1612 Commits

Author SHA1 Message Date
Dan Gohman
cd4c03e886 Don't do (X != Y) ? X : Y -> X for floating-point values; it doesn't
handle NaN properly.

Do (X une Y) ? X : Y  -> X if one of X and Y is not zero.

llvm-svn: 96955
2010-02-23 17:17:57 +00:00
Dan Gohman
8a0eb36d23 Remove the code which constant-folded ptrtoint(inttoptr(x)+c) to
getelementptr. Despite only doing so in the case where x is a known
array object and c can be converted to an index within range, this
could still be invalid if c is actually the address of an object
allocated outside of LLVM. Also, SCEVExpander, the original motivation
for this code, has since been improved to avoid inttoptr+ptroint in
more cases.

llvm-svn: 96950
2010-02-23 16:35:41 +00:00
Dan Gohman
e7f6feb469 Convert this test to FileCheck and add a testcase for PR3574.
llvm-svn: 96851
2010-02-23 01:28:09 +00:00
Evan Cheng
3688b8fa68 Instcombine constant folding can normalize gep with negative index to index with large offset. When instcombine objsize checking transformation sees these geps where the offset seemingly point out of bound, it should just return "i don't know" rather than asserting.
llvm-svn: 96825
2010-02-22 23:34:00 +00:00
Dan Gohman
d8abbf0af6 Add a test for canonicalizing ConstantExpr operands.
llvm-svn: 96820
2010-02-22 23:07:52 +00:00
Dan Gohman
754e4a9801 Constant-fold certain comparisons with infinity and negative infinity.
llvm-svn: 96777
2010-02-22 04:06:03 +00:00
Dan Gohman
6b1e2a829d Teach ScalarEvolution how to compute a tripcount for a loop with
true or false as its exit condition. These are usually eliminated by
SimplifyCFG, but the may be left around during a pass which wishes
to preserve the CFG.

llvm-svn: 96683
2010-02-19 18:12:07 +00:00
Dan Gohman
cf39be32bf Fold bswap(undef) to undef.
llvm-svn: 96432
2010-02-17 00:54:58 +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
6fbfe5897c fix PR6305 by handling BlockAddress in a helper function
called by jump threading.

llvm-svn: 96263
2010-02-15 20:47:49 +00:00
Eric Christopher
843a4cc43c Fix a problem where we had bitcasted operands that gave us
odd offsets since the bitcasted pointer size and the offset pointer
size are going to be different types for the GEP vs base object.

llvm-svn: 96134
2010-02-13 23:38:01 +00:00
Chris Lattner
75879be9d8 1. modernize the constantmerge pass, using densemap/smallvector.
2. don't bother trying to merge globals in non-default sections,
   doing so is quite dubious at best anyway.
3. fix a bug reported by Arnaud de Grandmaison where we'd try to
   merge two globals in different address spaces.

llvm-svn: 95995
2010-02-12 18:17:23 +00:00
Chris Lattner
554003f481 rename test
llvm-svn: 95993
2010-02-12 18:05:00 +00:00
Dan Gohman
45774ce0ad Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.

llvm-svn: 95975
2010-02-12 10:34:29 +00:00
Eric Christopher
cccdc13662 Make sure that ConstantExpr offsets also aren't off of extern
symbols.

Thanks to Duncan Sands for the testcase!

llvm-svn: 95877
2010-02-11 17:44:04 +00:00
Chris Lattner
4e8137d678 Rename ValueRequiresCast to ShouldOptimizeCast, to better reflect
what it does.  Enhance it to return false to optimizing vector
sign extensions from vector comparisions, which is the idiom used
to get a splatted vector for a vector comparison.

Doing this breaks vector-casts.ll, add some compensating 
transformations to handle the important case they cover without
depending on this canonicalization.

This fixes rdar://7434900 a serious pessimization of vector compares.

llvm-svn: 95855
2010-02-11 06:26:33 +00:00
Chris Lattner
1d4eb8fac4 convert to filecheck.
llvm-svn: 95854
2010-02-11 06:24:37 +00:00
Chris Lattner
c053cbbc4d Make DSE only scan blocks that are reachable from the entry
block.  Other blocks may have pointer cycles that will crash
basicaa and other alias analyses.  In any case, there is no
point wasting cycles optimizing dead blocks.  This fixes 
rdar://7635088

llvm-svn: 95852
2010-02-11 05:11:54 +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
Chris Lattner
d924f63692 Make jump threading honor x|undef -> true and x&undef -> false,
instead of considering x|undef -> x, which may not be true.

llvm-svn: 95850
2010-02-11 04:40:44 +00:00
Eric Christopher
531ea566a6 Add ConstantExpr handling to Intrinsic::objectsize lowering.
Update testcase accordingly now that we can optimize another
section.

llvm-svn: 95846
2010-02-11 01:48:54 +00:00
Eric Christopher
7b7028fd24 Move Intrinsic::objectsize lowering back to InstCombineCalls and
enable constant 0 offset lowering.

llvm-svn: 95691
2010-02-09 21:24:27 +00:00
Eric Christopher
ad1aa86276 Pull these back out, they're a little too aggressive and time
consuming for a simple optimization.

llvm-svn: 95671
2010-02-09 17:29:18 +00:00
Chris Lattner
9b6a1789e5 fix PR6193, only considering sign extensions *from i1* for this
xform.

llvm-svn: 95642
2010-02-09 01:12:41 +00:00
Eric Christopher
9f85e7eb16 Add a new pass to do llvm.objsize lowering using SCEV.
Initial skeleton and SCEVUnknown lowering implemented,
the rest should come relatively quickly.  Move testcase
to new directory.

Move pass to right before SimplifyLibCalls - which is
moved down a bit so we can take advantage of a few opts.

llvm-svn: 95628
2010-02-09 00:35:38 +00:00
Bob Wilson
a10e65c852 Add a test for my change to disable reassociation for i1 types.
llvm-svn: 95465
2010-02-06 01:16:25 +00:00
Jakob Stoklund Olesen
916f48a054 Teach SimplifyCFG about magic pointer constants.
Weird code sometimes uses pointer constants other than null. This patch
teaches SimplifyCFG to build switch instructions in those cases.

Code like this:

void f(const char *x) {
  if (!x)
    puts("null");
  else if ((uintptr_t)x == 1)
    puts("one");
  else if (x == (char*)2 || x == (char*)3)
    puts("two");
  else if ((intptr_t)x == 4)
    puts("four");
  else
    puts(x);
}

Now becomes a switch:

define void @f(i8* %x) nounwind ssp {
entry:
  %magicptr23 = ptrtoint i8* %x to i64            ; <i64> [#uses=1]
  switch i64 %magicptr23, label %if.else16 [
    i64 0, label %if.then
    i64 1, label %if.then2
    i64 2, label %if.then9
    i64 3, label %if.then9
    i64 4, label %if.then14
  ]

Note that LLVM's own DenseMap uses magic pointers.

llvm-svn: 95439
2010-02-05 22:03:18 +00:00
Chris Lattner
64ffd11d49 fix logical-select to invoke filecheck right, and fix hte instcombine
xform it is checking to actually pass.  There is no need to match
m_SelectCst<0, -1> since instcombine canonicalizes that into not(sext).

Add matches for sext(not(x)) in addition to not(sext(x)).

llvm-svn: 95420
2010-02-05 19:53:02 +00:00
Eric Christopher
04371b4f12 Remove this code for now. I have a better idea and will rewrite with
that in mind.

llvm-svn: 95402
2010-02-05 19:04:06 +00:00
Eric Christopher
107a1fbf61 Temporarily revert this since it appears to have caused a build
failure.

llvm-svn: 95294
2010-02-04 06:41:27 +00:00
Eric Christopher
42fa84a880 Rework constant expr and array handling for objectsize instcombining.
Fix bugs where we would compute out of bounds as in bounds, and where
we couldn't know that the linker could override the size of an array.

Add a few new testcases, change existing testcase to use a private
global array instead of extern.

llvm-svn: 95283
2010-02-04 02:55:34 +00:00
Eric Christopher
f12e18db21 If we're dealing with a zero-length array, don't lower to any
particular size, we just don't know what the length is yet.

llvm-svn: 95266
2010-02-03 23:56:07 +00:00
Evan Cheng
27a41d5473 Revert 94937 and move the noreturn check to codegen.
llvm-svn: 95198
2010-02-03 03:55:59 +00:00
Eric Christopher
d86233c118 Recommit this, looks like it wasn't the cause.
llvm-svn: 95165
2010-02-03 00:21:58 +00:00
Eric Christopher
e67d01a9a8 Hopefully temporarily revert this.
llvm-svn: 95154
2010-02-02 23:01:31 +00:00
Eric Christopher
4264e7e46f Re-add strcmp and known size object size checking optimization.
Passed bootstrap and nightly test run here.

llvm-svn: 95145
2010-02-02 22:10:43 +00:00
Chris Lattner
8e2c471614 don't turn (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B
for vectors.  Codegen is generating awful code or segfaulting
in various cases (e.g. PR6204).

llvm-svn: 95058
2010-02-02 02:43:51 +00:00
Chris Lattner
302240d73e fix a crash in loop unswitch on a loop invariant vector condition.
llvm-svn: 95055
2010-02-02 02:26:54 +00:00
Chris Lattner
29bb9272a6 remove an unreduced testcase, rename another.
llvm-svn: 95054
2010-02-02 02:23:37 +00:00
Chris Lattner
94eb4b285b fix PR6195, a bug constant folding scalar -> vector compares.
llvm-svn: 94997
2010-02-01 20:04:40 +00:00
Chris Lattner
3c46e14137 fix PR6197 - infinite recursion in ipsccp due to block addresses
evaluateICmpRelation wasn't handling blockaddress.

llvm-svn: 94993
2010-02-01 19:35:08 +00:00
Dan Gohman
e5e1b7b05a Generalize target-independent folding rules for sizeof to handle more
cases, and implement target-independent folding rules for alignof and
offsetof. Also, reassociate reassociative operators when it leads to
more folding.

Generalize ScalarEvolution's isOffsetOf to recognize offsetof on
arrays. Rename getAllocSizeExpr to getSizeOfExpr, and getFieldOffsetExpr
to getOffsetOfExpr, for consistency with analagous ConstantExpr routines.

Make the target-dependent folder promote GEP array indices to
pointer-sized integers, to make implicit casting explicit and exposed
to subsequent folding.

And add a bunch of testcases for this new functionality, and a bunch
of related existing functionality.

llvm-svn: 94987
2010-02-01 18:27:38 +00:00
Chris Lattner
846a52e228 fix rdar://7590304, a miscompilation of objc apps on arm. The caller
of objc message send was getting marked arm_apcscc, but the prototype
isn't.  This is fine at runtime because objcmsgsend is implemented in
assembly.  Only turn a mismatched caller and callee into 'unreachable'
if the callee is a definition.

llvm-svn: 94986
2010-02-01 18:11:34 +00:00
Chris Lattner
2cecedf081 fix rdar://7590304, an infinite loop in instcombine. In the invoke
case, instcombine can't zap the invoke for fear of changing the CFG.
However, we have to do something to prevent the next iteration of
instcombine from inserting another store -> undef before the invoke
thereby getting into infinite iteration between dead store elim and
store insertion.

Just zap the callee to null, which will prevent the next iteration
from doing anything.

llvm-svn: 94985
2010-02-01 18:04:58 +00:00
Eli Friedman
690c7f4dfd Remove test which is no longer relevant.
llvm-svn: 94944
2010-01-31 04:40:45 +00:00
Eli Friedman
a2cc2875fc Simplify/generalize the xor+add->sign-extend instcombine.
llvm-svn: 94943
2010-01-31 04:29:12 +00:00
Eli Friedman
37a8197b61 Add a small transform: transform -(X<<Y) to (-X<<Y) when the shift has a single
use and X is free to negate.

llvm-svn: 94941
2010-01-31 02:30:23 +00:00
Evan Cheng
d86d3fe0c3 Do not mark no-return calls tail calls. It'll screw up special calls like longjmp and it doesn't make much sense for performance reason. If my logic is faulty, please let me know.
llvm-svn: 94937
2010-01-31 00:59:31 +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
2e51136f80 Remove ARM-specific calling convention from this test. Target data is
needed for this test, but otherwise, there's nothing ARM-specific about
it and no need to specify the calling convention.

llvm-svn: 94862
2010-01-30 00:40:23 +00:00