7c5f9c35d1
sketch more of this out.
...
llvm-svn: 122567
2010-12-26 20:45:45 +00:00
9cb1035f94
move isBytewiseValue out to ValueTracking.h/cpp
...
llvm-svn: 122565
2010-12-26 20:15:01 +00:00
81ae3f299a
actually add the file...
...
llvm-svn: 122563
2010-12-26 19:39:38 +00:00
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
30342fb1fd
Simplify code.
...
llvm-svn: 122561
2010-12-26 15:23:45 +00:00
d729d0dcdb
don't lose TD info
...
llvm-svn: 122556
2010-12-25 20:52:04 +00:00
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
6fcd32e7d7
Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.
...
llvm-svn: 122554
2010-12-25 20:37:57 +00:00
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
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
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
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
18b762a946
Preserve the address space when generating bitcasts for MemTransferInst in ConvertToScalarInfo
...
llvm-svn: 122462
2010-12-23 01:41:32 +00:00
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
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
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
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
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
12470778d7
Remove dead code.
...
llvm-svn: 122371
2010-12-21 22:31:24 +00:00
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
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
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
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
eaff500c7b
Oops, forgot to add the pass itself!
...
llvm-svn: 122265
2010-12-20 21:07:42 +00:00
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
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
2bca3a67b3
Reduce indentation.
...
llvm-svn: 122249
2010-12-20 16:21:59 +00:00
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
27ca8ebd4b
fix PR8807 by making transformConstExprCastCall aware of byval arguments.
...
llvm-svn: 122238
2010-12-20 08:36:38 +00:00
7398965b67
various cleanups for transformConstExprCastCall
...
llvm-svn: 122237
2010-12-20 08:25:06 +00:00
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
0099744506
pull byval processing out to its own helper function.
...
llvm-svn: 122235
2010-12-20 07:57:41 +00:00
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
1991c47ec1
Avoid dropping the address space when InstCombine optimizes memset
...
llvm-svn: 122215
2010-12-20 01:05:30 +00:00
4fb9dd4c74
fix an oversight caught by Frits!
...
llvm-svn: 122204
2010-12-19 23:24:04 +00:00
b6252a376a
tidy up
...
llvm-svn: 122190
2010-12-19 20:24:28 +00:00
3e635d2e99
move a transformation to a more logical place, simplifying it.
...
llvm-svn: 122183
2010-12-19 19:43:52 +00:00
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
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
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
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
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
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
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
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
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
fb888622c3
revert r122164, I'm going to go with a different approach.
...
llvm-svn: 122168
2010-12-19 04:23:03 +00:00
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
6b8b4855ff
simplify this a bit.
...
llvm-svn: 122156
2010-12-18 20:22:49 +00:00
5e3605552e
Whitespace fixes. No functionality change.
...
llvm-svn: 122110
2010-12-17 23:27:41 +00:00
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
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
e5f49c4ff2
SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.
...
llvm-svn: 122054
2010-12-17 10:48:14 +00:00
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
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
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
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
e1a17a3473
Make memcpyopt TBAA-aware.
...
llvm-svn: 121944
2010-12-16 02:51:19 +00:00
4467aa5294
Preserve TBAA tags when doing load PRE.
...
llvm-svn: 121921
2010-12-15 23:53:55 +00:00
1cf8881299
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.
Fixes <rdar://problem/8558713>.
llvm-svn: 121905
2010-12-15 22:32:38 +00:00
a4fcd2418d
Move Value::getUnderlyingObject to be a standalone
...
function so that it can live in Analysis instead of
VMCore.
llvm-svn: 121885
2010-12-15 20:02:24 +00:00
0a2c416894
Move Sub simplifications and additional Add simplifications out of
...
instcombine and into InstructionSimplify.
llvm-svn: 121861
2010-12-15 14:07:39 +00:00
3d1803495e
Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
...
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
e893e2601e
make qsort predicate more conformant by returning 0 for equal values.
...
llvm-svn: 121838
2010-12-15 04:52:41 +00:00
35609d97ae
Fix PR8790, another instance where unreachable code can cause instruction simplification to fail,
...
this case involve a select that simplifies to itself.
llvm-svn: 121817
2010-12-15 00:55:35 +00:00
15c85c916f
Cleanup trailing whitespace.
...
llvm-svn: 121816
2010-12-15 00:52:44 +00:00
7499b452c1
- Insert new instructions before DomBlock's terminator,
...
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
335f0e4ad4
fix two significant issues with FoldTwoEntryPHINode:
...
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
dc20a7d38c
remove the instsimplify logic I added in r121754. It is apparently
...
breaking the selfhost builds, though I can't fathom how.
llvm-svn: 121761
2010-12-14 07:53:03 +00:00
9ac168d0ab
clean up logic, convert std::set to SmallPtrSet, handle the case
...
when all 2-entry phis are simplified away.
llvm-svn: 121760
2010-12-14 07:41:39 +00:00
9fd838d31b
tidy up a bit, move DEBUG down to when we commit to doing the transform so we
...
don't print it unless the xform happens.
llvm-svn: 121758
2010-12-14 07:23:10 +00:00
b42d293faa
use SimplifyInstruction instead of reimplementing part of it.
...
llvm-svn: 121757
2010-12-14 07:20:29 +00:00
fb73de482c
simplify GetIfCondition by using getSinglePredecessor.
...
llvm-svn: 121756
2010-12-14 07:15:21 +00:00
0f4d67bd88
use AddPredecessorToBlock in 3 places instead of a manual loop.
...
llvm-svn: 121755
2010-12-14 07:09:42 +00:00
a07cc6f4fd
make FoldTwoEntryPHINode use instsimplify a bit, make
...
GetIfCondition faster by avoiding pred_iterator. No
really interesting change.
llvm-svn: 121754
2010-12-14 07:00:00 +00:00
afd2a8cfbb
remove the dead (and terrible) llvm::RemoveSuccessor function.
...
llvm-svn: 121753
2010-12-14 06:51:55 +00:00
d7beca3782
improve DEBUG's a bit, switch to eraseFromParent() to simplify
...
code a bit, switch from constant folding to instsimplify.
llvm-svn: 121751
2010-12-14 06:17:25 +00:00
5a9d59d918
reapply my recent change that disables a piece of the switch formation
...
work, but fixes 400.perlbmk.
llvm-svn: 121749
2010-12-14 05:57:30 +00:00
3e5648896e
Fix recent buildbot breakage by pulling SimplifyCFG back to its state as of r121694, the most recent state
...
where I'm confident there were no crashes or miscompilations. XFAIL the test added since then for now.
llvm-svn: 121733
2010-12-13 23:49:28 +00:00
a6e5d5694a
temporarily disable part of my previous patch, which causes an iterator invalidation issue, causing a crash on some versions of perlbmk.
...
llvm-svn: 121728
2010-12-13 23:02:19 +00:00
2d434e594e
add some DEBUG's.
...
llvm-svn: 121711
2010-12-13 19:55:30 +00:00
1e155ab7e1
Fix sort predicate. qsort(3)'s predicate semantics differ from std::sort's. Fixes PR 8780.
...
llvm-svn: 121705
2010-12-13 18:20:38 +00:00
fb836f8c1a
reinstate my patch: the miscompile was caused by an inverted branch in the
...
'and' case.
llvm-svn: 121695
2010-12-13 08:12:19 +00:00
79db357d80
Completely disable the optimization I added in r121680 until
...
I can track down a miscompile. This should bring the buildbots
back to life
llvm-svn: 121693
2010-12-13 07:41:29 +00:00
fbeb55844b
Make simplifycfg reprocess newly formed "br (cond1 | cond2)" conditions
...
when simplifying, allowing them to be eagerly turned into switches. This
is the last step required to get "Example 7" from this blog post:
http://blog.regehr.org/archives/320
On X86, we now generate this machine code, which (to my eye) seems better
than the ICC generated code:
_crud: ## @crud
## BB#0: ## %entry
cmpb $33, %dil
jb LBB0_4
## BB#1: ## %switch.early.test
addb $-34, %dil
cmpb $58, %dil
ja LBB0_3
## BB#2: ## %switch.early.test
movzbl %dil, %eax
movabsq $288230376537592865, %rcx ## imm = 0x400000017001421
btq %rax, %rcx
jb LBB0_4
LBB0_3: ## %lor.rhs
xorl %eax, %eax
ret
LBB0_4: ## %lor.end
movl $1, %eax
ret
llvm-svn: 121690
2010-12-13 07:00:06 +00:00
1d05761df4
make this logic a bit simpler.
...
llvm-svn: 121689
2010-12-13 06:36:51 +00:00
25c3af35d8
split all the guts of SimplifyCFGOpt::run out into one function
...
per terminator kind.
llvm-svn: 121688
2010-12-13 06:25:44 +00:00
cb570f87e5
fix a bug in r121680 that upset the various buildbots.
...
llvm-svn: 121687
2010-12-13 05:34:18 +00:00
a6db741f3d
refactor the speculative execution logic to be factored into the cond branch code instead of
...
doing a cfg search for every block simplified.
llvm-svn: 121686
2010-12-13 05:26:52 +00:00
466f54ffcf
simplify a bunch of code.
...
llvm-svn: 121685
2010-12-13 05:20:28 +00:00
6df7bdd810
move HoistThenElseCodeToIf up to a more logical and efficient-to-handle place.
...
llvm-svn: 121684
2010-12-13 05:15:29 +00:00
2e3832d9a0
move 'MergeBlocksIntoPredecessor' call earlier. Use
...
getSinglePredecessor to simplify code.
llvm-svn: 121683
2010-12-13 05:10:48 +00:00
a69c443459
factor new code out to a SimplifyBranchOnICmpChain helper function.
...
llvm-svn: 121681
2010-12-13 05:03:41 +00:00
a442f24a36
enhance the "change or icmp's into switch" xform to handle one value in an
...
'or sequence' that it doesn't understand. This allows us to optimize
something insane like this:
int crud (unsigned char c, unsigned x)
{
if(((((((((( (int) c <= 32 ||
(int) c == 46) || (int) c == 44)
|| (int) c == 58) || (int) c == 59) || (int) c == 60)
|| (int) c == 62) || (int) c == 34) || (int) c == 92)
|| (int) c == 39) != 0)
foo();
}
into:
define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
%cmp = icmp ult i8 %c, 33
br i1 %cmp, label %if.then, label %switch.early.test
switch.early.test: ; preds = %entry
switch i8 %c, label %if.end [
i8 39, label %if.then
i8 44, label %if.then
i8 58, label %if.then
i8 59, label %if.then
i8 60, label %if.then
i8 62, label %if.then
i8 46, label %if.then
i8 92, label %if.then
i8 34, label %if.then
]
by pulling the < comparison out ahead of the newly formed switch.
llvm-svn: 121680
2010-12-13 04:50:38 +00:00
5a177e681e
merge two very similar functions into one that has a bool argument.
...
llvm-svn: 121678
2010-12-13 04:26:26 +00:00
9b1af510cb
don't bother handling non-canonical icmp's
...
llvm-svn: 121676
2010-12-13 04:18:32 +00:00
395252d93e
inline a function, making the result much simpler.
...
llvm-svn: 121675
2010-12-13 04:15:19 +00:00
62cc76e9cc
Fix my previous patch to handle a degenerate case that the llvm-gcc
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bootstrap buildbot tripped over.
llvm-svn: 121674
2010-12-13 03:43:57 +00:00
11dafaa3ec
convert some methods to be static functions
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llvm-svn: 121673
2010-12-13 03:30:12 +00:00
4642d79fb0
zap two more std::sorts.
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llvm-svn: 121672
2010-12-13 03:24:30 +00:00
Chris Lattner