Commit Graph

7642 Commits

Author SHA1 Message Date
Benjamin Kramer
56442dfdcf SimplifyCFG: Turn switches into sub+icmp+branch if possible.
This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.

We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.

The testcase from README.txt now compiles into
  decl  %edi
  cmpl  $3, %edi
  sbbl  %eax, %eax
  andl  $1, %eax
  ret

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 15:56:22 +00:00
Nick Lewycky
8eb3e54592 Remove wasteful caching. This isn't needed for correctness because any function
that might have changed been affected by a merge elsewhere will have been
removed from the function set, and it isn't needed for performance because we
call grow() ahead of time to prevent reallocations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124717 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 05:31:01 +00:00
Dan Gohman
5195b71941 Conservatively, clear optional flags, such as nsw, when performing
reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124713 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 02:05:46 +00:00
Dan Gohman
46985a1440 Fix reassociate to clear optional flags, such as nsw.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124712 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 02:02:34 +00:00
Anders Carlsson
77bc49e5e2 Recognize and simplify
(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124567 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-30 22:01:13 +00:00
Francois Pichet
337c081138 Unbreak the MSVC build.
The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124545 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 20:06:16 +00:00
Frits van Bommel
31726c154d Call SimplifyFDivInst() in InstCombiner::visitFDiv().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 17:50:27 +00:00
Frits van Bommel
1fca2c32cc Move InstCombine's knowledge of fdiv to SimplifyInstruction().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124534 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 15:26:31 +00:00
Evan Cheng
60f5ad46c2 Add a test for TCE return duplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 04:53:35 +00:00
Evan Cheng
c3f507f98a Re-apply r124518 with fix. Watch out for invalidated iterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 04:46:23 +00:00
Evan Cheng
b0a42fdb36 Revert r124518. It broke Linux self-host.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124522 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 02:43:04 +00:00
Evan Cheng
5e6940788f Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124518 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 01:29:26 +00:00
Andrew Trick
04317cc618 Implementation of path profiling.
Modified patch by Adam Preuss.

This builds on the existing framework for block tracing, edge profiling and optimal edge profiling.
See -help-hidden for new flags.
For documentation, see the technical report "Implementation of Path Profiling..." in llvm.org/pubs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 01:09:53 +00:00
Duncan Sands
593faa53fa My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC
benchmarks, and that it can be simplified to X/Y.  (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case).  This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too.  This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too.  It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124487 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 16:51:11 +00:00
Nick Lewycky
468ee0a90d Rename functions to follow coding standard. Also rejiggers comments. No
functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124482 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 08:43:14 +00:00
Nick Lewycky
8b5964381e Add a doxygen comment for this class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 08:19:00 +00:00
Nick Lewycky
285cf8040d Reorder for readability. (Chris, is this what you meant?)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124479 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 07:36:21 +00:00
Evan Cheng
1b5c0cb71d Revert r124462. There are a few big regressions that I need to fix first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 07:12:38 +00:00
Nick Lewycky
07317f7d33 Reduce the number of functions we look at in the first pass, and preallocate
the function equality set.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124475 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 05:48:15 +00:00
Nick Lewycky
df3bfae151 Fold select + select where both selects are on the same condition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124469 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 03:28:10 +00:00
Evan Cheng
40f64cb0de - Stop simplifycfg from duplicating "ret" instructions into unconditional
branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
  allocation is done.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124462 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 02:19:21 +00:00
Benjamin Kramer
9c1858cf4a Unbreak the build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124426 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 20:30:54 +00:00
Nick Lewycky
c9d69489eb Expound upon this comparison!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124406 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 19:51:31 +00:00
Nick Lewycky
dfc5972974 Use dyn_cast instead of isa+cast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124404 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 19:42:43 +00:00
Nick Lewycky
25296e25fd Fix surprising missed optimization in mergefunc where we forgot to consider
that relationships like "i8* null" is equivalent to "i32* null".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124368 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 08:38:19 +00:00
Duncan Sands
37f87c7aa9 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124287 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 10:08:38 +00:00
Nick Lewycky
f6c63c2320 AttrListPtr has an overloaded operator== which does this for us, we should use
it. No functionality change!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 09:23:19 +00:00
Nick Lewycky
207c193e7e Teach mergefunc that intptr_t is the same width as a pointer. We still can't
merge vector<intptr_t>::push_back() and vector<void*>::push_back() because
Enumerate() doesn't realize that "i64* null" and "i8** null" are equivalent.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124285 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 09:13:58 +00:00
Nick Lewycky
388f4918fb There are no vectors of pointer or arrays, so we don't need to check vector
elements for type equivalence.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124284 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 08:50:18 +00:00
Nick Lewycky
b38824f866 Teach mergefunc how to emit aliases safely again -- but keep it turned it off
for now. It's controlled by the HasGlobalAliases variable which is not attached
to any flag yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 08:56:50 +00:00
Dan Gohman
bd1801b555 Give GetUnderlyingObject a TargetData, to keep it in sync
with BasicAA's DecomposeGEPExpression, which recently began
using a TargetData. This fixes PR8968, though the testcase
is awkward to reduce.

Also, update several off GetUnderlyingObject's users
which happen to have a TargetData handy to pass it in.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124134 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 18:53:32 +00:00
Chris Lattner
867be59684 fix PR9017, a bug where we'd assert when promoting in unreachable
code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124100 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 03:29:07 +00:00
Chris Lattner
51e62f0f73 fix PR9015, a crash linking recursive metadata.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124099 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 03:18:24 +00:00
Chris Lattner
e3357863aa enhance SRoA to promote allocas that are used by PHI nodes. This often
occurs because instcombine sinks loads and inserts phis.  This kicks in 
on such apps as 175.vpr, eon, 403.gcc, xalancbmk and a bunch of times in
spec2006 in some app that uses std::deque.

This resolves the last of rdar://7339113.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124090 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 01:07:11 +00:00
Chris Lattner
c87c50a39c Enhance SRoA to promote allocas that are used by selects in some
common cases.  This triggers a surprising number of times in SPEC2K6
because min/max idioms end up doing this.  For example, code from the
STL ends up looking like this to SRoA:

  %202 = load i64* %__old_size, align 8, !tbaa !3
  %203 = load i64* %__old_size, align 8, !tbaa !3
  %204 = load i64* %__n, align 8, !tbaa !3
  %205 = icmp ult i64 %203, %204
  %storemerge.i = select i1 %205, i64* %__n, i64* %__old_size
  %206 = load i64* %storemerge.i, align 8, !tbaa !3

We can now promote both the __n and the __old_size allocas.

This addresses another chunk of rdar://7339113, poor codegen on
stringswitch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124088 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 22:04:55 +00:00
Ted Kremenek
584520e8e2 Null initialize a few variables flagged by
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124073 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 17:05:06 +00:00
Chris Lattner
145c532e68 Enhance SRoA to be more aggressive about scalarization of aggregate allocas
that have PHI or select uses of their element pointers.  This can often happen
when instcombine sinks two loads into a successor, inserting a phi or select.

With this patch, we can scalarize the alloca, but the pinned elements are not
yet promoted.  This is still a win for large aggregates where only one element
is used.  This fixes rdar://8904039 and part of rdar://7339113 (poor codegen
on stringswitch).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124070 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 08:27:54 +00:00
Cameron Zwarich
491d8d4370 Convert two std::vectors to SmallVectors for a 3.4% speedup running -scalarrepl
on test-suite + SPEC2000 & SPEC2006.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124068 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 08:03:04 +00:00
Chris Lattner
6c95d24927 have AllocaInfo store the alloca being inspected, simplifying callers.
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124067 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 07:29:29 +00:00
Chris Lattner
d01a0da090 Rearrange some code a bit. Change MarkUnsafe to
handle the "Transformation preventing inst" printing, 
so that -scalarrepl -debug will always print the rejected
instruction.  No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124066 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 07:05:44 +00:00
Chris Lattner
85a7c69085 remove an old hack that avoided creating MMX datatypes. The
X86 backend has been fixed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124064 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 06:40:33 +00:00
Dan Gohman
8fb25c53bd Actually check memcpy lengths, instead of just commenting about
how they should be checked.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123999 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 22:07:57 +00:00
Owen Anderson
5d2e188962 Just because we have determined that an (fcmp | fcmp) is true for A < B,
A == B, and A > B, does not mean we can fold it to true.  We still need to
check for A ? B (A unordered B).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123993 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 19:39:42 +00:00
Nick Lewycky
e7c85a4c1d SCCP doesn't actually preserve the CFG. It will delete and insert terminator
instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123973 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 08:38:09 +00:00
Chris Lattner
cd151d2f95 fix PR9013, an infinite loop in instcombine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123968 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 05:29:50 +00:00
Chris Lattner
084fe6243a update obsolete comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123965 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 05:08:26 +00:00
Nick Lewycky
acf4a7c0e6 Don't try to pull vector bitcasts that change the number of elements through
a select. A vector select is pairwise on each element so we'd need a new
condition with the right number of elements to select on. Fixes PR8994.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123963 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 02:30:43 +00:00
Duncan Sands
9d32f60a6f At -O123 the early-cse pass is run before instcombine has run. According to my
auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0.
This patch adds this transform and some related logic to InstructionSimplify
and removes some of the logic from instcombine (unfortunately not all because
there are several situations in which instcombine can improve things by making
new instructions, whereas instsimplify is not allowed to do this).  At -O2 this
often results in more than 15% more simplifications by early-cse, and results in
hundreds of lines of bitcode being eliminated from the testsuite.  I did see some
small negative effects in the testsuite, for example a few additional instructions
in three programs.  One program, 483.xalancbmk, got an additional 35 instructions,
which seems to be due to a function getting an additional instruction and then
being inlined all over the place.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123911 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20 13:21:55 +00:00
Rafael Espindola
c4440e3e30 Add unnamed_addr when we can show that address of a global is not used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123834 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 16:32:21 +00:00
Chris Lattner
435b4d2eba fix rdar://8878965, a regression I introduced with the recent
llvm.objectsize changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123771 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-18 20:53:04 +00:00