA format no matter whether
struct-path-tbaa is no, and we can auto-upgrade existing bc files, the support
for scalar TBAA format can be dropped.

Existing testing cases are updated to use the struct-path aware TBAA format.

llvm-svn: 191538
2013-09-27 18:34:27 +00:00
Benjamin Kramer 2939dd3d11 MemoryBuiltins: Reinstate optimizing (uninitialized) loads from operator new.
llvm-svn: 191315
2013-09-24 17:34:29 +00:00
Shuxin Yang 6e35094bbf Resurrect r191017 " GVN proceeds in the presence of dead code" plus a fix to PR17307 & 17308.
The problem of r191017 is that when GVN fabricate a val-number for a dead instruction (in order
to make following expr-PRE happy), it forget to fabricate a leader-table entry for it as well.

llvm-svn: 191118
2013-09-20 23:12:57 +00:00
Joerg Sonnenberger cf90a12170 Delete empty files.
llvm-svn: 191105
2013-09-20 20:40:22 +00:00
Joerg Sonnenberger 1fbe323649 Revert r191017, it results in segmentation faults in Qt.
llvm-svn: 191104
2013-09-20 20:33:57 +00:00
Shuxin Yang 74c9a170b8 GVN proceeds in the presence of dead code.
This is how it ignores the dead code:
1) When a dead branch target, say block B, is identified, all the
    blocks dominated by B is dead as well.

2) The PHIs of those blocks in dominance-frontier(B) is updated such
   that the operands corresponding to dead predecessors are replaced
   by "UndefVal".

   Using lattice's jargon, the "UndefVal" is the "Top" in essence.
   Phi node like this "phi(v1 bb1, undef xx)" will be optimized into
   "v1" if v1 is constant, or v1 is an instruction which dominate this
   PHI node.

3) When analyzing the availability of a load L, all dead mem-ops which
   L depends on disguise as a load which evaluate exactly same value as L.

4) The dead mem-ops will be materialized as "UndefVal" during code motion.

llvm-svn: 191017
2013-09-19 17:22:51 +00:00
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
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
Nick Lewycky c0514629c9 Eliminate trivial redundant loads across nocapture+readonly calls to uncaptured
pointer arguments.

llvm-svn: 185776
2013-07-07 10:15:16 +00:00
Matt Arsenault c23753a53e Fix unchecked uses of DominatorTree in MemoryDependenceAnalysis.
Use unknown results for places where it would be needed

llvm-svn: 181176
2013-05-06 02:07:24 +00:00
Nadav Rotem 7b7585d153 Revert 179071 because it is not the right way to support non standard new/new[] operators.
llvm-svn: 179084
2013-04-09 04:43:46 +00:00
Nadav Rotem 9dd90ac5b4 c++ new operators are not malloc-like functions because they do not return uninitialized memory.
Users may overide new-operators and implement any function that they like.

llvm-svn: 179071
2013-04-08 23:40:47 +00:00
Jan Wen Voung 6dc3076080 Revert the test moves from 176733. Use "REQUIRES: asserts" instead.
llvm-svn: 176873
2013-03-12 16:27:52 +00:00
Jan Wen Voung 7857a64909 Disable statistics on Release builds and move tests that depend on -stats.
Summary:
Statistics are still available in Release+Asserts (any +Asserts builds),
and stats can also be turned on with LLVM_ENABLE_STATS.

Move some of the FastISel stats that were moved under DEBUG()
back out of DEBUG(), since stats are disabled across the board now.

Many tests depend on grepping "-stats" output.  Move those into
a orig_dir/Stats/. so that they can be marked as unsupported
when building without statistics.

Differential Revision: http://llvm-reviews.chandlerc.com/D486

llvm-svn: 176733
2013-03-08 22:56:31 +00:00
Manman Ren fe5a61edbe Memory Dependence Analysis: fix a miscompile that uses DT to approxmiate the
reachablity.

We conservatively approximate the reachability analysis by saying it is not
reachable if there is a single path starting from "From" and the path does not
reach "To".

rdar://12801584

llvm-svn: 171512
2013-01-04 19:19:47 +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 56bf2e1830 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: 171250
2012-12-30 02:33:22 +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
NAKAMURA Takumi 5a495a5c96 llvm/test/Transforms/GVN/null-aliases-nothing.ll: Fix a RUN line not to emit ModuleID.
Larry Evans reported it fails if source tree contains "load", like "download".

llvm-svn: 171243
2012-12-30 00:33:26 +00:00
Jakub Staszak 0a74fc8d6c unHECKify test. It was fixed by Chris in 2009.
llvm-svn: 170017
2012-12-12 20:43:00 +00:00
Patrik Hägglund 3eb16c543e Add error handling in getInt.
Accordingly, update a testcase with a broken datalayout string.

Also, we never parse negative numbers, because '-' is used as a
separator. Therefore, use unsigned as result type.

llvm-svn: 168785
2012-11-28 12:13:12 +00:00
NAKAMURA Takumi 43ab4ef9ba llvm/ConstantFolding.cpp: Make ReadDataFromGlobal() and FoldReinterpretLoadFromConstPtr() Big-endian-aware.
llvm-svn: 167595
2012-11-08 20:34:25 +00:00
Hal Finkel 69b07a2c3a Update GVN to support vectors of pointers.
GVN will now generate ptrtoint instructions for vectors of pointers.
Fixes PR14166.

llvm-svn: 166624
2012-10-24 21:22:30 +00:00
Bill Wendling 5858b56ce3 Ignore unreachable blocks when doing memory dependence analysis on non-local
loads. It's not really profitable and may result in GVN going into an infinite
loop when it hits constructs like this:

     %x = gep %some.type %x, ...

Found via an LTO build of LLVM.

llvm-svn: 166490
2012-10-23 18:37:11 +00:00
Benjamin Kramer 8bcc971174 Make MemoryBuiltins aware of TargetLibraryInfo.
This disables malloc-specific optimization when -fno-builtin (or -ffreestanding)
is specified. This has been a problem for a long time but became more severe
with the recent memory builtin improvements.

Since the memory builtin functions are used everywhere, this required passing
TLI in many places. This means that functions that now have an optional TLI
argument, like RecursivelyDeleteTriviallyDeadFunctions, won't remove dead
mallocs anymore if the TLI argument is missing. I've updated most passes to do
the right thing.

Fixes PR13694 and probably others.

llvm-svn: 162841
2012-08-29 15:32:21 +00:00
Benjamin Kramer 2f47a3fb07 Fix broken check lines.
I really need to find a way to automate this, but I can't come up with a regex
that has no false positives while handling tricky cases like custom check
prefixes.

llvm-svn: 162097
2012-08-17 12:28:26 +00:00
Rafael Espindola cc80cdebb9 Teach GVN to reason about edges dominating uses. This allows it to handle cases
where some fact lake a=b dominates a use in a phi, but doesn't dominate the
basic block itself.

This feature could also be implemented by splitting critical edges, but at least
with the current algorithm reasoning about the dominance directly is faster.

The time for running "opt -O2" in the testcase in pr10584 is 1.003 times slower
and on gcc as a single file it is 1.0007 times faster.

llvm-svn: 162023
2012-08-16 15:09:43 +00:00
Chandler Carruth ff123d5c63 Fix the remaining TCL-style quotes found in the testsuite. This is
another mechanical change accomplished though the power of terrible Perl
scripts.

I have manually switched some "s to 's to make escaping simpler.

While I started this to fix tests that aren't run in all configurations,
the massive number of tests is due to a really frustrating fragility of
our testing infrastructure: things like 'grep -v', 'not grep', and
'expected failures' can mask broken tests all too easily.

Essentially, I'm deeply disturbed that I can change the testsuite so
radically without causing any change in results for most platforms. =/

llvm-svn: 159547
2012-07-02 19:09:46 +00:00
Chandler Carruth 5da53436d5 Convert the uses of '|&' to use '2>&1 |' instead, which works on old
versions of Bash. In addition, I can back out the change to the lit
built-in shell test runner to support this.

This should fix the majority of fallout on Darwin, but I suspect there
will be a few straggling issues.

llvm-svn: 159544
2012-07-02 18:37:59 +00:00
Chandler Carruth a5a29f970e Convert all tests using TCL-style quoting to use shell-style quoting.
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.

If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.

Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.

Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s

llvm-svn: 159525
2012-07-02 12:47:22 +00:00
Rafael Espindola 47d988c54c When gvn decides to replace an instruction with another, we have to patch the
replacement to make it at least as generic as the instruction being replaced.
This includes:
* dropping nsw/nuw flags
* getting the least restrictive tbaa and fpmath metadata
* merging ranges

Fixes PR12979.

llvm-svn: 157958
2012-06-04 22:44:21 +00:00
Duncan Sands 4df5e96d3a Fix PR12858, a crash due to GVN's PRE not fully removing an instruction from the
leader table.  That's because it wasn't expecting instructions to turn up as
leader for a value number that is not its own, but equality propagation could
create this situation.  One solution is to have the leader table use a WeakVH
but this slows down GVN by about 5%.  Instead just have equality propagation not
add instructions to the leader table, only constants and arguments.  In theory
this might cause GVN to run more (each time it changes something it runs again)
but it doesn't seem to occur enough to cause a slow down.

llvm-svn: 157251
2012-05-22 14:17:53 +00:00
Jakob Stoklund Olesen 4e55044ff5 Don't PRE compares.
CodeGenPrepare sinks compare instructions down to their uses to prevent
live flags and predicate registers across basic blocks.

PRE of a compare instruction prevents that, forcing the i1 compare
result into a general purpose register.  That is usually more expensive
than the redundant compare PRE was trying to eliminate in the first
place.

llvm-svn: 153657
2012-03-29 17:22:39 +00:00
Duncan Sands 4d928e7dff Nick pointed out on IRC that GVN's propagateEquality wasn't propagating
equalities into phi node operands for which the equality is known to
hold in the incoming basic block.  That's because replaceAllDominatedUsesWith
wasn't handling phi nodes correctly in general (that this didn't give wrong
results was just luck: the specific way GVN uses replaceAllDominatedUsesWith
precluded wrong changes to phi nodes).

llvm-svn: 152006
2012-03-04 13:25:19 +00:00
Duncan Sands bb2fe65542 Have GVN also do condition propagation when the right-hand side is not
a constant.  This fixes PR1768.

llvm-svn: 151713
2012-02-29 11:12:03 +00:00
Duncan Sands 27f459519d When performing a conditional branch depending on the value of a comparison
%cmp (eg: A==B) we already replace %cmp with "true" under the true edge, and
with "false" under the false edge.  This change enhances this to replace the
negated compare (A!=B) with "false" under the true edge and "true" under the
false edge.  Reported to improve perlbench results by 1%.

llvm-svn: 151517
2012-02-27 08:14:30 +00:00
Duncan Sands 926d101640 Teach GVN that x+y is the same as y+x and that x<y is the same as y>x.
llvm-svn: 151365
2012-02-24 15:16:31 +00:00
Eli Bendersky 924f9a671d Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.
Patch reviewed by Daniel Dunbar. It will be followed by additional cleanup patches.

llvm-svn: 150664
2012-02-16 06:28:33 +00:00
Duncan Sands 4b613497f0 Reduce the number of dom queries made by GVN's conditional propagation
logic by half: isOnlyReachableViaThisEdge was trying to be clever and
handle the case of a branch to a basic block which is contained in a
loop.  This costs a domtree lookup and is completely useless due to
GVN's position in the pass pipeline: all loops have preheaders at this
point, which means it is enough for isOnlyReachableViaThisEdge to check
that Dst has only one predecessor.  (I checked this theoretical argument
by running over the entire nightly testsuite, and indeed it is so!).

llvm-svn: 149838
2012-02-05 18:25:50 +00:00
Nick Lewycky 063ae5897c Fix crasher in GVN due to my recent capture tracking changes.
llvm-svn: 145047
2011-11-21 19:42:56 +00:00
Nick Lewycky 7013a19e8a Refactor capture tracking (which already had a couple flags for whether returns
and stores capture) to permit the caller to see each capture point and decide
whether to continue looking.

Use this inside memdep to do an analysis that basicaa won't do. This lets us
solve another devirtualization case, fixing PR8908!

llvm-svn: 144580
2011-11-14 22:49:42 +00:00
Duncan Sands c52af46484 Teach GVN to also propagate switch cases. For example, in this code
switch (n) {
    case 27:
      do_something(x);
    ...
  }
the call do_something(x) will be replaced with do_something(27).  In
gcc-as-one-big-file this results in the removal of about 500 lines of
bitcode (about 0.02%), so has about 1/10 of the effect of propagating
branch conditions.

llvm-svn: 141360
2011-10-07 08:29:06 +00:00
Duncan Sands f4f47ccd12 GVN does simple propagation of conditions: when it sees a conditional
branch "br i1 %x, label %if_true, label %if_false" then it replaces
"%x" with "true" in places only reachable via the %if_true arm, and
with "false" in places only reachable via the %if_false arm.  Except
that actually it doesn't: if value numbering shows that %y is equal
to %x then, yes, %y will be turned into true/false in this way, but
any occurrences of %x itself are not transformed.  Fix this.  What's
more, it's often the case that %x is an equality comparison such as
"%x = icmp eq %A, 0", in which case every occurrence of %A that is
only reachable via the %if_true arm can be replaced with 0.  Implement
this and a few other variations on this theme.  This reduces the number
of lines of LLVM IR in "GCC as one big file" by 0.2%.  It has a bigger
impact on Ada code, typically reducing the number of lines of bitcode
by around 0.4% by removing repeated compiler generated checks.  Passes
the LLVM nightly testsuite and the Ada ACATS testsuite.

llvm-svn: 141177
2011-10-05 14:28:49 +00:00
Duncan Sands e90dd0587e Generalize GVN's conditional propagation logic slightly:
it's OK for the false/true destination to have multiple
predecessors as long as the extra ones are dominated by
the branch destination.

llvm-svn: 141176
2011-10-05 14:17:01 +00:00
Duncan Sands ba60b04148 Mark the eh.typeid.for intrinsic as being 'const', which it is inside
any given function.  As pointed out by John McCall, this is needed to
have redundant eh.typeid.for tests be eliminated in the presence of
cleanups.

llvm-svn: 139360
2011-09-09 07:50:37 +00:00
Duncan Sands 524c33a27f When inlining exception handling code into another function, ensure that
duplicate tests are eliminated (for example if the two functions both have
a catch clause catching the same type, ensure the redundant one is removed).
Note that it would probably be safe to say that eh.typeid.for is 'const',
but since two calls to it with the same argument can give different results
(but only if the calls are in different functions), it seems more correct to
mark it only 'pure'; this doesn't get in the way of the optimization.

llvm-svn: 139236
2011-09-07 16:44:14 +00:00
Jakub Staszak 63a3a0e010 Extra CHECK-NOT to make sure that GVN transform works properly.
llvm-svn: 139012
2011-09-02 17:40:39 +00:00
Jakub Staszak 7470fb01d0 Compare type size instead of type _store_ size to make sure that BitCastInst
will be valid. This fixes PR10820.

llvm-svn: 139005
2011-09-02 14:57:37 +00:00
Bill Wendling e88632d667 Update some tests to the new EH scheme.
llvm-svn: 138925
2011-09-01 00:58:03 +00:00
Eli Friedman 9a468153e1 Atomic load/store handling for the passes using memdep (GVN, DSE, memcpyopt).
llvm-svn: 137888
2011-08-17 22:22:24 +00:00
Lang Hames c5c191b0a4 Added test cases for GVN signed intrinsics recognition, r134777.
llvm-svn: 134778
2011-07-09 00:36:54 +00:00
Lang Hames 29cd98fd52 Make GVN look through extractvalues for recognised intrinsics. GVN can then CSE ops that match values produced by the intrinsics.
llvm-svn: 134677
2011-07-08 01:50:54 +00:00
Jay Foad 29ed2e3bdc This is an automatically reduced test case that crashed in GVN, at some
point during the development of the phi operand changes.

llvm-svn: 133436
2011-06-20 14:46:47 +00:00
Chris Lattner 80ed9dc9e5 rip out a ton of intrinsic modernization logic from AutoUpgrade.cpp, which is
for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.

llvm-svn: 133337
2011-06-18 06:05:24 +00:00
Dan Gohman baf1afb289 Add a testcase to demonstrate the problem where phi translation is
ignored for clobbering partial-alias loads.

llvm-svn: 132633
2011-06-04 07:05:05 +00:00
Dan Gohman a471751c24 Disable the main feature of 130180, the elimination of loads that are
redundant with partially-aliasing loads.

When computing what portion of a clobbering load value is needed,
it doesn't consider phi-translation which may have occurred
between the clobbing load and the redundant load.

llvm-svn: 132631
2011-06-04 06:48:50 +00:00
Eli Friedman b576b1675c When marking a block as being unanalyzable, use "Clobber" on the terminator instead of the first instruction in the block. This is a bit of a hack; "Clobber" isn't really the right marking in the first place. memdep doesn't really have any way of properly expressing "unanalyzable" at the moment. Using it on the terminator is much less ambiguous than using it on an arbitrary instruction, though.
In the given testcase, the "Clobber" was pointing to a load, and GVN was incorrectly assuming that meant that the "Clobber" load overlapped the load being analyzed (when they are actually unrelated).

The included testcase tests both this commit and r132434.

Part two of rdar://9429882.  (r132434 was mislabeled.)

llvm-svn: 132442
2011-06-02 00:08:52 +00:00
Chris Lattner f0d59072de fix PR9841 by having GVN not process dead loads. This was
causing it to get into infinite loops when it would widen a 
load (which can necessarily leave around dead loads).

llvm-svn: 131847
2011-05-22 07:03:34 +00:00
Chris Lattner a10327f531 remove a trivial test, make some other tests less trivial.
llvm-svn: 131846
2011-05-22 07:02:43 +00:00
Chris Lattner cc87723178 make this test less trivial.
llvm-svn: 131845
2011-05-22 06:59:33 +00:00
Chris Lattner 1777601a74 final step needed to resolve PR6627, which allows us to flatten the code down to
a nice and tidy:
  %x1 = load i32* %0, align 4
  %1 = icmp eq i32 %x1, 1179403647
  br i1 %1, label %if.then, label %if.end

instead of doing lots of loads and branches.  May the FreeBSD bootloader
long fit in its allocated space.

llvm-svn: 130416
2011-04-28 18:15:47 +00:00
Chris Lattner 827a270a2a teach GVN to widen integer loads when they are overaligned, when doing an
wider load would allow elimination of subsequent loads, and when the wider
load is still a native integer type.  This eliminates a ton of loads on 
various benchmarks involving struct fields, though it is somewhat hobbled
by clang not being very aggressive about field alignment.

This is yet another step along the way towards resolving PR6627.

llvm-svn: 130390
2011-04-28 07:29:08 +00:00
Chris Lattner 6b96621a8a remove support for llvm.invariant.end from memdep. It is a
work-in-progress that is not progressing, and it has issues.

llvm-svn: 130247
2011-04-26 21:50:51 +00:00
Chris Lattner eb045f9c02 Improve the bail-out predicate to really only kick in when phi
translation fails.  We were bailing out in some cases that would
cause us to miss GVN'ing some non-local cases away.

llvm-svn: 130206
2011-04-26 17:41:02 +00:00
Chris Lattner 6f83d06ffa Enhance MemDep: When alias analysis returns a partial alias result,
return it as a clobber.  This allows GVN to do smart things.

Enhance GVN to be smart about the case when a small load is clobbered
by a larger overlapping load.  In this case, forward the value.  This
allows us to compile stuff like this:

int test(void *P) {
  int tmp = *(unsigned int*)P;
  return tmp+*((unsigned char*)P+1);
}

into:

_test:                                  ## @test
	movl	(%rdi), %ecx
	movzbl	%ch, %eax
	addl	%ecx, %eax
	ret

which has one load.  We already handled the case where the smaller
load was from a must-aliased base pointer.

llvm-svn: 130180
2011-04-26 01:21:15 +00:00
Owen Anderson 5ab8d4b5e5 Give GVN back the ability to perform simple conditional propagation on conditional branch values.
I still think that LVI should be handling this, but that capability is some ways off in the future,
and this matters for some significant benchmarks.

llvm-svn: 122378
2010-12-21 23:54:34 +00:00
Dan Gohman 4467aa5294 Preserve TBAA tags when doing load PRE.
llvm-svn: 121921
2010-12-15 23:53:55 +00:00
Owen Anderson c21c100f3d Completely rework the datastructure GVN uses to represent the value number to leader mapping. Previously,
this was a tree of hashtables, and a query recursed into the table for the immediate dominator ad infinitum
if the initial lookup failed.  This led to really bad performance on tall, narrow CFGs.

We can instead replace it with what is conceptually a multimap of value numbers to leaders (actually
represented by a hashtable with a list of Value*'s as the value type), and then
determine which leader from that set to use very cheaply thanks to the DFS numberings maintained by
DominatorTree.  Because there are typically few duplicates of a given value, this scan tends to be
quite fast.  Additionally, we use a custom linked list and BumpPtr allocation to avoid any unnecessary
allocation in representing the value-side of the multimap.

This change brings with it a 15% (!) improvement in the total running time of GVN on 403.gcc, which I
think is pretty good considering that includes all the "real work" being done by MemDep as well.

The one downside to this approach is that we can no longer use GVN to perform simple conditional progation,
but that seems like an acceptable loss since we now have LVI and CorrelatedValuePropagation to pick up
the slack.  If you see conditional propagation that's not happening, please file bugs against LVI or CVP.

llvm-svn: 119714
2010-11-18 18:32:40 +00:00
Dan Gohman 2e1fc849b2 Add support for PHI-translating sext, zext, and trunc instructions,
enabling more PRE. PR8586.

llvm-svn: 119704
2010-11-18 17:05:13 +00:00
Duncan Sands 4581ddc123 Teach InstructionSimplify about phi nodes. I chose to have it simply
offload the work to hasConstantValue rather than do something more
complicated (such handling mutually recursive phis) because (1) it is
not clear it is worth it; and (2) if it is worth it, maybe such logic
would be better placed in hasConstantValue.  Adjust some GVN tests
which are now cleaned up much further (eg: all phi nodes are removed).

llvm-svn: 119043
2010-11-14 13:30:18 +00:00
Duncan Sands 8c58ba4199 Testcase to go along with commit 118923 ("Have GVN simplify instructions
as it goes").  Before -std-compile-opts only got it down to
  %a = tail call i32 @foo(i32 0) readnone
  %x = tail call i32 @foo(i32 %a) readnone
  %y = tail call i32 @foo(i32 %a) readnone
  %z = icmp eq i32 %x, %y
  ret i1 %z
while now -basicaa -gvn alone reduce it to
  %a = call i32 @foo(i32 0) readnone
  %x = call i32 @foo(i32 %a) readnone
  ret i1 true

llvm-svn: 119009
2010-11-13 21:33:19 +00:00
Dan Gohman 0a6021a54d Enhance GVN to do more precise alias queries for non-local memory
references. For example, this allows gvn to eliminate the load in
this example:

  void foo(int n, int* p, int *q) {
    p[0] = 0;
    p[1] = 1;
    if (n) {
      *q = p[0];
    }
  }

llvm-svn: 118714
2010-11-10 20:37:15 +00:00
Dan Gohman 02538ac4d3 Make BasicAliasAnalysis a normal AliasAnalysis implementation which
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.

Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.

Update tests to explicitly request -basicaa.

llvm-svn: 116720
2010-10-18 18:04:47 +00:00
Owen Anderson 13a642da0b Now that the profitable bits of EnableFullLoadPRE have been enabled by default, rip out the remainder.
Anyone interested in more general PRE would be better served by implementing it separately, to get real
anticipation calculation, etc.

llvm-svn: 115337
2010-10-01 20:02:55 +00:00
Owen Anderson 3170a25a84 We do want to allow LoadPRE to perform LICM-like transformations: we already consider PHI nodes to be negligible for
code size (making this transform code size neutral), and it allows us to hoist values out of loops, which is always
a good thing.

llvm-svn: 115205
2010-09-30 20:53:04 +00:00
Owen Anderson b590a927cd LoadPRE was not properly checking that the load it was PRE'ing post-dominated the block it was being hoisted to.
Splitting critical edges at the merge point only addressed part of the issue; it is also possible for non-post-domination
to occur when the path from the load to the merge has branches in it.  Unfortunately, full anticipation analysis is
time-consuming, so for now approximate it.  This is strictly more conservative than real anticipation, so we will miss
some cases that real PRE would allow, but we also no longer insert loads into paths where they didn't exist before. :-)

This is a very slight net positive on SPEC for me (0.5% on average).  Most of the benchmarks are largely unaffected, but
when it pays off it pays off decently: 181.mcf improves by 4.5% on my machine.

llvm-svn: 114785
2010-09-25 05:26:18 +00:00
Duncan Sands 68c30907cc Correct bogus module triple specifications.
llvm-svn: 112469
2010-08-30 10:48:29 +00:00
Rafael Espindola 29dda21e96 Remove arm_apcscc from the test files. It is the default and doing this
matches what llvm-gcc and clang now produce.

llvm-svn: 106221
2010-06-17 15:18:27 +00:00
Chris Lattner 5a62d6e578 Fix PR7052, patch by Jakub Staszak!
llvm-svn: 103347
2010-05-08 20:01:44 +00:00
Nick Lewycky d4c0f86a5e Fix intrinsic signature in this test.
llvm-svn: 101674
2010-04-17 21:12:55 +00:00
Bob Wilson ca51425d94 Re-commit my previous SSAUpdater changes. The previous version naively tried
to determine where to place PHIs by iteratively comparing reaching definitions
at each block.  That was just plain wrong.  This version now computes the
dominator tree within the subset of the CFG where PHIs may need to be placed,
and then places the PHIs in the iterated dominance frontier of each definition.
The rest of the patch is mostly the same, with a few more performance
improvements added in.

llvm-svn: 101612
2010-04-17 03:08:24 +00:00
Chris Lattner 3ae2dd2ba5 add newlines at the end of files.
llvm-svn: 100705
2010-04-07 22:53:17 +00:00
Bob Wilson f1aa4743d9 Revert all my SSAUpdater patches. The PHI placement algorithm is not correct
(what was I thinking?) and there's also a problem with LCSSA.  I'll try again
later with fixes.

--- Reverse-merging r100263 into '.':
U    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100177 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100148 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100147 into '.':
U    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100131 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100130 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100126 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100050 into '.':
D    test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
--- Reverse-merging r100047 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp

llvm-svn: 100264
2010-04-03 03:50:38 +00:00
Bob Wilson b9fb48bff7 Add a redundant PHI testcase for SSAUpdater to go with svn r100047.
llvm-svn: 100050
2010-03-31 21:38:43 +00:00
Chris Lattner 0563804982 fix PR6642, GVN forwarding from memset to load of the base of the memset.
llvm-svn: 99488
2010-03-25 05:58:19 +00:00
Devang Patel aaecdaeb5d Remove tests that checks @llvm.dbg.stoppoint handling.
llvm-svn: 97493
2010-03-01 20:33:48 +00:00
Chris Lattner d35a728a34 stop using anders-aa
llvm-svn: 97492
2010-03-01 20:24:50 +00:00
Bob Wilson 6bfacb7393 Testcase for critical edge splitting with load PRE.
llvm-svn: 96385
2010-02-16 20:48:55 +00:00
Chris Lattner f492ece81e a testcase that doesn't crash GVN but could someday.
llvm-svn: 95851
2010-02-11 05:08:05 +00:00
Bob Wilson 56600a15ad Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.

llvm-svn: 94875
2010-01-30 04:42:39 +00:00
Bob Wilson 7577e948e4 Avoid creating redundant PHIs in SSAUpdater::GetValueInMiddleOfBlock.
This was already being done in SSAUpdater::GetValueAtEndOfBlock so I've
just changed SSAUpdater to check for existing PHIs in both places.

llvm-svn: 94690
2010-01-27 22:01:02 +00:00
Dan Gohman fb4193625a Delete useless trailing semicolons.
llvm-svn: 92740
2010-01-05 17:55:26 +00:00
Chris Lattner 25bf6f8946 fix an overly conservative caching issue that caused memdep to
cache a pointer as being unavailable due to phi trans in the
wrong place.  This would cause later queries to fail even when
they didn't involve phi trans.

llvm-svn: 91787
2009-12-19 21:29:22 +00:00
Chris Lattner 95b431dd32 fix inconsistent use of tabs
llvm-svn: 91783
2009-12-19 20:44:43 +00:00
Chris Lattner 9ccc879006 Fix PR5744, a case where we were getting the pointer size instead of the
value size.  This only manifested when memdep inprecisely returns clobber,
which is do to a caching issue in the PR5744 testcase.  We can 'efficiently
emulate' this by using '-no-aa'

llvm-svn: 91004
2009-12-10 00:11:45 +00:00
Chris Lattner ca5f9cb18b fix hte last remaining known (by me) phi translation bug. When we reanalyze
clobbers to forward pieces of large stores to small loads, we need to consider
the properly phi translated pointer in the store block.

llvm-svn: 90978
2009-12-09 18:21:46 +00:00
Chris Lattner 9f9010ef47 Add a minor optimization: if we haven't changed the operands of an
add, there is no need to scan the world to find the same add again.
This invalidates the previous testcase, which wasn't wonderful anyway,
because it needed a run of instcombine to permute the use-lists in 
just the right way to before GVN was run (so it was really fragile).
Not a big loss.

llvm-svn: 90973
2009-12-09 17:27:45 +00:00
Chris Lattner fa2e536831 fix PR5733, a case where we'd replace an add with a lexically identical
binary operator that wasn't an add.  In this case, a xor.  Whoops.

llvm-svn: 90971
2009-12-09 17:18:49 +00:00
Chris Lattner 8f77035568 merge crash-2.ll into crash.ll
llvm-svn: 90969
2009-12-09 17:17:26 +00:00
Chris Lattner 10398e74ae the code in GVN that tries to forward large loads to small
stores is not phi translating, thus it miscompiles really
crazy testcases.  This is from inspection, I haven't seen
this in the wild.

llvm-svn: 90930
2009-12-09 02:43:05 +00:00
Chris Lattner 972e6d8d00 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.

llvm-svn: 90926
2009-12-09 01:59:31 +00:00
Chris Lattner 778cb92235 constant fold loads from memcpy's from global constants. This is important
because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.

llvm-svn: 90698
2009-12-06 05:29:56 +00:00
Chris Lattner 93236ba327 add support for forwarding mem intrinsic values to non-local loads.
llvm-svn: 90697
2009-12-06 04:54:31 +00:00
Chris Lattner 42376066eb Handle forwarding local memsets to loads. For example, we optimize this:
short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  

llvm-svn: 90695
2009-12-06 01:57:02 +00:00
Chris Lattner eb5bb1bf78 merge two tests.
llvm-svn: 90691
2009-12-06 01:47:24 +00:00
Chris Lattner 1c21aaca06 Small and carefully crafted testcase showing a miscompilation by GVN
that I'm working on.  This is manifesting as a miscompile of 255.vortex
on some targets.  No check lines yet because it fails.

llvm-svn: 90520
2009-12-04 02:12:12 +00:00
Owen Anderson 0b6e260066 Fix this crasher, and add a FIXME for a missed optimization.
llvm-svn: 90408
2009-12-03 03:43:29 +00:00
Chris Lattner 65812b58f2 add a failing testcase.
llvm-svn: 90380
2009-12-03 01:46:18 +00:00
Owen Anderson b9878ee6b6 Cleanup/remove some parts of the lifetime region handling code in memdep and GVN,
per Chris' comments.  Adjust testcases to match.

llvm-svn: 90304
2009-12-02 07:35:19 +00:00
Chris Lattner 367b5eafb7 minimize this a bit more.
llvm-svn: 90216
2009-12-01 07:30:01 +00:00
Chris Lattner fd75b90d81 merge 2009-11-29-ReverseMap.ll into crash.ll
llvm-svn: 90212
2009-12-01 06:22:10 +00:00
Nick Lewycky 8a29dd4c7f Add a testcase for the current llvm-gcc build failure.
llvm-svn: 90112
2009-11-30 07:02:18 +00:00
Chris Lattner 0d39613f65 add PR#
llvm-svn: 90049
2009-11-29 01:28:58 +00:00
Chris Lattner 73d45454be Add a testcase for:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j] = G[j] + G[j+1] + G[j-1];
}

which we now compile to one load in the loop:

LBB1_2:                                                     ## %bb
	movsd	16(%rsi,%rax,8), %xmm2
	incq	%rdx
	addsd	%xmm2, %xmm1
	addsd	%xmm1, %xmm0
	movapd	%xmm2, %xmm1
	movsd	%xmm0, 8(%rsi,%rax,8)
	incq	%rax
	cmpq	%rcx, %rax
	jne	LBB1_2

instead of:

LBB1_2:                                                     ## %bb
	movsd	8(%rsi,%rax,8), %xmm0
	addsd	16(%rsi,%rax,8), %xmm0
	addsd	(%rsi,%rax,8), %xmm0
	movsd	%xmm0, 8(%rsi,%rax,8)
	incq	%rax
	cmpq	%rcx, %rax
	jne	LBB1_2

llvm-svn: 90048
2009-11-29 01:15:43 +00:00
Chris Lattner a73adac52e add a testcase for
void test9(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

llvm-svn: 90047
2009-11-29 01:04:40 +00:00
Chris Lattner 32140312ca reenable load address insertion in load pre. This allows us to
handle cases like this:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

where G[1] isn't live into the loop.

llvm-svn: 90041
2009-11-28 16:08:18 +00:00
Chris Lattner cf0b198827 disable value insertion for now, I need to figure out how
to inform GVN about the newly inserted values.  This fixes 
PR5631.

llvm-svn: 90022
2009-11-27 22:50:07 +00:00
Chris Lattner d141f885a1 I accidentally implemented this :)
llvm-svn: 90014
2009-11-27 19:56:00 +00:00
Chris Lattner 2f0354ecf0 add support for recursive phi translation and phi
translation of add with immediate.  This allows us
to optimize this function:

void test(int N, double* G) {
  long j;
  G[1] = 1;
    for (j = 1; j < N - 1; j++)
        G[j+1] = G[j] + G[j+1];
}

to only do one load every iteration of the loop.

llvm-svn: 90013
2009-11-27 19:11:31 +00:00
Chris Lattner e66f84e012 add two simple test cases we now optimize (to one load in the loop each) and one we don't (corresponding to the fixme I added yesterday).
llvm-svn: 90012
2009-11-27 18:08:30 +00:00
Chris Lattner 25be93dfed teach GVN's load PRE to insert computations of the address in predecessors
where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)

llvm-svn: 89997
2009-11-27 08:25:10 +00:00
Chris Lattner 41a5bba4e0 add some tests for memdep phi translation + PRE.
llvm-svn: 89996
2009-11-27 06:42:42 +00:00
Chris Lattner fa76d23c1d this test is failing, and is expected to.
llvm-svn: 89995
2009-11-27 06:36:28 +00:00
Chris Lattner 4f1552bde7 filecheckize
llvm-svn: 89994
2009-11-27 06:33:09 +00:00
Chris Lattner 66426c70e6 rename test.
llvm-svn: 89993
2009-11-27 06:31:55 +00:00
Chris Lattner a9a76ccf56 Fix phi translation in load PRE to agree with the phi
translation done by memdep, and reenable gep translation 
again.

llvm-svn: 89992
2009-11-27 06:31:14 +00:00
Chris Lattner b018bda665 redisable this, my bootstrap worked because it wasn't an optimized build, whoops.
llvm-svn: 89991
2009-11-27 05:53:01 +00:00
Chris Lattner fb8a718fc3 try again.
llvm-svn: 89990
2009-11-27 05:19:56 +00:00
Chris Lattner 14444f5c1a this is causing buildbot failures, disable for now.
llvm-svn: 89985
2009-11-27 01:52:22 +00:00
Chris Lattner 5030c6ab21 teach phi translation of GEPs to simplify geps like 'gep x, 0'.
This allows us to compile the example from PR5313 into:

LBB1_2:                                                     ## %bb
	incl	%ecx
	movb	%al, (%rsi)
	movslq	%ecx, %rax
	movb	(%rdi,%rax), %al
	testb	%al, %al
	jne	LBB1_2

instead of:

LBB1_2:                                                     ## %bb
	movslq	%eax, %rcx
	incl	%eax
	movb	(%rdi,%rcx), %cl
	movb	%cl, (%rsi)
	movslq	%eax, %rcx
	cmpb	$0, (%rdi,%rcx)
	jne	LBB1_2

llvm-svn: 89981
2009-11-27 00:34:38 +00:00
Chris Lattner 4c88e814b8 teach memdep to do trivial PHI translation of GEPs. More to
come.

llvm-svn: 89979
2009-11-27 00:07:37 +00:00
Chris Lattner 9bd2136ca3 Teach memdep to phi translate bitcasts. This allows us to compile
the example in GCC PR16799 to:

LBB1_2:                                                     ## %bb1
	movl	%eax, %eax
	subq	%rax, %rdi
	movq	%rdi, (%rcx)
	movl	(%rdi), %eax
	testl	%eax, %eax
	je	LBB1_2

instead of:

LBB1_2:                                                     ## %bb1
	movl	(%rdi), %ecx
	subq	%rcx, %rdi
	movq	%rdi, (%rax)
	cmpl	$0, (%rdi)
	je	LBB1_2

llvm-svn: 89978
2009-11-26 23:41:07 +00:00
Chris Lattner dfaa592de1 convert to filecheck
llvm-svn: 89977
2009-11-26 23:32:59 +00:00
Benjamin Kramer e986c44a9b Try to work around grep's "Binary file (standard input) matches" complaints seen
on ppc buildbot.

llvm-svn: 89452
2009-11-20 09:53:25 +00:00
Dan Gohman 94e617627d Extend CaptureTracking to indicate when a value is never stored, even
if it is not ultimately captured. Teach BasicAliasAnalysis that a 
local object address which does not escape and is never stored does
not alias with a value resulting from a load.

llvm-svn: 89398
2009-11-19 21:57:48 +00:00
Dan Gohman ccb4584edd Default-addressspace null pointers don't alias anything. This allows
GVN to be more aggressive. Patch by Hans Wennborg! (with a comment added by me)

llvm-svn: 86582
2009-11-09 19:29:11 +00:00
Owen Anderson 2b2bd28973 Treat lifetime begin/end markers as allocations/frees respectively for the
purposes for GVN/DSE.

llvm-svn: 85383
2009-10-28 07:05:35 +00:00
Owen Anderson fc16e5a98f Be more careful about invariance reasoning on "store" queries. Stores still need
to depend on Ref and ModRef calls within the invariant region.

llvm-svn: 85380
2009-10-28 06:30:52 +00:00
Owen Anderson d0e86d57c1 Add trivial support for the invariance intrinsics to memdep. This logic is
purely local for now.

llvm-svn: 85378
2009-10-28 06:18:42 +00:00
Duncan Sands de3f2c26c6 Check that GVN performs this transform even if the calls
themselves are not marked readonly, but only the called
functions.

llvm-svn: 84253
2009-10-16 12:18:23 +00:00
Victor Hernandez 70e8505eb1 Memory dependence analysis was incorrectly stopping to scan for stores to a pointer at bitcast uses of a malloc call.
It should continue scanning until the malloc call, and this patch fixes that.

llvm-svn: 83931
2009-10-13 01:42:53 +00:00
Chris Lattner b6c65faa64 switch GVN to use SSAUpdater. Besides removing a lot of complexity
from GVN, this also speeds it up, inserts fewer PHI nodes (see the
testcase) and allows it to remove more loads (due to fewer PHI nodes
standing in the way).

llvm-svn: 83746
2009-10-10 23:50:30 +00:00
Chris Lattner 9045f235d2 fix PR5016, a crash I introduced in GVN handing first class
arrays and structs, which cannot be bitcast to integers.

llvm-svn: 82460
2009-09-21 17:24:04 +00:00
Chris Lattner 4d8af2f1ae enable non-local analysis and PRE of large store -> little load.
This doesn't kick in too much because of phi translation issues,
but this can be resolved in the future.

llvm-svn: 82447
2009-09-21 06:48:08 +00:00
Chris Lattner e2b8a80487 add pr#
llvm-svn: 82440
2009-09-21 05:57:47 +00:00
Chris Lattner 0a9616d906 Improve GVN to be able to forward substitute a small load
from a piece of a large store when both are in the same block.

This allows clang to compile the testcase in PR4216 to this code:

_test_bitfield:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$-65536, %ecx
	orl	$32962, %eax
	andl	$40186, %eax
	orl	%ecx, %eax
	ret

This is not ideal, but is a whole lot better than the code produced
by llvm-gcc:

_test_bitfield:
	movw	$-32574, %ax
	orw	4(%esp), %ax
	andw	$-25350, %ax
	movw	%ax, 4(%esp)
	movw	7(%esp), %cx
	shlw	$8, %cx
	movzbl	6(%esp), %edx
	orw	%cx, %dx
	movzwl	%dx, %ecx
	shll	$16, %ecx
	movzwl	%ax, %eax
	orl	%ecx, %eax
	ret

and dramatically better than that produced by gcc 4.2:

_test_bitfield:
	pushl	%ebx
	call	L3
"L00000000001$pb":
L3:
	popl	%ebx
	movl	8(%esp), %eax
	leal	0(,%eax,4), %edx
	sarb	$7, %dl
	movl	%eax, %ecx
	andl	$7168, %ecx
	andl	$-7201, %ebx
	movzbl	%dl, %edx
	andl	$1, %edx
	sall	$5, %edx
	orl	%ecx, %ebx
	orl	%edx, %ebx
	andl	$24, %eax
	andl	$-58336, %ebx
	orl	%eax, %ebx
	orl	$32962, %ebx
	movl	%ebx, %eax
	popl	%ebx
	ret

llvm-svn: 82439
2009-09-21 05:57:11 +00:00
Chris Lattner b9f2bf46f7 fix a FileCheck bug where:
; CHECK: foo
; CHECK-NOT: foo
; CHECK: bar

would always fail.

llvm-svn: 82424
2009-09-21 02:30:42 +00:00
Daniel Dunbar ffb60d566f Work around a FileCheck bug, for now.
llvm-svn: 82416
2009-09-20 23:30:31 +00:00
Chris Lattner 7e6d56ebc5 Revert r82404, it is causing a bootstrap miscompile. This is very very
scary, as it indicates a lurking bug. yay.

llvm-svn: 82411
2009-09-20 22:44:26 +00:00
Chris Lattner 973f14c8fa this was not supposed to be committed
llvm-svn: 82409
2009-09-20 22:36:11 +00:00
Chris Lattner 236d2d5e7b implement and document support for CHECK-NOT
llvm-svn: 82408
2009-09-20 22:35:26 +00:00
Chris Lattner eea16a168a improve memdep to eliminate bitcasts (and aliases, and noop geps)
early for the stated reasons: this allows it to find more 
equivalences and depend less on code layout.

llvm-svn: 82404
2009-09-20 21:00:18 +00:00
Chris Lattner a0aa8fb6a6 Move CoerceAvailableValueToLoadType earlier in GVN.cpp. Hook it up
so that nonlocal and partially redundant loads can use it as well.
The testcase shows examples of craziness this can handle.  This triggers
*many* times in 176.gcc.

llvm-svn: 82403
2009-09-20 20:09:34 +00:00
Chris Lattner 1dd48c34e5 enhance GVN to forward substitute a stored value to a load
(and load -> load) when the base pointers must alias but when
they are different types.  This occurs very very frequently in
176.gcc and other code that uses bitfields a lot.

llvm-svn: 82399
2009-09-20 19:03:47 +00:00
Dan Gohman 1880092722 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.

llvm-svn: 81537
2009-09-11 18:01:28 +00:00
Dan Gohman 72a13d2476 Use opt -S instead of piping bitcode output through llvm-dis.
llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Dan Gohman 9737a63ed8 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.

llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Daniel Dunbar b9ea94c990 Eliminate uses of %prcontext.
- I'd appreciate it if someone else eyeballs my changes to make sure I captured
   the intent of the test.

llvm-svn: 81083
2009-09-05 11:35:16 +00:00
Dan Gohman 22571485b3 Change PHINode::hasConstantValue to have a DominatorTree argument
instead of a bool argument, and to do the dominator check itself.
This makes it eaiser to use when DominatorTree information is
available.

llvm-svn: 80920
2009-09-03 15:34:35 +00:00
Chris Lattner 2f0c1c44d5 Move the re-sort of invalidated NonLocalPointerDeps cache earlier
so that all code paths get it.  PR4256 was about a case where the
phi translation loop would find all preds in the Visited cache, so
it could get by without re-sorting the NonLocalPointerDeps cache.
Fix this by resorting it earlier, there is no reason not to do this.

This patch inspired by Jakub Staszak's patch.

llvm-svn: 75476
2009-07-13 17:14:23 +00:00
Dale Johannesen 81b6463ed0 This fixes a bug introduced in 72661, which can
move loads back past a check that the load address
is valid, see new testcase.  The test that went
in with 72661 has exactly this case, except that
the conditional it's moving past is checking
something else; I've settled for changing that
test to reference a global, not a pointer.  It
may be possible to scan all the tests you pass and
make sure none of them are checking any component
of the address, but it's not trivial and I'm not
trying to do that here.

llvm-svn: 73632
2009-06-17 20:48:23 +00:00
Owen Anderson cc0c75c74d Be more aggressive in doing LoadPRE by tracing backwards when a block only has
a single predecessor.

Patch by Jakub Staszak.

llvm-svn: 72661
2009-05-31 09:03:40 +00:00
Chris Lattner 02274a7171 make memdep use the getModRefInfo method for stores instead of the
low-level alias() method, allowing it to reason more aggressively
about pointers into constant memory.  PR4189

llvm-svn: 72403
2009-05-25 21:28:56 +00:00
Owen Anderson 98f912bf13 Reapply r68211, with the miscompilations it caused fixed.
llvm-svn: 68262
2009-04-01 23:53:49 +00:00
Dan Gohman c4971721ea Revert r68172. It caused regressions in
Applications/Burg/burg
  Applications/ClamAV/clamscan
and many other tests.

llvm-svn: 68211
2009-04-01 16:37:47 +00:00
Owen Anderson ff5961b46c Enhance GVN to propagate simple conditionals. This fixes PR3921.
llvm-svn: 68172
2009-04-01 01:20:45 +00:00
John Criswell 073e4d16c5 Do not attempt to do parial redundancy elimination on void values.
Also fixed a punctuation error in the header comment.
This fixes PR3775.

llvm-svn: 66542
2009-03-10 15:04:53 +00:00
Devang Patel e8c6d3102d Skip DbgInfoIntrinsic.
llvm-svn: 66244
2009-03-06 02:59:27 +00:00
Owen Anderson ad4254935f Add a test for r61358, which I forgot to add way back when.
llvm-svn: 64904
2009-02-18 07:50:22 +00:00
Chris Lattner 3f4591c89f fix two more cases where we could let the NLPDI cache get unsorted.
With this, sqlite3 now passes.

llvm-svn: 62839
2009-01-23 07:12:16 +00:00
Chris Lattner f09619d533 Fix PR3358, a really nasty bug where recursive phi translated
analyses could be run without the caches properly sorted.  This
can fix all sorts of weirdness.  Many thanks to Bill for coming
up with the 'issorted' verification idea.

llvm-svn: 62757
2009-01-22 07:04:01 +00:00
Chris Lattner 8b4be37275 fix PR3217: fully cached queries need to be verified against the
visited set before they are used.  If used, their blocks need to be
added to the visited set so that subsequent queries don't use conflicting
pointer values in the cache result blocks.

llvm-svn: 61080
2008-12-16 07:10:09 +00:00
Chris Lattner 81ee731852 Add a testcase for GCC PR 23455, which lpre handles now. Add some
comments about why we're not getting other cases.

llvm-svn: 61032
2008-12-15 07:49:24 +00:00
Chris Lattner 3c2c36b590 gvn now hoists this load out of the hot non-call path.
llvm-svn: 61028
2008-12-15 06:34:48 +00:00
Chris Lattner b2429e2d69 Adjust testcase to make it more stable across visitation order changes,
unbreaking it after r61024.

llvm-svn: 61025
2008-12-15 04:42:00 +00:00
Chris Lattner 69131fd872 make GVN try to rename inputs to the resultant replaced values, which
cleans up the generated code a bit.  This should have the added benefit of
not randomly renaming functions/globals like my previous patch did. :)

llvm-svn: 61023
2008-12-15 03:46:38 +00:00
Chris Lattner ff9f3dba12 Implement initial support for PHI translation in memdep. This means that
memdep keeps track of how PHIs affect the pointer in dep queries, which 
allows it to eliminate the load in cases like rle-phi-translate.ll, which
basically end up being:

BB1:
   X = load P
   br BB3
BB2:
   Y = load Q
   br BB3
BB3:
   R = phi [P] [Q]
   load R

turning "load R" into a phi of X/Y.  In addition to additional exposed
opportunities, this makes memdep safe in many cases that it wasn't before
(which is required for load PRE) and also makes it substantially more 
efficient.  For example, consider:


bb1:  // has many predecessors.
   P = some_operator()
   load P

In this example, previously memdep would scan all the predecessors of BB1
to see if they had something that would mustalias P.  In some cases (e.g.
test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end
up eliminating something.  In many other cases though, it would scan and not
find anything useful.  MemDep now stops at a block if the pointer is defined
in that block and cannot be phi translated to predecessors.  This causes it
to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not
scanning tons of stuff that is unlikely to be useful.  For example, this
speeds up GVN as a whole from 3.928s to 2.448s (60%)!.  IMO, scalar GVN 
should be enhanced to simplify the rle-must-alias pointer base anyway, which
would allow the loads to be eliminated.

In the future, this should be enhanced to phi translate through geps and 
bitcasts as well (as indicated by FIXMEs) making memdep even more powerful.

llvm-svn: 61022
2008-12-15 03:35:32 +00:00
Chris Lattner a236dc44d6 another random testcase that shouldn't crash gvn and is
good for coverage with future changes.

llvm-svn: 61011
2008-12-14 21:20:46 +00:00
Chris Lattner 9b9a145694 RLE isn't smart enough to eliminate this safely yet.
llvm-svn: 60994
2008-12-13 21:04:20 +00:00
Chris Lattner d923519cc5 rename some tests to be more uniform in naming convention.
llvm-svn: 60988
2008-12-13 18:47:40 +00:00
Chris Lattner 9e24267120 gvn should never crash on this.
llvm-svn: 60987
2008-12-13 18:39:44 +00:00
Bill Wendling 293b9181e5 Temporarily revert r60973. It's inexplicably causing a failure when self-hosting LLVM:
llvm[2]: Linking Release executable opt (without symbols)
...
Undefined symbols:
  "llvm::APFloat::IEEEsingle", referenced from:
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
  "llvm::APFloat::IEEEdouble", referenced from:
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
ld: symbol(s) not found

This is in release mode. To replicate, compile llvm and llvm-gcc in optimized
mode. Then build llvm, in optimized mode, with the newly created compiler.

llvm-svn: 60977
2008-12-13 09:28:44 +00:00
Chris Lattner 1e29f7c97d make RLE preserve the name of the load that it replaces. This is just
a pretification of the IR.

llvm-svn: 60973
2008-12-13 07:22:47 +00:00
Chris Lattner 0318b56f0e loosen up an assertion that isn't valid when called from
invalidateCachedPointerInfo.  Thanks to Bill for sending me
a testcase.

llvm-svn: 60805
2008-12-09 22:45:32 +00:00
Chris Lattner 702e46ed54 Teach BasicAA::getModRefInfo(CallSite, CallSite) some
tricks based on readnone/readonly functions.

Teach memdep to look past readonly calls when analyzing
deps for a readonly call.  This allows elimination of a
few more calls from 403.gcc:

before:
     63 gvn    - Number of instructions PRE'd
 153986 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

after:
     63 gvn    - Number of instructions PRE'd
 153991 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

5 calls isn't much, but this adds plumbing for the next change.

llvm-svn: 60794
2008-12-09 21:19:42 +00:00
Chris Lattner c100828026 Fix test/Transforms/GVN/pre-load.ll
llvm-svn: 60594
2008-12-05 17:04:12 +00:00
Chris Lattner 1db9bbe802 Implement PRE of loads in the GVN pass with a pretty cheap and
straight-forward implementation.  This does not require any extra
alias analysis queries beyond what we already do for non-local loads.

Some programs really really like load PRE.  For example, SPASS triggers
this ~1000 times, ~300 times in 255.vortex, and ~1500 times on 403.gcc.

The biggest limitation to the implementation is that it does not split
critical edges.  This is a huge killer on many programs and should be
addressed after the initial patch is enabled by default.

The implementation of this should incidentally speed up rejection of 
non-local loads because it avoids creating the repl densemap in cases 
when it won't be used for fully redundant loads.

This is currently disabled by default.
Before I turn this on, I need to fix a couple of miscompilations in
the testsuite, look at compile time performance numbers, and look at
perf impact.  This is pretty close to ready though.

llvm-svn: 60408
2008-12-02 08:16:11 +00:00
Owen Anderson 35bd70c07a Add a test for my previous PRE fix.
llvm-svn: 60394
2008-12-02 04:25:42 +00:00
Chris Lattner 8facc59e72 testcase for my previous commit.
llvm-svn: 60315
2008-12-01 01:42:03 +00:00
Chris Lattner c40039c736 don't require GVN to work on dead values, just make the
test return the loaded value.

llvm-svn: 60252
2008-11-29 21:21:48 +00:00
Owen Anderson b22a640fe4 A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks.
llvm-svn: 53032
2008-07-02 17:20:16 +00:00
Owen Anderson 1fb47ad928 Use the -enable-pre flag so this test doesn't fail.
llvm-svn: 52784
2008-06-26 17:03:28 +00:00
Owen Anderson 6a903bc601 Add local PRE to GVN. This only operates in cases where it would not increase code size, namely when the instantiated expression
would only need to be created in one predecessor.

llvm-svn: 52471
2008-06-18 21:41:49 +00:00
Gabor Greif 1e427c3264 sabre brings to my attention that the 'tr' suffix is also obsolete
llvm-svn: 51349
2008-05-20 21:00:03 +00:00
Gabor Greif f45ff35bfe Rename the last test with .llx extension to .ll, resolve duplicate test by renaming to isnan2. Now that no test has llx ending there is no need to search for them from dg.exp too.
llvm-svn: 51328
2008-05-20 19:52:04 +00:00
Owen Anderson 525aa89356 Add a testcase for non-local CSE of read-only calls.
llvm-svn: 51025
2008-05-13 08:17:44 +00:00