Commit Graph

4244 Commits

Author SHA1 Message Date
Chris Lattner
077707ccc0 Fix the crash on SimplifyLibCalls/2005-05-20-sprintf-crash.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52295 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 04:10:21 +00:00
Chris Lattner
c5dc660ea0 Fix a case where tailcallelim wouldn't set the changed bit when it made a change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52267 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-14 00:49:48 +00:00
Eli Friedman
6903a24f32 Don't skip over instructions other than loads that might read memory
when trying to sink stores.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52259 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 22:02:12 +00:00
Dan Gohman
e562b1725e Protect ChangeCompareStride from situations in which it is possible
for it to generate use-before-def IR, such as in this testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52258 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 21:43:41 +00:00
Eli Friedman
66fe80aa57 Make sure SimplifyStoreAtEndOfBlock doesn't mess with loops; the
structure checks are incorrect if the blocks aren't distinct.
Fixes PR2435.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52257 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 21:17:49 +00:00
Wojciech Matyjewicz
900872186d Use recently added getTruncateOrZeroExtend method to make the code shorter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 17:02:03 +00:00
Gabor Greif
52ed363fd3 fix a minor deviation from the original in my previous commit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52247 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12 21:51:29 +00:00
Gabor Greif
177dd3ff11 op_iterator-ify some loops, low hanging fruit only, there is more
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52246 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12 21:37:33 +00:00
Evan Cheng
502a4f5162 Do not speculatively execute an instruction by hoisting it to its predecessor BB if any of its operands are defined but not used in BB. The transformation will prevent the operand from being sunk into the use block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52244 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12 21:15:59 +00:00
Evan Cheng
0d0ca8572f Revert 52223.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52243 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12 20:55:39 +00:00
Owen Anderson
af4240ac2d Switch GVN to use ScopedHashTable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52242 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12 19:25:32 +00:00
Gabor Greif
6725cb5f1c op_iterator-ify some loops, fix 80col violations
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52226 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11 21:38:51 +00:00
Evan Cheng
797d95188d For now, avoid generating FP select instructions in order to speculatively execute integer arithmetic instructions. FP selects are more likely to be expensive (even compared to branch on fcmp). This is not a wonderful solution but I rather err on the side of conservative.
This fixes the heapsort performance regressions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52224 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11 19:18:20 +00:00
Evan Cheng
bb318c073e Avoid duplicating loop header which leads to unnatural loops (and just seem like general badness to me, likely to cause code explosion).
Patch by Florian Brandner.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52223 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11 19:07:54 +00:00
Matthijs Kooijman
a9012eca1a Teach instruction combining about the extractvalue. It can succesfully fold
useless insert-extract chains, similar to how it folds them for vectors.

Add a testcase for this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52217 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11 14:05:05 +00:00
Matthijs Kooijman
b4d6a5a76c Clarify a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52212 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11 09:00:12 +00:00
Gabor Greif
f7ea3638e0 op_iterator-ify loops
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52191 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-10 22:03:26 +00:00
Chris Lattner
313f0e63f7 lower calls to abs to inline code, PR2337
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52138 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-09 08:26:51 +00:00
Chris Lattner
18d73c206e Fix PR2411, where ip constant prop would propagate the
result of a weak function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52137 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-09 07:58:07 +00:00
Duncan Sands
8e4eb09b1e Remove comparison methods for MVT. The main cause
of apint codegen failure is the DAG combiner doing
the wrong thing because it was comparing MVT's using
< rather than comparing the number of bits.  Removing
the < method makes this mistake impossible to commit.
Instead, add helper methods for comparing bits and use
them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52098 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-08 20:54:56 +00:00
Chris Lattner
7d8ab4efbc Limit the icmp+phi merging optimization to the cases where it is profitable:
don't make i1 phis when it won't be possible to eliminate them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52097 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-08 20:52:11 +00:00
Evan Cheng
4d09efd7b8 Speculatively execute a block when the the block is the then part of a triangle shape and it contains a single, side effect free, cheap instruction. The branch is eliminated by adding a select instruction. i.e.
Turn                                                                                                                                                                                                       
BB:                                                                                                                                                                                                        
    %t1 = icmp                                                                                                                                                                                             
    br i1 %t1, label %BB1, label %BB2                                                                                                                                                                      
BB1:                                                                                                                                                                                                       
    %t3 = add %t2, c                                                                                                                                                                                       
    br label BB2                                                                                                                                                                                           
BB2:                                                                                                                                                                                                       
=>                                                                                                                                                                                                         
BB:                                                                                                                                                                                                        
    %t1 = icmp                                                                                                                                                                                             
    %t4 = add %t2, c                                                                                                                                                                                       
    %t3 = select i1 %t1, %t2, %t3


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52073 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-07 08:52:29 +00:00
Devang Patel
4c37c07ee3 LoopSimplify preserves AA.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52053 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-06 17:50:58 +00:00
Duncan Sands
83ec4b6711 Wrap MVT::ValueType in a struct to get type safety
and better control the abstraction.  Rename the type
to MVT.  To update out-of-tree patches, the main
thing to do is to rename MVT::ValueType to MVT, and
rewrite expressions like MVT::getSizeInBits(VT) in
the form VT.getSizeInBits().  Use VT.getSimpleVT()
to extract a MVT::SimpleValueType for use in switch
statements (you will get an assert failure if VT is
an extended value type - these shouldn't exist after
type legalization).
This results in a small speedup of codegen and no
new testsuite failures (x86-64 linux).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52044 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-06 12:08:01 +00:00
Zhou Sheng
cc41940dff As Chris suggested, handle the situation if ShAmt larger than BitWidth,
otherwise, opt might crash.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52041 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-06 08:32:05 +00:00
Zhou Sheng
17183ab973 If BitWidth equals to ShtAmt, the RHSKnownZero[BitWidth-ShiftAmt-1] will
crash the opt. Just fix this.

Test case in llvm/test/Transforms/InstCombine/2008-06-05-ashr-crash.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52003 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 14:23:44 +00:00
Matthijs Kooijman
02518140ac Learn ScalarReplAggregrates how stores and loads of first class aggregrates
work and how to replace them into individual values. Also, when trying to
replace an aggregrate that is used by load or store with a single (large)
integer, don't crash (but don't replace the aggregrate either).

Also adds a testcase for both structs and arrays.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51997 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 12:51:53 +00:00
Matthijs Kooijman
47c6fd7317 Let StructRetPromotion check if all if its users are really calls or invokesn,
not other instructions. This fixes a crash with the added testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51992 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 08:57:20 +00:00
Matthijs Kooijman
257da0a7fc Let StructRetPromotion check if it's users are really calling it and not
passing its pointer. Fixes test with added testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51991 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 08:48:32 +00:00
Matthijs Kooijman
41335411a8 Use use_iterator::getOperandNo instead of CallSite::hasArgument to check if a
function is passed as an argument instead of called. Also do this check a bit
earlier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51990 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 08:34:25 +00:00
Matthijs Kooijman
845f524c25 Update comments and documentation to reflect that GCSE and ValueNumbering are
deprecated by the GVN and GVNPRE passes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51983 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-05 07:55:49 +00:00
Owen Anderson
10a05bfff0 Remove unneeded #include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51955 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-04 18:28:10 +00:00
Matthijs Kooijman
227c27dd06 Replace two manual loops with calls to CallSite::hasArguments (no functional changes).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51947 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-04 16:57:50 +00:00
Duncan Sands
a0fcc08e65 Change packed struct layout so that field sizes
are the same as in unpacked structs, only field
positions differ.  This only matters for structs
containing x86 long double or an apint; it may
cause backwards compatibility problems if someone
has bitcode containing a packed struct with a
field of one of those types.
The issue is that only 10 bytes are needed to
hold an x86 long double: the store size is 10
bytes, but the ABI size is 12 or 16 bytes (linux/
darwin) which comes from rounding the store size
up by the alignment.  Because it seemed silly not
to pack an x86 long double into 10 bytes in a
packed struct, this is what was done.  I now
think this was a mistake.  Reserving the ABI size
for an x86 long double field even in a packed
struct makes things more uniform: the ABI size is
now always used when reserving space for a type.
This means that developers are less likely to
make mistakes.  It also makes life easier for the
CBE which otherwise could not represent all LLVM
packed structs (PR2402).
Front-end people might need to adjust the way
they create LLVM structs - see following change
to llvm-gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51928 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-04 08:21:45 +00:00
Owen Anderson
269db29bdb LoopIndexSplit can sometimes result in cases where a block in its own domfrontier.
Don't crash when we encounter one of these.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51915 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-03 18:29:48 +00:00
Dan Gohman
c702a9ed1c Fix whitespace in whitespace-significant pseudocode in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51890 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-03 00:57:21 +00:00
Devang Patel
2f170997b5 Update dom tree. Fix PR 2372.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51887 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-02 22:52:56 +00:00
Chris Lattner
833f25d79e move CannotBeNegativeZero to ValueTracking. Simplify some signbit comparisons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51864 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-02 01:29:46 +00:00
Chris Lattner
173234a68f move ComputeMaskedBits, MaskedValueIsZero, and ComputeNumSignBits
out of instcombine into a new file in libanalysis.  This also teaches
ComputeNumSignBits about the number of sign bits in a constantint.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51863 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-02 01:18:21 +00:00
Owen Anderson
009e4f7609 Fix two issues that Eli Friedman pointed out, where would misoptimized code like:
char a[200];
init(a, a+200);

OR

int a[200];
char* b = (char*)a;
char* c = (char*)a;
foo(b, c);


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51850 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-01 22:26:26 +00:00
Owen Anderson
12cb36c115 Don't remove the memcpy when call slot substitution fails.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51848 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-01 21:52:16 +00:00
Duncan Sands
f413cdfb0b When simplifying a call to a bitcast function, tighten up
the conditions for performing the transform when only the
function declaration is available: no longer allow turning
i32 into i64 for example.  Only allow changing between
pointer types, and between pointer types and integers of
the same size.  For return values ptr -> intptr was already
allowed; I added ptr -> ptr and intptr -> ptr while there.
As shown by a recent objc testcase, changing the way
parameters/return values are passed can be fatal when calling
code written in assembler that directly manipulates call
arguments and return values unless the transform has no
impact on the way they are passed at the codegen level.
While it is possible to imagine an ABI that treats integers
of pointer size differently to pointers, I don't think LLVM
supports any so the transform should now be safe while still
being useful.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51834 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-01 07:38:42 +00:00
Nick Lewycky
517e1f5cd7 Peer through sext/zext when looking for not(cmp).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51819 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-31 19:01:33 +00:00
Nick Lewycky
9419ddb289 Add more i1 optimizations. add, sub, mul, s/udiv on i1 are now simplified away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51817 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-31 17:59:52 +00:00
Nick Lewycky
fd12a0b20b Adding i1 is always Xor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51816 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-31 17:10:28 +00:00
Gabor Greif
ba2c487424 rewrite operand loops to use iterators
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51789 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-30 21:24:22 +00:00
Owen Anderson
427de86ada Since LCSSA switched over to DenseMap, we have to be more careful to avoid iterator invalidation. Fixes PR2385.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51777 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-30 17:31:01 +00:00
Matthijs Kooijman
494661c623 Use eraseFromParent() instead of doing that manually in two places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51770 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-30 12:35:46 +00:00
Dan Gohman
b99e2e20b2 const-ify getOpcode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51698 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 19:53:46 +00:00
Duncan Sands
a806a87e29 Add a newline at the end of this file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51680 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 14:38:23 +00:00
Owen Anderson
038a8746c9 Replace the old ADCE implementation with a new one that more simply solves
the one case that ADCE catches that normal DCE doesn't: non-induction variable
loop computations.

This implementation handles this problem without using postdominators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51668 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 08:45:13 +00:00
Owen Anderson
cd5e6dda7e Remove debugging code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51666 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 08:15:48 +00:00
Gabor Greif
5e46321d66 convert more operand loops to iterator formulation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51663 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 01:59:18 +00:00
Chris Lattner
a935db8ea2 Implement PR2370: memmove(x,x,size) -> noop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51636 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-28 05:30:41 +00:00
Duncan Sands
43e2a03530 Fix some constructs that gcc-4.4 warns about.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51591 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-27 11:50:51 +00:00
Nick Lewycky
6918a9141e InequalityGraph::node() can create new nodes, invalidating iterators across
the set of nodes. Fix makeEqual to handle this by creating the new node first
then iterating across them second.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51573 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-27 00:59:05 +00:00
Nick Lewycky
70ef629d46 Grammaro.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51572 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-26 22:49:36 +00:00
Duncan Sands
28c3cff825 Factor code to copy global value attributes like
the section or the visibility from one global
value to another: copyAttributesFrom.  This is
particularly useful for duplicating functions:
previously this was done by explicitly copying
each attribute in turn at each place where a
new function was created out of an old one, with
the result that obscure attributes were regularly
forgotten (like the collector or the section).
Hopefully now everything is uniform and nothing
is forgotten.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51567 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-26 19:58:59 +00:00
Owen Anderson
78ecf0d7b1 Use a DenseMap instead of an std::map, speeding up the testcase in PR2368 by about a third.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51565 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-26 10:07:43 +00:00
Nick Lewycky
3dfd7bf511 "ret (constexpr)" can't be folded into a Constant. Add a method to
Analysis/ConstantFolding to fold ConstantExpr's, then make instcombine use it
to try to use targetdata to fold constant expressions on void instructions.

Also extend the icmp(inttoptr, inttoptr) folding to handle the case where
int size != ptr size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51559 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-25 20:56:15 +00:00
Chris Lattner
393f7eb60a Fix a serious brain-o. Obviously no-one reviewed my patch :(
This fixes PR2359


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51536 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-24 04:06:28 +00:00
Chris Lattner
60301608f8 Fix PR2358 by resolving calls with undef arguments to overdefined.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51535 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-24 03:59:33 +00:00
Evan Cheng
3cc8f9bfef Remove x86.sse2.loadh.pd and x86.sse2.loadl.pd. These will be lowered into load and shuffle instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51521 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-24 00:07:06 +00:00
Dan Gohman
02dea8b39f Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places to
use it instead of duplicating its functionality.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 21:05:58 +00:00
Matthijs Kooijman
214142cd4f Replace some weird usage of UserOp1 introduced in r49492 by a plain if.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51482 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 16:17:48 +00:00
Matthijs Kooijman
5e179a23e3 Restucture a part of the SimplifyCFG pass and include a testcase.
The SimplifyCFG pass looks at basic blocks that contain only phi nodes,
followed by an unconditional branch. In a lot of cases, such a block (BB) can
be merged into their successor (Succ).

This merging is performed by TryToSimplifyUncondBranchFromEmptyBlock. It does
this by taking all phi nodes in the succesor block Succ and expanding them to
include the predecessors of BB. Furthermore, any phi nodes in BB are moved to
Succ and expanded to include the predecessors of Succ as well.

Before attempting this merge, CanPropagatePredecessorsForPHIs checks to see if
all phi nodes can be properly merged. All functional changes are made to
this function, only comments were updated in
TryToSimplifyUncondBranchFromEmptyBlock.

In the original code, CanPropagatePredecessorsForPHIs looks quite convoluted
and more like stack of checks added to handle different kinds of situations
than a comprehensive check. In particular the first check in the function did
some value checking for the case that BB and Succ have a common predecessor,
while the last check in the function simply rejected all cases where BB and
Succ have a common predecessor. The first check was still useful in the case
that BB did not contain any phi nodes at all, though, so it was not completely
useless.

Now, CanPropagatePredecessorsForPHIs is restructured to to look a lot more
similar to the code that actually performs the merge. Both functions now look
at the same phi nodes in about the same order.  Any conflicts (phi nodes with
different values for the same source) that could arise from merging or moving
phi nodes are detected. If no conflicts are found, the merge can happen.

Apart from only restructuring the checks, two main changes in functionality
happened.

Firstly, the old code rejected blocks with common predecessors in most cases.
The new code performs some extra checks so common predecessors can be handled
in a lot of cases. Wherever common predecessors still pose problems, the
blocks are left untouched.

Secondly, the old code rejected the merge when values (phi nodes) from BB were
used in any other place than Succ. However, it does not seem that there is any
situation that would require this check. Even more, this can be proven.

Consider that BB is a block containing of a single phi node "%a" and a branch
to Succ. Now, since the definition of %a will dominate all of its uses, BB
will dominate all blocks that use %a. Furthermore, since the branch from BB to
Succ is unconditional, Succ will also dominate all uses of %a.

Now, assume that one predecessor of Succ is not dominated by BB (and thus not
dominated by Succ). Since at least one use of %a (but in reality all of them)
is reachable from Succ, you could end up at a use of %a without passing
through it's definition in BB (by coming from X through Succ). This is a
contradiction, meaning that our original assumption is wrong. Thus, all
predecessors of Succ must also be dominated by BB (and thus also by Succ).

This means that moving the phi node %a from BB to Succ does not pose any
problems when the two blocks are merged, and any use checks are not needed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51478 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 09:09:41 +00:00
Matthijs Kooijman
992e97eed3 Indent fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51477 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 07:57:02 +00:00
Nick Lewycky
18b3da6c34 Constant integer vectors may also be negated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51476 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 04:54:45 +00:00
Nick Lewycky
7d26bd8e97 Typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51475 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 04:39:38 +00:00
Nick Lewycky
02d639fcc0 Revert X + X --> X * 2 optz'n which pessimizes heavily on x86.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51474 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 04:34:58 +00:00
Nick Lewycky
8539fe26b7 Implement X + X for vectors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51472 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 04:14:51 +00:00
Nick Lewycky
39ac3b57bc Fix a recently added optimization to not crash on vectors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51471 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 03:26:47 +00:00
Dan Gohman
a332f17c8c Generalize the new code in instcombine's ComputeNumSignBits for handling
and/or to handle more cases (such as this add-sitofp.ll testcase), and
port it to selectiondag's ComputeNumSignBits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51469 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 02:28:01 +00:00
Dan Gohman
8f8e269270 Use isSingleValueType instead of isFirstClassType to
exclude struct and array types.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51467 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 01:52:21 +00:00
Dale Johannesen
9bca583f9d Allow for switch with no cases. Was causing fault
in gcc.dg/pr27531-1.c.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51464 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 01:01:31 +00:00
Dan Gohman
399101a599 Use isSingleValueType instead of isFirstClassType to
exclude struct and array types.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51459 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 00:17:26 +00:00
Dan Gohman
31e5bdccf2 Use isSingleValueType instead of isFirstClassType to
exclude struct and array types.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51456 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 00:12:03 +00:00
Chris Lattner
19d9d4364e rewrite the validity checking for memory promotion to be simpler,
more aggressive, and more correct.  Verify that we only attempt to
promote loads and stores.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51406 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-22 03:22:42 +00:00
Chris Lattner
29d929363d Use 'continue' to reduce nesting in this loop. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51399 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-22 00:53:38 +00:00
Dan Gohman
010ee2d955 When LSR is replacing an instruction, call
ScalarEvolution::deleteValueFromRecords on it before doing the
replaceAllUsesWith, because ScalarEvolution looks at the instruction's
users to find SCEV references to the instruction's SCEV object in its
internal maps.

Move all of LSR's loop-related state clearing after processing the loop
and before cleaning up dead PHI nodes. This eliminates all of LSR's SCEV
references just before the calls to ScalarEvolution::deleteValueFromRecords
so that when ScalarEvolution drops its own SCEV references, the reference
counts will reach zero and the SCEVs will be deleted immediately.

These changes fix some compiler aborts involving ScalarEvolution holding
onto and reusing SCEV objects for instructions that have been deleted.
No regression test unfortunately; because the symptoms were due to
dangling pointers, reduced testcases ended up being fairly arbitrary.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51359 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-21 00:54:12 +00:00
Dan Gohman
f35c8822a3 Port SelectionDAG's ComputeNumSignBits-using code to instcombine,
now that instcombine also has ComputeNumSignBits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51350 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 21:01:12 +00:00
Matthijs Kooijman
6e7b322d36 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 07:26:45 +00:00
Chris Lattner
3d28b1b35b Teach instcombine 4 new xforms:
(add (sext x), cst) --> (sext (add x, cst'))
  (add (sext x), (sext y)) --> (sext (add int x, y))
  (add double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
  (add double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))

This generally reduces conversions.  For example MiBench/telecomm-gsm
gets these simplifications:

HACK2: 	%tmp67.i142.i.i = sext i16 %tmp6.i141.i.i to i32		; <i32> [#uses=1]
	%tmp23.i139.i.i = sext i16 %tmp2.i138.i.i to i32		; <i32> [#uses=1]
	%tmp8.i143.i.i = add i32 %tmp67.i142.i.i, %tmp23.i139.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i121.i.i = sext i16 %tmp6.i120.i.i to i32		; <i32> [#uses=1]
	%tmp23.i118.i.i = sext i16 %tmp2.i117.i.i to i32		; <i32> [#uses=1]
	%tmp8.i122.i.i = add i32 %tmp67.i121.i.i, %tmp23.i118.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i.i190.i = sext i16 %tmp6.i.i189.i to i32		; <i32> [#uses=1]
	%tmp23.i.i187.i = sext i16 %tmp2.i.i186.i to i32		; <i32> [#uses=1]
	%tmp8.i.i191.i = add i32 %tmp67.i.i190.i, %tmp23.i.i187.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i173.i.i.i = sext i16 %tmp6.i172.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i170.i.i.i = sext i16 %tmp2.i169.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i174.i.i.i = add i32 %tmp67.i173.i.i.i, %tmp23.i170.i.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i152.i.i.i = sext i16 %tmp6.i151.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i149.i.i.i = sext i16 %tmp2.i148.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i153.i.i.i = add i32 %tmp67.i152.i.i.i, %tmp23.i149.i.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i.i.i.i = sext i16 %tmp6.i.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i.i5.i.i = sext i16 %tmp2.i.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i.i7.i.i = add i32 %tmp67.i.i.i.i, %tmp23.i.i5.i.i		; <i32> [#uses=3]


This also fixes a bug in ComputeNumSignBits handling select and
makes it more aggressive with and/or.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51302 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 05:46:13 +00:00
Chris Lattner
851627892d fix two issues Neil noticed, thanks!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51296 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 03:50:52 +00:00
Dan Gohman
ca756ae886 Refine the fix in r51169 to only apply when the operand val being
replaced is a PHI. This prevents it from inserting uses before defs
in the case that it isn't a PHI and it depends on other instructions
later in the block. This fixes the 447.dealII regression on x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51292 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 03:01:48 +00:00
Dan Gohman
76d402beb9 Make AssociativeOpt static.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51290 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 01:14:05 +00:00
Devang Patel
52abbf5d8a Do not erase induction variable increment if it is used outside the loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51280 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 22:23:55 +00:00
Dan Gohman
45b4e48b18 Add a ComputeNumSignBits function for use by instcombine, based on the
code in SelectionDAG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51279 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 22:14:15 +00:00
Chris Lattner
7be1c454c9 switch to Type::getFPMantissaWidth instead of reinventing it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51275 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 21:17:23 +00:00
Chris Lattner
0a2d74bd53 minor cleanups, teach instcombine that sitofp/uitofp cannot
produce a negative zero.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51272 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 20:27:56 +00:00
Chris Lattner
0c7a9a04e7 convert fptosi(sitofp x) -> x if the fp value has enough bits in its mantissa
to accurately represent the integer.  This triggers 9 times in 471.omnetpp,
though 8 of those seem to be inlined from the same place.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51271 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 20:25:04 +00:00
Chris Lattner
a540623ab1 Fold FP comparisons where one operand is converted from an integer
type and the other operand is a constant into integer comparisons.
This happens surprisingly frequently (e.g. 10 times in 471.omnetpp),
which are things like this:

	%tmp8283 = sitofp i32 %tmp82 to double	
	%tmp1013 = fcmp ult double %tmp8283, 0.0

Clearly comparing tmp82 against i32 0 is cheaper here.

this also triggers 8 times in gobmk, including this one:

	%tmp375376 = sitofp i32 %tmp375 to double
	%tmp377 = fcmp ogt double %tmp375376, 8.150000e+01

which is comparing an integer against 81.5 :).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51268 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 20:18:56 +00:00
Chris Lattner
9d60ba9d28 remove debug output
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51264 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 20:03:53 +00:00
Chris Lattner
5e0d71877c be more aggressive about transforming add -> or when the operands have no
intersecting bits.  This triggers all over the place, for example in lencode,
with adds of stuff like:

	%tmp580 = mul i32 %tmp579, 2	
	%tmp582 = and i32 %b8, 1
and

	%tmp28 = shl i32 %abs.i, 1		
	%sign.0 = select i1 %tmp23, i32 1, i32 0
and
	%tmp344 = shl i32 %tmp343, 2	
	%tmp346 = and i32 %tmp96, 3

etc.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51263 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 20:01:56 +00:00
Duncan Sands
ec00fcb33d Fix PR2341 - when the length is 4 use an i32 not
an i16!  Cleaned up trailing whitespace while there.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51240 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-19 09:27:24 +00:00
Nate Begeman
1d6e4091f6 Teach GVN to not assert on vector comparisons
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51230 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-18 19:49:05 +00:00
Chris Lattner
47c9909a26 Fix PR2339
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51226 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-18 04:11:26 +00:00
Nick Lewycky
fc1efbbfbc Move isTrueWhenEqual to ICmpInst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51215 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-17 07:33:39 +00:00
Dale Johannesen
1f7580c5eb Less conservative verison of previous patch,
suggested by Duncan.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51211 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-16 23:18:52 +00:00
Dale Johannesen
6796629611 Weak functions not declared non-throwing might be
replaced at linktime with a body that throws, even
if the body in this file does not.  Make PruneEH
be more conservative in this case.
g++.dg/eh/weak1.C



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51207 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-16 21:31:48 +00:00