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
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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.
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llvm-svn: 122554
2010-12-25 20:37:57 +00:00
Jeffrey Yasskin
9b43f33620
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.
llvm-svn: 122458
2010-12-23 00:58:24 +00:00
Duncan Sands
3b8af41a3e
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.
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
eaff500c7b
Oops, forgot to add the pass itself!
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llvm-svn: 122265
2010-12-20 21:07:42 +00:00
Duncan Sands
a436cbe4bf
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.
llvm-svn: 122264
2010-12-20 20:54:37 +00:00
Chris Lattner
0f11495289
when eliding a byval copy due to inlining a readonly function, we have
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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.
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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
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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
Chris Lattner
6b8b4855ff
simplify this a bit.
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llvm-svn: 122156
2010-12-18 20:22:49 +00:00
Benjamin Kramer
e5f49c4ff2
SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.
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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
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
9ac168d0ab
clean up logic, convert std::set to SmallPtrSet, handle the case
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when all 2-entry phis are simplified away.
llvm-svn: 121760
2010-12-14 07:41:39 +00:00
Chris Lattner
9fd838d31b
tidy up a bit, move DEBUG down to when we commit to doing the transform so we
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don't print it unless the xform happens.
llvm-svn: 121758
2010-12-14 07:23:10 +00:00
Chris Lattner
b42d293faa
use SimplifyInstruction instead of reimplementing part of it.
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llvm-svn: 121757
2010-12-14 07:20:29 +00:00
Chris Lattner
fb73de482c
simplify GetIfCondition by using getSinglePredecessor.
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llvm-svn: 121756
2010-12-14 07:15:21 +00:00
Chris Lattner
0f4d67bd88
use AddPredecessorToBlock in 3 places instead of a manual loop.
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llvm-svn: 121755
2010-12-14 07:09:42 +00:00
Chris Lattner
a07cc6f4fd
make FoldTwoEntryPHINode use instsimplify a bit, make
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GetIfCondition faster by avoiding pred_iterator. No
really interesting change.
llvm-svn: 121754
2010-12-14 07:00:00 +00:00
Chris Lattner
afd2a8cfbb
remove the dead (and terrible) llvm::RemoveSuccessor function.
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llvm-svn: 121753
2010-12-14 06:51:55 +00:00
Chris Lattner
d7beca3782
improve DEBUG's a bit, switch to eraseFromParent() to simplify
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code a bit, switch from constant folding to instsimplify.
llvm-svn: 121751
2010-12-14 06:17:25 +00:00
Chris Lattner
5a9d59d918
reapply my recent change that disables a piece of the switch formation
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work, but fixes 400.perlbmk.
llvm-svn: 121749
2010-12-14 05:57:30 +00:00
Owen Anderson
3e5648896e
Fix recent buildbot breakage by pulling SimplifyCFG back to its state as of r121694, the most recent state
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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
Chris Lattner
a6e5d5694a
temporarily disable part of my previous patch, which causes an iterator invalidation issue, causing a crash on some versions of perlbmk.
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llvm-svn: 121728
2010-12-13 23:02:19 +00:00
Chris Lattner
2d434e594e
add some DEBUG's.
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llvm-svn: 121711
2010-12-13 19:55:30 +00:00
Benjamin Kramer
1e155ab7e1
Fix sort predicate. qsort(3)'s predicate semantics differ from std::sort's. Fixes PR 8780.
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llvm-svn: 121705
2010-12-13 18:20:38 +00:00
Chris Lattner
fb836f8c1a
reinstate my patch: the miscompile was caused by an inverted branch in the
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'and' case.
llvm-svn: 121695
2010-12-13 08:12:19 +00:00
Chris Lattner
79db357d80
Completely disable the optimization I added in r121680 until
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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
Chris Lattner
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
Chris Lattner
1d05761df4
make this logic a bit simpler.
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llvm-svn: 121689
2010-12-13 06:36:51 +00:00
Chris Lattner
25c3af35d8
split all the guts of SimplifyCFGOpt::run out into one function
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per terminator kind.
llvm-svn: 121688
2010-12-13 06:25:44 +00:00
Chris Lattner
cb570f87e5
fix a bug in r121680 that upset the various buildbots.
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llvm-svn: 121687
2010-12-13 05:34:18 +00:00
Chris Lattner
a6db741f3d
refactor the speculative execution logic to be factored into the cond branch code instead of
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doing a cfg search for every block simplified.
llvm-svn: 121686
2010-12-13 05:26:52 +00:00
Chris Lattner
466f54ffcf
simplify a bunch of code.
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llvm-svn: 121685
2010-12-13 05:20:28 +00:00
Chris Lattner
6df7bdd810
move HoistThenElseCodeToIf up to a more logical and efficient-to-handle place.
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llvm-svn: 121684
2010-12-13 05:15:29 +00:00
Chris Lattner
2e3832d9a0
move 'MergeBlocksIntoPredecessor' call earlier. Use
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getSinglePredecessor to simplify code.
llvm-svn: 121683
2010-12-13 05:10:48 +00:00
Chris Lattner
a69c443459
factor new code out to a SimplifyBranchOnICmpChain helper function.
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llvm-svn: 121681
2010-12-13 05:03:41 +00:00
Chris Lattner
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
Chris Lattner
5a177e681e
merge two very similar functions into one that has a bool argument.
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llvm-svn: 121678
2010-12-13 04:26:26 +00:00
Chris Lattner
9b1af510cb
don't bother handling non-canonical icmp's
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llvm-svn: 121676
2010-12-13 04:18:32 +00:00
Chris Lattner
395252d93e
inline a function, making the result much simpler.
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llvm-svn: 121675
2010-12-13 04:15:19 +00:00
Chris Lattner
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
Chris Lattner
11dafaa3ec
convert some methods to be static functions
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llvm-svn: 121673
2010-12-13 03:30:12 +00:00
Chris Lattner
4642d79fb0
zap two more std::sorts.
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llvm-svn: 121672
2010-12-13 03:24:30 +00:00
Chris Lattner
d9bacc088a
fix a fairly serious oversight with switch formation from
...
or'd conditions. Previously we'd compile something like this:
int crud (unsigned char c) {
return c == 62 || c == 34 || c == 92;
}
into:
switch i8 %c, label %lor.rhs [
i8 62, label %lor.end
i8 34, label %lor.end
]
lor.rhs: ; preds = %entry
%cmp8 = icmp eq i8 %c, 92
br label %lor.end
lor.end: ; preds = %entry, %entry, %lor.rhs
%0 = phi i1 [ true, %entry ], [ %cmp8, %lor.rhs ], [ true, %entry ]
%lor.ext = zext i1 %0 to i32
ret i32 %lor.ext
which failed to merge the compare-with-92 into the switch. With this patch
we simplify this all the way to:
switch i8 %c, label %lor.rhs [
i8 62, label %lor.end
i8 34, label %lor.end
i8 92, label %lor.end
]
lor.rhs: ; preds = %entry
br label %lor.end
lor.end: ; preds = %entry, %entry, %entry, %lor.rhs
%0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ]
%lor.ext = zext i1 %0 to i32
ret i32 %lor.ext
which is much better for codegen's switch lowering stuff. This kicks in 33 times
on 176.gcc (for example) cutting 103 instructions off the generated code.
llvm-svn: 121671
2010-12-13 03:18:54 +00:00