Commit Graph

692 Commits

Author SHA1 Message Date
Chandler Carruth
ece6c6bb63 Revert the series of commits starting with r166578 which introduced the
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.

These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.

Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)

After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.

Summary of reverted revisions:

r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
         Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
         since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
         on the address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167221 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-01 08:07:29 +00:00
Benjamin Kramer
974d98d730 SCEV validator: Ignore CouldNotCompute/undef on both sides. This is mostly noise and blocks finding more severe bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166873 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-27 11:36:07 +00:00
Benjamin Kramer
cb8b8ea2b6 SCEV validator: Add workarounds for some common false positives due to the way it handles strings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166872 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-27 10:45:01 +00:00
Benjamin Kramer
ff18310274 Add a basic verifier for SCEV's backedge taken counts.
Enabled with -verify-scev. This could be extended significantly but hopefully
catches the common cases now. Note that it's not enabled by default in any
configuration because the way it tries to distinguish SCEVs is still fragile and
may produce false positives. Also the test-suite isn't clean yet, one example
is that it fails if a pass drops an NSW bit but it's still present in SCEV's
cached. Cleaning up all those cases will take some time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166786 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-26 17:31:32 +00:00
Hal Finkel
8c65549318 getSmallConstantTripMultiple should never return zero.
When the trip count is -1, getSmallConstantTripMultiple could return zero,
and this would cause runtime loop unrolling to assert. Instead of returning
zero, one is now returned (consistent with the existing overflow cases).
Fixes PR14167.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166612 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-24 19:46:44 +00:00
Micah Villmow
aa76e9e2cf Add in support for getIntPtrType to get the pointer type based on the address space.
This checkin also adds in some tests that utilize these paths and updates some of the
clients.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166578 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-24 15:52:52 +00:00
Micah Villmow
3574eca1b0 Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:38:25 +00:00
Sylvestre Ledru
94c22716d6 Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164768 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-27 10:14:43 +00:00
Sylvestre Ledru
7e2c793a2b Fix a typo 'iff' => 'if'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164767 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-27 09:59:43 +00:00
Manman Ren
286c4dc355 Release build: guard dump functions with
"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"

No functional change. Update r163344.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163679 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12 05:06:18 +00:00
Manman Ren
cc77eece74 Release build: guard dump functions with "ifndef NDEBUG"
No functional change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163344 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 19:55:56 +00:00
Nick Lewycky
6ce2471806 Stay rational; don't assert trying to take the square root of a negative value.
If it's negative, the loop is already proven to be infinite. Fixes PR13489!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161107 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-01 09:14:36 +00:00
Andrew Trick
8b7036b0f4 Factor SCEV traversal code so I can use it elsewhere. No functionality.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160203 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-13 23:33:03 +00:00
Dan Gohman
655b5a48b9 Delete code for folding undefs in ScalarEvolution. It's invalid in
obscure ways, and it isn't actually important in the real world.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159969 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-09 23:51:20 +00:00
Benjamin Kramer
992c25a3fc Reduce use list thrashing by using DenseMap's find_as for maps with ValueHandle keys.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159497 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-30 22:37:15 +00:00
Nick Lewycky
4d3bba5be4 If the step value is a constant zero, the loop isn't going to terminate. Fixes
the assert reported in PR13228!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159393 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-28 23:44:57 +00:00
Benjamin Kramer
d9b0b02561 Fix typos found by http://github.com/lyda/misspell-check
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157885 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-02 10:20:22 +00:00
Benjamin Kramer
127563b216 Make sure that we're dealing with a binary SCEVExpr when simplifying.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-30 18:42:43 +00:00
Benjamin Kramer
6cf07a80ff Teach SCEV's icmp simplification logic that a-b == 0 is equivalent to a == b.
This also required making recursive simplifications until
nothing changes or a hard limit (currently 3) is hit.

With the simplification in place indvars can canonicalize
loops of the form
for (unsigned i = 0; i < a-b; ++i)
into
for (unsigned i = 0; i != a-b; ++i)
which used to fail because SCEV created a weird umax expr
for the backedge taken count.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157701 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-30 18:32:23 +00:00
Andrew Trick
fe3516f9a5 SCEV: Handle a corner case reducing AddRecExpr * AddRecExpr
If integer overflow causes one of the terms to reach zero, that can
force the entire expression to zero.

Fixes PR12929: cast<Ty>() argument of incompatible type

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157673 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-30 03:35:20 +00:00
Andrew Trick
97178aedb5 Reformat the loop that does AddRecExpr * AddRecExpr reduction.
No functionality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157672 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-30 03:35:17 +00:00
Andrew Trick
8aa22019ca SCEV: Add MarkPendingLoopPredicates to avoid recursive isImpliedCond.
getUDivExpr attempts to simplify by checking for overflow.
isLoopEntryGuardedByCond then evaluates the loop predicate which
may lead to the same getUDivExpr causing endless recursion.

Fixes PR12868: clang 3.2 segmentation fault.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157092 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-19 00:48:25 +00:00
Nuno Lopes
ac94bd88d8 reuse the result of some expensive computations in getSignExtendExpr() and getZeroExtendExpr()
this gives a speedup of > 80 in a debug build in the test case of PR12825 (php_sha512_crypt_r)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156849 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-15 20:20:14 +00:00
Nuno Lopes
39de32f497 minor simplification to code: Ty is already a SCEV type; don't need to run getEffectiveSCEVType() twice
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156823 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-15 15:44:38 +00:00
Dan Gohman
ac84461e5a Rewrite ScalarEvolution::hasOperand to use an explicit worklist instead
of recursion, to avoid excessive stack usage on deep expressions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156554 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-10 17:21:30 +00:00
Benjamin Kramer
86df062791 Revert "SCEV: When expanding a GEP the final addition to the base pointer has NUW but not NSW."
This isn't right either, reverting for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154910 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-17 06:33:57 +00:00
Benjamin Kramer
c77764591b SCEV: When expanding a GEP the final addition to the base pointer has NUW but not NSW.
Found by inspection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154262 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-07 17:19:26 +00:00
Rafael Espindola
26c8dcc692 Always compute all the bits in ComputeMaskedBits.
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154011 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-04 12:51:34 +00:00
Andrew Trick
eb6dd23c95 SCEV fix: Handle loop invariant loads.
Fixes PR11882: NULL dereference in ComputeLoadConstantCompareExitLimit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153480 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-26 22:33:59 +00:00
Chris Lattner
dada586f16 switch SCEV to use the new ConstantFoldLoadThroughGEPIndices function
instead of its own hard coded thing, allowing it to handle 
ConstantDataSequential and fixing some obscure bugs (e.g. it would
previously crash on a CAZ of vector type).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148788 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-24 05:49:24 +00:00
David Blaikie
4d6ccb5f68 More dead code removal (using -Wunreachable-code)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148578 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-20 21:51:11 +00:00
Benjamin Kramer
07df1b4d1a Remove obviously invalid early exit that prevented analyzing ConstantAggregateZeros.
Found by the clang static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148540 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-20 14:42:25 +00:00
Andrew Trick
3eada319fc Clarified the SCEV getSmallConstantTripCount interface with in-your-face comments.
This interface is misleading and dangerous, but it is actually what we need for unrolling.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147926 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-11 06:52:55 +00:00
Andrew Trick
f8fd841a4b Expose isNonConstantNegative to users of ScalarEvolution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147700 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-07 00:27:31 +00:00
Chad Rosier
aab8e28d5e Fix a few more places where TargetData/TargetLibraryInfo is not being passed.
Add FIXMEs to places that are non-trivial to fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145661 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-02 01:26:24 +00:00
Chad Rosier
00737bdb48 Last bit of TargetLibraryInfo propagation. Also fixed a case for TargetData
where it appeared beneficial to pass.
More of rdar://10500969

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145630 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01 21:29:16 +00:00
Chad Rosier
618c1dbd29 Propagate TargetLibraryInfo throughout ConstantFolding.cpp and
InstructionSimplify.cpp.  Other fixups as needed.
Part of rdar://10500969

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145559 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01 03:08:23 +00:00
Andrew Trick
ecb35ece5c SCEV fix. In general, Add/Mul expressions should not inherit NSW/NUW.
This reverts r139450, fixes r139453, and adds much needed comments and a
unit test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145367 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-29 02:16:38 +00:00
Andrew Trick
121d78f7e7 Make SCEV print <nsw><nuw> for Add/MulExpr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145364 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-29 02:06:35 +00:00
Benjamin Kramer
13c3c75176 SCEV: Actually set overflow flags on add expressions.
setFlags doesn't modify its arguments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145007 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-20 10:24:36 +00:00
Andrew Trick
79f0bfcc20 Fix SCEV overly optimistic back edge taken count for multi-exit loops.
Fixes PR11375: Different results for 'clang++ huh.cpp'...


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144746 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-16 00:52:40 +00:00
Nick Lewycky
d7ecff49d9 Don't try to loop on iterators that are potentially invalidated inside the loop. Fixes PR11361!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144454 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12 03:09:12 +00:00
Nick Lewycky
89d093d5b6 Don't forget to check FlagNW when determining whether an AddRecExpr will wrap
or not. Patch by Brendon Cahoon!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144173 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09 07:11:37 +00:00
Duncan Sands
f8a9eb1fa6 Restore commits 142790 and 142843 - they weren't breaking the build
bots.  Original commit messages:
- Reapply r142781 with fix. Original message:

  Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
  loop header when computing the trip count.

  With this, we now constant evaluate:
    struct ListNode { const struct ListNode *next; int i; };
    static const struct ListNode node1 = {0, 1};
    static const struct ListNode node2 = {&node1, 2};
    static const struct ListNode node3 = {&node2, 3};
    int test() {
      int sum = 0;
      for (const struct ListNode *n = &node3; n != 0; n = n->next)
        sum += n->i;
      return sum;
    }

- Now that we look at all the header PHIs, we need to consider all the header PHIs
  when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
  torture testsuite!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142919 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-25 12:28:52 +00:00
Duncan Sands
526c80bae4 Speculatively revert commits 142790 and 142843 to see if it fixes
the dragonegg and llvm-gcc self-host buildbots.  Original commit
messages:
- Reapply r142781 with fix. Original message:

  Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
  loop header when computing the trip count.

  With this, we now constant evaluate:
    struct ListNode { const struct ListNode *next; int i; };
    static const struct ListNode node1 = {0, 1};
    static const struct ListNode node2 = {&node1, 2};
    static const struct ListNode node3 = {&node2, 3};
    int test() {
      int sum = 0;
      for (const struct ListNode *n = &node3; n != 0; n = n->next)
        sum += n->i;
      return sum;
    }

- Now that we look at all the header PHIs, we need to consider all the header PHIs
when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142916 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-25 09:26:43 +00:00
Nick Lewycky
3846163aee Now that we look at all the header PHIs, we need to consider all the header PHIs
when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142843 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24 21:02:38 +00:00
Nick Lewycky
7c3fc57472 Reapply r142781 with fix. Original message:
Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
  loop header when computing the trip count.

  With this, we now constant evaluate:
    struct ListNode { const struct ListNode *next; int i; };
    static const struct ListNode node1 = {0, 1};
    static const struct ListNode node2 = {&node1, 2};
    static const struct ListNode node3 = {&node2, 3};
    int test() {
      int sum = 0;
      for (const struct ListNode *n = &node3; n != 0; n = n->next)
        sum += n->i;
      return sum;
    }


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142790 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24 06:57:05 +00:00
Nick Lewycky
5bef0eb1de PHI nodes not in the loop header aren't part of the loop iteration initial
state. Furthermore, they might not have two operands. This fixes the underlying
issue behind the crashes introduced in r142781.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142788 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24 05:51:01 +00:00
Nick Lewycky
38af3d5a8d Speculatively revert r142781. Bots are showing
Assertion `i_nocapture < OperandTraits<PHINode>::operands(this) && "getOperand() out of range!"' failed.
coming out of indvars.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142786 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24 04:00:25 +00:00
Nick Lewycky
795cb48f1a Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
  struct ListNode { const struct ListNode *next; int i; };
  static const struct ListNode node1 = {0, 1};
  static const struct ListNode node2 = {&node1, 2};
  static const struct ListNode node3 = {&node2, 3};
  int test() {
    int sum = 0;
    for (const struct ListNode *n = &node3; n != 0; n = n->next)
      sum += n->i;
    return sum;
  }


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142781 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-23 23:43:14 +00:00