Commit Graph

761 Commits

Author SHA1 Message Date
Benjamin Kramer
f50125ecaa DAGCombine add (sext i1), X into sub X, (zext i1) if sext from i1 is illegal. The latter usually compiles into smaller code.
example code:
unsigned foo(unsigned x, unsigned y) {
  if (x != 0) y--;
  return y;
}

before:
  _foo:                           ## @foo
    cmpl  $1, 4(%esp)             ## encoding: [0x83,0x7c,0x24,0x04,0x01]
    sbbl  %eax, %eax              ## encoding: [0x19,0xc0]
    notl  %eax                    ## encoding: [0xf7,0xd0]
    addl  8(%esp), %eax           ## encoding: [0x03,0x44,0x24,0x08]
    ret                           ## encoding: [0xc3]

after:
  _foo:                           ## @foo
    cmpl  $1, 4(%esp)             ## encoding: [0x83,0x7c,0x24,0x04,0x01]
    movl  8(%esp), %eax           ## encoding: [0x8b,0x44,0x24,0x08]
    adcl  $-1, %eax               ## encoding: [0x83,0xd0,0xff]
    ret                           ## encoding: [0xc3]



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122455 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 23:17:45 +00:00
Chris Lattner
cbf68dfbc0 Fix a bug in ReduceLoadWidth that wasn't handling extending
loads properly.  We miscompiled the testcase into:

_test:                                  ## @test
	movl	$128, (%rdi)
	movzbl	1(%rdi), %eax
	ret

Now we get a proper:

_test:                                  ## @test
	movl	$128, (%rdi)
	movsbl	(%rdi), %eax
	movzbl	%ah, %eax
	ret

This fixes PR8757.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122392 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 08:02:57 +00:00
Chris Lattner
7a2a7faf9c more cleanups, move a check for "roundedness" earlier to reject
unhanded cases faster and simplify code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122391 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 08:01:44 +00:00
Chris Lattner
4c32bc24de reduce indentation and improve comments, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122389 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-22 07:36:50 +00:00
Dale Johannesen
c72b18cdc8 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122366 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 21:55:50 +00:00
Dale Johannesen
d0cf2585a0 Revert 122353-122355 for the moment, they broke stuff.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122360 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 21:22:27 +00:00
Dale Johannesen
a83bf35d16 Add a new transform to DAGCombiner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122355 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 20:10:51 +00:00
Dale Johannesen
5ecc340e34 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122354 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 20:06:19 +00:00
Dale Johannesen
efc96dd38c Shift by the word size is invalid IR; don't create it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122353 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 20:00:06 +00:00
Chris Lattner
90b0364cff fix some typos
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122349 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 18:05:22 +00:00
Chris Lattner
f1b4eafbfe 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122310 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 02:38:05 +00:00
Dale Johannesen
025cc6e1be Cosmetic changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122259 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-20 20:10:50 +00:00
Bob Wilson
d727343a40 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122102 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 23:06:49 +00:00
Dale Johannesen
f5daf8bb7f 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122090 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 21:45:49 +00:00
Chris Lattner
33e77d3cb9 take care of some todos, transforming [us]mul_lohi into
a wider mul if the wider mul is legal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121848 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 06:04:19 +00:00
Chris Lattner
1a0fbe2cf4 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121846 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 05:51:39 +00:00
Chris Lattner
de1c3605a6 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.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121696 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 08:39:01 +00:00
Eric Christopher
503a64dcd4 80-col fixups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121356 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 04:48:06 +00:00
Jay Foad
40f8f6264d 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 08:25:19 +00:00
Bob Wilson
bebfbc560b Fix a comment typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120235 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-28 06:51:19 +00:00
Wesley Peck
bf17cfa3f9 Renaming ISD::BIT_CONVERT to ISD::BITCAST to better reflect the LLVM IR concept.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119990 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 03:31:01 +00:00
Duncan Sands
b9064bb964 Fix thinko: we must turn select(anyext, sext) into sext(select)
not anyext(select).  Spotted by Frits van Bommel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119739 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-18 21:16:28 +00:00
Duncan Sands
dcfd3a798f 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119728 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-18 20:05:18 +00:00
Dan Gohman
6a559cd695 Fix DAGCombiner to avoid folding a sext-in-reg or similar through a shl
in order to fold it into a load.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118471 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-09 01:54:35 +00:00
Eric Christopher
d81f17acb4 Just return undef for invalid masks or elts, and since we're doing that,
just do it earlier too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118195 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03 20:44:42 +00:00
Eric Christopher
caebdd44f3 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118164 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03 09:36:40 +00:00
Dan Gohman
394d6298bc Fix DAGCombiner to avoid going into an infinite loop when it
encounters (and:i64 (shl:i64 (load:i64), 1), 0xffffffff).
This fixes rdar://8606584.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118143 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03 01:47:46 +00:00
Bob Wilson
46455096be Remove DAG combiner patch to fold vector splats. Instcombiner does it now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117720 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29 22:03:02 +00:00
Bob Wilson
0f1db1a6c6 Teach the DAG combiner to fold a splat of a splat. Radar 8597790.
Also do some minor refactoring to reduce indentation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117558 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28 17:06:14 +00:00
Dan Gohman
f96e4bd2a3 Make CodeGen TBAA-aware.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116890 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-20 00:31:05 +00:00
Evan Cheng
2a135ae530 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115571 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-04 22:41:01 +00:00
Chris Lattner
2831a19495 fix rdar://8494845 + PR8244 - a miscompile exposed by my patch in r101350
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115294 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-01 05:36:09 +00:00
Owen Anderson
ed1088afb5 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>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114599 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-22 22:58:22 +00:00
Owen Anderson
bc146b0a4d 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114473 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 20:42:50 +00:00
Chris Lattner
6229d0acb8 update a bunch of code to use the MachinePointerInfo version of getStore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114461 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 18:41:36 +00:00
Chris Lattner
da2d8e1032 eliminate an old SelectionDAG::getTruncStore method, propagating
MachinePointerInfo around more.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114452 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 17:42:31 +00:00
Chris Lattner
3d6ccfba31 propagate MachinePointerInfo through various uses of the old
SelectionDAG::getExtLoad overload, and eliminate it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114446 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 17:04:51 +00:00
Chris Lattner
fa45901eaa convert dagcombine off the old form of getLoad. This fixes several bugs
with SVOffset computation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114442 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 16:08:50 +00:00
Chris Lattner
f165806655 simplify DAGCombiner::SimplifySelectOps step #2/2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114437 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 15:58:55 +00:00
Chris Lattner
1806161a0b substantially reduce indentation and simplify DAGCombiner::SimplifySelectOps.
no functionality change (step #1)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114436 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 15:46:59 +00:00
Chris Lattner
85ca106632 a few more trivial updates. This fixes PerformInsertVectorEltInMemory to not
pass a completely incorrect SrcValue, which would result in a miscompile with
combiner-aa.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114411 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 07:32:19 +00:00
Owen Anderson
4a9f150926 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114348 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-20 20:39:59 +00:00
Owen Anderson
0dcc814276 Revert r114312 while I sort out some issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114313 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-19 21:01:26 +00:00
Owen Anderson
d910fb2f12 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114312 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-19 19:51:55 +00:00
Dan Gohman
24bde5bce1 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112861 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 21:18:42 +00:00
Nate Begeman
e0efc216eb 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109519 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-27 18:02:18 +00:00
Owen Anderson
54026c0f1b Remove r108639 now that it is handled by InstCombine instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108688 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-19 08:10:24 +00:00
Owen Anderson
3ecdfafe3b 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>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108639 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-18 08:47:54 +00:00
Duncan Sands
3472766f9e Convert some tab stops into spaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108130 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12 08:16:59 +00:00
Bob Wilson
f1d93ca920 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107941 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 00:38:12 +00:00