2522d2df06
more tests not making the jump into the brave new world.
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llvm-svn: 134820
2011-07-09 16:57:10 +00:00
b10a0f223a
Add r134057 back, but splice the predecessor after the successors phi
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nodes.
Original message:
Let simplify cfg simplify bb with only debug and lifetime intrinsics.
llvm-svn: 134182
2011-06-30 20:14:24 +00:00
96ed721d9b
Temporarily revert r134057: "Let simplify cfg simplify bb with only debug and
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lifetime intrinsics" due to buildbot failures.
llvm-svn: 134071
2011-06-29 16:22:11 +00:00
4c0dfcec7e
Let simplify cfg simplify bb with only debug and lifetime intrinsics.
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llvm-svn: 134057
2011-06-29 05:25:47 +00:00
4ab4a8e63a
Fix PR10103: Less code for enum type translation.
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In cases such as the attached test, where the case value for a switch
destination is used in a phi node that follows the destination, it
might be better to replace that value with the condition value of the
switch, so that more blocks can be folded away with
TryToSimplifyUncondBranchFromEmptyBlock because there are less
conflicts in the phi node.
llvm-svn: 133344
2011-06-18 10:28:47 +00:00
33de427cd6
remove parser support for the obsolete "multiple return values" syntax, which
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was replaced with return of a "first class aggregate".
llvm-svn: 133245
2011-06-17 06:49:41 +00:00
4f163dfed1
If the block that we're threading through is jumped to by an indirect branch,
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then we don't want to set the destination in the indirect branch to the
destination. This is because the indirect branch needs its destinations to have
had their block addresses taken. This isn't so of the new critical edge that's
split during this process. If it turns out that the destination block has only
one predecessor, and that being a BB with an indirect branch, then it won't be
marked as 'used' and may be removed.
PR10072
llvm-svn: 132638
2011-06-04 09:42:04 +00:00
ad964559ef
Add a parameter to ConstantFoldTerminator() that callers can use to ask it to also clean up the condition of any conditional terminator it folds to be unconditional, if that turns the condition into dead code. This just means it calls RecursivelyDeleteTriviallyDeadInstructions() in strategic spots. It defaults to the old behavior.
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I also changed -simplifycfg, -jump-threading and -codegenprepare to use this to produce slightly better code without any extra cleanup passes (AFAICT this was the only place in -simplifycfg where now-dead conditions of replaced terminators weren't being cleaned up). The only other user of this function is -sccp, but I didn't read that thoroughly enough to figure out whether it might be holding pointers to instructions that could be deleted by this.
llvm-svn: 131855
2011-05-22 16:24:18 +00:00
3f60a0b411
Add test for PR9946.
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llvm-svn: 131621
2011-05-19 02:35:26 +00:00
d96205c4e5
SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.
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llvm-svn: 131345
2011-05-14 15:57:25 +00:00
616044acd5
SimplifyCFG: Expose phi node folding cost threshold as command line parameter
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llvm-svn: 130528
2011-04-29 18:47:38 +00:00
e3511e15e0
SimplifyCFG: Add CostRemaining parameter to DominatesMergePoint
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llvm-svn: 130527
2011-04-29 18:47:31 +00:00
61f6602acd
SimplifyCFG: Add Trunc, ZExt and SExt to the list of cheap instructions for phi node folding
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llvm-svn: 130526
2011-04-29 18:47:25 +00:00
12bf0ab4b5
Simplify cfg inserts a call to trap when unreachable code is detected. Assign DebugLoc to this new trap instruction.
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llvm-svn: 130315
2011-04-27 17:59:27 +00:00
eb045f9c02
Improve the bail-out predicate to really only kick in when phi
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translation fails. We were bailing out in some cases that would
cause us to miss GVN'ing some non-local cases away.
llvm-svn: 130206
2011-04-26 17:41:02 +00:00
bc3d8b212f
Do not let debug info interfer with branch folding.
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llvm-svn: 129114
2011-04-07 23:11:25 +00:00
197c35298a
While hoisting common code from if/else, hoist debug info intrinsics if they match.
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llvm-svn: 129078
2011-04-07 17:27:36 +00:00
c4414c6e92
PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
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of pointers in an std::map.
llvm-svn: 127650
2011-03-15 02:23:35 +00:00
1885d21700
Fix mistyped CHECK lines.
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llvm-svn: 127366
2011-03-09 22:07:31 +00:00
aac35b3fbb
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.
llvm-svn: 127299
2011-03-09 00:48:33 +00:00
8ae07996c9
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.
llvm-svn: 126647
2011-02-28 09:44:07 +00:00
ceb5daa567
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.
llvm-svn: 126481
2011-02-25 10:33:33 +00:00
dfdca1a14d
SimplifyCFG: GEPs with just one non-constant index are also cheap.
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llvm-svn: 126452
2011-02-24 23:26:09 +00:00
27361a7124
SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
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llvm-svn: 126445
2011-02-24 22:46:11 +00:00
8d6a8c130b
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.
llvm-svn: 125056
2011-02-07 22:37:28 +00:00
62aa46b852
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.
llvm-svn: 124826
2011-02-03 22:51:41 +00:00
f4ea1d5f79
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
llvm-svn: 124724
2011-02-02 15:56:22 +00:00
d983eba7dc
Re-apply r124518 with fix. Watch out for invalidated iterator.
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llvm-svn: 124526
2011-01-29 04:46:23 +00:00
65b8ccf6ac
Revert r124518. It broke Linux self-host.
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llvm-svn: 124522
2011-01-29 02:43:04 +00:00
d4eff31476
Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
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llvm-svn: 124518
2011-01-29 01:29:26 +00:00
aaa9606b2f
Revert r124462. There are a few big regressions that I need to fix first.
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llvm-svn: 124478
2011-01-28 07:12:38 +00:00
417fca86c4
- 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.
llvm-svn: 124462
2011-01-28 02:19:21 +00:00
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
d14b0f1db7
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.
llvm-svn: 122045
2010-12-17 06:20:15 +00:00
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
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
f130661688
fix yet anohter broken line
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llvm-svn: 121750
2010-12-14 06:09:07 +00:00
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
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
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
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
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
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
fbeb55844b
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
llvm-svn: 121690
2010-12-13 07:00:06 +00:00
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
bc9e6d9dbe
make these tests a bit less fragile
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llvm-svn: 121682
2010-12-13 05:10:30 +00:00
a442f24a36
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.
llvm-svn: 121680
2010-12-13 04:50:38 +00:00
a737721d14
merge two tests
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llvm-svn: 121679
2010-12-13 04:45:56 +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
d9bacc088a
fix a fairly serious oversight with switch formation from
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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
Chris Lattner