Commit Graph

1099 Commits

Author SHA1 Message Date
Duncan Sands
f2641e1bc1 Add codegen support for vector select (in the IR this means a select
with a vector condition); such selects become VSELECT codegen nodes.
This patch also removes VSETCC codegen nodes, unifying them with SETCC
nodes (codegen was actually often using SETCC for vector SETCC already).
This ensures that various DAG combiner optimizations kick in for vector
comparisons.  Passes dragonegg bootstrap with no testsuite regressions
(nightly testsuite as well as "make check-all").  Patch mostly by
Nadav Rotem.

llvm-svn: 139159
2011-09-06 19:07:46 +00:00
Duncan Sands
a098436b32 Split the init.trampoline intrinsic, which currently combines GCC's
init.trampoline and adjust.trampoline intrinsics, into two intrinsics
like in GCC.  While having one combined intrinsic is tempting, it is
not natural because typically the trampoline initialization needs to
be done in one function, and the result of adjust trampoline is needed
in a different (nested) function.  To get around this llvm-gcc hacks the
nested function lowering code to insert an additional parent variable
holding the adjust.trampoline result that can be accessed from the child
function.  Dragonegg doesn't have the luxury of tweaking GCC code, so it
stored the result of adjust.trampoline in the memory GCC set aside for
the trampoline itself (this is always available in the child function),
and set up some new memory (using an alloca) to hold the trampoline.
Unfortunately this breaks Go which allocates trampoline memory on the
heap and wants to use it even after the parent has exited (!).  Rather
than doing even more hacks to get Go working, it seemed best to just use
two intrinsics like in GCC.  Patch mostly by Sanjoy Das.

llvm-svn: 139140
2011-09-06 13:37:06 +00:00
Eli Friedman
342e8df0e0 Basic x86 code generation for atomic load and store instructions.
llvm-svn: 138478
2011-08-24 20:50:09 +00:00
Nadav Rotem
b66b866f46 Revert r137562 because it caused PR10674
llvm-svn: 137719
2011-08-16 14:34:29 +00:00
Nadav Rotem
6858b344ed Fix PR 10635. When generating integer constants, the constant element type may
be illegal, even if the requested vector type is legal. Testcase is one of the
disabled ARM tests in the vector-select patch.

llvm-svn: 137562
2011-08-13 20:31:45 +00:00
Eli Friedman
04c5025cd5 Don't create a ridiculous EXTRACT_ELEMENT. PR10563.
The testcase looks extremely fragile, so I'm adding an assertion which should catch any cases like this.

llvm-svn: 136711
2011-08-02 18:38:35 +00:00
Eli Friedman
adec587d5c Misc optimizer+codegen work for 'cmpxchg' and 'atomicrmw'. They appear to be
working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)

llvm-svn: 136457
2011-07-29 03:05:32 +00:00
Eli Friedman
26a484852e Code generation for 'fence' instruction.
llvm-svn: 136283
2011-07-27 22:21:52 +00:00
Jeffrey Yasskin
7a16288157 Add APInt(numBits, ArrayRef<uint64_t> bigVal) constructor to prevent future ambiguity
errors like the one corrected by r135261.  Migrate all LLVM callers of the old
constructor to the new one.

llvm-svn: 135431
2011-07-18 21:45:40 +00:00
Chris Lattner
229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Nadav Rotem
db213c0400 Add assertion for the chain value type
llvm-svn: 135143
2011-07-14 10:37:54 +00:00
Cameron Zwarich
f03fa189ca Add an intrinsic and codegen support for fused multiply-accumulate. The intent
is to use this for architectures that have a native FMA instruction.

llvm-svn: 134742
2011-07-08 21:39:21 +00:00
Lang Hames
5a00499e87 Add functions 'hasPredecessor' and 'hasPredecessorHelper' to SDNode. The
hasPredecessorHelper function allows predecessors to be cached to speed up
repeated invocations. This fixes PR10186.

X.isPredecessorOf(Y) now just calls Y.hasPredecessor(X)

Y.hasPredecessor(X) calls Y.hasPredecessorHelper(X, Visited, Worklist) with
empty Visited and Worklist sets (i.e. no caching over invocations).

Y.hasPredecessorHelper(X, Visited, Worklist) caches search state in Visited
and Worklist to speed up repeated calls. The Visited set is searched for X
before going to the worklist to further search the DAG if necessary.

llvm-svn: 134592
2011-07-07 04:31:51 +00:00
Eric Christopher
ea336c797c Grammar and 80-col.
llvm-svn: 134555
2011-07-06 22:41:18 +00:00
Benjamin Kramer
e1fc29b6ac Don't allocate empty read-only SmallVectors during SelectionDAG deallocation.
llvm-svn: 133348
2011-06-18 13:13:44 +00:00
Devang Patel
5de2375db8 Remove dead code.
llvm-svn: 131974
2011-05-24 18:27:52 +00:00
Evan Cheng
88f9137fd7 - Teach SelectionDAG::isKnownNeverZero to return true (op x, c) when c is
non-zero.
- Teach X86 cmov optimization to eliminate the cmov from ctlz, cttz extension
  when the source of X86ISD::BSR / X86ISD::BSF is proven to be non-zero.

rdar://9490949

llvm-svn: 131948
2011-05-24 01:48:22 +00:00
Devang Patel
efec7715ec Revert 121907 (it causes llc crash) and apply original patch from PR9817.
llvm-svn: 131926
2011-05-23 22:04:42 +00:00
Devang Patel
c4d9a84159 While replacing all uses of a SDValue with another value, do not forget to transfer SDDbgValue.
llvm-svn: 131907
2011-05-23 17:35:08 +00:00
Owen Anderson
66fd073974 Other parts of the SelectionDAG framework assume that targets use their pointer type for vector indices. Make the vector unrolling code respect that.
llvm-svn: 130733
2011-05-02 22:25:45 +00:00
Evan Cheng
c5c2cfa381 sext(undef) = 0, because the top bits will all be the same.
zext(undef) = 0, because the top bits will be zero.

llvm-svn: 127649
2011-03-15 02:22:10 +00:00
Evan Cheng
37139edc8c BIT_CONVERT has been renamed to BITCAST.
llvm-svn: 127600
2011-03-14 18:19:52 +00:00
Evan Cheng
d2f3b01797 Minor optimization. sign-ext/anyext of undef is still undef.
llvm-svn: 127598
2011-03-14 18:15:55 +00:00
Owen Anderson
cd526fa15e Use the correct LHS type when determining the legalization of a shift's RHS type.
llvm-svn: 127163
2011-03-07 18:29:47 +00:00
Bob Wilson
24b3ba5990 Avoid exponential blow-up when printing DAGs.
David Greene changed CannotYetSelect() to print the full DAG including multiple
copies of operands reached through different paths in the DAG.  Unfortunately
this blows up exponentially in some cases.  The depth limit of 100 is way too
high to prevent this -- I'm seeing a message string of 150MB with a depth of
only 40 in one particularly bad case, even though the DAG has less than 200
nodes.  Part of the problem is that the printing code is following chain
operands, so if you fail to select an operation with a chain, the printer will
follow all the chained operations back to the entry node.

llvm-svn: 126899
2011-03-02 23:38:06 +00:00
Owen Anderson
b2c80da4ae Allow targets to specify a the type of the RHS of a shift parameterized on the type of the LHS.
llvm-svn: 126518
2011-02-25 21:41:48 +00:00
Cameron Zwarich
3cf9280214 Add a getNumSignBits() method to APInt.
llvm-svn: 126379
2011-02-24 10:00:20 +00:00
Devang Patel
b7ae3ccb84 Do not lose debug info of an inlined function argument even if the argument is only used through GEPs.
This time with a fix that avoids using invalidated DenseMap iterator.

llvm-svn: 125984
2011-02-18 22:43:42 +00:00
Cameron Zwarich
0a1a36dc46 Roll out r125794 to help diagnose the llvm-gcc-i386-linux-selfhost failure.
llvm-svn: 125830
2011-02-18 04:58:10 +00:00
Devang Patel
f922a431ee Do not lose debug info of an inlined function argument even if the argument is only used through GEPs.
llvm-svn: 125794
2011-02-17 23:33:27 +00:00
Stuart Hastings
81c4306005 Swap VT and DebugLoc operands of getExtLoad() for consistency with
other getNode() methods.  Radar 9002173.

llvm-svn: 125665
2011-02-16 16:23:55 +00:00
Chris Lattner
eaa8341d3b fix two comment thinkos
llvm-svn: 125481
2011-02-14 06:14:42 +00:00
Chris Lattner
46c01a30f4 Enhance ComputeMaskedBits to know that aligned frameindexes
have their low bits set to zero.  This allows us to optimize
out explicit stack alignment code like in stack-align.ll:test4 when
it is redundant.

Doing this causes the code generator to start turning FI+cst into
FI|cst all over the place, which is general goodness (that is the
canonical form) except that various pieces of the code generator
don't handle OR aggressively.  Fix this by introducing a new
SelectionDAG::isBaseWithConstantOffset predicate, and using it
in places that are looking for ADD(X,CST).  The ARM backend in
particular was missing a lot of addressing mode folding opportunities
around OR.

llvm-svn: 125470
2011-02-13 22:25:43 +00:00
Chris Lattner
e95d195014 Revisit my fix for PR9028: the issue is that DAGCombine was
generating i8 shift amounts for things like i1024 types.  Add
an assert in getNode to prevent this from occuring in the future,
fix the buggy transformation, revert my previous patch, and
document this gotcha in ISDOpcodes.h

llvm-svn: 125465
2011-02-13 19:09:16 +00:00
Devang Patel
639dd997eb Remove comment about an argument that was removed couple of years ago.
llvm-svn: 125054
2011-02-07 21:58:52 +00:00
Matt Beaumont-Gay
29c8c8fe92 Take Bill Wendling's suggestion for structuring a couple of asserts.
llvm-svn: 124688
2011-02-01 22:12:50 +00:00
Devang Patel
1cec755494 Speculatively revert r124380.
llvm-svn: 124397
2011-01-27 19:15:01 +00:00
Devang Patel
3b266a2780 While legalizing SDValues do not drop SDDbgValues, trasfer them to new legal nodes.
Take 2. This includes fix for dragonegg crash.

llvm-svn: 124380
2011-01-27 17:43:53 +00:00
Matt Beaumont-Gay
a148c59231 Try harder to not have unused variables.
llvm-svn: 124350
2011-01-27 02:39:27 +00:00
Matt Beaumont-Gay
0cddbf2bdf Opt-mode -Wunused-variable cleanup
llvm-svn: 124346
2011-01-27 01:47:50 +00:00
David Greene
bab5e6ed0e [AVX] Add INSERT_SUBVECTOR and support it on x86. This provides a
default implementation for x86, going through the stack in a similr
fashion to how the codegen implements BUILD_VECTOR.  Eventually this
will get matched to VINSERTF128 if AVX is available.

llvm-svn: 124307
2011-01-26 19:13:22 +00:00
David Greene
b6f1611928 [AVX] Support EXTRACT_SUBVECTOR on x86. This provides a default
implementation of EXTRACT_SUBVECTOR for x86, going through the stack
in a similr fashion to how the codegen implements BUILD_VECTOR.
Eventually this will get matched to VEXTRACTF128 if AVX is available.

llvm-svn: 124292
2011-01-26 15:38:49 +00:00
Devang Patel
efc6b16e4b Provide an interface to transfer SDDbgValue from one SDNode to another.
llvm-svn: 124245
2011-01-25 23:27:42 +00:00
Ted Kremenek
3c4408ceb6 Null initialize a few variables flagged by
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.

llvm-svn: 124073
2011-01-23 17:05:06 +00:00
Anton Korobeynikov
2f93128109 Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.
llvm-svn: 123170
2011-01-10 12:39:04 +00:00
Jakob Stoklund Olesen
1331a15b0c Replace TargetRegisterInfo::printReg with a PrintReg class that also works without a TRI instance.
Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.

llvm-svn: 123107
2011-01-09 03:05:53 +00:00
Evan Cheng
3ae2b79aa3 Re-implement r122936 with proper target hooks. Now getMaxStoresPerMemcpy
etc. takes an option OptSize. If OptSize is true, it would return
the inline limit for functions with attribute OptSize.

llvm-svn: 122952
2011-01-06 06:52:41 +00:00
Evan Cheng
c052ba7ff3 Revert r122936. I'll re-implement the change.
llvm-svn: 122949
2011-01-06 06:17:53 +00:00
Evan Cheng
06536e7158 r105228 reduced the memcpy / memset inline limit to 4 with -Os to avoid blowing
up freebsd bootloader. However, this doesn't make much sense for Darwin, whose
-Os is meant to optimize for size only if it doesn't hurt performance.
rdar://8821501

llvm-svn: 122936
2011-01-06 01:04:47 +00:00
Benjamin Kramer
25e6e06e42 Try to reuse the value when lowering memset.
This allows us to compile:
  void test(char *s, int a) {
    __builtin_memset(s, a, 15);
  }
into 1 mul + 3 stores instead of 3 muls + 3 stores.

llvm-svn: 122710
2011-01-02 19:57:05 +00:00
Benjamin Kramer
2fdea4c8f1 Lower the i8 extension in memset to a multiply instead of a potentially long series of shifts and ors.
We could implement a DAGCombine to turn x * 0x0101 back into logic operations
on targets that doesn't support the multiply or it is slow (p4) if someone cares
enough.

Example code:
  void test(char *s, int a) {
      __builtin_memset(s, a, 4);
  }
before:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    movl  %eax, %ecx
    shll  $8, %ecx
    orl %eax, %ecx
    movl  %ecx, %eax
    shll  $16, %eax
    orl %ecx, %eax
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret
after:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    imull $16843009, %eax, %eax   ## imm = 0x1010101
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret

llvm-svn: 122707
2011-01-02 19:44:58 +00:00
Chris Lattner
3e5fbd74ed rename MVT::Flag to MVT::Glue. "Flag" is a terrible name for
something that just glues two nodes together, even if it is
sometimes used for flags.

llvm-svn: 122310
2010-12-21 02:38:05 +00:00
Chris Lattner
440b2804ff teach MaskedValueIsZero how to analyze ADDE. This is
enough to teach it that ADDE(0,0) is known 0 except the 
low bit, for example.

llvm-svn: 122191
2010-12-19 20:38:28 +00:00
Duncan Sands
d2e70b5442 Catch attempts to remove a deleted node from the CSE maps. Better to
catch this here rather than later after accessing uninitialized memory
etc.  Fires when compiling the testcase in PR8237.

llvm-svn: 121635
2010-12-12 13:22:50 +00:00
Jay Foad
583abbc4df PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

llvm-svn: 121120
2010-12-07 08:25:19 +00:00
Benjamin Kramer
31920b0a2a Remove unneeded zero arrays.
llvm-svn: 120910
2010-12-04 15:28:22 +00:00
Jay Foad
25a5e4ca1f PR5207: Rename overloaded APInt methods set(), clear(), flip() to
setAllBits(), setBit(unsigned), etc.

llvm-svn: 120564
2010-12-01 08:53:58 +00:00
Michael J. Spencer
447762da85 Merge System into Support.
llvm-svn: 120298
2010-11-29 18:16:10 +00:00
Wesley Peck
527da1b6e2 Renaming ISD::BIT_CONVERT to ISD::BITCAST to better reflect the LLVM IR concept.
llvm-svn: 119990
2010-11-23 03:31:01 +00:00
Benjamin Kramer
f6fb58a216 Silence Release build warnings about unused functions.
llvm-svn: 119903
2010-11-20 15:53:24 +00:00
Duncan Sands
7c601ded34 On X86, MEMBARRIER, MFENCE, SFENCE, LFENCE are not target memory intrinsics,
so don't claim they are.  They are allocated using DAG.getNode, so attempts
to access MemSDNode fields results in reading off the end of the allocated
memory.  This fixes crashes with "llc -debug" due to debug code trying to
print MemSDNode fields for these barrier nodes (since the crashes are not
deterministic, use valgrind to see this).  Add some nasty checking to try
to catch this kind of thing in the future.

llvm-svn: 119901
2010-11-20 11:25:00 +00:00
Mon P Wang
88ff56caa3 Make isScalarToVector to return false if the node is a scalar. This will prevent
DAGCombine from making an illegal transformation of bitcast of a scalar to a
vector into a scalar_to_vector.

llvm-svn: 119819
2010-11-19 19:08:12 +00:00
Dale Johannesen
ed0d840838 Do not throw away alignment when generating the DAG for
memset; we may need it to decide between MOVAPS and MOVUPS
later.  Adjust a test that was looking for wrong code.
PR 3866 / 8675131.

llvm-svn: 119605
2010-11-18 01:35:23 +00:00
Duncan Sands
6c25ca4f2b When passing a parameter using the 'byval' mechanism, inline code needs to be used
to perform the copy, which may be of lots of memory [*].  It would be good if the
fall-back code generated something reasonable, i.e. did the copy in a loop, rather
than vast numbers of loads and stores.  Add a note about this.  Currently target
specific code seems to always kick in so this is more of a theoretical issue rather
than a practical one now that X86 has been fixed.
[*] It's amazing how often people pass mega-byte long arrays by copy...

llvm-svn: 118275
2010-11-05 15:20:29 +00:00
Duncan Sands
1462777017 Simplify uses of MVT and EVT. An MVT can be compared directly
with a SimpleValueType, while an EVT supports equality and
inequality comparisons with SimpleValueType.

llvm-svn: 118169
2010-11-03 12:17:33 +00:00
Dale Johannesen
e660f4d072 Use a MemIntrinsicSDNode for ISD::PREFETCH, which touches
memory, so a MachineMemOperand is useful (not propagated
into the MachineInstr yet).  No functional change except
for dump output.

llvm-svn: 117413
2010-10-26 23:11:10 +00:00
Dan Gohman
a94cc6dfe8 Make CodeGen TBAA-aware.
llvm-svn: 116890
2010-10-20 00:31:05 +00:00
Jim Grosbach
bbdc5d2ef9 Add a pre-dispatch SjLj EH hook on the unwind edge for targets to do any
setup they require. Use this for ARM/Darwin to rematerialize the base
pointer from the frame pointer when required. rdar://8564268

llvm-svn: 116879
2010-10-19 23:27:08 +00:00
Chris Lattner
a4f199720d finish pushing MachinePointerInfo through selectiondags. At this point,
I think I've audited all uses, so it should be dependable for address spaces,
and the pointer+offset info should also be accurate when there.

llvm-svn: 114464
2010-09-21 18:58:22 +00:00
Chris Lattner
6963c1f789 eliminate an old SelectionDAG::getTruncStore method, propagating
MachinePointerInfo around more.

llvm-svn: 114452
2010-09-21 17:42:31 +00:00
Chris Lattner
5e39ffd02f eliminate last SelectionDAG::getLoad old entrypoint, on to stores.
llvm-svn: 114450
2010-09-21 17:28:52 +00:00
Chris Lattner
ea952f05a5 fix the code that infers SV info to be correct when dealing
with an indexed load/store that has an offset in the index.

llvm-svn: 114449
2010-09-21 17:24:05 +00:00
Chris Lattner
3d178ed4d4 propagate MachinePointerInfo through various uses of the old
SelectionDAG::getExtLoad overload, and eliminate it.

llvm-svn: 114446
2010-09-21 17:04:51 +00:00
Chris Lattner
1ffcf527c7 continue MachinePointerInfo'izing, eliminating use of one of the old
getLoad overloads.

llvm-svn: 114443
2010-09-21 16:36:31 +00:00
Chris Lattner
2510de2bea reimplement memcpy/memmove/memset lowering to use MachinePointerInfo
instead of srcvalue/offset pairs.  This corrects SV info for mem 
operations whose size is > 32-bits.

llvm-svn: 114401
2010-09-21 05:40:29 +00:00
Chris Lattner
bc419ba98f add overloads for SelectionDAG::getLoad, getStore, getTruncStore that take a
MachinePointerInfo.  Among other virtues, this doesn't silently  truncate the
svoffset to 32-bits.

llvm-svn: 114399
2010-09-21 05:10:45 +00:00
Chris Lattner
d2d58ada70 simplify interface to SelectionDAG::getMemIntrinsicNode, making it take a MachinePointerInfo
llvm-svn: 114397
2010-09-21 04:57:15 +00:00
Chris Lattner
15d84c460a chagne interface to SelectionDAG::getAtomic to take a MachinePointerInfo,
eliminating some weird "infer a frame address" logic which was dead.

llvm-svn: 114396
2010-09-21 04:53:42 +00:00
Chris Lattner
b5f4920979 force clients of MachineFunction::getMachineMemOperand to provide a
MachinePointerInfo, propagating the type out a level of API.  Remove
the old MachineFunction::getMachineMemOperand impl.

llvm-svn: 114393
2010-09-21 04:46:39 +00:00
Owen Anderson
b92b13d8a0 Invert the logic of reachesChainWithoutSideEffects(). What we want to check is that there is
NO path to the destination containing side effects, not that SOME path contains no side effects.
In  practice, this only manifests with CombinerAA enabled, because otherwise the chain has little
to no branching, so "any" is effectively equivalent to "all".

llvm-svn: 114268
2010-09-18 04:45:14 +00:00
Bruno Cardoso Lopes
d9ef4a1a24 zap unused method. x86 is the only user and already has a more powerfull version
llvm-svn: 112571
2010-08-31 02:36:20 +00:00
Oscar Fuentes
40b31ad3ee Prefix next' iterator operation with llvm::'.
Fixes potential ambiguity problems on VS 2010.

Patch by nobled!

llvm-svn: 110029
2010-08-02 06:00:15 +00:00
Dan Gohman
2e00e3b12d Make SDNode::dump() print a newline at the end.
llvm-svn: 109234
2010-07-23 16:37:47 +00:00
Gabor Greif
59f9970ba5 keep in 80 cols
llvm-svn: 109122
2010-07-22 17:18:03 +00:00
Evan Cheng
55f0c6b9fc Split -enable-finite-only-fp-math to two options:
-enable-no-nans-fp-math and -enable-no-infs-fp-math. All of the current codegen fp math optimizations only care whether the fp arithmetics arguments and results can never be NaN.

llvm-svn: 108465
2010-07-15 22:07:12 +00:00
Evan Cheng
1c349f18f8 Move getExtLoad() and (some) getLoad() DebugLoc argument after EVT argument for consistency sake.
llvm-svn: 107820
2010-07-07 22:15:37 +00:00
Devang Patel
a3ca21b228 Propagate debug loc.
llvm-svn: 107710
2010-07-06 22:08:15 +00:00
Evan Cheng
f3aeb2c22c Infer alignments of fixed frame objects when they are constructed. This ensures remat'ed loads from fixed slots have the right alignments.
llvm-svn: 107591
2010-07-04 18:52:05 +00:00
Rafael Espindola
2041abd958 When splitting a VAARG, remember its alignment.
This produces terrible but correct code.

llvm-svn: 106952
2010-06-26 18:22:20 +00:00
Duncan Sands
2dc70bea54 Remove variables which are assigned to but for which the value
is not used.  Spotted by gcc-4.6.

llvm-svn: 106854
2010-06-25 14:48:39 +00:00
Dan Gohman
463f26b4be Eliminate the other half of the BRCOND optimization, and update
as many tests as possible.

llvm-svn: 106749
2010-06-24 15:24:03 +00:00
Dan Gohman
df6b33e778 Eliminate the first have of the optimization which eliminates BRCOND
when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.

I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.

llvm-svn: 106748
2010-06-24 15:04:11 +00:00
Dan Gohman
600f62b3ba Reapply r106634, now that the bug it exposed is fixed.
llvm-svn: 106746
2010-06-24 14:30:44 +00:00
Daniel Dunbar
4df321b7ad Revert r106263, "Fold the ShrinkDemandedOps pass into the regular DAGCombiner pass,"... it was causing both 'file' (with clang) and 176.gcc (with llvm-gcc) to be miscompiled.
llvm-svn: 106634
2010-06-23 17:09:26 +00:00
Dan Gohman
dd41bba517 Use A.append(...) instead of A.insert(A.end(), ...) when A is a
SmallVector, and other SmallVector simplifications.

llvm-svn: 106452
2010-06-21 19:47:52 +00:00
Dan Gohman
96ca25eba5 Don't replace the old Ordering object with a new one; just clear()
the old one.

llvm-svn: 106284
2010-06-18 15:40:58 +00:00
Dan Gohman
a4f46b3ef8 Don't call clear() on DbgInfo when it's going to be deleted anyway.
Don't replace the old DbgInfo with a new one when clear() on the
old one is sufficient.

llvm-svn: 106283
2010-06-18 15:36:18 +00:00
Dan Gohman
92c11acdb8 Change UpdateNodeOperands' operand and return value from SDValue to
SDNode *, since it doesn't care about the ResNo value.

llvm-svn: 106282
2010-06-18 15:30:29 +00:00
Dan Gohman
b92156d5e4 Fold the ShrinkDemandedOps pass into the regular DAGCombiner pass,
which is faster, simpler, and less surprising.

llvm-svn: 106263
2010-06-18 01:05:21 +00:00
Dan Gohman
0883789ec4 Handle ext(ext(x)) -> ext(x) immediately, since it's simple.
llvm-svn: 106256
2010-06-18 00:08:30 +00:00