Commit Graph

15 Commits

Author SHA1 Message Date
Duncan Sands
6f1d799415 Eliminate switch cases that can never match, for example removes all
negative switch cases if the branch condition is known to be positive.
Inspired by a recent improvement to GCC's VRP.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152405 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-09 13:45:18 +00:00
Benjamin Kramer
8979e5f372 LVI: Recognize the form instcombine canonicalizes range checks into when forming constant ranges.
This could probably be made a lot smarter, but this is a common case and doesn't require LVI to scan a lot
of code. With this change CVP can optimize away the "shift == 0" case in Hashing.h that only gets hit when
"shift" is in a range not containing 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151919 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-02 15:34:43 +00:00
Eli Bendersky
0f0c411079 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.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150664 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16 06:28:33 +00:00
Nick Lewycky
33d84007b5 Test for lazy value info's ability to prove the absense of NULLs in pointers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123601 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 21:57:20 +00:00
Owen Anderson
86e8a700f5 Fix PR8790, another instance where unreachable code can cause instruction simplification to fail,
this case involve a select that simplifies to itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121817 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 00:55:35 +00:00
Owen Anderson
b20955f319 Update testcase since we're no longer doing the constant forwarding inline with correlated value propagation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117712 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29 21:18:23 +00:00
Owen Anderson
b86f57c606 Add missing RUN line to this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114106 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-16 18:46:23 +00:00
Owen Anderson
c2ce21ad51 It is possible, under specific circumstances involving ptrtoint ConstantExpr's, for LVI to end up trying to merge
a Constant into a ConstantRange.  Handle this conservatively for now, rather than asserting.  The testcase is
more complex that I would like, but the manifestation of the problem is sensitive to iteration orders and the state of the
LVI cache, and I have not been able to reproduce it with manually constructed or simplified cases.

Fixes PR8162.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114103 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-16 18:28:33 +00:00
Owen Anderson
4b91c3ac96 Fix PR8161, in which an unreachable loop causes recursive instruction simplification to try
to replace an instruction with itself.  Add a predicate to the simplifier to prevent this case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114097 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-16 17:42:36 +00:00
Owen Anderson
597dad35b8 Propagate non-local comparisons. Fixes PR1757.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113025 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-03 22:47:08 +00:00
Owen Anderson
1593dd6779 Add support for simplifying a load from a computed value to a load from a global when it
is provable that they're equivalent.  This fixes PR4855.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112994 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-03 19:08:37 +00:00
Owen Anderson
ba4d0a005c Add PR number to test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112971 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-03 16:58:25 +00:00
Owen Anderson
df0b94bcea Fix typo. I accidentally edited the wrong file before my last commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112851 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 19:52:06 +00:00
Owen Anderson
66048c2169 Fix a bug in LazyValueInfo that CorrelatedValuePropagation exposed: In the LVI lattice, undef and the full set ConstantRange should not
be treated as equivalent.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112843 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 18:23:58 +00:00
Owen Anderson
8320006473 Rename test directory to reflect new pass name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112592 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 07:50:31 +00:00