Commit Graph

2599 Commits

Author SHA1 Message Date
Nick Lewycky dd1d3df524 A dead malloc, a free(NULL) and a free(undef) are all trivially dead
instructions.

This doesn't introduce any optimizations we weren't doing before (except
potentially due to pass ordering issues), now passes will eliminate them sooner
as part of their own cleanups.

llvm-svn: 142787
2011-10-24 04:35:36 +00:00
Cameron Zwarich 057fbb1a10 The element insertion code in scalar replacement doesn't handle incorrect
element types, even though the element extraction code does. It is surprising
that this bug has been here for so long. Fixes <rdar://problem/10318778>.

llvm-svn: 142740
2011-10-23 07:02:10 +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 32f8051d66 A non-escaping malloc in the entry block is not unlike an alloca. Do dead-store
elimination on them too.

llvm-svn: 142735
2011-10-22 21:59:35 +00:00
Eli Friedman 688db1d6d0 Remap blockaddress correctly when inlining a function. Fixes PR10162.
llvm-svn: 142684
2011-10-21 20:45:19 +00:00
Eli Friedman ce818277fc Extend instcombine's shufflevector simplification to handle more cases where the input and output vectors have different sizes. Patch by Xiaoyi Guo.
llvm-svn: 142671
2011-10-21 19:06:29 +00:00
Eli Friedman 1923a330e6 Refactor code from inlining and globalopt that checks whether a function definition is unused, and enhance it so it can tell that functions which are only used by a blockaddress are in fact dead. This probably doesn't happen much on most code, but the Linux kernel's _THIS_IP_ can trigger this issue with blockaddress. (GlobalDCE can also handle the given tescase, but we only run that at -O3.) Found while looking at PR11180.
llvm-svn: 142572
2011-10-20 05:23:42 +00:00
Nick Lewycky 462098824f "@string = constant i8 0" is a value i8* string of length zero. Analyze that
correctly in GetStringLength, fixing PR11181!

llvm-svn: 142558
2011-10-20 00:34:35 +00:00
Dan Gohman a7107f992e Teach the ARC optimizer about the !clang.arc.copy_on_escape metadata
tag on objc_retainBlock calls, which indicates that they may be
optimized away. rdar://10211286.

llvm-svn: 142298
2011-10-17 22:53:25 +00:00
Lang Hames e7594abd87 Fixed quoting on default data layout option.
llvm-svn: 142286
2011-10-17 21:54:43 +00:00
Bill Wendling c68c8cb8d4 Add support for the Objective-C personality function to the instruction
combining of the landingpad instruction. The ObjC personality function acts
almost identically to the C++ personality function. In particular, it uses
"null" as a "catch-all" value.

llvm-svn: 142256
2011-10-17 21:20:24 +00:00
Dan Gohman 1736c14b85 Suppress partial retain+release elimination when there's a
possibility that it will span multiple CFG diamonds/triangles which
could have different controlling predicates.  rdar://10282956

llvm-svn: 142222
2011-10-17 18:48:25 +00:00
Bill Wendling 63a4ea1859 Correct over-zealous removal of hack.
Some code want to check that *any* call within a function has the 'returns
twice' attribute, not just that the current function has one.

llvm-svn: 142221
2011-10-17 18:43:40 +00:00
Bill Wendling 42cf65fe51 Temporarily XFAIL waiting for a fix.
llvm-svn: 142215
2011-10-17 18:25:32 +00:00
Chandler Carruth 3e8aa65bc2 Add a routine to swap branch instruction operands, and update any
profile metadata at the same time. Use it to preserve metadata attached
to a branch when re-writing it in InstCombine.

Add metadata to the canonicalize_branch InstCombine test, and check that
it is tranformed correctly.

Reviewed by Nick Lewycky!

llvm-svn: 142168
2011-10-17 01:11:57 +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
Andrew Trick fd4ca0f4ac Fix SCEVExpander assert during LSR: "argument of incompatible type".
Just because we're dealing with a GEP doesn't mean we can assert the
SCEV has a pointer type. The fix is simply to ignore the SCEV pointer
type, which we really didn't need.
Fixes PR11138 webkit crash.

llvm-svn: 142058
2011-10-15 06:19:55 +00:00
Andrew Trick 870c1a3f15 Reapply r141870, SCEV expansion of post-inc.
Speculatively reapply to see if this test case still crashes on
linux. I may have fixed it in my last checkin.

llvm-svn: 141895
2011-10-13 21:55:29 +00:00
Andrew Trick 41c253c35c Revert r141870. The test case crashes on linux with data corruption. A deeper issue was exposed.
llvm-svn: 141873
2011-10-13 17:58:24 +00:00
Andrew Trick e15d6e14e3 LSR: Reuse the post-inc expansion of expressions.
This avoids unnecessary expansion of expressions and allows the SCEV
expander to work on expression DAGs, not just trees.
Fixes PR11090.

llvm-svn: 141870
2011-10-13 17:31:47 +00:00
Lang Hames 850f7b3cdc Removed colons from some target datalayout strings in test, since they don't match the required format.
llvm-svn: 141825
2011-10-12 22:24:17 +00:00
Cameron Zwarich 1a761dcfbd Fix PR11106 by correcting a typo that has been in the code for over a year. This
would have never worked, since the element type of a vector type is never a
vector type. Also fix the conditional to be more direct in checking whether
EltTy is a vector type.

llvm-svn: 141713
2011-10-11 21:26:40 +00:00
Cameron Zwarich ab3a9b3baf Add a test for PR10565.
llvm-svn: 141647
2011-10-11 06:10:37 +00:00
Cameron Zwarich d7515ccc47 Remove a lot of the fancy scalar replacement code for dealing with llvm-gcc's
lowering of NEON code. It provides little-to-no benefit now and only introduces
additional complexity.

llvm-svn: 141646
2011-10-11 06:10:30 +00:00
Andrew Trick f9201c572e Move replaceCongruentIVs into SCEVExapander and bias toward "expanded"
IVs.

Indvars previously chose randomly between congruent IVs. Now it will
bias the decision toward IVs that SCEVExpander likes to create. This
was not done to fix any problem, it's just a welcome side effect of
factoring code.

llvm-svn: 141633
2011-10-11 02:28:51 +00:00
Lang Hames 44c78f809b Added a testcase for r141599, rdar://problem/10063881.
llvm-svn: 141628
2011-10-11 01:32:10 +00:00
Andrew Trick ce0cb3a101 Unit test for LSR phi reuse in r141442.
llvm-svn: 141472
2011-10-08 02:34:51 +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
Eli Friedman 3e3aecbc2c PR11061: Make simplifylibcalls fold strcmp("", x) correctly.
While I'm here, fix the related issue with strncmp, add some actual tests for strcmp and strncmp, and start using StringRef::compare for constant folding instead of using strcmp/strncmp so that the optimized IR isn't dependent on the host's implementation of strcmp.

llvm-svn: 141227
2011-10-05 22:27:16 +00:00
Jim Grosbach 8f9acfac89 Revert 141203. InstCombine is looping on unit tests.
llvm-svn: 141209
2011-10-05 20:44:29 +00:00
Rafael Espindola 79d0c4f4b0 Check for the returns_twice attribute in callsFunctionThatReturnsTwice. This
fixes PR11038, but there are still some cleanups to be done.

llvm-svn: 141204
2011-10-05 20:05:13 +00:00
Jim Grosbach e37e030137 Update InstCombine worklist after instruction transform is complete.
When updating the worklist for InstCombine, the Add/AddUsersToWorklist
functions may access the instruction(s) being added, for debug output for
example. If the instructions aren't yet added to the basic block, this
can result in a crash. Finish the instruction transformation before
adjusting the worklist instead.

rdar://10238555

llvm-svn: 141203
2011-10-05 20:05:00 +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
Andrew Trick 8de329a9fc LSR should avoid redundant edge splitting.
This handles the case in which LSR rewrites an IV user that is a phi and
splits critical edges originating from a switch.
Fixes <rdar://problem/6453893> LSR is not splitting edges "nicely"

llvm-svn: 141059
2011-10-04 03:50:44 +00:00
Andrew Trick bf51f97c28 Unit test for r140919, loop unroll heuristics.
llvm-svn: 141049
2011-10-04 00:07:02 +00:00
Rafael Espindola cc349c8dd8 Add the returns_twice attribute to LLVM.
llvm-svn: 141001
2011-10-03 14:45:37 +00:00
Nick Lewycky 99fb091f65 Add a new icmp+select optz'n. Also shows off the load(cst) folding added in
r140966.

llvm-svn: 140969
2011-10-02 10:37:37 +00:00
Jim Grosbach 24ff834671 float comparison to double 'zero' constant can just be a float 'zero.'
InstCombine was incorrectly considering the conversion of the constant
zero to be unsafe.

We want to transform:
define float @bar(float %x) nounwind readnone optsize ssp {
  %conv = fpext float %x to double
  %cmp = fcmp olt double %conv, 0.000000e+00
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}

Into:
define float @bar(float %x) nounwind readnone optsize ssp {
  %cmp = fcmp olt float %x, 0.000000e+00   ; <---- This
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}


rdar://10215914

llvm-svn: 140869
2011-09-30 18:45:50 +00:00
Duncan Sands d6c0011d92 Add forgotten tests that the cleanup flag is cleared if there
is a catch-all landingpad clause.

llvm-svn: 140858
2011-09-30 17:00:34 +00:00
Duncan Sands 5c05579f94 Inlining often produces landingpad instructions with repeated
catch or repeated filter clauses.  Teach instcombine a bunch
of tricks for simplifying landingpad clauses.  Currently the
code only recognizes the GNU C++ and Ada personality functions,
but that doesn't stop it doing a bunch of "generic" transforms
which are hopefully fine for any real-world personality function.
If these "generic" transforms turn out not to be generic, they
can always be conditioned on the personality function.  Probably
someone should add the ObjC++ personality function.  I didn't as
I don't know anything about it.

llvm-svn: 140852
2011-09-30 13:12:16 +00:00
Dan Gohman 4ac148dcbc When eliminating unnecessary retain+autorelease on return values,
handle the case where the retain is in a different basic block.
rdar://10210274.

llvm-svn: 140815
2011-09-29 22:27:34 +00:00
Dan Gohman 2053a5dd64 Don't eliminate objc_retainBlock calls on stack objects if the
objc_retainBlock call is potentially responsible for copying
the block to the heap to extend its lifetime. rdar://10209613.

llvm-svn: 140814
2011-09-29 22:25:23 +00:00
Andrew Trick 8c219ecd1a Test case for r140670: indvars should hoist sext.
llvm-svn: 140671
2011-09-28 02:13:32 +00:00
Benjamin Kramer 547b6c5ecd Stop emitting instructions with the name "tmp" they eat up memory and have to be uniqued, without any benefit.
If someone prefers %tmp42 to %42, run instnamer.

llvm-svn: 140634
2011-09-27 20:39:19 +00:00
Bill Wendling 90f90da156 Split the landing pad basic block with the correct function. Also merge the
split landingpad instructions into a PHI node.
PR11016

llvm-svn: 140592
2011-09-27 00:59:31 +00:00
Eli Friedman c064f2c33e Convert more tests over to the new atomic instructions.
llvm-svn: 140559
2011-09-26 20:27:49 +00:00
Eli Friedman bda9e7af58 Upgrade a couple more tests to the new atomic instructions.
llvm-svn: 140558
2011-09-26 20:15:56 +00:00
Eli Friedman f9b785f185 PR10987: add a missed safety check to isSafePHIToSpeculate in scalarrepl.
llvm-svn: 140327
2011-09-22 18:56:30 +00:00