Chris Lattner
bdce5720ad
add a list of opportunities for future improvement.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122701 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 18:32:09 +00:00
Duncan Sands
67fb341f8b
Fix PR8702 by not having LoopSimplify claim to preserve LCSSA form. As described
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in the PR, the pass could break LCSSA form when inserting preheaders. It probably
would be easy enough to fix this, but since currently we always go into LCSSA form
after running this pass, doing so is not urgent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122695 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 13:38:21 +00:00
Chris Lattner
cf078f2b20
Allow loop-idiom to run on multiple BB loops, but still only scan the loop
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header for now for memset/memcpy opportunities. It turns out that loop-rotate
is successfully rotating loops, but *DOESN'T MERGE THE BLOCKS*, turning "for
loops" into 2 basic block loops that loop-idiom was ignoring.
With this fix, we form many *many* more memcpy and memsets than before, including
on the "history" loops in the viterbi benchmark, which look like this:
for (j=0; j<MAX_history; ++j) {
history_new[i][j+1] = history[2*i][j];
}
Transforming these loops into memcpy's speeds up the viterbi benchmark from
11.98s to 3.55s on my machine. Woo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122685 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:58:36 +00:00
Chris Lattner
6b04160dd8
remove debugging code.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122683 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:37:13 +00:00
Chris Lattner
4ce31fb574
add some -stats output.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122682 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:36:44 +00:00
Chris Lattner
d9e079706e
improve loop rotation to use CodeMetrics to analyze the
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size of a loop header instead of its own code size estimator.
This allows it to handle bitcasts etc more precisely.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122681 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:35:53 +00:00
Chris Lattner
e2c4392091
teach loop idiom recognition to form memcpy's from simple loops.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122678 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 03:37:56 +00:00
Nick Lewycky
abd6c75409
Remove functions from the FnSet when one of their callee's is being merged. This
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maintains the guarantee that the DenseSet expects two elements it contains to
not go from inequal to equal under its nose.
As a side-effect, this also lets us switch from iterating to a fixed-point to
actually maintaining a work queue of functions to look at again, and we don't
add thunks to our work queue so we don't need to detect and ignore them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122677 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 02:46:33 +00:00
Chris Lattner
d91ed10b70
fix a globalopt crash on two Adobe-C++ testcases that the recent
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loop idiom pass exposed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122674 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 22:31:46 +00:00
Chris Lattner
bafa117e8f
add a validity check that was missed, fixing a crash on the
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new testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122662 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 20:12:04 +00:00
Chris Lattner
a64cbf067d
improve validity check to handle constant-trip-count loops more
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aggressively. In practice, this doesn't help anything though,
see the todo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122660 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 19:54:22 +00:00
Chris Lattner
30980b6815
implement the "no aliasing accesses in loop" safety check. This pass
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should be correct now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122659 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 19:39:01 +00:00
Duncan Sands
8a3d29cf10
Simplify this pass by using a depth-first iterator to ensure that all
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operands are visited before the instructions themselves.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122647 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-31 17:49:05 +00:00
Duncan Sands
fea0b8b666
Zap dead instructions harder.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122645 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-31 16:17:54 +00:00
Benjamin Kramer
1928236514
Make a bunch of symbols internal.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122642 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-30 22:34:44 +00:00
Chris Lattner
95ae676bc8
simplify this, isBytewiseValue handles the extra check. We still
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check for "multiple of a byte" in size to make it clear that the
>> 3 below is safe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122604 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-28 18:53:48 +00:00
Duncan Sands
7922d34b60
Silence gcc warning about an unused variable when doing a release build.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122593 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-28 09:41:15 +00:00
Chris Lattner
2e12f1ac6e
fix some issues Frits noticed, add AliasAnalysis as a dependency
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122585 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 18:39:08 +00:00
Benjamin Kramer
def548f9a0
BuildLibCalls: Nuke EmitMemCpy, EmitMemMove and EmitMemSet. They are dead and superseded by IRBuilder.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122576 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 00:25:32 +00:00
Benjamin Kramer
a1bf4ca773
SimplifyLibCalls: Use IRBuilder to simplify code.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122575 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 00:16:46 +00:00
Chris Lattner
9f39188def
have loop-idiom nuke instructions that feed stores that get removed.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122574 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 00:03:23 +00:00
Chris Lattner
a92ff91a96
implement enough of the memset inference algorithm to recognize and insert
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memsets. This is still missing one important validity check, but this is enough
to compile stuff like this:
void test0(std::vector<char> &X) {
for (std::vector<char>::iterator I = X.begin(), E = X.end(); I != E; ++I)
*I = 0;
}
void test1(std::vector<int> &X) {
for (long i = 0, e = X.size(); i != e; ++i)
X[i] = 0x01010101;
}
With:
$ clang t.cpp -S -o - -O2 -emit-llvm | opt -loop-idiom | opt -O3 | llc
to:
__Z5test0RSt6vectorIcSaIcEE: ## @_Z5test0RSt6vectorIcSaIcEE
## BB#0: ## %entry
subq $8, %rsp
movq (%rdi), %rax
movq 8(%rdi), %rsi
cmpq %rsi, %rax
je LBB0_2
## BB#1: ## %bb.nph
subq %rax, %rsi
movq %rax, %rdi
callq ___bzero
LBB0_2: ## %for.end
addq $8, %rsp
ret
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__Z5test1RSt6vectorIiSaIiEE: ## @_Z5test1RSt6vectorIiSaIiEE
## BB#0: ## %entry
subq $8, %rsp
movq (%rdi), %rax
movq 8(%rdi), %rdx
subq %rax, %rdx
cmpq $4, %rdx
jb LBB1_2
## BB#1: ## %for.body.preheader
andq $-4, %rdx
movl $1, %esi
movq %rax, %rdi
callq _memset
LBB1_2: ## %for.end
addq $8, %rsp
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122573 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 23:42:51 +00:00
Chris Lattner
61db1f56d0
start using irbuilder to make mem intrinsics in a few passes.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122572 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 22:57:41 +00:00
Chris Lattner
22920b5986
sketch more of this out.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122567 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 20:45:45 +00:00
Chris Lattner
bb89710ddd
move isBytewiseValue out to ValueTracking.h/cpp
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122565 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 20:15:01 +00:00
Chris Lattner
e6bb649ec6
actually add the file...
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122563 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 19:39:38 +00:00
Chris Lattner
b0db161f5b
Start of a pass for recognizing memset and memcpy idioms.
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No functionality yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122562 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 19:32:44 +00:00
Benjamin Kramer
3fed0d917d
Simplify code.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122561 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 15:23:45 +00:00
Chris Lattner
ae47be1ea0
don't lose TD info
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122556 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-25 20:52:04 +00:00
Chris Lattner
7569d79de1
switch the inliner alignment enforcement stuff to use the
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getOrEnforceKnownAlignment function, which simplifies the code
and makes it stronger.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122555 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-25 20:42:38 +00:00
Chris Lattner
687140c818
Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122554 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-25 20:37:57 +00:00
Benjamin Kramer
49c7e3e290
Fix a thinko pointed out by Frits van Bommel: looking through global variables in isBytewiseValue is not safe.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122550 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-24 22:23:59 +00:00
Benjamin Kramer
a112087e42
MemCpyOpt: Turn memcpys from a constant into a memset if possible.
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This allows us to compile "int cst[] = {-1, -1, -1};" into
movl $-1, 16(%rsp)
movq $-1, 8(%rsp)
instead of
movl _cst+8(%rip), %eax
movl %eax, 16(%rsp)
movq _cst(%rip), %rax
movq %rax, 8(%rsp)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122548 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-24 21:17:12 +00:00
Owen Anderson
ec3953ff95
When determining if we can fold (x >> C1) << C2, the bits that we need to verify are zero
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are not the low bits of x, but the bits that WILL be the low bits after the operation completes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122529 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23 23:56:24 +00:00
Owen Anderson
d5f8684b16
It is possible for SimplifyCFG to cause PHI nodes to become redundant too late in the optimization
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pipeline to be caught by instcombine, and it's not feasible to catch them in SimplifyCFG because the
use-lists are in an inconsistent state at the point where it could know that it need to simplify them.
Instead, have CodeGenPrepare look for trivially redundant PHIs as part of its general cleanup effort.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122516 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23 20:57:35 +00:00
Mon P Wang
e90a6333c3
Preserve the address space when generating bitcasts for MemTransferInst in ConvertToScalarInfo
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122462 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23 01:41:32 +00:00
Jeffrey Yasskin
8e68c38735
Change all self assignments X=X to (void)X, so that we can turn on a
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new gcc warning that complains on self-assignments and
self-initializations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122458 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23 00:58:24 +00:00
Benjamin Kramer
4ac19470dc
InstCombine: creating selects from -1 and 0 is fine, they combine into a sext from i1.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122453 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 23:12:15 +00:00
Duncan Sands
37bf92b523
Add a generic expansion transform: A op (B op' C) -> (A op B) op' (A op C)
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if both A op B and A op C simplify. This fires fairly often but doesn't
make that much difference. On gcc-as-one-file it removes two "and"s and
turns one branch into a select.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122399 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 13:36:08 +00:00
Duncan Sands
a3c44a5280
Add some statistics, good for understanding how much more powerful
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instcombine is compared to instsimplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122397 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 09:40:51 +00:00
Owen Anderson
f056838956
Give GVN back the ability to perform simple conditional propagation on conditional branch values.
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I still think that LVI should be handling this, but that capability is some ways off in the future,
and this matters for some significant benchmarks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122378 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 23:54:34 +00:00
Owen Anderson
491e0307a8
Remove dead code.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122371 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 22:31:24 +00:00
Benjamin Kramer
aad94aa437
GVN's Expression is not POD-like (it contains a SmallVector). Simplify code while at it.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122362 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 21:30:19 +00:00
Duncan Sands
1cd0f4637b
Visit instructions deterministically. Use a FIFO so as to approximately
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visit instructions before their uses, since InstructionSimplify does a
better job in that case. All this prompted by Frits van Bommel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122343 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 17:08:55 +00:00
Duncan Sands
e95cc25a22
If an instruction simplifies, try again to simplify any uses of it. This is
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not very important since the pass is only used for testing, but it does make
it more realistic. Suggested by Frits van Bommel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122336 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 16:12:03 +00:00
Duncan Sands
82fdab3358
Pull a few more simplifications out of instcombine (there are still
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plenty left though!), in particular for multiplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122330 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 14:00:22 +00:00
Duncan Sands
69fdf876e1
Oops, forgot to add the pass itself!
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122265 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-20 21:07:42 +00:00
Duncan Sands
43ff68ded0
Add a new convenience pass for testing InstructionSimplify. Previously
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it could only be tested indirectly, via instcombine, gvn or some other
pass that makes use of InstructionSimplify, which means that testcases
had to be carefully contrived to dance around any other transformations
that that pass did.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122264 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-20 20:54:37 +00:00
Benjamin Kramer
b0de244f23
Add a check missing from my last commit and avoid a potential overflow situation.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122258 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-20 20:00:31 +00:00
Benjamin Kramer
4dc1ac0947
Reduce indentation.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122249 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-20 16:21:59 +00:00