Chris Lattner
bf0aa927cc
split dom frontier handling stuff out to its own DominanceFrontier header,
...
so that Dominators.h is *just* domtree. Also prune #includes a bit.
llvm-svn: 122714
2011-01-02 22:09:33 +00:00
Chris Lattner
704541bb23
sketch out a new early cse pass. No functionality yet.
...
llvm-svn: 122713
2011-01-02 21:47:05 +00:00
Chris Lattner
9c69406f2b
fix a miscompilation of tramp3d-v4: when forming a memcpy, we have to make
...
sure that the loop we're promoting into a memcpy doesn't mutate the input
of the memcpy. Before we were just checking that the dest of the memcpy
wasn't mod/ref'd by the loop.
llvm-svn: 122712
2011-01-02 21:14:18 +00:00
Chris Lattner
5702a43c09
If a loop iterates exactly once (has backedge count = 0) then don't
...
mess with it. We'd rather peel/unroll it than convert all of its
stores into memsets.
llvm-svn: 122711
2011-01-02 20:24:21 +00:00
Nick Lewycky
5361b84184
Also remove functions that use complex constant expressions in terms of
...
another function.
llvm-svn: 122705
2011-01-02 19:16:44 +00:00
Chris Lattner
8455b6e45e
enhance loop idiom recognition to scan *all* unconditionally executed
...
blocks in a loop, instead of just the header block. This makes it more
aggressive, able to handle Duncan's Ada examples.
llvm-svn: 122704
2011-01-02 19:01:03 +00:00
Chris Lattner
0cdc6f62a5
make inSubLoop much more efficient.
...
llvm-svn: 122703
2011-01-02 18:53:08 +00:00
Chris Lattner
27497ece96
rip out isExitBlockDominatedByBlockInLoop, calling DomTree::dominates instead.
...
isExitBlockDominatedByBlockInLoop is a relic of the days when domtree was
*just* a tree and didn't have DFS numbers. Checking DFS numbers is faster
and easier than "limiting the search of the tree".
llvm-svn: 122702
2011-01-02 18:45:39 +00:00
Chris Lattner
0469e01c02
add a list of opportunities for future improvement.
...
llvm-svn: 122701
2011-01-02 18:32:09 +00:00
Duncan Sands
64f1c0dcda
Fix PR8702 by not having LoopSimplify claim to preserve LCSSA form. As described
...
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.
llvm-svn: 122695
2011-01-02 13:38:21 +00:00
Chris Lattner
ddf58010bd
Allow loop-idiom to run on multiple BB loops, but still only scan the loop
...
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.
llvm-svn: 122685
2011-01-02 07:58:36 +00:00
Chris Lattner
5b5a043d82
remove debugging code.
...
llvm-svn: 122683
2011-01-02 07:37:13 +00:00
Chris Lattner
12f91befce
add some -stats output.
...
llvm-svn: 122682
2011-01-02 07:36:44 +00:00
Chris Lattner
679572e584
improve loop rotation to use CodeMetrics to analyze the
...
size of a loop header instead of its own code size estimator.
This allows it to handle bitcasts etc more precisely.
llvm-svn: 122681
2011-01-02 07:35:53 +00:00
Chris Lattner
85b6d81d41
teach loop idiom recognition to form memcpy's from simple loops.
...
llvm-svn: 122678
2011-01-02 03:37:56 +00:00
Nick Lewycky
4e250c8245
Remove functions from the FnSet when one of their callee's is being merged. This
...
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.
llvm-svn: 122677
2011-01-02 02:46:33 +00:00
Chris Lattner
1903c42b97
fix a globalopt crash on two Adobe-C++ testcases that the recent
...
loop idiom pass exposed.
llvm-svn: 122674
2011-01-01 22:31:46 +00:00
Chris Lattner
a3514441e0
add a validity check that was missed, fixing a crash on the
...
new testcase.
llvm-svn: 122662
2011-01-01 20:12:04 +00:00
Chris Lattner
91a4435875
improve validity check to handle constant-trip-count loops more
...
aggressively. In practice, this doesn't help anything though,
see the todo.
llvm-svn: 122660
2011-01-01 19:54:22 +00:00
Chris Lattner
8b3baf6d75
implement the "no aliasing accesses in loop" safety check. This pass
...
should be correct now.
llvm-svn: 122659
2011-01-01 19:39:01 +00:00
Duncan Sands
2c440fa403
Simplify this pass by using a depth-first iterator to ensure that all
...
operands are visited before the instructions themselves.
llvm-svn: 122647
2010-12-31 17:49:05 +00:00
Duncan Sands
6cc7126ed9
Zap dead instructions harder.
...
llvm-svn: 122645
2010-12-31 16:17:54 +00:00
Benjamin Kramer
570dd787a6
Make a bunch of symbols internal.
...
llvm-svn: 122642
2010-12-30 22:34:44 +00:00
Chris Lattner
65a699d4d0
simplify this, isBytewiseValue handles the extra check. We still
...
check for "multiple of a byte" in size to make it clear that the
>> 3 below is safe.
llvm-svn: 122604
2010-12-28 18:53:48 +00:00
Duncan Sands
5cf10e691b
Silence gcc warning about an unused variable when doing a release build.
...
llvm-svn: 122593
2010-12-28 09:41:15 +00:00
Chris Lattner
cb18bfa3d2
fix some issues Frits noticed, add AliasAnalysis as a dependency
...
llvm-svn: 122585
2010-12-27 18:39:08 +00:00
Benjamin Kramer
84bd73c527
BuildLibCalls: Nuke EmitMemCpy, EmitMemMove and EmitMemSet. They are dead and superseded by IRBuilder.
...
llvm-svn: 122576
2010-12-27 00:25:32 +00:00
Benjamin Kramer
7cba269dfb
SimplifyLibCalls: Use IRBuilder to simplify code.
...
llvm-svn: 122575
2010-12-27 00:16:46 +00:00
Chris Lattner
b9fe685b9a
have loop-idiom nuke instructions that feed stores that get removed.
...
llvm-svn: 122574
2010-12-27 00:03:23 +00:00
Chris Lattner
29e14edc8d
implement enough of the memset inference algorithm to recognize and insert
...
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
...
__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
llvm-svn: 122573
2010-12-26 23:42:51 +00:00
Chris Lattner
6cf8d6cc6e
start using irbuilder to make mem intrinsics in a few passes.
...
llvm-svn: 122572
2010-12-26 22:57:41 +00:00
Chris Lattner
7c5f9c35d1
sketch more of this out.
...
llvm-svn: 122567
2010-12-26 20:45:45 +00:00
Chris Lattner
9cb1035f94
move isBytewiseValue out to ValueTracking.h/cpp
...
llvm-svn: 122565
2010-12-26 20:15:01 +00:00
Chris Lattner
81ae3f299a
actually add the file...
...
llvm-svn: 122563
2010-12-26 19:39:38 +00:00
Chris Lattner
2ef535a4e4
Start of a pass for recognizing memset and memcpy idioms.
...
No functionality yet.
llvm-svn: 122562
2010-12-26 19:32:44 +00:00
Benjamin Kramer
30342fb1fd
Simplify code.
...
llvm-svn: 122561
2010-12-26 15:23:45 +00:00
Chris Lattner
d729d0dcdb
don't lose TD info
...
llvm-svn: 122556
2010-12-25 20:52:04 +00:00
Chris Lattner
20fca48341
switch the inliner alignment enforcement stuff to use the
...
getOrEnforceKnownAlignment function, which simplifies the code
and makes it stronger.
llvm-svn: 122555
2010-12-25 20:42:38 +00:00
Chris Lattner
6fcd32e7d7
Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.
...
llvm-svn: 122554
2010-12-25 20:37:57 +00:00
Benjamin Kramer
b90b2f0635
Fix a thinko pointed out by Frits van Bommel: looking through global variables in isBytewiseValue is not safe.
...
llvm-svn: 122550
2010-12-24 22:23:59 +00:00
Benjamin Kramer
ea9152e551
MemCpyOpt: Turn memcpys from a constant into a memset if possible.
...
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)
llvm-svn: 122548
2010-12-24 21:17:12 +00:00
Owen Anderson
226ac14afb
When determining if we can fold (x >> C1) << C2, the bits that we need to verify are zero
...
are not the low bits of x, but the bits that WILL be the low bits after the operation completes.
llvm-svn: 122529
2010-12-23 23:56:24 +00:00
Owen Anderson
5d690d4168
It is possible for SimplifyCFG to cause PHI nodes to become redundant too late in the optimization
...
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.
llvm-svn: 122516
2010-12-23 20:57:35 +00:00
Mon P Wang
18b762a946
Preserve the address space when generating bitcasts for MemTransferInst in ConvertToScalarInfo
...
llvm-svn: 122462
2010-12-23 01:41:32 +00:00
Jeffrey Yasskin
9b43f33620
Change all self assignments X=X to (void)X, so that we can turn on a
...
new gcc warning that complains on self-assignments and
self-initializations.
llvm-svn: 122458
2010-12-23 00:58:24 +00:00
Benjamin Kramer
8ef5001b27
InstCombine: creating selects from -1 and 0 is fine, they combine into a sext from i1.
...
llvm-svn: 122453
2010-12-22 23:12:15 +00:00
Duncan Sands
fbb9ac3cca
Add a generic expansion transform: A op (B op' C) -> (A op B) op' (A op C)
...
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.
llvm-svn: 122399
2010-12-22 13:36:08 +00:00
Duncan Sands
3547d2ebd8
Add some statistics, good for understanding how much more powerful
...
instcombine is compared to instsimplify.
llvm-svn: 122397
2010-12-22 09:40:51 +00:00
Owen Anderson
5ab8d4b5e5
Give GVN back the ability to perform simple conditional propagation on conditional branch values.
...
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.
llvm-svn: 122378
2010-12-21 23:54:34 +00:00
Owen Anderson
12470778d7
Remove dead code.
...
llvm-svn: 122371
2010-12-21 22:31:24 +00:00
Benjamin Kramer
43493c089f
GVN's Expression is not POD-like (it contains a SmallVector). Simplify code while at it.
...
llvm-svn: 122362
2010-12-21 21:30:19 +00:00
Duncan Sands
3b8af41a3e
Visit instructions deterministically. Use a FIFO so as to approximately
...
visit instructions before their uses, since InstructionSimplify does a
better job in that case. All this prompted by Frits van Bommel.
llvm-svn: 122343
2010-12-21 17:08:55 +00:00
Duncan Sands
e7cbb64ec0
If an instruction simplifies, try again to simplify any uses of it. This is
...
not very important since the pass is only used for testing, but it does make
it more realistic. Suggested by Frits van Bommel.
llvm-svn: 122336
2010-12-21 16:12:03 +00:00
Duncan Sands
d0eb6d39f8
Pull a few more simplifications out of instcombine (there are still
...
plenty left though!), in particular for multiplication.
llvm-svn: 122330
2010-12-21 14:00:22 +00:00
Duncan Sands
eaff500c7b
Oops, forgot to add the pass itself!
...
llvm-svn: 122265
2010-12-20 21:07:42 +00:00
Duncan Sands
a436cbe4bf
Add a new convenience pass for testing InstructionSimplify. Previously
...
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.
llvm-svn: 122264
2010-12-20 20:54:37 +00:00
Benjamin Kramer
f7957d0463
Add a check missing from my last commit and avoid a potential overflow situation.
...
llvm-svn: 122258
2010-12-20 20:00:31 +00:00
Benjamin Kramer
2bca3a67b3
Reduce indentation.
...
llvm-svn: 122249
2010-12-20 16:21:59 +00:00
Benjamin Kramer
68531baea9
Teach InstCombine to merge (icmp ult (X + CA), C1) | (icmp eq X, C2) into (icmp ult (X + CA), C1 + 1) if C2 + CA == C1.
...
InstCombine creates these so now we compile x == 23 || x == 24 || x == 25 to
%x.off = add i32 %x, -23
%1 = icmp ult i32 %x.off, 3
instead of
%x.off = add i32 %x, -23
%1 = icmp ult i32 %x.off, 2
%cmp3 = icmp eq i32 %x, 25
%ret2 = or i1 %1, %cmp3
llvm-svn: 122248
2010-12-20 16:18:51 +00:00
Chris Lattner
27ca8ebd4b
fix PR8807 by making transformConstExprCastCall aware of byval arguments.
...
llvm-svn: 122238
2010-12-20 08:36:38 +00:00
Chris Lattner
7398965b67
various cleanups for transformConstExprCastCall
...
llvm-svn: 122237
2010-12-20 08:25:06 +00:00
Chris Lattner
0f11495289
when eliding a byval copy due to inlining a readonly function, we have
...
to make sure that the reused alloca has sufficient alignment.
llvm-svn: 122236
2010-12-20 08:10:40 +00:00
Chris Lattner
0099744506
pull byval processing out to its own helper function.
...
llvm-svn: 122235
2010-12-20 07:57:41 +00:00
Chris Lattner
7394680a00
fix PR8769, a miscompilation by inliner when inlining a function with a byval
...
argument. The generated alloca has to have at least the alignment of the
byval, if not, the client may be making assumptions that the new alloca won't
satisfy.
llvm-svn: 122234
2010-12-20 07:45:28 +00:00
Mon P Wang
1991c47ec1
Avoid dropping the address space when InstCombine optimizes memset
...
llvm-svn: 122215
2010-12-20 01:05:30 +00:00
Chris Lattner
4fb9dd4c74
fix an oversight caught by Frits!
...
llvm-svn: 122204
2010-12-19 23:24:04 +00:00
Chris Lattner
b6252a376a
tidy up
...
llvm-svn: 122190
2010-12-19 20:24:28 +00:00
Chris Lattner
3e635d2e99
move a transformation to a more logical place, simplifying it.
...
llvm-svn: 122183
2010-12-19 19:43:52 +00:00
Chris Lattner
5e0c0c72e9
recognize an unsigned add with overflow idiom into uadd.
...
This resolves a README entry and technically resolves PR4916,
but we still get poor code for the testcase in that PR because
GVN isn't CSE'ing uadd with add, filed as PR8817.
Previously we got:
_test7: ## @test7
addq %rsi, %rdi
cmpq %rdi, %rsi
movl $42, %eax
cmovaq %rsi, %rax
ret
Now we get:
_test7: ## @test7
addq %rsi, %rdi
movl $42, %eax
cmovbq %rsi, %rax
ret
llvm-svn: 122182
2010-12-19 19:37:52 +00:00
Chris Lattner
33dc3f0cfa
optimize uadd(x, cst) into a comparison when the normal
...
result is dead. This is required for my next patch to not
regress the testsuite.
llvm-svn: 122181
2010-12-19 19:35:32 +00:00
Chris Lattner
ce2995ae58
use IC.ReplaceInstUsesWith instead of a raw RAUW so that uses of
...
the old thing end up on the instcombine worklist. Not doing this
can cause an extra top-level iteration of instcombine, burning
compile time.
llvm-svn: 122179
2010-12-19 18:38:44 +00:00
Chris Lattner
79874566ce
generalize the sadd creation code to not require that the
...
sadd formed is half the size of the original type. We can
now compile this into a sadd.i8:
unsigned char X(char a, char b) {
int res = a+b;
if ((unsigned )(res+128) > 255U)
abort();
return res;
}
llvm-svn: 122178
2010-12-19 18:35:09 +00:00
Chris Lattner
c56c845377
fix another miscompile in the llvm.sadd formation logic: it wasn't
...
checking to see if the high bits of the original add result were dead.
Inserting a smaller add and zexting back to that size is not good enough.
This is likely to be the fix for 8816.
llvm-svn: 122177
2010-12-19 18:22:06 +00:00
Chris Lattner
f29562db25
fix a bug (possibly 8816) in the sadd forming xform: it isn't
...
profitable (or safe) to promote code when the add-with-constant
has other uses.
llvm-svn: 122175
2010-12-19 17:59:02 +00:00
Chris Lattner
ee61c1d820
rework the code added in r122072 to pull it out to its own
...
helper function, clean up comments, and reduce indentation.
No functionality change.
llvm-svn: 122174
2010-12-19 17:52:50 +00:00
Chris Lattner
408a684d29
Enhance LICM to promote alias sets whose pointers themselves are stored,
...
which doesn't affect the memory address being promoted.
llvm-svn: 122172
2010-12-19 05:57:25 +00:00
Chris Lattner
3337a81450
fix PR8602, a bug in an assertion: a volatile store *of* a pointer
...
does not make the alias set for that pointer volatile, just stores
*to* the pointer.
llvm-svn: 122171
2010-12-19 05:51:54 +00:00
Chris Lattner
fb888622c3
revert r122164, I'm going to go with a different approach.
...
llvm-svn: 122168
2010-12-19 04:23:03 +00:00
Chris Lattner
583ec6fa44
first step to fixing PR8642: don't fold away empty basic blocks
...
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.
llvm-svn: 122164
2010-12-19 03:02:34 +00:00
Chris Lattner
6b8b4855ff
simplify this a bit.
...
llvm-svn: 122156
2010-12-18 20:22:49 +00:00
Bill Wendling
5e3605552e
Whitespace fixes. No functionality change.
...
llvm-svn: 122110
2010-12-17 23:27:41 +00:00
Nate Begeman
7aa18bf46a
Add vector versions of some existing scalar transforms to aid codegen in matching psign & pblend operations to the IR produced by clang/gcc for their C idioms.
...
llvm-svn: 122105
2010-12-17 23:12:19 +00:00
Owen Anderson
1294ea7d53
Reapply r121905 (automatic synthesis of @llvm.sadd.with.overflow) with a fix for a bug that manifested itself
...
on the DragonEgg self-host bot. Unfortunately, the testcase is pretty messy and doesn't reduce well due to
interactions with other parts of InstCombine.
llvm-svn: 122072
2010-12-17 18:08:00 +00:00
Benjamin Kramer
e5f49c4ff2
SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.
...
llvm-svn: 122054
2010-12-17 10:48:14 +00:00
Chris Lattner
d14b0f1db7
improve switch formation to handle small range
...
comparisons formed by comparisons. For example,
this:
void foo(unsigned x) {
if (x == 0 || x == 1 || x == 3 || x == 4 || x == 6)
bar();
}
compiles into:
_foo: ## @foo
## BB#0: ## %entry
cmpl $6, %edi
ja LBB0_2
## BB#1: ## %entry
movl %edi, %eax
movl $91, %ecx
btq %rax, %rcx
jb LBB0_3
instead of:
_foo: ## @foo
## BB#0: ## %entry
cmpl $2, %edi
jb LBB0_4
## BB#1: ## %switch.early.test
cmpl $6, %edi
ja LBB0_3
## BB#2: ## %switch.early.test
movl %edi, %eax
movl $88, %ecx
btq %rax, %rcx
jb LBB0_4
This catches a bunch of cases in GCC, which look like this:
%804 = load i32* @which_alternative, align 4, !tbaa !0
%805 = icmp ult i32 %804, 2
%806 = icmp eq i32 %804, 3
%or.cond121 = or i1 %805, %806
%807 = icmp eq i32 %804, 4
%or.cond124 = or i1 %or.cond121, %807
br i1 %or.cond124, label %.thread, label %808
turning this into a range comparison.
llvm-svn: 122045
2010-12-17 06:20:15 +00:00
Dan Gohman
93dc2b808f
Revert r64460. strtol and friends cannot be marked readonly, even with
...
a null endptr argument, because they may write to errno.
This fixes a seflhost miscompile observed on Linux targets when TBAA
was enabled.
llvm-svn: 122014
2010-12-17 01:09:43 +00:00
Frits van Bommel
9bbe849fc3
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.
...
This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.
llvm-svn: 121966
2010-12-16 12:16:00 +00:00
Duncan Sands
8d1ab6f6e1
Speculatively revert commit 121905 since it looks like it might have broken the
...
dragonegg self-host buildbot. Original commit message:
Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics. This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.
llvm-svn: 121965
2010-12-16 09:40:54 +00:00
Dan Gohman
e1a17a3473
Make memcpyopt TBAA-aware.
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llvm-svn: 121944
2010-12-16 02:51:19 +00:00
Dan Gohman
4467aa5294
Preserve TBAA tags when doing load PRE.
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llvm-svn: 121921
2010-12-15 23:53:55 +00:00
Owen Anderson
1cf8881299
Add an InstCombine transform to recognize instances of manual overflow-safe addition
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(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics. This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.
Fixes <rdar://problem/8558713>.
llvm-svn: 121905
2010-12-15 22:32:38 +00:00
Dan Gohman
a4fcd2418d
Move Value::getUnderlyingObject to be a standalone
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function so that it can live in Analysis instead of
VMCore.
llvm-svn: 121885
2010-12-15 20:02:24 +00:00
Duncan Sands
0a2c416894
Move Sub simplifications and additional Add simplifications out of
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instcombine and into InstructionSimplify.
llvm-svn: 121861
2010-12-15 14:07:39 +00:00
Frits van Bommel
3d1803495e
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.
llvm-svn: 121859
2010-12-15 09:51:20 +00:00
Chris Lattner
e893e2601e
make qsort predicate more conformant by returning 0 for equal values.
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llvm-svn: 121838
2010-12-15 04:52:41 +00:00
Owen Anderson
35609d97ae
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.
llvm-svn: 121817
2010-12-15 00:55:35 +00:00
Owen Anderson
15c85c916f
Cleanup trailing whitespace.
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llvm-svn: 121816
2010-12-15 00:52:44 +00:00
Chris Lattner
7499b452c1
- Insert new instructions before DomBlock's terminator,
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which is simpler than finding a place to insert in BB.
- Don't perform the 'if condition hoisting' xform on certain
i1 PHIs, as it interferes with switch formation.
This re-fixes "example 7", without breaking the world hopefully.
llvm-svn: 121764
2010-12-14 08:46:09 +00:00
Chris Lattner
335f0e4ad4
fix two significant issues with FoldTwoEntryPHINode:
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first, it can kick in on blocks whose conditions have been
folded to a constant, even though one of the edges will be
trivially folded.
second, it doesn't clean up the "if diamond" that it just
eliminated away. This is a problem because other simplifycfg
xforms kick in depending on the order of block visitation,
causing pointless work.
llvm-svn: 121762
2010-12-14 08:01:53 +00:00
Chris Lattner
dc20a7d38c
remove the instsimplify logic I added in r121754. It is apparently
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breaking the selfhost builds, though I can't fathom how.
llvm-svn: 121761
2010-12-14 07:53:03 +00:00