Commit Graph

419 Commits

Author SHA1 Message Date
Chris Lattner fba5cdfce1 rework FoldBranchToCommonDest to exit earlier when there is a bonus
instruction around, reducing work.

Greatly simplify handling of debug instructions.  There is no need to
build up a vector of them and then move them into the one predecessor
if we're processing a block.  Instead just rescan the block and *copy*
them into the pred.  If a block gets merged into multiple preds, this
will retain more debug info.

llvm-svn: 129502
2011-04-14 02:44:53 +00:00
Chris Lattner 7d4cdae564 comment cleanup, use moveBefore instead of removeFromParent+insertBefore.
llvm-svn: 129319
2011-04-11 23:24:57 +00:00
Devang Patel bc3d8b212f Do not let debug info interfer with branch folding.
llvm-svn: 129114
2011-04-07 23:11:25 +00:00
Devang Patel 197c35298a While hoisting common code from if/else, hoist debug info intrinsics if they match.
llvm-svn: 129078
2011-04-07 17:27:36 +00:00
Devang Patel e48ddf863b Simplify. isIdenticalToWhenDefined() checks opcode.
llvm-svn: 129041
2011-04-07 00:30:15 +00:00
Devang Patel d715ec82b4 While folding branch to a common destination into a predecessor, copy dbg values also.
llvm-svn: 129035
2011-04-06 22:37:20 +00:00
Jay Foad 52131344a2 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad e0938d8a87 (Almost) always call reserveOperandSpace() on newly created PHINodes.
llvm-svn: 128535
2011-03-30 11:19:20 +00:00
Eli Friedman c4414c6e92 PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
of pointers in an std::map.

llvm-svn: 127650
2011-03-15 02:23:35 +00:00
Eli Friedman aac35b3fbb PR9420; an instruction before an unreachable is guaranteed not to have any
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
Frits van Bommel 8ae07996c9 Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
Based on a patch by Alistair Lynn.

llvm-svn: 126647
2011-02-28 09:44:07 +00:00
Benjamin Kramer ceb5daa567 Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
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
Benjamin Kramer dfdca1a14d SimplifyCFG: GEPs with just one non-constant index are also cheap.
llvm-svn: 126452
2011-02-24 23:26:09 +00:00
Benjamin Kramer 27361a7124 SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
llvm-svn: 126445
2011-02-24 22:46:11 +00:00
Benjamin Kramer 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.
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
Benjamin Kramer 62aa46b852 SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
This transforms another 1000 switches in gcc.c.

llvm-svn: 124826
2011-02-03 22:51:41 +00:00
Benjamin Kramer f4ea1d5f79 SimplifyCFG: Turn switches into sub+icmp+branch if possible.
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
Evan Cheng d983eba7dc Re-apply r124518 with fix. Watch out for invalidated iterator.
llvm-svn: 124526
2011-01-29 04:46:23 +00:00
Evan Cheng 65b8ccf6ac Revert r124518. It broke Linux self-host.
llvm-svn: 124522
2011-01-29 02:43:04 +00:00
Evan Cheng d4eff31476 Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
llvm-svn: 124518
2011-01-29 01:29:26 +00:00
Evan Cheng aaa9606b2f Revert r124462. There are a few big regressions that I need to fix first.
llvm-svn: 124478
2011-01-28 07:12:38 +00:00
Evan Cheng 417fca86c4 - Stop simplifycfg from duplicating "ret" instructions into unconditional
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
Frits van Bommel 8e158495f1 Factor the actual simplification out of SimplifyIndirectBrOnSelect and into a new helper function so it can be reused in e.g. an upcoming SimplifySwitchOnSelect.
No functional change.

llvm-svn: 123234
2011-01-11 12:52:11 +00:00
Chris Lattner 6b8b4855ff simplify this a bit.
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.
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.
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
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
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.
llvm-svn: 121757
2010-12-14 07:20:29 +00:00
Chris Lattner fb73de482c simplify GetIfCondition by using getSinglePredecessor.
llvm-svn: 121756
2010-12-14 07:15:21 +00:00
Chris Lattner 0f4d67bd88 use AddPredecessorToBlock in 3 places instead of a manual loop.
llvm-svn: 121755
2010-12-14 07:09:42 +00:00
Chris Lattner 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
Chris Lattner 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
Chris Lattner 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
Owen Anderson 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
Chris Lattner 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
Chris Lattner 2d434e594e add some DEBUG's.
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.
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
'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
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.
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
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.
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
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.
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.
llvm-svn: 121684
2010-12-13 05:15:29 +00:00
Chris Lattner 2e3832d9a0 move 'MergeBlocksIntoPredecessor' call earlier. Use
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.
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.
llvm-svn: 121678
2010-12-13 04:26:26 +00:00
Chris Lattner 9b1af510cb don't bother handling non-canonical icmp's
llvm-svn: 121676
2010-12-13 04:18:32 +00:00
Chris Lattner 395252d93e inline a function, making the result much simpler.
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
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
llvm-svn: 121673
2010-12-13 03:30:12 +00:00
Chris Lattner 4642d79fb0 zap two more std::sorts.
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
Chris Lattner 7c8e6047d6 convert an std::sort to array_pod_sort.
llvm-svn: 121669
2010-12-13 02:00:58 +00:00
Chris Lattner 1475987634 move the "br (X == 0 | X == 1), T, F" -> switch optimization to a new
location in simplifycfg.  In the old days, SimplifyCFG was never run on
the entry block, so we had to scan over all preds of the BB passed into
simplifycfg to do this xform, now we can just check blocks ending with
a condbranch.  This avoids a scan over all preds of every simplified 
block, which should be a significant compile-time perf win on functions
with lots of edges.  No functionality change.

llvm-svn: 121668
2010-12-13 01:57:34 +00:00
Chris Lattner 4088e2b8e4 reduce indentation and generally simplify code, no functionality change.
llvm-svn: 121667
2010-12-13 01:47:07 +00:00
Chris Lattner 7cb7867d7a use getFirstNonPHIOrDbg to simplify this code.
llvm-svn: 121664
2010-12-13 01:28:06 +00:00
Frits van Bommel 8fb69ee805 Teach SimplifyCFG to turn
(indirectbr (select cond, blockaddress(@fn, BlockA),
                            blockaddress(@fn, BlockB)))
into
  (br cond, BlockA, BlockB).

llvm-svn: 120943
2010-12-05 18:29:03 +00:00
Duncan Sands 31c803b2ba Fix PR8445: a block with no predecessors may be the entry block, in which case
it isn't unreachable and should not be zapped.  The check for the entry block
was missing in one case: a block containing a unwind instruction.  While there,
do some small cleanups: "M" is not a great name for a Function* (it would be
more appropriate for a Module*), change it to "Fn"; use Fn in more places.

llvm-svn: 117224
2010-10-24 12:23:30 +00:00
Dan Gohman 250b754428 Instead, teach SimplifyCFG to trim non-address-taken blocks from
indirectbr destination lists.

llvm-svn: 111122
2010-08-16 14:41:14 +00:00
Dan Gohman 4a63fad976 Teach SimplifyCFG how to simplify indirectbr instructions.
- Eliminate redundant successors.
 - Convert an indirectbr with one successor into a direct branch.

Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.

llvm-svn: 111060
2010-08-14 00:29:42 +00:00
Gabor Greif 36f25dfd33 pass dereferenced iterator to dyn_cast
llvm-svn: 109098
2010-07-22 11:43:44 +00:00
Owen Anderson 13700ebb02 Remove unneeded check, and correct style.
llvm-svn: 108427
2010-07-15 16:38:22 +00:00
Owen Anderson 2cfe91379b Extend SimplifyCFG's common-destination folding heuristic to allow a single
"bonus" instruction to be speculatively executed.  Add a heuristic to
ensure we're not tripping up out-of-order execution by checking that this bonus
instruction only uses values that were already guaranteed to be available.

This allows us to eliminate the short circuit in (x&1)&&(x&2).

llvm-svn: 108351
2010-07-14 19:52:16 +00:00
Gabor Greif 8629f12bb8 cache dereferenced iterators
llvm-svn: 108133
2010-07-12 10:59:23 +00:00
Gabor Greif 329c4d8ed9 cache result of operator*
llvm-svn: 107974
2010-07-09 15:25:09 +00:00
Dan Gohman 39027c403c Fix a grammaro.
llvm-svn: 99917
2010-03-30 20:04:57 +00:00
Gabor Greif b469818279 fix two cases where the arguments were extracted from the wrong range out of the InvokeInst
spotted by baldrick -- thanks\!

llvm-svn: 99914
2010-03-30 19:20:53 +00:00
Bill Wendling ee84f27536 Make returns more consistent with others.
llvm-svn: 98490
2010-03-14 10:40:28 +00:00
Duncan Sands 19d0b47b1f There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Duncan Sands 9dff9bec31 Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!

llvm-svn: 96223
2010-02-15 16:12:20 +00:00
Jakob Stoklund Olesen 916f48a054 Teach SimplifyCFG about magic pointer constants.
Weird code sometimes uses pointer constants other than null. This patch
teaches SimplifyCFG to build switch instructions in those cases.

Code like this:

void f(const char *x) {
  if (!x)
    puts("null");
  else if ((uintptr_t)x == 1)
    puts("one");
  else if (x == (char*)2 || x == (char*)3)
    puts("two");
  else if ((intptr_t)x == 4)
    puts("four");
  else
    puts(x);
}

Now becomes a switch:

define void @f(i8* %x) nounwind ssp {
entry:
  %magicptr23 = ptrtoint i8* %x to i64            ; <i64> [#uses=1]
  switch i64 %magicptr23, label %if.else16 [
    i64 0, label %if.then
    i64 1, label %if.then2
    i64 2, label %if.then9
    i64 3, label %if.then9
    i64 4, label %if.then14
  ]

Note that LLVM's own DenseMap uses magic pointers.

llvm-svn: 95439
2010-02-05 22:03:18 +00:00
Benjamin Kramer a81a6dff0d Convert a ton of simple integer type equality tests to the new predicate.
llvm-svn: 92760
2010-01-05 20:07:06 +00:00
Benjamin Kramer ccce8bae14 Avoid going through the LLVMContext for type equality where it's safe to dereference the type pointer.
llvm-svn: 92726
2010-01-05 13:12:22 +00:00
David Greene 725c7c3f2e Change errs() to dbgs().
llvm-svn: 92604
2010-01-05 01:26:52 +00:00
Devang Patel be94f23992 Remove dead debug info intrinsics.
Intrinsic::dbg_stoppoint
 Intrinsic::dbg_region_start 
 Intrinsic::dbg_region_end 
 Intrinsic::dbg_func_start
AutoUpgrade simply ignores these intrinsics now.

llvm-svn: 92557
2010-01-05 01:10:40 +00:00
Jim Grosbach d831ef4945 Move EliminateDuplicatePHINodes() from SimplifyCFG.cpp to Local.cpp
llvm-svn: 90324
2009-12-02 17:06:45 +00:00
Jim Grosbach cc69a1ba9a Make EliminateDuplicatePHINodes() available as a utility function
llvm-svn: 89297
2009-11-19 02:02:10 +00:00
Chris Lattner cbd18fc93d refactor TryToSimplifyUncondBranchFromEmptyBlock out of SimplifyCFG.
llvm-svn: 86666
2009-11-10 05:59:26 +00:00
Chris Lattner 46b5c642b9 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.

llvm-svn: 86231
2009-11-06 04:27:31 +00:00
Dan Gohman 7f7d97eb73 Add a comment about a missed opportunity.
llvm-svn: 85635
2009-10-30 23:15:43 +00:00
Dan Gohman 1a95106602 Teach SimplifyCFG how to eliminate duplicate PHI nodes within a block.
This reduces codesize on a variety of codes by 1-2% on x86-64. It also
helps clean up after SSAUpdater.

llvm-svn: 85626
2009-10-30 22:39:04 +00:00
Chris Lattner 19788ca686 change simplifycfg to not duplicate 'unwind' instructions. Hopefully
this will increase the likelihood of common code getting sunk towards
the unwind.

llvm-svn: 83996
2009-10-13 18:13:05 +00:00
Nick Lewycky 42fb7452df Instruction::clone does not need to take an LLVMContext&. Remove that and
update all the callers.

llvm-svn: 82889
2009-09-27 07:38:41 +00:00
Dan Gohman c8a27f2a5c Rename Instruction::isIdenticalTo to Instruction::isIdenticalToWhenDefined,
and introduce a new Instruction::isIdenticalTo which tests for full
identity, including the SubclassOptionalData flags. Also, fix the
Instruction::clone implementations to preserve the SubclassOptionalData
flags. Finally, teach several optimizations how to handle
SubclassOptionalData correctly, given these changes.

This fixes the counterintuitive behavior of isIdenticalTo not comparing
the full value, and clone not returning an identical clone, as well as
some subtle bugs that could be caused by these.

Thanks to Nick Lewycky for reporting this, and for an initial patch!

llvm-svn: 80038
2009-08-25 22:11:20 +00:00
Daniel Dunbar 5e0a58bef4 Fix -Asserts warnings.
llvm-svn: 79849
2009-08-23 10:29:55 +00:00
Chris Lattner b25de3ff60 eliminate the "Value" printing methods that print to a std::ostream.
This required converting a bunch of stuff off DOUT and other cleanups.

llvm-svn: 79819
2009-08-23 04:37:46 +00:00
Eli Friedman d56fca4708 Fix for PR3016: detect the tricky case, where there are
unfoldable references to a PHI node in the block being folded, and disable
the transformation in that case.  The correct transformation of such PHI
nodes depends on whether BB dominates Succ, and dominance is expensive 
to compute here.  (Alternatively, it's possible to check whether any 
uses are live, but that's also essentially a dominance calculation. 
Another alternative is to use reg2mem, but it probably isn't a good idea to
use that in simplifycfg.)

Also, remove some incorrect code from CanPropagatePredecessorsForPHIs 
which is made unnecessary with this patch: it didn't consider the case 
where a PHI node in BB has multiple uses.

llvm-svn: 79174
2009-08-16 04:23:49 +00:00
Owen Anderson 55f1c09e31 Push LLVMContexts through the IntegerType APIs.
llvm-svn: 78948
2009-08-13 21:58:54 +00:00
Dan Gohman 5476cfdb15 Remove a bunch more now-unnecessary Context arguments.
llvm-svn: 78809
2009-08-12 16:23:25 +00:00
Owen Anderson b292b8ce70 Move more code back to 2.5 APIs.
llvm-svn: 77635
2009-07-30 23:03:37 +00:00
Daniel Dunbar 6115b39ffd Remove Value::getName{Start,End}, the last of the old Name APIs.
llvm-svn: 77152
2009-07-26 09:48:23 +00:00
Daniel Dunbar 0dd5e1ed39 More migration to raw_ostream, the water has dried up around the iostream hole.
- Some clients which used DOUT have moved to DEBUG. We are deprecating the
   "magic" DOUT behavior which avoided calling printing functions when the
   statement was disabled. In addition to being unnecessary magic, it had the
   downside of leaving code in -Asserts builds, and of hiding potentially
   unnecessary computations.

llvm-svn: 77019
2009-07-25 00:23:56 +00:00
Owen Anderson edb4a70325 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
llvm-svn: 77011
2009-07-24 23:12:02 +00:00
Owen Anderson 47db941fd3 Get rid of the Pass+Context magic.
llvm-svn: 76702
2009-07-22 00:24:57 +00:00
Eli Friedman b8f6a4fc8e Replace isTrapping with a new, similar method called
isSafeToSpeculativelyExecute. The new method is a bit closer to what 
the callers actually care about in that it rejects more things callers 
don't want.  It also adds more precise handling for integer 
division, and unifies code for analyzing the legality of a speculative 
load.

llvm-svn: 76150
2009-07-17 04:28:42 +00:00
Owen Anderson 542619e6d5 Move more functionality over to LLVMContext.
llvm-svn: 75497
2009-07-13 20:58:05 +00:00
Owen Anderson 1e5f00e7a7 This started as a small change, I swear. Unfortunately, lots of things call the [I|F]CmpInst constructors. Who knew!?
llvm-svn: 75200
2009-07-09 23:48:35 +00:00
Owen Anderson 38264b1554 "LLVMContext* " --> "LLVMContext *"
llvm-svn: 74878
2009-07-06 23:00:19 +00:00
Owen Anderson 39f00cc1d4 Thread LLVMContext through the constant folding APIs, which touches a lot of files.
llvm-svn: 74844
2009-07-06 18:42:36 +00:00
Owen Anderson e70b637033 More LLVMContext-ification.
llvm-svn: 74807
2009-07-05 22:41:43 +00:00
Dan Gohman c8ca49659a Teach LoopSimplify how to merge multiple loop exits into a single exit,
when one of them can be converted to a trivial icmp and conditional
branch.

This addresses what is essentially a phase ordering problem.
SimplifyCFG knows how to do this transformation, but it doesn't do so
if the primary block has any instructions in it other than an icmp and
a branch. In the given testcase, the block contains other instructions,
however they are loop-invariant and can be hoisted. SimplifyCFG doesn't
have LoopInfo though, so it can't hoist them. And, it's important that
the blocks be merged before LoopRotation, as it doesn't support
multiple-exit loops.

llvm-svn: 74396
2009-06-27 21:30:38 +00:00
Dale Johannesen 9df78ee1ae Fix the crash in this test. This is basically the same
problem addressed in 31284, but the patch there only
addressed the case where an invoke is the first thing in
a block.

llvm-svn: 73416
2009-06-15 20:59:27 +00:00
Dan Gohman a5b9645c4b Split the Add, Sub, and Mul instruction opcodes into separate
integer and floating-point opcodes, introducing
FAdd, FSub, and FMul.

For now, the AsmParser, BitcodeReader, and IRBuilder all preserve
backwards compatability, and the Core LLVM APIs preserve backwards
compatibility for IR producers. Most front-ends won't need to change
immediately.

This implements the first step of the plan outlined here:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt

llvm-svn: 72897
2009-06-04 22:49:04 +00:00
Dale Johannesen 1ac1969e09 Reuse existing getUnderlyingObject instead of
adding another copy.

llvm-svn: 71783
2009-05-14 18:41:18 +00:00
Dale Johannesen 3181652363 Handle some additonal cases of external weak globals.
llvm-svn: 71717
2009-05-13 20:55:30 +00:00
Dale Johannesen 69921959b4 Don't generate a select whose operand is load of a weak
external.  These may have address 0 and are not safe
to execute unconditionally.

llvm-svn: 71688
2009-05-13 18:25:07 +00:00
Dan Gohman 9a6fef0a52 Simplify code by using SmallVector's pop_back_val() instead of
separate back() and pop_back() calls.

llvm-svn: 71089
2009-05-06 17:22:41 +00:00
Dale Johannesen e4f361212b Fix comment typo.
llvm-svn: 67307
2009-03-19 17:23:29 +00:00
Dale Johannesen cecfa6e08d Fix one more place where debug info affected
codegen (speculative execution).

llvm-svn: 66859
2009-03-13 01:05:24 +00:00
Dale Johannesen ed6f5a8253 Previous debug info fix to this code wasn't quite
right; did the wrong thing when there are exactly 11
non-debug instructions, followed by debug info.
Remove a FIXME since it's apparently been fixed along the way.

llvm-svn: 66840
2009-03-12 23:18:09 +00:00
Dale Johannesen 7f99d22f2f There already was a class to force deterministic
sorting of ConstantInt's; unreinvent wheel.

llvm-svn: 66824
2009-03-12 21:01:11 +00:00
Dale Johannesen 578d8bfc3c Another missing check for debug intrinsics.
llvm-svn: 66800
2009-03-12 17:42:45 +00:00
Dale Johannesen 9cdb9bb3e5 Allow for switch values bigger than 64 bits.
llvm-svn: 66751
2009-03-12 01:20:06 +00:00
Dale Johannesen 5a41b2def5 Fix some nondeterministic behavior when forwarding
from a switch table.  Multiple table entries that
branch to the same place were being sorted by the
pointer value of the ConstantInt*; changed to sort
by the actual value of the ConstantInt.

llvm-svn: 66749
2009-03-12 01:00:26 +00:00
Devang Patel 84fceff969 Ignore dbg info, while estimating size of jump through block.
llvm-svn: 66554
2009-03-10 18:00:05 +00:00
Dale Johannesen 6e447e08ee Fix another case where debug info interferes with
an optimization.

llvm-svn: 66288
2009-03-06 21:08:33 +00:00
Devang Patel 5aed7765b8 While hoisting instruction to speculatively execute simple bb, ignore dbg intrinsics.
llvm-svn: 66255
2009-03-06 06:00:17 +00:00
Bill Wendling 7fcd6148f7 Remove accidental check-ins in r65960. :-(
llvm-svn: 65961
2009-03-03 19:25:16 +00:00
Bill Wendling a68fc7af63 Use > instead of >=. We want to promote aggregates of 128-bytes.
llvm-svn: 65960
2009-03-03 19:18:49 +00:00
Zhou Sheng 264e46e1e9 Ignore dbg info intrinsics when folding conditional branch to
conditional branch predecessors.

llvm-svn: 65509
2009-02-26 06:56:37 +00:00
Zhou Sheng 5d9cc1763b Don't block basic block with only SwitchInst to fold into predecessors.
llvm-svn: 65456
2009-02-25 15:34:27 +00:00
Devang Patel e288082644 While folding unconditional return move DbgRegionEndInst into the predecessor, instead of removing it. This fixes following tests from llvmgcc42 testsuite.
gcc.c-torture/execute/20000605-3.c
gcc.c-torture/execute/20020619-1.c
gcc.c-torture/execute/20030920-1.c
gcc.c-torture/execute/loop-ivopts-1.c

llvm-svn: 65353
2009-02-24 00:05:16 +00:00
Devang Patel 316705027b If llvm.dbg.region.end is disappearing then remove corresponding llvm.dbg.func.start also.
llvm-svn: 64278
2009-02-11 01:29:06 +00:00
Devang Patel 654e47f366 Ignore dbg intrinsic while folding unconditional branch.
llvm-svn: 64242
2009-02-10 22:14:17 +00:00
Devang Patel 02f58e1e8d Revert rev. 63876. It is causing llvm-gcc bootstrap failure.
llvm-svn: 63888
2009-02-05 21:46:41 +00:00
Devang Patel 5922e26d1a Ignore dbg intrinsics while propagating conditional expression info.
llvm-svn: 63876
2009-02-05 19:15:39 +00:00
Devang Patel 086b212277 Ignore dbg intrinsics while folding switch instruction.
llvm-svn: 63802
2009-02-05 00:30:42 +00:00
Devang Patel 916fdce16d Ignore dbg intrinsics.
llvm-svn: 63781
2009-02-04 21:39:48 +00:00
Devang Patel fd9f635103 While folding vallue comparison terminators ignore dbg intrinsics.
llvm-svn: 63700
2009-02-04 01:06:11 +00:00
Devang Patel f10e287c65 Ignore dbg intrinsics while hoisting common code in the two blocks up into the branch block.
llvm-svn: 63687
2009-02-04 00:03:08 +00:00
Devang Patel 2032cadd0f Do not let dbg intrinsic block folding of two entry phi node.
llvm-svn: 63671
2009-02-03 22:12:02 +00:00
Chris Lattner c59945b4bd another fix for PR3354
llvm-svn: 62561
2009-01-20 01:15:41 +00:00
Bill Wendling caf1d22243 Doxygen-ify comments.
llvm-svn: 62546
2009-01-19 23:43:56 +00:00
Chris Lattner ea9f1d3c47 Fix a problem exposed by PR3354: simplifycfg was making a potentially
trapping instruction be executed unconditionally.

llvm-svn: 62541
2009-01-19 23:03:13 +00:00
Bill Wendling 534d2e0bae Temporarily revert r62487. It's causing this error during a release bootstrap of
llvm-gcc. Most likely, it's miscompiling one of the "gen*" programs:

/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./prev-gcc/xgcc -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./prev-gcc/ -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.6.0/bin/ -c -g -O2 -mdynamic-no-pic -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -mdynamic-no-pic -DHAVE_CONFIG_H -DGENERATOR_FILE -I. -Ibuild -I../../llvm-gcc.src/gcc -I../../llvm-gcc.src/gcc/build -I../../llvm-gcc.src/gcc/../include -I./../intl -I../../llvm-gcc.src/gcc/../libcpp/include  -I../../llvm-gcc.src/gcc/../libdecnumber -I../libdecnumber -I/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.obj/include -I/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/include -DENABLE_LLVM -I/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.obj/../llvm.src/include  -D_DEBUG  -D_GNU_SOURCE -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS   -o build/gencondmd.o build/gencondmd.c
../../llvm-gcc.src/gcc/config/i386/mmx.md:926: error: expected '}' before ')' token
../../llvm-gcc.src/gcc/config/i386/mmx.md:926: warning: excess elements in struct initializer
../../llvm-gcc.src/gcc/config/i386/mmx.md:926: warning: (near initialization for 'insn_conditions[4]')
../../llvm-gcc.src/gcc/config/i386/mmx.md:926: error: expected '}' before ')' token
../../llvm-gcc.src/gcc/config/i386/mmx.md:926: error: expected ',' or ';' before ')' token
../../llvm-gcc.src/gcc/config/i386/mmx.md:927: error: expected identifier or '(' before ',' token
../../llvm-gcc.src/gcc/config/i386/sse.md:3458: error: expected identifier or '(' before ',' token
...

llvm-svn: 62506
2009-01-19 08:46:20 +00:00
Chris Lattner f2bb4ea39c Fix PR3016, a bug which can occur do to an invalid assumption:
we assumed a CFG structure that would be valid when all code in 
the function is reachable, but not all code is necessarily 
reachable.  Do a simple, but horrible, CFG walk to check for this
case.

llvm-svn: 62487
2009-01-19 02:46:28 +00:00
Chris Lattner e381d7026f reduce indentation by using 'continue', no functionality change.
llvm-svn: 62477
2009-01-19 02:07:32 +00:00
Chris Lattner 54f0c61d71 Fix some problems in SpeculativelyExecuteBB. Basically,
because of dead code, a phi could use the speculated instruction
that was not in "BB2".  Make this check explicit and tighten up 
some other corners.  This fixes PR3292.  No testcase becauase this
depends entirely on visitation order of blocks and requires a 
sequence of 8 passes to repro.

llvm-svn: 62476
2009-01-19 00:36:37 +00:00
Chris Lattner e1c01e4e2b Make this a bit more explicit about which cases need the
check.  No functionality change.

llvm-svn: 62474
2009-01-18 23:22:07 +00:00
Eli Friedman cb61afb546 Add a helper to remove a branch and DCE the condition, and use it
consistently for deleting branches.  In addition to being slightly 
more readable, this makes SimplifyCFG a bit better 
about cleaning up after itself when it makes conditions unused.

llvm-svn: 61100
2008-12-16 20:54:32 +00:00
Chris Lattner f50d7f76c6 fix a bug I introduced in simplifycfg handling single entry phi
nodes. FoldSingleEntryPHINodes deletes the PHI, so there is no
need to delete it afterward.

llvm-svn: 60653
2008-12-07 07:22:45 +00:00