Commit Graph

63 Commits

Author SHA1 Message Date
Duncan Sands 5651452076 Stop reassociate from looking through expressions of arbitrary complexity. This
is a temporary measure until my fix for PR13021 is ready.

llvm-svn: 160778
2012-07-26 09:26:40 +00:00
Chandler Carruth a5a29f970e Convert all tests using TCL-style quoting to use shell-style quoting.
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.

If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.

Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.

Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s

llvm-svn: 159525
2012-07-02 12:47:22 +00:00
Duncan Sands 369c6d270b Fix a reassociate crash on sozefx when compiling with dragonegg+gcc-4.7 due to
the optimizers producing a multiply expression with more multiplications than
the original (!).

llvm-svn: 159426
2012-06-29 13:25:06 +00:00
Duncan Sands 514db117bd Some reassociate optimizations create new instructions, which they insert just
before the expression root.  Any existing operators that are changed to use one
of them needs to be moved between it and the expression root, and recursively
for the operators using that one.  When I rewrote RewriteExprTree I accidentally
inverted the logic, resulting in the compacting going down from operators to
operands rather than up from operands to the operators using them, oops.  Fix
this, resolving PR12963.

llvm-svn: 159265
2012-06-27 14:19:00 +00:00
Nick Lewycky bfb07fb562 Remove a dangling reference to a deleted instruction. Fixes PR13185!
llvm-svn: 159096
2012-06-24 01:44:08 +00:00
Duncan Sands 7838603ffc Fix issues (infinite loop and/or crash) with self-referential instructions, for
example degenerate phi nodes and binops that use themselves in unreachable code.
Thanks to Charles Davis for the testcase that uncovered this can of worms.

llvm-svn: 158508
2012-06-15 08:37:50 +00:00
Duncan Sands 409d8ae165 It is possible for several constants which aren't individually absorbing to
combine to the absorbing element.  Thanks to nbjoerg on IRC for pointing this 
out.

llvm-svn: 158399
2012-06-13 12:15:56 +00:00
Duncan Sands 67cd591989 Use std::map rather than SmallMap because SmallMap assumes that the value has
POD type, causing memory corruption when mapping to APInts with bitwidth > 64.
Merge another crash testcase into crash.ll while there.

llvm-svn: 158369
2012-06-12 20:16:51 +00:00
Duncan Sands d7aeefebd6 Now that Reassociate's LinearizeExprTree can look through arbitrary expression
topologies, it is quite possible for a leaf node to have huge multiplicity, for
example: x0 = x*x, x1 = x0*x0, x2 = x1*x1, ... rapidly gives a value which is x
raised to a vast power (the multiplicity, or weight, of x).  This patch fixes
the computation of weights by correctly computing them no matter how big they
are, rather than just overflowing and getting a wrong value.  It turns out that
the weight for a value never needs more bits to represent than the value itself,
so it is enough to represent weights as APInts of the same bitwidth and do the
right overflow-avoiding dance steps when computing weights.  As a side-effect it
reduces the number of multiplies needed in some cases of large powers.  While
there, in view of external uses (eg by the vectorizer) I made LinearizeExprTree
static, pushing the rank computation out into users.  This is progress towards
fixing PR13021.

llvm-svn: 158358
2012-06-12 14:33:56 +00:00
Duncan Sands 9a5cf92250 Revert commit 158073 while waiting for a fix. The issue is that reassociate
can move instructions within the instruction list.  If the instruction just
happens to be the one the basic block iterator is pointing to, and it is
moved to a different basic block, then we get into an infinite loop due to
the iterator running off the end of the basic block (for some reason this
doesn't fire any assertions).  Original commit message:

Grab-bag of reassociate tweaks.  Unify handling of dead instructions and
instructions to reoptimize.  Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on).  No need for WeakVH any more: use
an AssertingVH instead.

llvm-svn: 158199
2012-06-08 13:37:30 +00:00
Duncan Sands 763da45e9e Grab-bag of reassociate tweaks. Unify handling of dead instructions and
instructions to reoptimize.  Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on).  No need for WeakVH any more: use
an AssertingVH instead.

llvm-svn: 158073
2012-06-06 14:53:10 +00:00
Duncan Sands 3c05cd3ea8 Since commit 157467, if reassociate isn't actually going to change an expression
then it doesn't alter the instructions composing it, however it would continue
to move the instructions to just before the expression root.  Ensure it doesn't
move them either, so now it really does nothing if there is nothing to do.  That
commit also ensured that nsw etc flags weren't cleared if the expression was not
being changed.  Tweak this a bit so that it doesn't clear flags on the initial
part of a computation either if that part didn't change but later bits did.

llvm-svn: 157518
2012-05-26 16:42:52 +00:00
Duncan Sands bddfb2f96b Make the reassociation pass more powerful so that it can handle expressions
with arbitrary topologies (previously it would give up when hitting a diamond
in the use graph for example).  The testcase from PR12764 is now reduced from
a pile of additions to the optimal 1617*%x0+208.  In doing this I changed the
previous strategy of dropping all uses for expression leaves to one of dropping
all but one use.  This works out more neatly (but required a bunch of tweaks)
and is also safer: some recently fixed bugs during recursive linearization were
because the linearization code thinks it completely owns a node if it has no uses
outside the expression it is linearizing.  But if the node was also in another
expression that had been linearized (and thus all uses of the node from that
expression dropped) then the conclusion that it is completely owned by the
expression currently being linearized is wrong.  Keeping one use from within each
linearized expression avoids this kind of mistake.

llvm-svn: 157467
2012-05-25 12:03:02 +00:00
Duncan Sands 3bbb1d50df Calling ReassociateExpression recursively is extremely dangerous since it will
replace the operands of expressions with only one use with undef and generate
a new expression for the original without using RAUW to update the original.
Thus any copies of the original expression held in a vector may end up
referring to some bogus value - and using a ValueHandle won't help since there
is no RAUW.  There is already a mechanism for getting the effect of recursion
non-recursively: adding the value to be recursed on to RedoInsts.  But it wasn't
being used systematically.  Have various places where recursion had snuck in at
some point use the RedoInsts mechanism instead.  Fixes PR12169.

llvm-svn: 156379
2012-05-08 12:16:05 +00:00
Owen Anderson f4f80e1f39 Teach reassociate to commute FMul's and FAdd's in order to canonicalize the order of their operands across instructions. This allows for greater CSE opportunities.
llvm-svn: 156323
2012-05-07 20:47:23 +00:00
Bill Wendling 274ba89d77 The value held in the vector may be RAUW'ed by some of the canonicalization
methods. Use a weak value handle to keep up with this.
PR12245

llvm-svn: 155984
2012-05-02 09:59:45 +00:00
Chandler Carruth 739ef80fd7 Teach the reassociate pass to fold chains of multiplies with repeated
elements to minimize the number of multiplies required to compute the
final result. This uses a heuristic to attempt to form near-optimal
binary exponentiation-style multiply chains. While there are some cases
it misses, it seems to at least a decent job on a very diverse range of
inputs.

Initial benchmarks show no interesting regressions, and an 8%
improvement on SPASS. Let me know if any other interesting results (in
either direction) crop up!

Credit to Richard Smith for the core algorithm, and helping code the
patch itself.

llvm-svn: 155616
2012-04-26 05:30:30 +00:00
Chandler Carruth 8ffa7c8afd Tidy up this test more:
1) Make the checked assertions a bit more precise. We really want the
   canonical forms coming out of reassociate to be exactly what is
   expected.
2) Remove other passes, and switch the test to actually directly check
   that reassociate makes the important transforms and
   canonicalizations.
3) Fold in a related test case now that we're using FileCheck. Make the
   same tidying changes to it.

llvm-svn: 155311
2012-04-22 10:11:26 +00:00
Chandler Carruth f6f57535ed FileCheck-ize a test, and tidy it up a touch.
llvm-svn: 155310
2012-04-22 10:11:23 +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
Benjamin Kramer c4189ff0fc Remove empty test.
llvm-svn: 136675
2011-08-02 02:47:45 +00:00
Owen Anderson bddf40e082 Revert r136503 and r136480 in an effort to fix non-determinism in the llvm-gcc buildbots on i386. Devang is looking into the root cause.
llvm-svn: 136674
2011-08-02 02:23:42 +00:00
Devang Patel 3e02522fee Clean up debug info after reassociation.
llvm-svn: 136480
2011-07-29 19:00:35 +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
Dan Gohman 1c6c34834b Fix reassociate to use a worklist instead of recursing when new
reassociation opportunities are exposed. This fixes a bug where
the nested reassociation expects to be the IR to be consistent,
but it isn't, because the outer reassociation has disconnected
some of the operands.  rdar://9167457

llvm-svn: 129324
2011-04-12 00:11:56 +00:00
Dan Gohman 154ed49784 Fix reassociate to postpone certain instruction deletions until
after it has finished all of its reassociations, because its
habit of unlinking operands and holding them in a datastructure
while working means that it's not easy to determine when an
instruction is really dead until after all its regular work is
done. rdar://9096268.

llvm-svn: 127424
2011-03-10 19:51:54 +00:00
Chris Lattner 3eb0af94c4 fix PR9215, preventing -reassociate from clearing nsw/nuw when
it swaps the LHS/RHS of a single binop.

llvm-svn: 125700
2011-02-17 01:29:24 +00:00
Dan Gohman 08d2c98c23 Fix reassociate to clear optional flags, such as nsw.
llvm-svn: 124712
2011-02-02 02:02:34 +00:00
Duncan Sands 69bdb585b2 Fix PR9039, a use-after-free in reassociate. The issue was that the
operand being factorized (and erased) could occur several times in Ops,
resulting in freed memory being used when the next occurrence in Ops was
analyzed.

llvm-svn: 124287
2011-01-26 10:08:38 +00:00
Chris Lattner c6c1523f59 fix a nice subtle reassociate bug which would only occur
in a very specific use pattern embodied in the carefully
reduced testcase.

llvm-svn: 97794
2010-03-05 07:18:54 +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
Chris Lattner 51d64e2a10 filecheckize
llvm-svn: 93775
2010-01-18 21:58:32 +00:00
Chris Lattner ab7087ad66 only factor from expressions whose uses are empty and whose
base is the right expression type.  This fixes PR5981.

llvm-svn: 93045
2010-01-09 06:01:36 +00:00
Chris Lattner f741d72b84 fix an infinite loop in reassociate building emacs.
llvm-svn: 92679
2010-01-05 04:55:35 +00:00
Chris Lattner 0c59ac3f41 When factoring multiply expressions across adds, factor both
positive and negative forms of constants together.  This 
allows us to compile:

int foo(int x, int y) {
    return (x-y) + (x-y) + (x-y);
}

into:

_foo:                                                       ## @foo
	subl	%esi, %edi
	leal	(%rdi,%rdi,2), %eax
	ret

instead of (where the 3 and -3 were not factored):

_foo:
        imull   $-3, 8(%esp), %ecx
        imull   $3, 4(%esp), %eax
        addl    %ecx, %eax
        ret

this started out as:
    movl    12(%ebp), %ecx
    imull   $3, 8(%ebp), %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    ret

This comes from PR5359.

llvm-svn: 92381
2010-01-01 01:13:15 +00:00
Chris Lattner 2f03e64094 test case we alredy get right.
llvm-svn: 92380
2010-01-01 00:50:00 +00:00
Chris Lattner fed3397654 reuse negates where possible instead of always creating them from scratch.
This allows us to optimize test12 into:

define i32 @test12(i32 %X) {
  %factor = mul i32 %X, -3                        ; <i32> [#uses=1]
  %Z = add i32 %factor, 6                         ; <i32> [#uses=1]
  ret i32 %Z
}

instead of:

define i32 @test12(i32 %X) {
  %Y = sub i32 6, %X                              ; <i32> [#uses=1]
  %C = sub i32 %Y, %X                             ; <i32> [#uses=1]
  %Z = sub i32 %C, %X                             ; <i32> [#uses=1]
  ret i32 %Z
}

llvm-svn: 92373
2009-12-31 20:34:32 +00:00
Chris Lattner 60b71b5c4d teach reassociate to factor x+x+x -> x*3. While I'm at it,
fix RemoveDeadBinaryOp to actually do something.

llvm-svn: 92368
2009-12-31 19:24:52 +00:00
Chris Lattner 4e3a5678af simple fix for an incorrect factoring which causes a
miscompilation, PR5458.

llvm-svn: 92354
2009-12-31 08:33:49 +00:00
Chris Lattner 2d3b53a68c merge some more tests in.
llvm-svn: 92353
2009-12-31 08:32:22 +00:00
Chris Lattner 19a4baa201 filecheckize
llvm-svn: 92352
2009-12-31 08:29:56 +00:00
Dan Gohman a080159a7c Convert more tests to avoid llvm-as.
llvm-svn: 81545
2009-09-11 18:36:27 +00:00
Dan Gohman 1880092722 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.

llvm-svn: 81537
2009-09-11 18:01:28 +00:00
Dan Gohman 22f339010c Use "opt < %s" instead of "opt %s" so that opt doesn't print the test
filename in the output, which interferes with the tests' grep lines.

llvm-svn: 81263
2009-09-08 22:57:49 +00:00
Dan Gohman 72a13d2476 Use opt -S instead of piping bitcode output through llvm-dis.
llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Dan Gohman 9737a63ed8 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.

llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Dan Gohman a5b9645c4b Split the Add, Sub, and Mul instruction opcodes into separate
integer and floating-point opcodes, introducing
FAdd, FSub, and FMul.

For now, the AsmParser, BitcodeReader, and IRBuilder all preserve
backwards compatability, and the Core LLVM APIs preserve backwards
compatibility for IR producers. Most front-ends won't need to change
immediately.

This implements the first step of the plan outlined here:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt

llvm-svn: 72897
2009-06-04 22:49:04 +00:00
Owen Anderson 2a6adfa4f0 Remove GCSE and LoadVN from the testsuite.
llvm-svn: 54832
2008-08-16 00:00:54 +00:00
Matthijs Kooijman d1057f49b4 Let some more tests ignore expected output on stderr.
Also, use > %t instead of -o %t for output in one test since that also works
when %t already exists.

This fixes 6 testcases.

llvm-svn: 52178
2008-06-10 15:04:14 +00:00
Gabor Greif 1e427c3264 sabre brings to my attention that the 'tr' suffix is also obsolete
llvm-svn: 51349
2008-05-20 21:00:03 +00:00