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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
459f4f8c25
tidy up
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122190 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 20:24:28 +00:00
1dec0d2704
Enhance LICM to promote alias sets whose pointers themselves are stored,
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which doesn't affect the memory address being promoted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122172 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 05:57:25 +00:00
1c0af0ed25
fix PR8602, a bug in an assertion: a volatile store *of* a pointer
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does not make the alias set for that pointer volatile, just stores
*to* the pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122171 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 05:51:54 +00:00
a0d172f7fe
revert r122164, I'm going to go with a different approach.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122168 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 04:23:03 +00:00
140f4a315b
first step to fixing PR8642: don't fold away empty basic blocks
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which have trapping constant exprs in them due to PHI nodes.
Eliminating them can cause the constant expr to be evalutated
on new paths if the input edges are critical.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122164 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 03:02:34 +00:00
c32046e6ea
Revert r64460. strtol and friends cannot be marked readonly, even with
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a null endptr argument, because they may write to errno.
This fixes a seflhost miscompile observed on Linux targets when TBAA
was enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122014 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 01:09:43 +00:00
01abcf339f
Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.
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This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121966 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16 12:16:00 +00:00
387f28aff4
Make memcpyopt TBAA-aware.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121944 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16 02:51:19 +00:00
f4177aa019
Preserve TBAA tags when doing load PRE.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121921 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 23:53:55 +00:00
5034dd318a
Move Value::getUnderlyingObject to be a standalone
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function so that it can live in Analysis instead of
VMCore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 20:02:24 +00:00
26e097ca4b
Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
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When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121859 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 09:51:20 +00:00
86e8a700f5
Fix PR8790, another instance where unreachable code can cause instruction simplification to fail,
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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
93f83deba1
Cleanup trailing whitespace.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121816 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 00:52:44 +00:00
e991b5fdd5
simplify code and reduce indentation
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121670 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 02:38:13 +00:00
8fdca6a873
enhance memcpyopt to zap memcpy's that have the same src/dst.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121362 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 07:45:45 +00:00
f7f35467a9
fix PR8753, eliminating a case where we'd infinitely make a
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substitution because it doesn't actually change the IR. Patch by
Jakub Staszak!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121361 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 07:39:50 +00:00
8e8cdc8fe0
Remove some dead code from the jump threading pass.
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The last uses of these functions were removed in r113852 when LazyValueInfo was permanently enabled and removed the need for them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121133 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 13:08:07 +00:00
40f8f6264d
PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
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zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 08:25:19 +00:00
6033b346e2
Implement jump threading of 'indirectbr' by keeping track of whether we're looking for ConstantInt*s or BlockAddress*s.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121066 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 23:36:56 +00:00
29d8d6b039
Use a stronger predicate here, pointed out by Duncan
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121040 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 21:48:10 +00:00
a9d4da85d6
add some DEBUG statements.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121038 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 21:13:51 +00:00
Chris Lattner
Duncan Sands
Benjamin Kramer
Owen Anderson
Mon P Wang
Jeffrey Yasskin
Dan Gohman
Frits van Bommel
Jay Foad