757 Commits

Author SHA1 Message Date
Dale Johannesen
a94e36bbee Reapply 122353-122355 with fixes. 122354 was wrong;
the shift type was needed one place, the shift count
type another.  The transform in 123555 had the same
problem.

llvm-svn: 122366
2010-12-21 21:55:50 +00:00
Dale Johannesen
87c47499c6 Revert 122353-122355 for the moment, they broke stuff.
llvm-svn: 122360
2010-12-21 21:22:27 +00:00
Dale Johannesen
caf42aa6a4 Add a new transform to DAGCombiner.
llvm-svn: 122355
2010-12-21 20:10:51 +00:00
Dale Johannesen
fa5dc82fda Get the type of a shift from the shift, not from its shift
count operand.  These should be the same but apparently are
not always, and this is cleaner anyway.  This improves the
code in an existing test.

llvm-svn: 122354
2010-12-21 20:06:19 +00:00
Dale Johannesen
d64931df77 Shift by the word size is invalid IR; don't create it.
llvm-svn: 122353
2010-12-21 20:00:06 +00:00
Chris Lattner
2a7ff99979 fix some typos
llvm-svn: 122349
2010-12-21 18:05:22 +00:00
Chris Lattner
3e5fbd74ed rename MVT::Flag to MVT::Glue. "Flag" is a terrible name for
something that just glues two nodes together, even if it is
sometimes used for flags.

llvm-svn: 122310
2010-12-21 02:38:05 +00:00
Dale Johannesen
0a291a36f2 Cosmetic changes.
llvm-svn: 122259
2010-12-20 20:10:50 +00:00
Bob Wilson
5408144add Fix a DAGCombiner crash when folding binary vector operations with constant
BUILD_VECTOR operands where the element type is not legal.  I had previously
changed this code to insert TRUNCATE operations, but that was just wrong.

llvm-svn: 122102
2010-12-17 23:06:49 +00:00
Dale Johannesen
cd538afa52 Add a transform to DAG Combiner. This improves the
code for the case where 32-bit divide by constant is
turned into 64-bit multiply by constant.  8771012.

llvm-svn: 122090
2010-12-17 21:45:49 +00:00
Chris Lattner
15090e1eb0 take care of some todos, transforming [us]mul_lohi into
a wider mul if the wider mul is legal.

llvm-svn: 121848
2010-12-15 06:04:19 +00:00
Chris Lattner
b86dceea1b when transforming a MULHS into a wider MUL, there is no need to SRA the
result, the top bits are truncated off anyway, just use SRL.

llvm-svn: 121846
2010-12-15 05:51:39 +00:00
Chris Lattner
10bd29f1d4 Add a couple dag combines to transform mulhi/mullo into a wider multiply
when the wider type is legal.  This allows us to compile:

define zeroext i16 @test1(i16 zeroext %x) nounwind {
entry:
	%div = udiv i16 %x, 33
	ret i16 %div
}

into:

test1:                                  # @test1
	movzwl	4(%esp), %eax
	imull	$63551, %eax, %eax      # imm = 0xF83F
	shrl	$21, %eax
	ret

instead of:

test1:                                  # @test1
        movw    $-1985, %ax             # imm = 0xFFFFFFFFFFFFF83F
        mulw    4(%esp)
        andl    $65504, %edx            # imm = 0xFFE0
        movl    %edx, %eax
        shrl    $5, %eax
        ret

Implementing rdar://8760399 and example #4 from:
http://blog.regehr.org/archives/320

We should implement the same thing for [su]mul_hilo, but I don't
have immediate plans to do this.

llvm-svn: 121696
2010-12-13 08:39:01 +00:00
Eric Christopher
d9e8eac235 80-col fixups.
llvm-svn: 121356
2010-12-09 04:48:06 +00:00
Jay Foad
583abbc4df PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

llvm-svn: 121120
2010-12-07 08:25:19 +00:00
Bob Wilson
f9b96c474f Fix a comment typo.
llvm-svn: 120235
2010-11-28 06:51:19 +00:00
Wesley Peck
527da1b6e2 Renaming ISD::BIT_CONVERT to ISD::BITCAST to better reflect the LLVM IR concept.
llvm-svn: 119990
2010-11-23 03:31:01 +00:00
Duncan Sands
c92331b984 Fix thinko: we must turn select(anyext, sext) into sext(select)
not anyext(select).  Spotted by Frits van Bommel.

llvm-svn: 119739
2010-11-18 21:16:28 +00:00
Duncan Sands
12f3b3b44f The DAGCombiner was threading select over pairs of extending loads even
if the extension types were not the same.  The result was that if you
fed a select with sext and zext loads, as in the testcase, then it
would get turned into a zext (or sext) of the select, which is wrong
in the cases when it should have been an sext (resp. zext).  Reported
and diagnosed by Sebastien Deldon.

llvm-svn: 119728
2010-11-18 20:05:18 +00:00
Dan Gohman
5db8921422 Fix DAGCombiner to avoid folding a sext-in-reg or similar through a shl
in order to fold it into a load.

llvm-svn: 118471
2010-11-09 01:54:35 +00:00
Eric Christopher
c6418b105a Just return undef for invalid masks or elts, and since we're doing that,
just do it earlier too.

llvm-svn: 118195
2010-11-03 20:44:42 +00:00
Eric Christopher
fcc9e6848a If we have an undef mask our Elt will be -1 for our access, handle
this by using an undef as a pointer.

Fixes rdar://8625016

llvm-svn: 118164
2010-11-03 09:36:40 +00:00
Dan Gohman
68fb004616 Fix DAGCombiner to avoid going into an infinite loop when it
encounters (and:i64 (shl:i64 (load:i64), 1), 0xffffffff).
This fixes rdar://8606584.

llvm-svn: 118143
2010-11-03 01:47:46 +00:00
Bob Wilson
08882be86c Remove DAG combiner patch to fold vector splats. Instcombiner does it now.
llvm-svn: 117720
2010-10-29 22:03:02 +00:00
Bob Wilson
f63da12be9 Teach the DAG combiner to fold a splat of a splat. Radar 8597790.
Also do some minor refactoring to reduce indentation.

llvm-svn: 117558
2010-10-28 17:06:14 +00:00
Dan Gohman
a94cc6dfe8 Make CodeGen TBAA-aware.
llvm-svn: 116890
2010-10-20 00:31:05 +00:00
Evan Cheng
c8d6cfd730 This DAG combine BRCOND transformation can look pass truncate of the operand:
//   %a = ...                                                                                                                                                                                  
    //   %b = and i32 %a, 2                                                                                                                                                                        
    //   %c = srl i32 %b, 1                                                                                                                                                                        
    //   brcond i32 %c ...                                                                                                                                                                         
    //                                                                                                                                                                                             
    // into                                                                                                                                                                                        
    //                                                                                                                                                                                             
    //   %a = ...                                                                                                                                                                                  
    //   %b = and i32 %a, 2                                                                                                                                                                        
    //   %c = setcc eq %b, 0                                                                                                                                                                       
    //   brcond %c ...

Make sure it restores local variable N1, which corresponds to the condition operand if it fails to match.

This apparently breaks TCE but since that backend isn't in the tree I don't have a test for it.

llvm-svn: 115571
2010-10-04 22:41:01 +00:00
Chris Lattner
a205055857 fix rdar://8494845 + PR8244 - a miscompile exposed by my patch in r101350
llvm-svn: 115294
2010-10-01 05:36:09 +00:00
Owen Anderson
3231d13ddd A select between a constant and zero, when fed by a bit test, can be efficiently
lowered using a series of shifts.
Fixes <rdar://problem/8285015>.

llvm-svn: 114599
2010-09-22 22:58:22 +00:00
Owen Anderson
5e65dfbb97 Reimplement r114460 in target-independent DAGCombine rather than target-dependent, by using
the predicate to discover the number of sign bits.  Enhance X86's target lowering to provide
a useful response to this query.

llvm-svn: 114473
2010-09-21 20:42:50 +00:00
Chris Lattner
676c61db0e update a bunch of code to use the MachinePointerInfo version of getStore.
llvm-svn: 114461
2010-09-21 18:41:36 +00:00
Chris Lattner
6963c1f789 eliminate an old SelectionDAG::getTruncStore method, propagating
MachinePointerInfo around more.

llvm-svn: 114452
2010-09-21 17:42:31 +00:00
Chris Lattner
3d178ed4d4 propagate MachinePointerInfo through various uses of the old
SelectionDAG::getExtLoad overload, and eliminate it.

llvm-svn: 114446
2010-09-21 17:04:51 +00:00
Chris Lattner
f72c3c08a4 convert dagcombine off the old form of getLoad. This fixes several bugs
with SVOffset computation.

llvm-svn: 114442
2010-09-21 16:08:50 +00:00
Chris Lattner
e32675253f simplify DAGCombiner::SimplifySelectOps step #2/2.
llvm-svn: 114437
2010-09-21 15:58:55 +00:00
Chris Lattner
254c445e63 substantially reduce indentation and simplify DAGCombiner::SimplifySelectOps.
no functionality change (step #1)

llvm-svn: 114436
2010-09-21 15:46:59 +00:00
Chris Lattner
a35499e2af a few more trivial updates. This fixes PerformInsertVectorEltInMemory to not
pass a completely incorrect SrcValue, which would result in a miscompile with
combiner-aa.

llvm-svn: 114411
2010-09-21 07:32:19 +00:00
Owen Anderson
272ff94916 When TCO is turned on, it is possible to end up with aliasing FrameIndex's. Therefore,
CombinerAA cannot assume that different FrameIndex's never alias, but can instead use
MachineFrameInfo to get the actual offsets of these slots and check for actual aliasing.

This fixes CodeGen/X86/2010-02-19-TailCallRetAddrBug.ll and CodeGen/X86/tailcallstack64.ll
when CombinerAA is enabled, modulo a different register allocation sequence.

llvm-svn: 114348
2010-09-20 20:39:59 +00:00
Owen Anderson
7b8d2ae912 Revert r114312 while I sort out some issues.
llvm-svn: 114313
2010-09-19 21:01:26 +00:00
Owen Anderson
ff82f8a35b Tentatively enabled DAGCombiner Alias Analysis by default. As far as I know,
r114268 fixed the last of the blockers to enabling it.  I will be monitoring
for failures.

llvm-svn: 114312
2010-09-19 19:51:55 +00:00
Dan Gohman
3c9b5f394b Don't narrow the load and store in a load+twiddle+store sequence unless
there are clearly no stores between the load and the store. This fixes
this miscompile reported as PR7833.

This breaks the test/CodeGen/X86/narrow_op-2.ll optimization, which is
safe, but awkward to prove safe. Move it to X86's README.txt.

llvm-svn: 112861
2010-09-02 21:18:42 +00:00
Nate Begeman
317b969ac5 Fix a crash in the dag combiner caused by ConstantFoldBIT_CONVERTofBUILD_VECTOR calling itself
recursively and returning a SCALAR_TO_VECTOR node, but assuming the input was always a BUILD_VECTOR.

llvm-svn: 109519
2010-07-27 18:02:18 +00:00
Owen Anderson
9c271e2835 Remove r108639 now that it is handled by InstCombine instead.
llvm-svn: 108688
2010-07-19 08:10:24 +00:00
Owen Anderson
f7f9c8a2f7 Add a DAGCombine xform to fold away redundant float->double->float conversions around sqrt instructions.
I am assured by people more knowledgeable than me that there are no rounding issues in eliminating this.

This fixed <rdar://problem/8197504>.

llvm-svn: 108639
2010-07-18 08:47:54 +00:00
Duncan Sands
41b4a6b36a Convert some tab stops into spaces.
llvm-svn: 108130
2010-07-12 08:16:59 +00:00
Bob Wilson
21eed476e8 Reenable DAG combining for vector shuffles. It looks like it was temporarily
disabled and then never turned back on again.  Adjust some tests, one because
this change avoids an unnecessary instruction, and the other to make it
continue testing what it was intended to test.

llvm-svn: 107941
2010-07-09 00:38:12 +00:00
Benjamin Kramer
0ae3f08c0d Merge the duplicated iabs optimization in DAGCombiner and let it detected a few more idioms.
llvm-svn: 107868
2010-07-08 12:09:56 +00:00
Evan Cheng
1c349f18f8 Move getExtLoad() and (some) getLoad() DebugLoc argument after EVT argument for consistency sake.
llvm-svn: 107820
2010-07-07 22:15:37 +00:00
Devang Patel
a3ca21b228 Propagate debug loc.
llvm-svn: 107710
2010-07-06 22:08:15 +00:00
Bob Wilson
269a89fd3a Unlike other targets, ARM now uses BUILD_VECTORs post-legalization so they
can't be changed arbitrarily by the DAGCombiner without checking if it is
running after legalization.

llvm-svn: 107097
2010-06-28 23:40:25 +00:00