Commit Graph

1339 Commits

Author SHA1 Message Date
Chris Lattner 1443bc52be Refactor some code, making it simpler.
When doing the initial pass of constant folding, if we get a constantexpr,
simplify the constant expr like we would do if the constant is folded in the
normal loop.

This fixes the missed-optimization regression in
Transforms/InstCombine/getelementptr.ll last night.

llvm-svn: 28224
2006-05-11 17:11:52 +00:00
Chris Lattner a36ee4ea34 Two changes:
1. Implement InstCombine/deadcode.ll by not adding instructions in unreachable
   blocks (due to constants in conditional branches/switches) to the worklist.
   This causes them to be deleted before instcombine starts up, leading to
   better optimization.

2. In the prepass over instructions, do trivial constprop/dce as we go.  This
   has the effect of improving the effectiveness of #1.  In addition, it
   *significantly* speeds up instcombine on test cases with large amounts of
   constant folding code (for example, that produced by code specialization
   or partial evaluation).  In one example, it speeds up instcombine from
   0.0589s to 0.0224s with a release build (a 2.6x speedup).

llvm-svn: 28215
2006-05-10 19:00:36 +00:00
Chris Lattner 4fe87d67c4 Patch to make some xforms preserve each other. Patch contributed by
Domagoj Babic!

llvm-svn: 28181
2006-05-09 04:13:41 +00:00
Chris Lattner 1d441adfbf Move some code around.
Make the "fold (and (cast A), (cast B)) -> (cast (and A, B))" transformation
only apply when both casts really will cause code to be generated.  If one or
both doesn't, then this xform doesn't remove a cast.

This fixes Transforms/InstCombine/2006-05-06-Infloop.ll

llvm-svn: 28141
2006-05-06 09:00:16 +00:00
Chris Lattner e745c7de0e Fix an infinite loop compiling oggenc last night.
llvm-svn: 28128
2006-05-05 20:51:30 +00:00
Chris Lattner 3af1053488 Implement InstCombine/cast.ll:test29
llvm-svn: 28126
2006-05-05 06:39:07 +00:00
Chris Lattner fb29692055 Fix Transforms/InstCombine/2006-05-04-DemandedBitCrash.ll
llvm-svn: 28101
2006-05-04 17:33:35 +00:00
Chris Lattner 2d3a02725d Add pass ID's for various passes, so they can be AddRequiredID. Patch by
Domagoj Babic!

llvm-svn: 28048
2006-05-02 04:24:36 +00:00
Chris Lattner 655d08fda8 Fix InstCombine/2006-04-28-ShiftShiftLongLong.ll
llvm-svn: 28019
2006-04-28 22:21:41 +00:00
Chris Lattner e63d808b6e Fix Transforms/Reassociate/2006-04-27-ReassociateVector.ll
llvm-svn: 28007
2006-04-28 04:14:49 +00:00
Chris Lattner b6cb64b7e6 Add support for inserting undef into a vector. This implements
Transforms/InstCombine/vec_insert_to_shuffle.ll

llvm-svn: 27997
2006-04-27 21:14:21 +00:00
Chris Lattner dae49df407 Fix Transforms/ScalarRepl/2006-04-20-PromoteCrash.ll
llvm-svn: 27912
2006-04-20 20:48:50 +00:00
Andrew Lenharth f89e630b2f Make code match cvs commit message :)
llvm-svn: 27881
2006-04-20 15:41:37 +00:00
Andrew Lenharth 61eae29ad6 If we can convert the return pointer type into an integer that IntPtrType
can be converted to losslessly, we can continue the conversion to a direct call.

llvm-svn: 27880
2006-04-20 14:56:47 +00:00
Chris Lattner 36dd7c98d1 Turn x86 unaligned load/store intrinsics into aligned load/store instructions
if the pointer is known aligned.

llvm-svn: 27781
2006-04-17 22:26:56 +00:00
Chris Lattner 9095186deb Fix a bug in the 'shuffle(undef,x,mask) -> shuffle(x, undef,mask')' xform
Make the insert/extract elt -> shuffle code more aggressive.

This fixes CodeGen/PowerPC/vec_shuffle.ll

llvm-svn: 27728
2006-04-16 00:51:47 +00:00
Chris Lattner 34cebe785d Canonicalize shuffle(undef,x,mask) -> shuffle(x, undef,mask').
llvm-svn: 27727
2006-04-16 00:03:56 +00:00
Chris Lattner 39fac448d6 significant cleanups to code that uses insert/extractelt heavily. This builds
maximal shuffles out of them where possible.

llvm-svn: 27717
2006-04-15 01:39:45 +00:00
Chris Lattner 3323ce165d Teach scalarrepl to promote unions of vectors and floats, producing
insert/extractelement operations.  This implements
Transforms/ScalarRepl/vector_promote.ll

llvm-svn: 27710
2006-04-14 21:42:41 +00:00
Reid Spencer 13a1a7a4a6 Get rid of a signed/unsigned compare warning.
llvm-svn: 27625
2006-04-12 19:28:15 +00:00
Chris Lattner b19a5c661b Turn casts into getelementptr's when possible. This enables SROA to be more
aggressive in some cases where LLVMGCC 4 is inserting casts for no reason.

This implements InstCombine/cast.ll:test27/28.

llvm-svn: 27620
2006-04-12 18:09:35 +00:00
Chris Lattner 2d37f920ad Implement vec_shuffle.ll:test3
llvm-svn: 27573
2006-04-10 23:06:36 +00:00
Chris Lattner fbb77a408b Implement InstCombine/vec_shuffle.ll:test[12]
llvm-svn: 27571
2006-04-10 22:45:52 +00:00
Chris Lattner 17bd60588c Add supprot for shufflevector
llvm-svn: 27513
2006-04-08 01:19:12 +00:00
Chris Lattner e79d249c29 Lower vperm(x,y, mask) -> shuffle(x,y,mask) if mask is constant. This allows
us to compile oh-so-realistic stuff like this:

 vec_vperm(A, B, (vector unsigned char){14});

to:
        vspltb v0, v0, 14

instead of:

        vspltisb v0, 14
        vperm v0, v2, v1, v0

llvm-svn: 27452
2006-04-06 19:19:17 +00:00
Chris Lattner caba72b6ff vector casts of casts are eliminable. Transform this:
%tmp = cast <4 x uint> %tmp to <4 x int>                ; <<4 x int>> [#uses=1]
        %tmp = cast <4 x int> %tmp to <4 x float>               ; <<4 x float>> [#uses=1]

into:

        %tmp = cast <4 x uint> %tmp to <4 x float>              ; <<4 x float>> [#uses=1]

llvm-svn: 27355
2006-04-02 05:43:13 +00:00
Chris Lattner ebca476b27 Allow transforming this:
%tmp = cast <4 x uint>* %testData to <4 x int>*         ; <<4 x int>*> [#uses=1]
        %tmp = load <4 x int>* %tmp             ; <<4 x int>> [#uses=1]

to this:

        %tmp = load <4 x uint>* %testData               ; <<4 x uint>> [#uses=1]
        %tmp = cast <4 x uint> %tmp to <4 x int>                ; <<4 x int>> [#uses=1]

llvm-svn: 27353
2006-04-02 05:37:12 +00:00
Chris Lattner f42d0aeda1 Turn altivec lvx/stvx intrinsics into loads and stores. This allows the
elimination of one load from this:

int AreSecondAndThirdElementsBothNegative( vector float *in ) {
#define QNaN 0x7FC00000
const vector unsigned int testData = (vector unsigned int)( QNaN, 0, 0, QNaN );
vector float test = vec_ld( 0, (float*) &testData );
return ! vec_any_ge( test, *in );
}

Now generating:

_AreSecondAndThirdElementsBothNegative:
        mfspr r2, 256
        oris r4, r2, 49152
        mtspr 256, r4
        li r4, lo16(LCPI1_0)
        lis r5, ha16(LCPI1_0)
        addi r6, r1, -16
        lvx v0, r5, r4
        stvx v0, 0, r6
        lvx v1, 0, r3
        vcmpgefp. v0, v0, v1
        mfcr r3, 2
        rlwinm r3, r3, 27, 31, 31
        xori r3, r3, 1
        cntlzw r3, r3
        srwi r3, r3, 5
        mtspr 256, r2
        blr

llvm-svn: 27352
2006-04-02 05:30:25 +00:00
Chris Lattner 6cf4914fd4 Fix InstCombine/2006-04-01-InfLoop.ll
llvm-svn: 27330
2006-04-01 22:05:01 +00:00
Chris Lattner dcd0792622 Fold A^(B&A) -> (B&A)^A
Fold (B&A)^A == ~B & A

This implements InstCombine/xor.ll:test2[56]

llvm-svn: 27328
2006-04-01 08:03:55 +00:00
Chris Lattner 8d1d8d364c If we can look through vector operations to find the scalar version of an
extract_element'd value, do so.

llvm-svn: 27323
2006-03-31 23:01:56 +00:00
Chris Lattner 92346c315e extractelement(undef,x) -> undef
llvm-svn: 27300
2006-03-31 18:25:14 +00:00
Chris Lattner 612fa8e6f3 Fix Transforms/InstCombine/2006-03-30-ExtractElement.ll
llvm-svn: 27261
2006-03-30 22:02:40 +00:00
Chris Lattner d70d9f5b24 Don't crash on packed logical ops
llvm-svn: 27125
2006-03-25 21:58:26 +00:00
Chris Lattner f365f5f0c1 Fix spello
llvm-svn: 27052
2006-03-24 07:14:34 +00:00
Chris Lattner 5821a6a17a add the actual cost to the debug info
llvm-svn: 27051
2006-03-24 07:14:00 +00:00
Jim Laskey 83f99115db Can't combine anymore - we don't have a chain through llvm.dbg intrinsics.
llvm-svn: 26992
2006-03-23 18:10:42 +00:00
Chris Lattner 7d80b4f366 silence a bogus gcc warning
llvm-svn: 26953
2006-03-22 17:27:24 +00:00
Chris Lattner d783c76c18 Teach cee to propagate through switch statements. This implements
Transforms/CorrelatedExprs/switch.ll

Patch contributed by Eric Kidd!

llvm-svn: 26872
2006-03-19 19:37:24 +00:00
Evan Cheng c28282bd87 - Fixed a bogus if condition.
- Added more debugging info.
- Allow reuse of IV of negative stride. e.g. -4 stride == 2 * iv of -2 stride.

llvm-svn: 26841
2006-03-18 08:03:12 +00:00
Evan Cheng f09f0ebd48 Sort StrideOrder so we can process the smallest strides first. This allows
for more IV reuses.

llvm-svn: 26837
2006-03-18 00:44:49 +00:00
Evan Cheng 4520698820 Allow users of iv / stride to be rewritten with expression that is a multiply
of a smaller stride even if they have a common loop invariant expression part.

llvm-svn: 26828
2006-03-17 19:52:23 +00:00
Evan Cheng 3df447d354 For each loop, keep track of all the IV expressions inserted indexed by
stride. For a set of uses of the IV of a stride which is a multiple
of another stride, do not insert a new IV expression. Rather, reuse the
previous IV and rewrite the uses as uses of IV expression multiplied by
the factor.

e.g.
x = 0 ...; x ++
y = 0 ...; y += 4
then use of y can be rewritten as use of 4*x for x86.

llvm-svn: 26803
2006-03-16 21:53:05 +00:00
Chris Lattner c5f866bb4a Implement a FIXME, recusively reassociating
A*A*B + A*A*C   -->   A*(A*B+A*C)   -->   A*(A*(B+C))

This implements Reassociate/mul-factor3.ll

llvm-svn: 26757
2006-03-14 16:04:29 +00:00
Chris Lattner 2fc319d444 extract some code into a method, no functionality change
llvm-svn: 26755
2006-03-14 07:11:11 +00:00
Chris Lattner d6bde46d85 Promote shifts by a constant to multiplies so that we can reassociate
(x<<1)+(y<<1) -> (X+Y)<<1.  This implements
Transforms/Reassociate/shift-factor.ll

llvm-svn: 26753
2006-03-14 06:55:18 +00:00
Evan Cheng c567c4efbb Added target lowering hooks which LSR consults to make more intelligent
transformation decisions.

llvm-svn: 26738
2006-03-13 23:14:23 +00:00
Chris Lattner fc34f8bb48 Fix a miscompilation of 188.ammp with the new CFE. 188.ammp is accessing
arrays out of range in a horrible way, but we shouldn't break it anyway.
Details in the comments.

llvm-svn: 26606
2006-03-08 01:05:29 +00:00
Chris Lattner 53ef5a032c Teach the alignment handling code to look through constant expr casts and GEPs
llvm-svn: 26580
2006-03-07 01:28:57 +00:00
Chris Lattner 82f2ef20b6 Teach instcombine to increase the alignment of memset/memcpy/memmove when
the pointer is known to come from either a global variable, alloca or
malloc.  This allows us to compile this:

  P = malloc(28);
  memset(P, 0, 28);

into explicit stores on PPC instead of a memset call.

llvm-svn: 26577
2006-03-06 20:18:44 +00:00
Chris Lattner 6bc98653c2 Make vector narrowing more effective, implementing
Transforms/InstCombine/vec_narrow.ll.  This add support for narrowing
extract_element(insertelement) also.

llvm-svn: 26538
2006-03-05 00:22:33 +00:00
Chris Lattner 4c065091d8 Add factoring of multiplications, e.g. turning A*A+A*B into A*(A+B).
Testcase here: Transforms/Reassociate/mulfactor.ll

llvm-svn: 26524
2006-03-04 09:31:13 +00:00
Chris Lattner 32c01df299 Canonicalize (X+C1)*C2 -> X*C2+C1*C2
This implements Transforms/InstCombine/add.ll:test31

llvm-svn: 26519
2006-03-04 06:04:02 +00:00
Chris Lattner 681ef2f083 Change this to work with renamed intrinsics.
llvm-svn: 26484
2006-03-03 01:34:17 +00:00
Chris Lattner 85dda9a2bd Generalize the REM folding code to handle another case Nick Lewycky
pointed out: realize the AND can provide factors and look through Casts.

llvm-svn: 26469
2006-03-02 06:50:58 +00:00
Chris Lattner c5b6c9a12a Fix a regression in a patch from a couple of days ago. This fixes
Transforms/InstCombine/2006-02-28-Crash.ll

llvm-svn: 26427
2006-02-28 19:47:20 +00:00
Chris Lattner b70f141893 Implement rem.ll:test[7-9] and PR712
llvm-svn: 26415
2006-02-28 05:49:21 +00:00
Chris Lattner 2a7c7b8bab Simplify some code now that the RHS of a rem can't be 0
llvm-svn: 26413
2006-02-28 05:40:55 +00:00
Chris Lattner 0de4a8d7b7 Rearrange some code, fold "rem X, 0", implementing rem.ll:test6
llvm-svn: 26411
2006-02-28 05:30:45 +00:00
Chris Lattner c7bfed0f7b Merge two almost-identical pieces of code.
Make this code more powerful by using ComputeMaskedBits instead of looking
for an AND operand.  This lets us fold this:

int %test23(int %a) {
        %tmp.1 = and int %a, 1
        %tmp.2 = seteq int %tmp.1, 0
        %tmp.3 = cast bool %tmp.2 to int  ;; xor tmp1, 1
        ret int %tmp.3
}

into: xor (and a, 1), 1
llvm-svn: 26396
2006-02-27 02:38:23 +00:00
Chris Lattner f5c8a0b83f Fold (A^B) == A -> B == 0
and  (A-B) == A  ->  B == 0

llvm-svn: 26394
2006-02-27 01:44:11 +00:00
Chris Lattner f78df7c14d Fold (X|C1)^C2 -> X^(C1|C2) when possible. This implements
InstCombine/or.ll:test23.

llvm-svn: 26385
2006-02-26 19:57:54 +00:00
Chris Lattner b580d26e7d Fix a problem that Nate noticed that boils down to an over conservative check
in the code that does "select C, (X+Y), (X-Y) --> (X+(select C, Y, (-Y)))".
We now compile this loop:

LBB1_1: ; no_exit
        add r6, r2, r3
        subf r3, r2, r3
        cmpwi cr0, r2, 0
        addi r7, r5, 4
        lwz r2, 0(r5)
        addi r4, r4, 1
        blt cr0, LBB1_4 ; no_exit
LBB1_3: ; no_exit
        mr r3, r6
LBB1_4: ; no_exit
        cmpwi cr0, r4, 16
        mr r5, r7
        bne cr0, LBB1_1 ; no_exit

into this instead:

LBB1_1: ; no_exit
        srawi r6, r2, 31
        add r2, r2, r6
        xor r6, r2, r6
        addi r7, r5, 4
        lwz r2, 0(r5)
        addi r4, r4, 1
        add r3, r3, r6
        cmpwi cr0, r4, 16
        mr r5, r7
        bne cr0, LBB1_1 ; no_exit

llvm-svn: 26356
2006-02-24 18:05:58 +00:00
Chris Lattner e5521db5bc Fix Regression/Transforms/LoopUnswitch/2006-02-22-UnswitchCrash.ll, which
caused SPASS to fail building last night.

We can't trivially unswitch a loop if the exit block has phi nodes in it,
because we don't know which predecessor to use.

llvm-svn: 26320
2006-02-22 23:55:00 +00:00
Chris Lattner 8a5a324dac Add some comments, simplify some code, and fix a bug that caused rewriting
to rewrite with the wrong value.

llvm-svn: 26311
2006-02-22 06:37:14 +00:00
Chris Lattner c2e3a7a4ce improved support for branch folding, still not enabled.
llvm-svn: 26289
2006-02-18 07:57:38 +00:00
Jeff Cohen 0add83e969 Fix bugs identified by VC++.
llvm-svn: 26287
2006-02-18 03:20:33 +00:00
Chris Lattner 19fa8ac938 Implement deletion of dead blocks, currently disabled.
llvm-svn: 26285
2006-02-18 02:42:34 +00:00
Chris Lattner cb853de534 a previous patch completely disabled trivial unswitching, this fixees it.
Thanks to nate for pointing this out :)

llvm-svn: 26280
2006-02-18 01:32:04 +00:00
Chris Lattner 29f771ba21 initial trivial support for folding branches that have now-constant destinations.
llvm-svn: 26279
2006-02-18 01:27:45 +00:00
Chris Lattner 8e44ff50b0 When unswitching a loop, make sure to update loop info with exit blocks in
the right loop.

llvm-svn: 26277
2006-02-18 00:55:32 +00:00
Chris Lattner baddba41c7 Fix loops where the header has an exit, fixing a loop-unswitch crash on crafty
llvm-svn: 26258
2006-02-17 06:39:56 +00:00
Chris Lattner 6fd136239b start of some new simplification code, not thoroughly tested, use at your own
risk :)

llvm-svn: 26248
2006-02-17 00:31:07 +00:00
Nate Begeman 8a77efe4f7 Rework the SelectionDAG-based implementations of SimplifyDemandedBits
and ComputeMaskedBits to match the new improved versions in instcombine.
Tested against all of multisource/benchmarks on ppc.

llvm-svn: 26238
2006-02-16 21:11:51 +00:00
Chris Lattner fa335f6083 Change SplitBlock to increment a BasicBlock::iterator, not an Instruction*. Apparently they do different things :)
This fixes a testcase that nate reduced from spass.

Also included are a couple minor code changes that don't affect the generated
code at all.

llvm-svn: 26235
2006-02-16 19:36:22 +00:00
Jeff Cohen 55f63f1b53 Fix VC++ warning.
llvm-svn: 26228
2006-02-16 04:07:37 +00:00
Chris Lattner ff42e81028 fix a bug where we unswitched the wrong way
llvm-svn: 26225
2006-02-16 01:24:41 +00:00
Chris Lattner fdff0bb43e Implement trivial unswitching for switch stmts. This allows us to trivial
unswitch this loop on 2 before sweating to unswitch on 1/3.

void test4(int N, int i, int C, int*P, int*Q) {
  int j;
  for (j = 0; j < N; ++j) {
    switch (C) {                // general unswitching.
    default: P[i+j] = 0; break;
    case 1: Q[i+j] = 0; break;
    case 3: P[i+j] = Q[i+j]; break;
    case 2: break;              //  TRIVIAL UNSWITCH on C==2
    }
  }
}

llvm-svn: 26223
2006-02-15 22:52:05 +00:00
Chris Lattner e5cb76d744 make "trivial" unswitching significantly more general. It can now handle
this for example:

  for (j = 0; j < N; ++j) {     // trivial unswitch
    if (C)
      P[i+j] = 0;
  }

turning it into the obvious code without bothering to duplicate an empty loop.

llvm-svn: 26220
2006-02-15 22:03:36 +00:00
Chris Lattner 65152d80ec Checking the wrong value. This caused us to emit silly code like
Y = seteq bool X, true
instead of just using X :)

llvm-svn: 26215
2006-02-15 19:05:52 +00:00
Chris Lattner 01db04efb0 more refactoring, no functionality change.
llvm-svn: 26194
2006-02-15 01:44:42 +00:00
Chris Lattner b0cbe7106e pull some code out into a function
llvm-svn: 26191
2006-02-15 00:07:43 +00:00
Chris Lattner 0b8ec1a132 Use statistics to keep track of what flavors of loops we are unswitching
llvm-svn: 26157
2006-02-14 01:01:41 +00:00
Chris Lattner 8b10ab3002 Implement Instcombine/and.ll:test34
llvm-svn: 26155
2006-02-13 23:07:23 +00:00
Chris Lattner 7d8522884b If any of the sign extended bits are demanded, the input sign bit is demanded
for a sign extension.

This fixes InstCombine/2006-02-13-DemandedMiscompile.ll and Ptrdist/bc.

llvm-svn: 26152
2006-02-13 22:41:07 +00:00
Chris Lattner 68e7475777 Be careful not to request or look at bits shifted in from outside the size
of the input.  This fixes the mediabench/gsm/toast failure last night.

llvm-svn: 26138
2006-02-13 06:09:08 +00:00
Chris Lattner f5b4ef7f58 remove some more dead special case code
llvm-svn: 26135
2006-02-12 08:07:37 +00:00
Chris Lattner 5b2edb1fca Eliminate special case hacks that are superceded by general purpose hacks
llvm-svn: 26134
2006-02-12 08:02:11 +00:00
Chris Lattner ee0f280743 Three changes:
1. Teach GetConstantInType to handle boolean constants.
2. Teach instcombine to fold (compare X, CST) when X has known 0/1 bits.
   Testcase here: set.ll:test22
3. Improve the "(X >> c1) & C2 == 0" folding code to allow a noop cast
   between the shift and and.  More aggressive bitfolding for other reasons
   was turning signed shr's into unsigned shr's, leaving the noop cast in
   the way.

llvm-svn: 26131
2006-02-12 02:07:56 +00:00
Chris Lattner 0157e7f55b Port the recent innovations in ComputeMaskedBits to SimplifyDemandedBits.
This allows us to simplify on conditions where bits are not known, but they
are not demanded either!  This also fixes a couple of bugs in
ComputeMaskedBits that were exposed during this work.

In the future, swaths of instcombine should be removed, as this code
subsumes a bunch of ad-hockery.

llvm-svn: 26122
2006-02-11 09:31:47 +00:00
Chris Lattner fbadd7e1ee implement unswitching of loops with switch stmts and selects in them
llvm-svn: 26114
2006-02-11 00:43:37 +00:00
Chris Lattner f1b151684d Update PHI nodes in successors of exit blocks.
llvm-svn: 26113
2006-02-10 23:26:14 +00:00
Chris Lattner fe4151efe7 Reform the unswitching code in terms of edge splitting, not block splitting.
llvm-svn: 26112
2006-02-10 23:16:39 +00:00
Chris Lattner ec6b40a093 Fix a case where UnswitchTrivialCondition broke critical edges with
phi's in the successors

llvm-svn: 26108
2006-02-10 19:08:15 +00:00
Chris Lattner 6e263155a6 add some notes, move some code around. Implement unswitching of loops
with branches on partially invariant computations.

llvm-svn: 26104
2006-02-10 02:30:37 +00:00
Chris Lattner 4935417a84 Move code around to be more logical, no functionality change.
llvm-svn: 26103
2006-02-10 02:01:22 +00:00
Chris Lattner 3fc3148b85 When unswitching a trivial loop, do admit we are doing it! :)
llvm-svn: 26102
2006-02-10 01:36:35 +00:00
Chris Lattner ed7a67b0de Implement unconditional unswitching of 'trivial' loops, those loops that contain
branches in their entry block that control whether or not the loop is a noop or not.

llvm-svn: 26101
2006-02-10 01:24:09 +00:00
Chris Lattner 4f0e66df6a Simplify control flow a bit, note that unswitch preserves canonical loop form
llvm-svn: 26098
2006-02-09 22:15:42 +00:00
Chris Lattner 8976219850 Make the threshold a parameter
llvm-svn: 26093
2006-02-09 20:15:48 +00:00
Chris Lattner 2826e0511b Simplify the loop-unswitch pass, by not even trying to unswitch loops with
uses of loop values outside the loop.  We need loop-closed SSA form to do
this right, or to use SSA rewriting if we really care.

llvm-svn: 26089
2006-02-09 19:14:52 +00:00
Chris Lattner 24cd2fa269 Fix 80-column violations
llvm-svn: 26088
2006-02-09 07:41:14 +00:00
Chris Lattner 4534dd59a3 Enhance MVIZ in three ways:
1. Teach it new tricks: in particular how to propagate through signed shr and sexts.
2. Teach it to return a bitset of known-1 and known-0 bits, instead of just zero.
3. Teach instcombine (AND X, C) to fold when we know all C bits of X.

This implements Regression/Transforms/InstCombine/bittest.ll, and allows
future things to be simplified.

llvm-svn: 26087
2006-02-09 07:38:58 +00:00
Chris Lattner ab2dc4d70d Simplify some code, reducing calls to MaskedValueIsZero. Implement a minor
optimization where we reduce the number of bits in AND masks when possible.

llvm-svn: 26056
2006-02-08 07:34:50 +00:00
Chris Lattner 5997cf9381 Use EraseInstFromFunction in a few cases to put the uses of the removed
instruction onto the worklist (in case they are now dead).

Add a really trivial local DSE implementation to help out bitfield code.
We now fold this:

struct S {
    unsigned char a : 1, b : 1, c : 1, d : 2, e : 3;
    S();
};

S::S() : a(0), b(0), c(1), d(0), e(6) {}

to this:

void %_ZN1SC1Ev(%struct.S* %this) {
entry:
        %tmp.1 = getelementptr %struct.S* %this, int 0, uint 0
        store ubyte 38, ubyte* %tmp.1
        ret void
}

much earlier (in gccas instead of only in gccld after DSE runs).

llvm-svn: 26050
2006-02-08 03:25:32 +00:00
Chris Lattner 06a0ed1ee0 Implement some more interesting select sccp cases. This implements:
test/Regression/Transforms/SCCP/select.ll

llvm-svn: 26049
2006-02-08 02:38:11 +00:00
Chris Lattner ddba3289b5 Fix a problem in my patch yesterday, causing a miscompilation of 176.gcc
llvm-svn: 26045
2006-02-08 01:20:23 +00:00
Chris Lattner 44314827d6 Fix Transforms/InstCombine/2006-02-07-SextZextCrash.ll
llvm-svn: 26040
2006-02-07 19:07:40 +00:00
Chris Lattner 92a6865321 Generalize MaskedValueIsZero into a ComputeMaskedNonZeroBits function, which
is just as efficient as MVIZ and is also more general.

Fix a few minor bugs introduced in recent patches

llvm-svn: 26036
2006-02-07 08:05:22 +00:00
Chris Lattner c3ebf40031 Make MaskedValueIsZero take a uint64_t instead of a ConstantIntegral as a
mask.  This allows the code to be simpler and more efficient.

Also, generalize some of the cases in MVIZ a bit, making it slightly more aggressive.

llvm-svn: 26035
2006-02-07 07:27:52 +00:00
Chris Lattner 77defbae0a Use Type::getIntegralTypeMask() to simplify some code
llvm-svn: 26034
2006-02-07 07:00:41 +00:00
Chris Lattner 2590e511d8 Implement the beginnings of a facility for simplifying expressions based on
'demanded bits', inspired by Nate's work in the dag combiner.  This isn't
complete, but needs to unrelated instcombiner changes to continue.

llvm-svn: 26033
2006-02-07 06:56:34 +00:00
Chris Lattner 2e90b732fa Turn A % (C << N), where C is 2^k, into A & ((C << N)-1) [urem only].
Turn A / (C1 << N), where C1 is "1<<C2" into A >> (N+C2) [udiv only].

Tested with: rem.ll:test5, div.ll:test10

llvm-svn: 26003
2006-02-05 07:54:04 +00:00
Chris Lattner d30c4991a1 Use SCEVExpander::InsertCastOfTo instead of our own code. This reduces
#LLVM LOC, and auto-cse's cast instructions.

llvm-svn: 25974
2006-02-04 09:52:43 +00:00
Chris Lattner 2959f0003e Fix two significant bugs in LSR:
1. When rewriting code in outer loops, sometimes we would insert code into
   inner loops that is invariant in that loop.
2. Notice that 4*(2+x) is 8+4*x and use that to simplify expressions.

This is a performance neutral change.

llvm-svn: 25964
2006-02-04 07:36:50 +00:00
Jeff Cohen 15a8c15a1f Improve compatibility with VC2005, patch by Morten Ofstad!
llvm-svn: 25661
2006-01-26 20:41:32 +00:00
Chris Lattner c0f633a598 Fix Regression/Transforms/ScalarRepl/2006-01-24-IllegalUnionPromoteCrash.ll
llvm-svn: 25587
2006-01-24 19:36:27 +00:00
Chris Lattner c597b8a55e Make iostream #inclusion explicit
llvm-svn: 25514
2006-01-22 23:32:06 +00:00
Chris Lattner e154abf9b3 Implement casts.ll:test26: a cast from float -> double -> integer, doesn't
need the float->double part.

llvm-svn: 25452
2006-01-19 07:40:22 +00:00
Robert Bocchino 6dce25019d Lowerpacked and SCCP support for the insertelement operation.
llvm-svn: 25406
2006-01-17 20:06:55 +00:00
Chris Lattner 307b7ea15f fix a crash due to missing parens
llvm-svn: 25363
2006-01-16 19:47:21 +00:00
Chris Lattner 0de2c7d3d8 This pass has never worked correctly. Remove.
llvm-svn: 25349
2006-01-16 01:06:00 +00:00
Chris Lattner ef530c24c1 FunctionPass's cannot do IPO things.
llvm-svn: 25315
2006-01-14 19:30:35 +00:00
Robert Bocchino a83529678e Added instcombine support for extractelement.
llvm-svn: 25299
2006-01-13 22:48:06 +00:00
Chris Lattner 503221f5c5 Do a simple instcombine xforms to delete llvm.stackrestore cases.
llvm-svn: 25294
2006-01-13 21:28:09 +00:00
Chris Lattner c66b223b28 Simplify this a tiny bit by using the new IntrinsicInst functionality.
llvm-svn: 25292
2006-01-13 20:11:04 +00:00
Chris Lattner cb36710ff9 Switch these to using ETForest instead of DominatorSet to compute itself.
Patch written by Daniel Berlin!

llvm-svn: 25202
2006-01-11 05:10:20 +00:00
Chris Lattner 48e4a2ebd8 Switch this to using ETForest instead of DominatorSet to compute itself.
Patch written by Daniel Berlin!

llvm-svn: 25201
2006-01-11 05:09:40 +00:00
Robert Bocchino bd518d153b Added lower packed support for the extractelement operation.
llvm-svn: 25180
2006-01-10 19:05:05 +00:00
Chris Lattner 9cbfbc21bb fix some 176.gcc miscompilation from my previous patch.
llvm-svn: 25137
2006-01-07 01:32:28 +00:00
Chris Lattner 330628a6d8 silence some bogus gcc warnings on fenris
llvm-svn: 25130
2006-01-06 17:59:59 +00:00
Chris Lattner eb372a0276 Enhance the shift-shift folding code to allow a no-op cast to occur in between
the shifts.

This allows us to fold this (which is the 'integer add a constant' sequence
from cozmic's scheme compmiler):

int %x(uint %anf-temporary776) {
        %anf-temporary777 = shr uint %anf-temporary776, ubyte 1
        %anf-temporary800 = cast uint %anf-temporary777 to int
        %anf-temporary804 = shl int %anf-temporary800, ubyte 1
        %anf-temporary805 = add int %anf-temporary804, -2
        %anf-temporary806 = or int %anf-temporary805, 1
        ret int %anf-temporary806
}

into this:

int %x(uint %anf-temporary776) {
        %anf-temporary776 = cast uint %anf-temporary776 to int
        %anf-temporary776.mask1 = add int %anf-temporary776, -2
        %anf-temporary805 = or int %anf-temporary776.mask1, 1
        ret int %anf-temporary805
}

note that instcombine already knew how to eliminate the AND that the two
shifts fold into.  This is tested by InstCombine/shift.ll:test26

-Chris

llvm-svn: 25128
2006-01-06 07:52:12 +00:00
Chris Lattner b330939d90 Simplify the code a bit more
llvm-svn: 25126
2006-01-06 07:22:22 +00:00
Chris Lattner 145539343f Extract a bunch of code out of visitShiftInst into FoldShiftByConstant. No
functionality changes.

llvm-svn: 25125
2006-01-06 07:12:35 +00:00
Duraid Madina 7a3ad6cae2 getting there...
llvm-svn: 25021
2005-12-26 13:48:44 +00:00
Chris Lattner 8c9e14620f Fix Transforms/ScalarRepl/2005-12-14-UnionPromoteCrash.ll, a crash on undefined
behavior in 126.gcc on big-endian systems.

llvm-svn: 24708
2005-12-14 17:23:59 +00:00
Chris Lattner 3b0a62d8a5 Implement a little hack for parity with GCC on crafty. This speeds up
186.crafty by about 16% (from 15.109s to 13.045s) on my system.

This turns allocas with unions/casts into scalars.  For example crafty has
something like this:

    union doub {
      unsigned short i[4];
      long long d;
    };
int f(long long a) {
  return ((union doub){.d=a}).i[1];
}

Instead of generating loads and stores to an alloca, we now promote the
whole thing to a scalar long value.

This implements: Transforms/ScalarRepl/AggregatePromote.ll

llvm-svn: 24667
2005-12-12 07:19:13 +00:00
Chris Lattner 077200737c getRawValue zero extens for unsigned values, use getsextvalue so that we
know that small negative values fit into the immediate field of addressing
modes.

llvm-svn: 24608
2005-12-05 18:23:57 +00:00
Chris Lattner dc4ffef633 Fix a bug where we didn't realize that vaarg reads memory. This fixes
Transforms/DeadStoreElimination/2005-11-30-vaarg.ll

llvm-svn: 24545
2005-11-30 19:38:22 +00:00
Andrew Lenharth 5fc3794e71 since reg2mem requires it, might as well mention that it preserves it
llvm-svn: 24491
2005-11-25 16:04:54 +00:00
Andrew Lenharth 061029dee2 Reg2Mem is something a pass may depend on, so allow that
llvm-svn: 24488
2005-11-22 22:14:23 +00:00
Andrew Lenharth 71b09bbb07 turns out, demotion and invokes and critical edges don't mix
llvm-svn: 24487
2005-11-22 21:45:19 +00:00
Chris Lattner 9c37f23645 Fix a crash building 176.gcc due to my recent patch, which only fixed
half the problem.

llvm-svn: 24414
2005-11-18 18:30:47 +00:00
Chris Lattner bca0be812d This was checking the wrong GEP expression. Fixing this fixes a gccas crash
compiling mysql reported by Ted Kremenek.

llvm-svn: 24402
2005-11-17 19:35:42 +00:00
Andrew Lenharth d9c13b1336 the pain isn't gone unless the phinodes are spilled too
llvm-svn: 24288
2005-11-10 19:39:09 +00:00
Andrew Lenharth 8e66c0c8a9 this works with backedges to the existing entry block alot better
llvm-svn: 24270
2005-11-10 17:35:34 +00:00
Andrew Lenharth 4130a4f061 The pass everyone has been waiting for!
Reg2Mem

for fun you can opt -reg2mem -mem2reg

llvm-svn: 24267
2005-11-10 01:58:38 +00:00
Nate Begeman 848622f87f Add support alignment of allocation instructions.
Add support for specifying alignment and size of setjmp jmpbufs.

No targets currently do anything with this information, nor is it presrved
in the bytecode representation.  That's coming up next.

llvm-svn: 24196
2005-11-05 09:21:28 +00:00
Chris Lattner 16b29e9562 Implement Transforms/TailCallElim/return-undef.ll, a trivial case
that has been sitting in my inbox since May 18. :)

llvm-svn: 24194
2005-11-05 08:21:11 +00:00
Chris Lattner dd0c174082 Turn sdiv into udiv if both operands have a clear sign bit. This occurs
a few times in crafty:

OLD:    %tmp.36 = div int %tmp.35, 8            ; <int> [#uses=1]
NEW:    %tmp.36 = div uint %tmp.35, 8           ; <uint> [#uses=0]
OLD:    %tmp.19 = div int %tmp.18, 8            ; <int> [#uses=1]
NEW:    %tmp.19 = div uint %tmp.18, 8           ; <uint> [#uses=0]
OLD:    %tmp.117 = div int %tmp.116, 8          ; <int> [#uses=1]
NEW:    %tmp.117 = div uint %tmp.116, 8         ; <uint> [#uses=0]
OLD:    %tmp.92 = div int %tmp.91, 8            ; <int> [#uses=1]
NEW:    %tmp.92 = div uint %tmp.91, 8           ; <uint> [#uses=0]

Which all turn into shrs.

llvm-svn: 24190
2005-11-05 07:40:31 +00:00