Commit Graph

77 Commits

Author SHA1 Message Date
Bjorn Steinbrink d20816fde9 Allow call-slop optzn for destinations with a suitable dereferenceable attribute
Summary:
Currently, call slot optimization requires that if the destination is an
argument, the argument has the sret attribute. This is to ensure that
the memory access won't trap. In addition to sret, we can also allow the
optimization to happen for arguments that have the new dereferenceable
attribute, which gives the same guarantee.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5832

llvm-svn: 219950
2014-10-16 19:43:08 +00:00
Chandler Carruth 18cee1defc Fix a really bad miscompile introduced in r216865 - the else-if logic
chain became completely broken here as *all* intrinsic users ended up
being skipped, and the ones that seemed to be singled out were actually
the exact wrong set.

This is a great example of why long else-if chains can be easily
confusing. Switch the entire code to use early exits and early continues
to have simpler (and more importantly, correct) logic here, as well as
fixing the reversed logic for detecting and continuing on lifetime
intrinsics.

I've also significantly cleaned up the test case and added another test
case demonstrating an example where the optimization is not (trivially)
safe to perform.

llvm-svn: 216871
2014-09-01 10:09:18 +00:00
Nick Lewycky fc243d54d2 Ignore lifetime intrinsics in use list for MemCpyOptimizer. Patch by Luqman Aden, review by Hal Finkel.
llvm-svn: 216865
2014-09-01 06:03:11 +00:00
Nick Lewycky 703e488ed9 Don't eliminate memcpy's when the address of the pointer may itself be relevant. Fixes PR18304. Patch by David Wiberg!
llvm-svn: 212970
2014-07-14 18:52:02 +00:00
Nick Lewycky 77d5fb40c8 Treat lifetime.start'd memory like we treat freshly alloca'd memory. Patch by Björn Steinbrink!
llvm-svn: 204876
2014-03-26 23:45:15 +00:00
Benjamin Kramer 3ef5e46b6d MemCpyOpt: When merging memsets also merge the trivial case of two memsets with the same destination.
The testcase is from PR19092, but I think the bug described there is actually a clang issue.

llvm-svn: 203489
2014-03-10 21:05:13 +00:00
Nick Lewycky 993849490e A memcpy out of an fresh alloca is a no-op, delete it. Patch by Patrick Walton!
llvm-svn: 200907
2014-02-06 06:29:19 +00:00
Matt Arsenault 84de61148b Handle an addrspacecast case in memcpyopt
llvm-svn: 199836
2014-01-22 21:53:19 +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 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
Shuxin Yang 140d592d84 Fix a potential bug in r183584.
r183584 tries to derive some info from the code *AFTER* a call and apply
these derived info to the code *BEFORE* the call, which is not always safe
as the call in question may never return, and in this case, the derived
info is invalid.
  
  Thank Duncan for pointing out this potential bug.

rdar://14073661 

llvm-svn: 183606
2013-06-08 04:56:05 +00:00
Shuxin Yang bd254f2601 Fix an assertion in MemCpyOpt pass.
The MemCpyOpt pass is capable of optimizing:
      callee(&S); copy N bytes from S to D.
    into:
      callee(&D);
subject to some legality constraints. 

  Assertion is triggered when the compiler tries to evalute "sizeof(typeof(D))",
while D is an opaque-typed, 'sret' formal argument of function being compiled.
i.e. the signature of the func being compiled is something like this:
  T caller(...,%opaque* noalias nocapture sret %D, ...)

  The fix is that when come across such situation, instead of calling some
utility functions to get the size of D's type (which will crash), we simply
assume D has at least N bytes as implified by the copy-instruction.

rdar://14073661 

llvm-svn: 183584
2013-06-07 22:45:21 +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
Bill Wendling 26b95756c1 Simplify the 'operator<' for the attribute object.
llvm-svn: 175252
2013-02-15 05:25:26 +00:00
Anna Zaks 269d1fa991 Revert "Fix testcase for attribute ordering."
This reverts commit 58f20a3cbfca7384fe5e25e095f18572736a4792.

llvm-svn: 175249
2013-02-15 04:15:53 +00:00
Anna Zaks 61040b915d Revert "Fix testcase for attribute ordering."
This reverts commit 997c6516ca161073a1d516ebca7c0ca7722f64e2.

llvm-svn: 175248
2013-02-15 04:15:50 +00:00
Bill Wendling f7d8d767fb Fix testcase for attribute ordering.
llvm-svn: 175238
2013-02-15 01:04:46 +00:00
Bill Wendling fa1d248ccf Fix testcase for attribute ordering.
llvm-svn: 175236
2013-02-15 00:58:25 +00:00
Bill Wendling 1c7cc8ae90 Remove the AttrBuilder form of the Attribute::get creators.
The AttrBuilder is for building a collection of attributes. The Attribute object
holds only one attribute. So it's not really useful for the Attribute object to
have a creator which takes an AttrBuilder.

This has two fallouts:

1. The AttrBuilder no longer holds its internal attributes in a bit-mask form.
2. The attributes are now ordered alphabetically (hence why the tests have changed).

llvm-svn: 174110
2013-01-31 23:16:25 +00:00
Duncan Sands a6d20010fe In my recent change to avoid use of underaligned memory I didn't notice that
cpyDest can be mutated in some cases, which would then cause a crash later if
indeed the memory was underaligned.  This brought down several buildbots, so
I guess the underaligned case is much more common than I thought!

llvm-svn: 165228
2012-10-04 13:53:21 +00:00
Duncan Sands c6ada69a14 The memcpy optimizer was happily doing call slot forwarding when the new memory
was less aligned than the old.  In the testcase this results in an overaligned
memset: the memset alignment was correct for the original memory but is too much
for the new memory.  Fix this by either increasing the alignment of the new
memory or bailing out if that isn't possible.  Should fix the gcc-4.7 self-host
buildbot failure.

llvm-svn: 165220
2012-10-04 10:54:40 +00:00
Benjamin Kramer 15a257dadd MemCpyOpt: When forming a memset from stores also take GEP constexprs into account.
This is common when storing to global variables.

llvm-svn: 163809
2012-09-13 16:29:49 +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
Chad Rosier a968caf8e0 Move the capture analysis from MemoryDependencyAnalysis to a more general place
so that it can be reused in MemCpyOptimizer.  This analysis is needed to remove
an unnecessary memcpy when returning a struct into a local variable.
rdar://11341081
PR12686

llvm-svn: 156776
2012-05-14 20:35:04 +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
Chad Rosier 8abf65a130 Probably not a good idea to convert a single vector load into a memcpy. We
don't do this now, but add a test case to prevent this from happening in the
future.
Additional test for rdar://9892684

llvm-svn: 145879
2011-12-06 00:19:08 +00:00
Chad Rosier 19446a07a7 Make the MemCpyOptimizer a bit more aggressive. I can't think of a scenerio
where this would be bad as the backend shouldn't have a problem inlining small
memcpys.
rdar://10510150

llvm-svn: 145865
2011-12-05 22:37:00 +00:00
Nick Lewycky 52340ac5f8 Oops! Fix test I forgot to submit as part of r142735.
llvm-svn: 142736
2011-10-22 22:07:31 +00:00
Nick Lewycky 84baea77ea Oops! Fix testcase.
llvm-svn: 142151
2011-10-16 20:20:15 +00:00
Nick Lewycky 0a7e9ccf04 When looking for dependencies on the src pointer, scan the src pointer. Scanning
on the memcpy call will pull up other unrelated stuff. Fixes PR11142.

llvm-svn: 142150
2011-10-16 20:13:32 +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
Chris Lattner b1ed91f397 Land the long talked about "type system rewrite" patch. This
patch brings numerous advantages to LLVM.  One way to look at it
is through diffstat:
 109 files changed, 3005 insertions(+), 5906 deletions(-)

Removing almost 3K lines of code is a good thing.  Other advantages
include:

1. Value::getType() is a simple load that can be CSE'd, not a mutating
   union-find operation.
2. Types a uniqued and never move once created, defining away PATypeHolder.
3. Structs can be "named" now, and their name is part of the identity that
   uniques them.  This means that the compiler doesn't merge them structurally
   which makes the IR much less confusing.
4. Now that there is no way to get a cycle in a type graph without a named
   struct type, "upreferences" go away.
5. Type refinement is completely gone, which should make LTO much MUCH faster
   in some common cases with C++ code.
6. Types are now generally immutable, so we can use "Type *" instead 
   "const Type *" everywhere.

Downsides of this patch are that it removes some functions from the C API,
so people using those will have to upgrade to (not yet added) new API.  
"LLVM 3.0" is the right time to do this.

There are still some cleanups pending after this, this patch is large enough
as-is.

llvm-svn: 134829
2011-07-09 17:41:24 +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
Chris Lattner 5756c16cdf make the asmparser reject function and type redefinitions. 'Merging' hasn't been
needed since llvm-gcc 3.4 days.

llvm-svn: 133248
2011-06-17 07:06:44 +00:00
Chris Lattner b90ed2233c manually upgrade a bunch of tests to modern syntax, and remove some that
are either unreduced or only test old syntax.

llvm-svn: 133228
2011-06-17 03:14:27 +00:00
Eli Friedman 5da0ff41d7 PR10067: Add missing safety check to call return transformation in MemCpyOpt::processStore. If something accesses the dest of the "copy" between the call and the copy, the performCallSlotOptzn transformation is not valid.
llvm-svn: 132485
2011-06-02 21:24:42 +00:00
Chris Lattner 83791ced7b Teach valuetracking that byval arguments with a specified alignment are
aligned.

Teach memcpyopt to not give up all hope when confonted with an underaligned
memcpy feeding an overaligned byval.  If the *source* of the memcpy can be
determined to be adequeately aligned, or if it can be forced to be, we can
eliminate the memcpy.

This addresses PR9794.  We now compile the example into:

define i32 @f(%struct.p* nocapture byval align 8 %q) nounwind ssp {
entry:
  %call = call i32 @g(%struct.p* byval align 8 %q) nounwind
  ret i32 %call
}

in both x86-64 and x86-32 mode.  We still don't get a tailcall though,
because tailcalls apparently can't handle byval.

llvm-svn: 131884
2011-05-23 00:03:39 +00:00
Dan Gohman 19e30d5a7d Actually check memcpy lengths, instead of just commenting about
how they should be checked.

llvm-svn: 123999
2011-01-21 22:07:57 +00:00
Chris Lattner dd5f60b7a7 revert 123144, reenabling the rest of memset formation.
llvm-svn: 123302
2011-01-12 03:25:15 +00:00
Chris Lattner 654098f411 revert r123146 which disabled code that wasn't the root cause
of the bootstrap miscompare issue.

llvm-svn: 123299
2011-01-12 01:52:23 +00:00
Chris Lattner ec1387cf4b fix typo
llvm-svn: 123148
2011-01-10 02:33:34 +00:00
Chris Lattner 4662bd4b13 another (more) aggressive attempt to bring llvm-gcc-i386-linux-selfhost
back to life.

llvm-svn: 123146
2011-01-10 00:47:34 +00:00
Chris Lattner 1017fa6746 temporarily disable memset formation from memsets in an effort to restore buildbot stability.
llvm-svn: 123144
2011-01-09 23:52:48 +00:00
Chris Lattner 9a1d63ba9f Merge memsets followed by neighboring memsets and other stores into
larger memsets.  Among other things, this fixes rdar://8760394 and
allows us to handle "Example 2" from http://blog.regehr.org/archives/320,
compiling it into a single 4096-byte memset:

_mad_synth_mute:                        ## @mad_synth_mute
## BB#0:                                ## %entry
	pushq	%rax
	movl	$4096, %esi             ## imm = 0x1000
	callq	___bzero
	popq	%rax
	ret

llvm-svn: 123089
2011-01-08 21:19:19 +00:00
Chris Lattner 5120ebf184 fix an issue in IsPointerOffset that prevented us from recognizing that
P and P+1 are relative to the same base pointer.

llvm-svn: 123087
2011-01-08 21:07:56 +00:00
Chris Lattner 4dc1fd938f enhance memcpyopt to merge a store and a subsequent
memset into a single larger memset.

llvm-svn: 123086
2011-01-08 20:54:51 +00:00
Chris Lattner 9dbbc49f74 merge two tests and filecheckify
llvm-svn: 123082
2011-01-08 20:27:22 +00:00
Chris Lattner 6cf8d6cc6e start using irbuilder to make mem intrinsics in a few passes.
llvm-svn: 122572
2010-12-26 22:57:41 +00:00
Benjamin Kramer ea9152e551 MemCpyOpt: Turn memcpys from a constant into a memset if possible.
This allows us to compile "int cst[] = {-1, -1, -1};" into
  movl  $-1, 16(%rsp)
  movq  $-1, 8(%rsp)
instead of
  movl  _cst+8(%rip), %eax
  movl  %eax, 16(%rsp)
  movq  _cst(%rip), %rax
  movq  %rax, 8(%rsp)

llvm-svn: 122548
2010-12-24 21:17:12 +00:00
Chris Lattner bc4457e317 enhance memcpyopt to zap memcpy's that have the same src/dst.
llvm-svn: 121362
2010-12-09 07:45:45 +00:00