d418194036
While folding branch to a common destination into a predecessor, copy dbg values also.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129035 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-06 22:37:20 +00:00
3ecfc861b4
Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
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PHINode::Create() giving the (known or expected) number of operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128537 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-30 11:28:46 +00:00
d8b4fb4aab
(Almost) always call reserveOperandSpace() on newly created PHINodes.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-30 11:19:20 +00:00
b1a6eab655
PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
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of pointers in an std::map.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127650 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 02:23:35 +00:00
2adc5b6a17
PR9420; an instruction before an unreachable is guaranteed not to have any
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reachable uses, but there still might be uses in dead blocks. Use the
standard solution of replacing all the uses with undef. This is
a rare case because it's very sensitive to phase ordering in SimplifyCFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127299 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 00:48:33 +00:00
f7b2a9d7df
Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
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Based on a patch by Alistair Lynn.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126647 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:44:07 +00:00
278be783b5
Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
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Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126481 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-25 10:33:33 +00:00
9ae59e3444
SimplifyCFG: GEPs with just one non-constant index are also cheap.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126452 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 23:26:09 +00:00
9b61c550c2
SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126445 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 22:46:11 +00:00
33828bcb24
SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.
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Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125056 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-07 22:37:28 +00:00
042b27f40e
SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
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This transforms another 1000 switches in gcc.c.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124826 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03 22:51:41 +00:00
56442dfdcf
SimplifyCFG: Turn switches into sub+icmp+branch if possible.
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This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.
We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.
The testcase from README.txt now compiles into
decl %edi
cmpl $3, %edi
sbbl %eax, %eax
andl $1, %eax
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 15:56:22 +00:00
c3f507f98a
Re-apply r124518 with fix. Watch out for invalidated iterator.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 04:46:23 +00:00
b0a42fdb36
Revert r124518. It broke Linux self-host.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124522 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 02:43:04 +00:00
5e6940788f
Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124518 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 01:29:26 +00:00
1b5c0cb71d
Revert r124462. There are a few big regressions that I need to fix first.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 07:12:38 +00:00
40f64cb0de
- Stop simplifycfg from duplicating "ret" instructions into unconditional
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branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
allocation is done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124462 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 02:19:21 +00:00
65fdded319
Factor the actual simplification out of SimplifyIndirectBrOnSelect and into a new helper function so it can be reused in e.g. an upcoming SimplifySwitchOnSelect.
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No functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123234 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 12:52:11 +00:00
a37029cd24
simplify this a bit.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122156 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-18 20:22:49 +00:00
14c0987bd9
SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122054 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 10:48:14 +00:00
e27db74a60
improve switch formation to handle small range
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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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 06:20:15 +00:00
ba3c815570
make qsort predicate more conformant by returning 0 for equal values.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121838 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 04:52:41 +00:00
3aff13b82a
- 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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121764 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 08:46:09 +00:00
60d410d7bb
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121762 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 08:01:53 +00:00
071edc81f2
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121761 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:53:03 +00:00
44da7ca421
clean up logic, convert std::set to SmallPtrSet, handle the case
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when all 2-entry phis are simplified away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121760 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:41:39 +00:00
e0b18e5912
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121758 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:23:10 +00:00
07ff3539f5
use SimplifyInstruction instead of reimplementing part of it.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121757 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:20:29 +00:00
995ba1bd49
simplify GetIfCondition by using getSinglePredecessor.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121756 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:15:21 +00:00
6de0a28dfb
use AddPredecessorToBlock in 3 places instead of a manual loop.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121755 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:09:42 +00:00
73c50a68a7
make FoldTwoEntryPHINode use instsimplify a bit, make
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GetIfCondition faster by avoiding pred_iterator. No
really interesting change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121754 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 07:00:00 +00:00
302ba6fc1c
improve DEBUG's a bit, switch to eraseFromParent() to simplify
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code a bit, switch from constant folding to instsimplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121751 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 06:17:25 +00:00
117f8cffc5
reapply my recent change that disables a piece of the switch formation
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work, but fixes 400.perlbmk.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121749 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 05:57:30 +00:00
2d9220e8f5
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121733 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 23:49:28 +00:00
f9a1b2a4cf
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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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121728 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 23:02:19 +00:00
94c58a0906
add some DEBUG's.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121711 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 19:55:30 +00:00
cf8b3257c0
Fix sort predicate. qsort(3)'s predicate semantics differ from std::sort's. Fixes PR 8780.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121705 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 18:20:38 +00:00
a9f6bbea62
reinstate my patch: the miscompile was caused by an inverted branch in the
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'and' case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121695 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 08:12:19 +00:00
92407e5895
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121693 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 07:41:29 +00:00
daa02ab70c
Make simplifycfg reprocess newly formed "br (cond1 | cond2)" conditions
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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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121690 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 07:00:06 +00:00
021c9d3bd4
make this logic a bit simpler.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121689 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 06:36:51 +00:00
3d5121314a
split all the guts of SimplifyCFGOpt::run out into one function
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per terminator kind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121688 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 06:25:44 +00:00
97bd89ece3
fix a bug in r121680 that upset the various buildbots.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:34:18 +00:00
979b8f1d8c
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121686 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:26:52 +00:00
eff7edf126
simplify a bunch of code.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121685 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:20:28 +00:00
ef5002ba85
move HoistThenElseCodeToIf up to a more logical and efficient-to-handle place.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121684 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:15:29 +00:00
ddb97a2bf1
move 'MergeBlocksIntoPredecessor' call earlier. Use
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getSinglePredecessor to simplify code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121683 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:10:48 +00:00
97fdb898f5
factor new code out to a SimplifyBranchOnICmpChain helper function.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121681 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:03:41 +00:00
7312a22ed6
enhance the "change or icmp's into switch" xform to handle one value in an
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'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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121680 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:50:38 +00:00
0aa749bde7
merge two very similar functions into one that has a bool argument.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121678 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:26:26 +00:00
