Commit Graph

44 Commits

Author SHA1 Message Date
Dan Gohman
70ff4cf1ba Finally re-apply r46959. This is made feasible by the combination
of r56230, r56232, and r56246.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56247 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-16 18:52:57 +00:00
Dan Gohman
c7e42fd5b2 Fix spacing in the grep line for this test, following the recent
SCEV-whitespace changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56234 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-16 01:37:08 +00:00
Dan Gohman
fd6edef87b Teach ScalarEvolution to consider loop preheaders in the search for
an if statement that guards a loop, to allow indvars to avoid smax
operations in more situations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56232 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-15 22:18:04 +00:00
Dan Gohman
8dae138d06 Fix WriteAsOperand to not emit a leading space character. Adjust
its callers to emit a space character before calling it when a
space is needed.

This fixes several spurious whitespace issues in
ScalarEvolution's debug dumps. See the test changes for
examples.

This also fixes odd space-after-tab indentation in the output
for switch statements, and changes calls from being printed like
this:
  call void @foo( i32 %x )
to this:
  call void @foo(i32 %x)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56196 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-14 17:21:12 +00:00
Dan Gohman
3837218ea0 Extend ScalarEvolution's executesAtLeastOnce logic to be able to
continue past the first conditional branch when looking for a
relevant test. This helps it avoid using MAX expressions in
loop trip counts in more cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54697 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-12 20:17:31 +00:00
Eli Friedman
b42a626122 PR2621: Improvements to the SCEV AddRec binomial expansion. This
version uses a new algorithm for evaluating the binomial coefficients 
which is significantly more efficient for AddRecs of more than 2 terms 
(see the comments in the code for details on how the algorithm works).  
It also fixes some bugs: it removes the arbitrary length restriction for 
AddRecs, it fixes the silent generation of incorrect code for AddRecs 
which require a wide calculation width, and it fixes an issue where we 
were incorrectly truncating the iteration count too far when evaluating 
an AddRec expression narrower than the induction variable.

There are still a few related issues I know of: I think there's 
still an issue with the SCEVExpander expansion of AddRec in terms of
the width of the induction variable used.  The hack to avoid generating 
too-wide integers shouldn't be necessary; instead, the callers should be 
considering the cost of the expansion before expanding it (in addition 
to not expanding too-wide integers, we might not want to expand 
expressions that are really expensive, especially when optimizing for 
size; calculating an length-17 32-bit AddRec currently generates about 250 
instructions of straight-line code on X86).  Also, for long 32-bit 
AddRecs on X86, CodeGen really sucks at scheduling the code.  I'm planning on 
filing follow-up PRs for these issues.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54332 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-04 23:49:06 +00:00
Eli Friedman
1fbffe0cef Another SCEV issue from PR2607; essentially the same issue, but this
time applying to the implicit comparison in smin expressions. The 
correct way to transform an inequality into the opposite 
inequality, either signed or unsigned, is with a not expression.

I looked through the SCEV code, and I don't think there are any more 
occurrences of this issue.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54194 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-30 04:36:32 +00:00
Eli Friedman
068acc3caa Fix for PR2607: SCEV miscomputing the loop count for loops with an
SGT exit condition.  Essentially, the correct way to flip an inequality 
in 2's complement is the not operator, not the negation operator.  
That said, the difference only affects cases involving INT_MIN.

Also, enhance the pre-test search logic to be a bit smarter about 
inequalities flipped with a not operator, so it can eliminate the smax 
from the iteration count for simple loops.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54184 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-30 00:04:08 +00:00
Wojciech Matyjewicz
de0f2382e4 Fix PR2088. Use modulo linear equation solver to compute loop iteration
count.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53810 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-20 15:55:14 +00:00
Nick Lewycky
e637727bed XFAIL this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53793 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-19 15:52:06 +00:00
Wojciech Matyjewicz
5c779a46b0 While testing particular algorithms to compute loop iteration count the brute
force evaluation (ComputeIterationCountExhaustively) should be turned off.

It doesn't apply to trip-count2.ll because this file tests the brute force
evaluation.

The test for PR2364 (2008-05-25-NegativeStepToZero.ll) currently fails
showing that the patch for this bug doesn't work. I'll fix it in a few hours
with a patch for PR2088.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53792 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-19 13:26:15 +00:00
Nick Lewycky
59cff12f88 Stop creating extraneous smax/umax in SCEV. This removes a regression where we
started complicating many loops ('for' loops, in fact).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53508 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-12 07:41:32 +00:00
Nick Lewycky
6f8abf929a Crash less. The i64 restriction in BinomialCoefficient caused some problems
with code that was expecting different bit widths for different values.

Make getTruncateOrZeroExtend a method on ScalarEvolution, and use it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52248 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 04:38:55 +00:00
Nick Lewycky
aadc6b68c7 Whoops -- forgot PR reference on this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51569 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-26 20:23:33 +00:00
Nick Lewycky
505242f9b6 Use {} instead of "" in RUN lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51561 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-26 01:27:08 +00:00
Nick Lewycky
04b35e8532 Don't treat values as signed when looking at loop steppings in HowForToNonZero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51560 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-25 23:43:32 +00:00
Evan Cheng
b9a905781e Temporarily reverting 46959.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47542 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-25 03:57:32 +00:00
Nick Lewycky
3e63076980 Add 'umax' similar to 'smax' SCEV. Closes PR2003.
Parse reversed smax and umax as smin and umin and express them with negative
or binary-not SCEVs (which are really just subtract under the hood).

Parse 'xor %x, -1' as (-1 - %x).

Remove dead code (ConstantInt::get always returns a ConstantInt).

Don't use getIntegerSCEV(-1, Ty). The first value is an int, then it gets
passed into a uint64_t. Instead, create the -1 directly from
ConstantInt::getAllOnesValue().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47360 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20 06:48:22 +00:00
Wojciech Matyjewicz
52f321f525 Now that ScalarEvolution::print writes to the correct stream, there is
no need to redirect stderr into stdout.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47009 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 15:12:40 +00:00
Wojciech Matyjewicz
2a9054cfd6 Change negative grep into positive one in my yesterday's testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47008 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 15:10:35 +00:00
Wojciech Matyjewicz
7b5b76835a Fix PR2002. Suppose n is the initial value for the induction
variable (with step 1) and m is its final value. Then, the correct trip 
count is SMAX(m,n)-n. Previously, we used SMAX(0,m-n), but m-n may 
overflow and can't in general be interpreted as signed.

Patch by Nick Lewycky.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47007 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 15:09:36 +00:00
Wojciech Matyjewicz
a089b10421 If the LHS of the comparison is a loop-invariant we also want to move it
to the RHS. This simple change allows to compute loop iteration count 
for loops with condition similar to the one in the testcase (which seems 
to be quite common).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46959 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-11 18:37:34 +00:00
Wojciech Matyjewicz
e3320a1bcc Fix PR1798 - an error in the evaluation of SCEVAddRecExpr at an
arbitrary iteration.

The patch:
1) changes SCEVSDivExpr into SCEVUDivExpr,
2) replaces PartialFact() function with BinomialCoefficient(); the 
computations (essentially, the division) in BinomialCoefficient() are 
performed with the apprioprate bitwidth necessary to avoid overflow; 
unsigned division is used instead of the signed one.

Computations in BinomialCoefficient() require support from the code 
generator for APInts. Currently, we use a hack rounding up the 
neccessary bitwidth to the nearest power of 2. The hack is easy to turn 
off in future.

One remaining issue: we assume the divisor of the binomial coefficient 
formula can be computed accurately using 16 bits. It means we can handle 
AddRecs of length up to 9. In future, we should use APInts to evaluate 
the divisor.

Thanks to Nicholas for cooperation!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46955 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-11 11:03:14 +00:00
Tanya Lattner
727842e9d7 Fix bug in regression tests that ignored stderr output in RUN lines. Updated tests and fixed broken run lines.
XFAILed 3 arm regressions (will file bugs)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44389 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-28 04:57:00 +00:00
Dan Gohman
88e84d1f20 Change grep '' to grep {}.
Change 2>&1 | to |&.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44344 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-27 00:10:35 +00:00
Nick Lewycky
c54c561c9f Add new SCEV, SCEVSMax. This allows LLVM to analyze do-while loops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44319 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-25 22:41:31 +00:00
Nick Lewycky
cf96db2c1d Be more careful when transforming | to +. Patch from Wojciech Matyjewicz.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44248 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-20 08:24:44 +00:00
Anton Korobeynikov
4e1a0e386c Reverted r44163 per request
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44177 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-15 18:33:16 +00:00
Nick Lewycky
65e2da3b4d Fix handling of overflow in loop calculation by adding new UDiv SCEV. This SCEV
is disabled in the sense that it will refuse to create one from a UDiv
instruction, until the code is better tested.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44163 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-15 06:30:50 +00:00
Nick Lewycky
9a2f93121b Build the correct range for loops with unusual bounds. Fix from Jay Foad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42394 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-27 14:12:54 +00:00
Nick Lewycky
f48a88054a Add reference to problem report.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40889 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-07 12:27:03 +00:00
Nick Lewycky
450770de65 Fix the dates on these tests. It's not September yet. Thanks Reid!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40869 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-06 20:00:11 +00:00
Nick Lewycky
d6dac0eebc Let scalar-evolution analyze loops with an unsigned comparison for the exit
condition. Fixes 1597.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40867 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-06 19:21:00 +00:00
Nick Lewycky
06323bfe03 Don't assume it's safe to transform a loop just because it's dominated by any
comparison. Fixes bug 1598.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40866 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-06 18:33:46 +00:00
Nick Lewycky
eefdebe002 Handle decrementing loops properly. Fixes PR1533.
Always pass the constant as the second parameter to HowManyLessThans.

Remove obsolete "isSigned" parameter.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39893 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-16 02:08:00 +00:00
John Criswell
e644ef7b09 Convert .cvsignore files
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37801 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-29 16:35:07 +00:00
Zhou Sheng
fc24a72d9e Add two test cases to cover apintification change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36476 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-26 16:44:48 +00:00
Reid Spencer
b477f7dd65 For PR1319:
Upgrade to use new Tcl exec based test harness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36066 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-15 09:31:07 +00:00
Reid Spencer
0f5aed5648 Make the llvm-runtest function much more amenable by eliminating all the
global variables that needed to be passed in. This makes it possible to
add new global variables with only a couple changes (Makefile and llvm-dg.exp)
instead of touching every single dg.exp file.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35918 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 19:56:59 +00:00
Reid Spencer
5373b721c0 Remove use of implementation keyword.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35412 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-28 02:38:26 +00:00
Reid Spencer
908504347b For PR411:
Update these tests to not use the same name even though the type of the
value differs. After PR411 hits, type planes will be gone and it will be
illegal for a name to be used twice, regardless of type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33660 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-30 16:16:01 +00:00
Reid Spencer
e3ff5ada8a For PR761:
Remove "target endian/pointersize" or add "target datalayout" to make
the test parse properly or set the datalayout because defaults changes.

For PR645:
Make global names use the @ prefix.

For llvm-upgrade changes:
Fix test cases or completely remove use of llvm-upgrade for test cases
that cannot survive the new renaming or upgrade capabilities.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33533 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-26 08:25:06 +00:00
Reid Spencer
b164c76709 Ignore the output directory.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33275 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-17 01:48:42 +00:00
Chris Lattner
d8523aa5de new testcase for pr1101
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33192 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-14 01:23:43 +00:00