Commit Graph

884 Commits

Author SHA1 Message Date
Chris Lattner b121ae1cec Do not fold (X + C1 != C2) if there are other users of the add. Doing
this transformation used to take a loop like this:

int Array[1000];
void test(int X) {
  int i;
  for (i = 0; i < 1000; ++i)
    Array[i] += X;
}

Compiled to LLVM is:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi uint [ 0, %entry ], [ %indvar.next, %no_exit ]            ; <uint> [#uses=2]
        %tmp.4 = getelementptr [1000 x int]* %Array, int 0, uint %indvar                ; <int*> [#uses=2]
        %tmp.7 = load int* %tmp.4               ; <int> [#uses=1]
        %tmp.9 = add int %tmp.7, %X             ; <int> [#uses=1]
        store int %tmp.9, int* %tmp.4
***     %indvar.next = add uint %indvar, 1              ; <uint> [#uses=2]
***     %exitcond = seteq uint %indvar.next, 1000               ; <bool> [#uses=1]
        br bool %exitcond, label %return, label %no_exit

and turn it into a loop like this:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi uint [ 0, %entry ], [ %indvar.next, %no_exit ]            ; <uint> [#uses=3]
        %tmp.4 = getelementptr [1000 x int]* %Array, int 0, uint %indvar                ; <int*> [#uses=2]
        %tmp.7 = load int* %tmp.4               ; <int> [#uses=1]
        %tmp.9 = add int %tmp.7, %X             ; <int> [#uses=1]
        store int %tmp.9, int* %tmp.4
***     %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
***     %exitcond = seteq uint %indvar, 999             ; <bool> [#uses=1]
        br bool %exitcond, label %return, label %no_exit

Note that indvar.next and indvar can no longer be coallesced.  In machine
code terms, this patch changes this code:

.LBBtest_1:     # no_exit
        mov %EDX, OFFSET Array
        mov %ESI, %EAX
        add %ESI, DWORD PTR [%EDX + 4*%ECX]
        mov %EDX, OFFSET Array
        mov DWORD PTR [%EDX + 4*%ECX], %ESI
        mov %EDX, %ECX
        inc %EDX
        cmp %ECX, 999
        mov %ECX, %EDX
        jne .LBBtest_1  # no_exit

into this:

.LBBtest_1:     # no_exit
        mov %EDX, OFFSET Array
        mov %ESI, %EAX
        add %ESI, DWORD PTR [%EDX + 4*%ECX]
        mov %EDX, OFFSET Array
        mov DWORD PTR [%EDX + 4*%ECX], %ESI
        inc %ECX
        cmp %ECX, 1000
        jne .LBBtest_1  # no_exit

We need better instruction selection to get this:

.LBBtest_1:     # no_exit
        add DWORD PTR [Array + 4*%ECX], EAX
        inc %ECX
        cmp %ECX, 1000
        jne .LBBtest_1  # no_exit

... but at least there is less register juggling

llvm-svn: 16473
2004-09-21 21:35:23 +00:00
Chris Lattner 42618551d5 Fix potential miscompilations: InstCombine/2004-09-20-BadLoadCombine*.llx
llvm-svn: 16447
2004-09-20 10:15:10 +00:00
Alkis Evlogimenos d59cebf87a Fix loop condition so that we don't decrement off the beginning of the
list.

llvm-svn: 16440
2004-09-20 06:42:58 +00:00
Chris Lattner 3e86084641 Prototype these functions more accurately
llvm-svn: 16432
2004-09-20 04:43:15 +00:00
Chris Lattner e6f13093e6 Make isSafeToLoadUnconditionally a bit smarter, implementing PR362 and
Regression/Transforms/InstCombine/CPP_min_max.llx

llvm-svn: 16409
2004-09-19 19:18:10 +00:00
Chris Lattner f62ea8ef4b Make instruction combining a bit more aggressive in the face of volatile
loads, and implement two new transforms: InstCombine/load.ll:test[56].

llvm-svn: 16404
2004-09-19 18:43:46 +00:00
Reid Spencer 6614946443 Convert code to compile with vc7.1.
Patch contributed by Paolo Invernizzi. Thanks Paolo!

llvm-svn: 16368
2004-09-15 17:06:42 +00:00
Chris Lattner f11216d24f Fix a bug in the previous checkin that broke 255.vortex
llvm-svn: 16355
2004-09-15 02:34:40 +00:00
Chris Lattner a346578d92 Make sure to update alias analysis information as we transform the function.
This fixes PR420 and Regression/Transforms/LICM/2004-09-14-AliasAnalysisInvalidate.llx

llvm-svn: 16348
2004-09-15 01:04:07 +00:00
Chris Lattner f41b80a05f Remove a long-dead pass. Actually, this pass was never used at all.
llvm-svn: 16337
2004-09-14 16:33:01 +00:00
Alkis Evlogimenos a5c04ee50f Fixes to make LLVM compile with vc7.1.
Patch contributed by Paolo Invernizzi!

llvm-svn: 16152
2004-09-03 18:19:51 +00:00
Reid Spencer 7c16caa336 Changes For Bug 352
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.

llvm-svn: 16137
2004-09-01 22:55:40 +00:00
Reid Spencer f39f66e3ef Initial checkin of a pass to lower packed operations to scalars operations.
This also registers the pass with opt with a -lower-packed command line
option.

Patch contributed by Brad Jones.

llvm-svn: 15987
2004-08-21 21:39:24 +00:00
Chris Lattner 4456da6a4c Fix InstCombine/2004-08-10-BoolSetCC.ll, a bug that is miscompiling
176.gcc.  Note that this is apparently not the only bug miscompiling gcc
though. :(

llvm-svn: 15639
2004-08-11 00:50:51 +00:00
Chris Lattner 8e7260652b Fix InstCombine/2004-08-09-RemInfLoop.llx
This should go into the 1.3 branch

llvm-svn: 15593
2004-08-09 21:05:48 +00:00
Alkis Evlogimenos 832437255d Stop using getValues().
llvm-svn: 15487
2004-08-04 08:44:43 +00:00
Chris Lattner 7aa2d4747a Fix a regression in InstCombine/xor.ll
llvm-svn: 15410
2004-08-01 19:42:59 +00:00
Misha Brukman 9c003d8f65 Fix De Morgan's name.
llvm-svn: 15343
2004-07-30 12:50:08 +00:00
Chris Lattner d4252a7c64 Start using the PatternMatcher a bit.
llvm-svn: 15342
2004-07-30 07:50:03 +00:00
Misha Brukman 63b38bd2ed Fix #includes of i*.h => Instructions.h as per PR403.
llvm-svn: 15334
2004-07-29 17:30:56 +00:00
Misha Brukman 2b3387a6d9 Fix #includes of i*.h => Instructions.h as per PR403.
llvm-svn: 15328
2004-07-29 17:05:13 +00:00
Robert Bocchino 7b5b86cd0f This change fixed a bug in the function visitMul. The prior version
assumed that a constant on the RHS of a multiplication was either an
IntConstant or an FPConstant.  It checked for an IntConstant and then,
if it did not find one, did a hard cast to an FPConstant.  That code
would crash if the RHS were a ConstantExpr that was neither an
IntConstant nor an FPConstant.  This version replaces the hard cast
with a dyn_cast.  It performs the same way for IntConstants and
FPConstants but does nothing, instead of crashing, for constant
expressions.

The regression test for this change is 2004-07-27-ConstantExprMul.ll.

llvm-svn: 15291
2004-07-27 21:02:21 +00:00
Brian Gaeke 38b79e8fbc Make the create...() functions for some of these passes return a FunctionPass *.
llvm-svn: 15276
2004-07-27 17:43:21 +00:00
Chris Lattner 50eb771d37 Fix hoisting of void typed values, e.g. calls
llvm-svn: 15263
2004-07-27 07:38:32 +00:00
Chris Lattner f29807169a Implement DeadStoreElim/alloca.llx by observing that allocas are dead at the
end of the function (either return or unwind)

llvm-svn: 15232
2004-07-26 06:14:11 +00:00
Chris Lattner e5ad26dbb3 Throttle back indvar substitution from creating multiplies in loops. This is bad bad bad.
llvm-svn: 15227
2004-07-26 02:47:12 +00:00
Chris Lattner 7b25bcdf52 * Substantially simplify how free instructions are handled (potentially fixing
a bug in DSE).
* Delete dead operand uses iteratively instead of recursively, using a
  SetVector.
* Defer deletion of dead operand uses until the end of processing, which means
  we don't have to bother with updating the AliasSetTracker.  This speeds up
  DSE substantially.

llvm-svn: 15204
2004-07-25 11:09:56 +00:00
Chris Lattner 4c1c1ac7e4 Free instructions kill values too. This implements DeadStoreElim/free.llx
llvm-svn: 15199
2004-07-25 07:58:38 +00:00
Chris Lattner bad6478b00 obvious fix
llvm-svn: 15162
2004-07-24 07:51:27 +00:00
Chris Lattner 3844c300de This is a trivial dead store elimination pass. It very very simple and
can be improved in many ways.  But: stop laughing, even with -basicaa it
deletes 15% of the stores in 252.eon :)

llvm-svn: 15101
2004-07-22 08:00:28 +00:00
Chris Lattner 51f7c9e56d Update GC intrinsics to take a pointer to the object as well as a pointer
to the field being updated.  Patch contributed by Tobias Nurmiranta

llvm-svn: 15097
2004-07-22 05:51:13 +00:00
Chris Lattner d8f5e2ccac * Further cleanup.
* Test for whether bits are shifted out during the optzn.

If so, the fold is illegal, though it can be handled explicitly for setne/seteq

This fixes the miscompilation of 254.gap last night, which was a latent bug
exposed by other optimizer improvements.

llvm-svn: 15085
2004-07-21 20:14:10 +00:00
Chris Lattner 1638de4499 Make cast-cast code a bit more defensive
"simplify" a bit of code for comparison/and folding

llvm-svn: 15082
2004-07-21 19:50:44 +00:00
Chris Lattner 4fbad968f8 Remove special casing of pointers and treat them generically as integers of
the appopriate size.  This gives us the ability to eliminate int -> ptr -> int

llvm-svn: 15063
2004-07-21 04:27:24 +00:00
Chris Lattner 11ffd59e37 Implement Transforms/InstCombine/IntPtrCast.ll
llvm-svn: 15029
2004-07-20 05:21:00 +00:00
Chris Lattner 44d0b9502a Implement InstCombine/GEPIdxCanon.ll
llvm-svn: 15024
2004-07-20 01:48:15 +00:00
Chris Lattner 4e2dbc6b4a Rewrite cast->cast elimination code completely based on the information we
actually care about.  Someday when the cast instruction is gone, we can do
better here, but this will do for now.  This implements
instcombine/cast.ll:test17/18 as well.

llvm-svn: 15018
2004-07-20 00:59:32 +00:00
Chris Lattner f3edc49ae2 Minor cleanup, no functionality change
llvm-svn: 14972
2004-07-18 18:59:44 +00:00
Reid Spencer f0a5bcaae4 Delete a redundant if branch.
llvm-svn: 14967
2004-07-18 08:34:52 +00:00
Reid Spencer c44cb6bd9f Expand the coercion of constants to include the newly constant Globals.
llvm-svn: 14966
2004-07-18 08:34:19 +00:00
Reid Spencer 539429d9b5 Delete a no-op loop.
llvm-svn: 14965
2004-07-18 08:32:43 +00:00
Reid Spencer 6c2b627e23 Expand the scope to include global values because they are now constants
too.

llvm-svn: 14964
2004-07-18 08:32:10 +00:00
Reid Spencer cb3fb5d4f5 bug 122:
- Replace ConstantPointerRef usage with GlobalValue usage

llvm-svn: 14953
2004-07-18 00:44:37 +00:00
Reid Spencer 874368790f bug 122:
- Replace ConstantPointerRef usage with GlobalValue usage
- Minimize redundant isa<GlobalValue> usage
- Correct isa<Constant> for GlobalValue subclass

llvm-svn: 14950
2004-07-18 00:38:32 +00:00
Reid Spencer ef784f01dd bug 122:
- Minimize redundant isa<GlobalValue> usage

llvm-svn: 14948
2004-07-18 00:32:14 +00:00
Reid Spencer c5afc9512b bug 122:
- Replace ConstantPointerRef usage with GlobalValue usage
- Correct isa<Constant> for GlobalValue subclass

llvm-svn: 14947
2004-07-18 00:31:05 +00:00
Reid Spencer 9e855c6832 bug 122:
- Minimize redundant isa<GlobalValue> usage
- Correct isa<Constant> for GlobalValue subclass

llvm-svn: 14946
2004-07-18 00:29:57 +00:00
Chris Lattner d79334df33 This patch was contributed by Daniel Berlin!
Speed up SCCP substantially by processing overdefined values quickly.  This
patch speeds up SCCP by about 30-40% on large testcases.

llvm-svn: 14861
2004-07-15 23:36:43 +00:00
Chris Lattner f2c018c0c1 Fix PR404 try #2
This version takes about 1s longer than the previous one (down to 2.35s),
but on the positive side, it actually works :)

llvm-svn: 14856
2004-07-15 08:20:22 +00:00
Chris Lattner daa12135da Revert previous patch until I get a bug fixed
llvm-svn: 14853
2004-07-15 05:36:31 +00:00
Chris Lattner 70177e402d Fix PR404: Loop simplify is really slow on 252.eon
This eliminates an N*N*logN algorithm from the loop simplify pass, replacing
it with a much simpler and faster alternative.  In a debug build, this reduces
gccas time on eon from 85s to 42s.

llvm-svn: 14851
2004-07-15 04:27:04 +00:00
Chris Lattner 9a63520b1a Fixes working towards PR341
llvm-svn: 14839
2004-07-15 01:50:47 +00:00
Chris Lattner ba7aef39fd Now that we codegen the portable "sizeof" efficiently, we can use it for
malloc lowering.  This means that lowerallocations doesn't need targetdata
anymore.  yaay.

llvm-svn: 14835
2004-07-15 01:08:08 +00:00
Chris Lattner 35e24774eb Factor some code to handle "load (constantexpr cast foo)" just like
"load (cast foo)".  This allows us to compile C++ code like this:

class Bclass {
  public: virtual int operator()() { return 666; }
};

class Dclass: public Bclass {
  public: virtual int operator()() { return 667; }
} ;

int main(int argc, char** argv) {
  Dclass x;
  return x();
}

Into this:

int %main(int %argc, sbyte** %argv) {
entry:
        call void %__main( )
        ret int 667
}

Instead of this:

int %main(int %argc, sbyte** %argv) {
entry:
        %x = alloca "struct.std::bad_typeid"            ; <"struct.std::bad_typeid"*> [#uses=3]
        call void %__main( )
        %tmp.1.i.i = getelementptr "struct.std::bad_typeid"* %x, uint 0, uint 0, uint 0         ; <int (...)***> [#uses=1]
        store int (...)** getelementptr ([3 x int (...)*]*  %vtable for Bclass, int 0, long 2), int (...)*** %tmp.1.i.i
        %tmp.3.i = getelementptr "struct.std::bad_typeid"* %x, int 0, uint 0, uint 0            ; <int (...)***> [#uses=1]
        store int (...)** getelementptr ([3 x int (...)*]*  %vtable for Dclass, int 0, long 2), int (...)*** %tmp.3.i
        %tmp.5 = load int ("struct.std::bad_typeid"*)** cast (int (...)** getelementptr ([3 x int (...)*]*  %vtable for Dclass, int 0, long 2) to int
("struct.std::bad_typeid"*)**)          ; <int ("struct.std::bad_typeid"*)*> [#uses=1]
        %tmp.6 = call int %tmp.5( "struct.std::bad_typeid"* %x )                ; <int> [#uses=1]
	ret int %tmp.6
        ret int 0
}

In order words, we now resolve the virtual function call.

llvm-svn: 14783
2004-07-13 01:49:43 +00:00
Chris Lattner 9eb9ccd9f6 Check to make sure types are sized before calling getTypeSize on them.
llvm-svn: 14649
2004-07-06 19:28:42 +00:00
Brian Gaeke a501be556f It doesn't matter what the 2nd operand is; if the GEP has 2 operands and
the first is a zero, we should leave it alone.

llvm-svn: 14648
2004-07-06 19:24:47 +00:00
Brian Gaeke 0e0fe8a2e9 Add helper function.
Don't touch GEPs for which DecomposeArrayRef is not going to do anything
special (e.g., < 2 indices, or 2 indices and the last one is a constant.)

llvm-svn: 14647
2004-07-06 18:15:39 +00:00
Chris Lattner 23b47b6af9 Implement rem.ll:test3
llvm-svn: 14640
2004-07-06 07:38:18 +00:00
Chris Lattner 98c6bdf251 Fix a minor bug where we would go into infinite loops on some constants
llvm-svn: 14638
2004-07-06 07:11:42 +00:00
Chris Lattner 7fd5f0745a Implement InstCombine/sub.ll:test15: X % -Y === X % Y
Also, remove X % -1 = 0, because it's not true for unsigneds, and the
signed case is superceeded by this new handling.

llvm-svn: 14637
2004-07-06 07:01:22 +00:00
Reid Spencer eb04d9bcb4 Add #include <iostream> since Value.h does not #include it any more.
llvm-svn: 14622
2004-07-04 12:19:56 +00:00
Chris Lattner 4c9c20af28 Implement add.ll:test22, a common case in MSIL files
llvm-svn: 14587
2004-07-03 00:26:11 +00:00
Chris Lattner 49df6cefa5 Do not call getTypeSize on a type that has no size
llvm-svn: 14584
2004-07-02 22:55:47 +00:00
Brian Gaeke e1a136fb4b Get rid of a dead variable, and fix a typo in a comment.
llvm-svn: 14560
2004-07-02 05:30:01 +00:00
Brian Gaeke 163c87fc32 Make this pass use a more specific debug message than "Processing:".
llvm-svn: 14541
2004-07-01 19:27:10 +00:00
Chris Lattner 6e07936ed2 Implement InstCombine/add.ll:test21
llvm-svn: 14443
2004-06-27 22:51:36 +00:00
Chris Lattner 7f4222237d New constant expression lowering pass to simplify your instruction selection needs.
Contributed by Vladimir Prus!

llvm-svn: 14399
2004-06-25 07:48:09 +00:00
Chris Lattner 7a002d6010 Two fixes. First, stop using the ugly shouldSubstituteIndVar method.
Second, disable substitution of quadratic addrec expressions to avoid putting
multiplies in loops!

llvm-svn: 14358
2004-06-24 06:49:18 +00:00
Chris Lattner c9e06336ab Make use of BinaryOperator::create* methods to shrinkify code.
llvm-svn: 14262
2004-06-20 05:04:01 +00:00
Chris Lattner 42ad646104 Now that dominator tree children are built in determinstic order, this horrible code
can go away

llvm-svn: 14254
2004-06-19 20:23:35 +00:00
Chris Lattner 4027500e1c Fix a nasty bug, noticed by Reid
llvm-svn: 14249
2004-06-19 18:15:50 +00:00
Chris Lattner ec2d34cc19 Fix one source of nondeterminism in the -licm pass: the hoist pass
was processing blocks in whatever order they happened to end up in the
dominator tree data structure.  Force an ordering.

llvm-svn: 14248
2004-06-19 08:56:43 +00:00
Chris Lattner b5f8eb8315 Do not loop over uses as we delete them. This causes iterators to be
invalidated out from under us.  This bug goes back to revision 1.1: scary.

llvm-svn: 14242
2004-06-19 02:02:22 +00:00
Chris Lattner 023a483c76 Implement Transforms/InstCombine/and.ll:test17, a common case that
occurs due to unordered comparison macros in math.h

llvm-svn: 14221
2004-06-18 06:07:51 +00:00
Chris Lattner 97bfcea262 Rename Type::PrimitiveID to TypeId and ::getPrimitiveID() to ::getTypeID()
Delete two functions that are now methods on the Type class

llvm-svn: 14200
2004-06-17 18:16:02 +00:00
Brian Gaeke 661963c63f Fix typo in DEBUG printout.
llvm-svn: 14196
2004-06-17 07:26:52 +00:00
Chris Lattner ee59d4bf04 Fix a bug in my checkin from last night that caused miscompilations of
186.crafty, fhourstones and 132.ijpeg.

Bugpoint makes really nasty miscompilations embarassingly easy to find.  It
narrowed it down to the instcombiner and this testcase (from fhourstones):

bool %l7153_l4706_htstat_loopentry_2E_4_no_exit_2E_4(int* %i, [32 x int]* %works, int* %tmp.98.out) {
newFuncRoot:
        %tmp.96 = load int* %i          ; <int> [#uses=1]
        %tmp.97 = getelementptr [32 x int]* %works, long 0, int %tmp.96         ; <int*> [#uses=1]
        %tmp.98 = load int* %tmp.97             ; <int> [#uses=2]
        %tmp.99 = load int* %i          ; <int> [#uses=1]
        %tmp.100 = and int %tmp.99, 7           ; <int> [#uses=1]
        %tmp.101 = seteq int %tmp.100, 7                ; <bool> [#uses=2]
        %tmp.102 = cast bool %tmp.101 to int            ; <int> [#uses=0]
        br bool %tmp.101, label %codeRepl4.exitStub, label %codeRepl3.exitStub

codeRepl4.exitStub:             ; preds = %newFuncRoot
        store int %tmp.98, int* %tmp.98.out
        ret bool true

codeRepl3.exitStub:             ; preds = %newFuncRoot
        store int %tmp.98, int* %tmp.98.out
        ret bool false
}

... which only has one combination performed on it:

$ llvm-as < t.ll | opt -instcombine -debug | llvm-dis
IC: Old =       %tmp.101 = seteq int %tmp.100, 7                ; <bool> [#uses=1]
    New =       setne int %tmp.100, 0           ; <bool>:<badref> [#uses=0]
IC: MOD =       br bool %tmp.101, label %codeRepl3.exitStub, label %codeRepl4.exitStub
IC: MOD =       %tmp.97 = getelementptr [32 x int]* %works, uint 0, int %tmp.96         ; <int*> [#uses=1]

It doesn't get much better than this.  :)

llvm-svn: 14109
2004-06-10 02:33:20 +00:00
Chris Lattner c8e7e298c1 More minor cleanups
llvm-svn: 14108
2004-06-10 02:12:35 +00:00
Chris Lattner df20a4d589 Eliminate many occurrances of Instruction::
llvm-svn: 14107
2004-06-10 02:07:29 +00:00
Chris Lattner 35167c3087 Implement InstCombine/select.ll:test15*
llvm-svn: 14095
2004-06-09 07:59:58 +00:00
Chris Lattner 396dbfe327 Be more careful about the order we put stuff onto the worklist. This allow us to
collapse this:
bool %le(int %A, int %B) {
        %c1 = setgt int %A, %B
        %tmp = select bool %c1, int 1, int 0
        %c2 = setlt int %A, %B
        %result = select bool %c2, int -1, int %tmp
        %c3 = setle int %result, 0
        ret bool %c3
}

into:

bool %le(int %A, int %B) {
        %c3 = setle int %A, %B          ; <bool> [#uses=1]
        ret bool %c3
}

which is handy, because the Java FE makes these sequences all over the place.

This is tested as: test/Regression/Transforms/InstCombine/JavaCompare.ll

llvm-svn: 14086
2004-06-09 05:08:07 +00:00
Chris Lattner 2dd017402b Implement select.ll:test14*
llvm-svn: 14083
2004-06-09 04:24:29 +00:00
Chris Lattner 523d3e6674 Fix one of the major things that is causing the C Backend to infinite loop
llvm-svn: 13872
2004-05-28 05:02:13 +00:00
Chris Lattner ed79d8af53 Fix InstCombine/load.ll & PR347.
This code hadn't been updated after the "structs with more than 256 elements"
related changes to the GEP instruction.  Also it was not handling the
ConstantAggregateZero class.

Now it does!

llvm-svn: 13834
2004-05-27 17:30:27 +00:00
Reid Spencer 297d7fe7e6 Remove unused header file.
llvm-svn: 13750
2004-05-25 08:51:36 +00:00
Reid Spencer 1cc31f264f Make this pass simply invoke SymbolTable::strip().
llvm-svn: 13749
2004-05-25 08:51:25 +00:00
Chris Lattner e1e10e1883 Implement InstCombine:shift.ll:test16, which turns (X >> C1) & C2 != C3
into (X & (C2 << C1)) != (C3 << C1), where the shift may be either left or
right and the compare may be any one.

This triggers 1546 times in 176.gcc alone, as it is a common pattern that
occurs for bitfield accesses.

llvm-svn: 13740
2004-05-25 06:32:08 +00:00
Chris Lattner 03841659a4 Implement instcombine/cast.ll:test16:
Canonicalize cast X to bool into a setne instruction

llvm-svn: 13736
2004-05-25 04:29:21 +00:00
Chris Lattner 99173879ad Spelling people's names right is kinda important
llvm-svn: 13702
2004-05-23 21:27:29 +00:00
Chris Lattner 289ba2ac4d Adjust to the changes in the AliasSetTracker interface
llvm-svn: 13690
2004-05-23 21:20:19 +00:00
Chris Lattner e67dbc2ae2 Add support for replacement of formal arguments with simpler expressions.
llvm-svn: 13689
2004-05-23 21:19:55 +00:00
Chris Lattner 099c8cfe90 Implement the -lowergc pass which is used by code generators (like the CBE)
that do not have builtin support for garbage collection.

llvm-svn: 13688
2004-05-23 21:19:22 +00:00
Chris Lattner 0026512bac This was not meant to be committed
llvm-svn: 13565
2004-05-13 20:56:34 +00:00
Chris Lattner c12c945cc4 Fix a nasty bug that caused us to unroll EXTREMELY large loops due to overflow
in the size calculation.

This is not something you want to see:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - UNROLLING!

The problem was that 2*2147483648 == 0.

Now we get:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - TOO LARGE: 4294967296>100

Thanks to some anonymous person playing with the demo page that repeatedly
caused zion to go into swapping land.  That's one way to ensure you'll get
a quick bugfix.  :)

Testcase here: Transforms/LoopUnroll/2004-05-13-DontUnrollTooMuch.ll

llvm-svn: 13564
2004-05-13 20:43:31 +00:00
Chris Lattner 8ec5f88c79 Fix stupid bug in my checkin yesterday
llvm-svn: 13429
2004-05-08 22:41:42 +00:00
Chris Lattner 5f667a6f58 Implement folding of GEP's like:
%tmp.0 = getelementptr [50 x sbyte]* %ar, uint 0, int 5         ; <sbyte*> [#uses=2]
        %tmp.7 = getelementptr sbyte* %tmp.0, int 8             ; <sbyte*> [#uses=1]

together.  This patch actually allows us to simplify and generalize the code.

llvm-svn: 13415
2004-05-07 22:09:22 +00:00
Chris Lattner d9e5813821 Fix PR336: The instcombine pass asserts when visiting load instruction
llvm-svn: 13400
2004-05-07 15:35:56 +00:00
Chris Lattner 9490849028 Do not mark instructions in unreachable sections of the function as live.
This fixes PR332 and ADCE/2004-05-04-UnreachableBlock.llx

llvm-svn: 13349
2004-05-04 17:00:46 +00:00
Chris Lattner dd1a86d858 Minor efficiency tweak, suggested by Patrick Meredith
llvm-svn: 13341
2004-05-04 15:19:33 +00:00
Chris Lattner 63d75af920 Make sure to reprocess instructions used by deleted instructions to avoid
missing opportunities for combination.

llvm-svn: 13309
2004-05-01 23:27:23 +00:00
Chris Lattner b643a9e675 Make sure the instruction combiner doesn't lose track of instructions
when replacing them, missing the opportunity to do simplifications

llvm-svn: 13308
2004-05-01 23:19:52 +00:00
Chris Lattner 652064e3b8 Fix a major pessimization in the instcombiner. If an allocation instruction
is only used by a cast, and the casted type is the same size as the original
allocation, it would eliminate the cast by folding it into the allocation.

Unfortunately, it was placing the new allocation instruction right before
the cast, which could pull (for example) alloca instructions into the body
of a function.  This turns statically allocatable allocas into expensive
dynamically allocated allocas, which is bad bad bad.

This fixes the problem by placing the new allocation instruction at the same
place the old one was, duh. :)

llvm-svn: 13289
2004-04-30 04:37:52 +00:00
Chris Lattner 2d3a7a6ff0 Changes to fix up the inst_iterator to pass to boost iterator checks. This
patch was graciously contributed by Vladimir Prus.

llvm-svn: 13185
2004-04-27 15:13:33 +00:00
Chris Lattner e20c334e65 Instcombine X/-1 --> 0-X
llvm-svn: 13172
2004-04-26 14:01:59 +00:00
Chris Lattner 83cd87efcd Move the scev expansion code into this pass, where it belongs. There is
still room for cleanup, but at least the code modification is out of the
analysis now.

llvm-svn: 13135
2004-04-23 21:29:48 +00:00
Chris Lattner c27302c79f Disable a previous patch that was causing indvars to loop infinitely :(
llvm-svn: 13108
2004-04-22 15:12:36 +00:00
Chris Lattner c1a682dda0 Fix an extremely serious thinko I made in revision 1.60 of this file.
llvm-svn: 13106
2004-04-22 14:59:40 +00:00
Chris Lattner af532f27e7 Implement a todo, rewriting all possible scev expressions inside of the
loop.  This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall.  Tommorows test
results will tell. :)

llvm-svn: 13103
2004-04-21 23:36:08 +00:00
Chris Lattner fb9a299f68 This code really wants to iterate over the OPERANDS of an instruction, not
over its USES.  If it's dead it doesn't have any uses!  :)

Thanks to the fabulous and mysterious Bill Wendling for pointing this out.  :)

llvm-svn: 13102
2004-04-21 22:29:37 +00:00
Chris Lattner dc7cc35088 Implement a fixme. The helps loops that have induction variables of different
types in them.  Instead of creating an induction variable for all types, it
creates a single induction variable and casts to the other sizes.  This generates
this code:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=4]
***     %j.0.0 = cast uint %indvar to short             ; <short> [#uses=1]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %tmp.7 = getelementptr short* %P, uint %indvar          ; <short*> [#uses=1]
        store short %j.0.0, short* %tmp.7
        %inc.0 = add int %indvar, 1             ; <int> [#uses=2]
        %tmp.2 = setlt int %inc.0, %N           ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %no_exit, label %loopexit

instead of:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi ushort [ %indvar.next, %no_exit ], [ 0, %entry ]          ; <ushort> [#uses=2]
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=3]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %indvar = cast ushort %indvar to short          ; <short> [#uses=1]
        %tmp.7 = getelementptr short* %P, uint %indvar          ; <short*> [#uses=1]
        store short %indvar, short* %tmp.7
        %inc.0 = add int %indvar, 1             ; <int> [#uses=2]
        %tmp.2 = setlt int %inc.0, %N           ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1
***     %indvar.next = add ushort %indvar, 1
        br bool %tmp.2, label %no_exit, label %loopexit

This is an improvement in register pressure, but probably doesn't happen that
often.

The more important fix will be to get rid of the redundant add.

llvm-svn: 13101
2004-04-21 22:22:01 +00:00
Chris Lattner c1aa21f5a7 Fix PR325
llvm-svn: 13081
2004-04-20 20:26:03 +00:00
Chris Lattner f48f777d4c Initial checkin of a simple loop unswitching pass. It still needs work,
but it's a start, and seems to do it's basic job.

llvm-svn: 13068
2004-04-19 18:07:02 +00:00
Chris Lattner bc02177fdc Add #include
llvm-svn: 13057
2004-04-19 03:01:23 +00:00
Chris Lattner fc44a25bcb Move isLoopInvariant to the Loop class
llvm-svn: 13051
2004-04-18 22:46:08 +00:00
Chris Lattner 827826320d Correct rewriting of exit blocks after my last patch
llvm-svn: 13048
2004-04-18 22:27:10 +00:00
Chris Lattner 35eaa55cfc Loop exit sets are no longer explicitly held, they are dynamically computed on demand.
llvm-svn: 13046
2004-04-18 22:15:13 +00:00
Chris Lattner d72c3eb54e Change the ExitBlocks list from being explicitly contained in the Loop
structure to being dynamically computed on demand.  This makes updating
loop information MUCH easier.

llvm-svn: 13045
2004-04-18 22:14:10 +00:00
Chris Lattner d15250240c Reduce the unrolling limit
llvm-svn: 13040
2004-04-18 18:06:14 +00:00
Chris Lattner 30ae18155d If the preheader of the loop was the entry block of the function, make sure
that the exit block of the loop becomes the new entry block of the function.

This was causing a verifier assertion on 252.eon.

llvm-svn: 13039
2004-04-18 17:38:42 +00:00
Chris Lattner 230bcb6b35 Be much more careful about how we update instructions outside of the loop
using instructions inside of the loop.  This should fix the MishaTest failure
from last night.

llvm-svn: 13038
2004-04-18 17:32:39 +00:00
Chris Lattner 4d52e1e401 After unrolling our single basic block loop, fold it into the preheader and exit
block.  The primary motivation for doing this is that we can now unroll nested loops.

This makes a pretty big difference in some cases.  For example, in 183.equake,
we are now beating the native compiler with the CBE, and we are a lot closer
with LLC.

I'm now going to play around a bit with the unroll factor and see what effect
it really has.

llvm-svn: 13034
2004-04-18 06:27:43 +00:00
Chris Lattner f2cc841619 Fix a bug: this does not preserve the CFG!
While we're at it, add support for updating loop information correctly.

llvm-svn: 13033
2004-04-18 05:38:37 +00:00
Chris Lattner 946b255977 Initial checkin of a simple loop unroller. This pass is extremely basic and
limited.  Even in it's extremely simple state (it can only *fully* unroll single
basic block loops that execute a constant number of times), it already helps improve
performance a LOT on some benchmarks, particularly with the native code generators.

llvm-svn: 13028
2004-04-18 05:20:17 +00:00
Chris Lattner c14da9600b Make the tail duplication threshold accessible from the command line instead of hardcoded
llvm-svn: 13025
2004-04-18 00:52:43 +00:00
Chris Lattner a814080025 If the loop executes a constant number of times, try a bit harder to replace
exit values.

llvm-svn: 13018
2004-04-17 18:44:09 +00:00
Chris Lattner 1e9ac1a45e Fix a HUGE pessimization on X86. The indvars pass was taking this
(familiar) function:

int _strlen(const char *str) {
    int len = 0;
    while (*str++) len++;
    return len;
}

And transforming it to use a ulong induction variable, because the type of
the pointer index was left as a constant long.  This is obviously very bad.

The fix is to shrink long constants in getelementptr instructions to intptr_t,
making the indvars pass insert a uint induction variable, which is much more
efficient.

Here's the before code for this function:

int %_strlen(sbyte* %str) {
entry:
        %tmp.13 = load sbyte* %str              ; <sbyte> [#uses=1]
        %tmp.24 = seteq sbyte %tmp.13, 0                ; <bool> [#uses=1]
        br bool %tmp.24, label %loopexit, label %no_exit

no_exit:                ; preds = %entry, %no_exit
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=2]
***     %indvar = phi ulong [ %indvar.next, %no_exit ], [ 0, %entry ]           ; <ulong> [#uses=2]
        %indvar1 = cast ulong %indvar to uint           ; <uint> [#uses=1]
        %inc.02.sum = add uint %indvar1, 1              ; <uint> [#uses=1]
        %inc.0.0 = getelementptr sbyte* %str, uint %inc.02.sum          ; <sbyte*> [#uses=1]
        %tmp.1 = load sbyte* %inc.0.0           ; <sbyte> [#uses=1]
        %tmp.2 = seteq sbyte %tmp.1, 0          ; <bool> [#uses=1]
        %indvar.next = add ulong %indvar, 1             ; <ulong> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %loopexit.loopexit, label %no_exit

loopexit.loopexit:              ; preds = %no_exit
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %inc.1 = add int %indvar, 1             ; <int> [#uses=1]
        ret int %inc.1

loopexit:               ; preds = %entry
        ret int 0
}


Here's the after code:

int %_strlen(sbyte* %str) {
entry:
        %inc.02 = getelementptr sbyte* %str, uint 1             ; <sbyte*> [#uses=1]
        %tmp.13 = load sbyte* %str              ; <sbyte> [#uses=1]
        %tmp.24 = seteq sbyte %tmp.13, 0                ; <bool> [#uses=1]
        br bool %tmp.24, label %loopexit, label %no_exit

no_exit:                ; preds = %entry, %no_exit
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=3]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %inc.0.0 = getelementptr sbyte* %inc.02, uint %indvar           ; <sbyte*> [#uses=1]
        %inc.1 = add int %indvar, 1             ; <int> [#uses=1]
        %tmp.1 = load sbyte* %inc.0.0           ; <sbyte> [#uses=1]
        %tmp.2 = seteq sbyte %tmp.1, 0          ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %loopexit, label %no_exit

loopexit:               ; preds = %entry, %no_exit
        %len.0.1 = phi int [ 0, %entry ], [ %inc.1, %no_exit ]          ; <int> [#uses=1]
        ret int %len.0.1
}

llvm-svn: 13016
2004-04-17 18:16:10 +00:00
Chris Lattner 885a6eb74d Even if there are not any induction variables in the loop, if we can compute
the trip count for the loop, insert one so that we can canonicalize the exit
condition.

llvm-svn: 13015
2004-04-17 18:08:33 +00:00
Chris Lattner 284d3b0311 Fix some really nasty dominance bugs that were exposed by my patch to
make the verifier more strict.  This fixes building zlib

llvm-svn: 13002
2004-04-16 18:08:07 +00:00
Chris Lattner 9e9b2b7474 Fix some of the strange CBE-only failures that happened last night.
llvm-svn: 12980
2004-04-16 06:03:17 +00:00
Chris Lattner d7a559e353 Fix a bug in the previous checkin: if the exit block is not the same as
the back-edge block, we must check the preincremented value.

llvm-svn: 12968
2004-04-15 20:26:22 +00:00
Chris Lattner 0cec5cb92c Change the canonical induction variable that we insert.
Instead of producing code like this:

Loop:
  X = phi 0, X2
  ...

  X2 = X + 1
  if (X != N-1) goto Loop

We now generate code that looks like this:

Loop:
  X = phi 0, X2
  ...

  X2 = X + 1
  if (X2 != N) goto Loop

This has two big advantages:
  1. The trip count of the loop is now explicit in the code, allowing
     the direct implementation of Loop::getTripCount()
  2. This reduces register pressure in the loop, and allows X and X2 to be
     put into the same register.

As a consequence of the second point, the code we generate for loops went
from:

.LBB2:  # no_exit.1
	...
        mov %EDI, %ESI
        inc %EDI
        cmp %ESI, 2
        mov %ESI, %EDI
        jne .LBB2 # PC rel: no_exit.1

To:

.LBB2:  # no_exit.1
	...
        inc %ESI
        cmp %ESI, 3
        jne .LBB2 # PC rel: no_exit.1

... which has two fewer moves, and uses one less register.

llvm-svn: 12961
2004-04-15 15:21:43 +00:00
Chris Lattner 6679e46b59 ADd a trivial instcombine: load null -> null
llvm-svn: 12940
2004-04-14 03:28:36 +00:00
Chris Lattner ff9362a8da Add SCCP support for constant folding calls, implementing:
test/Regression/Transforms/SCCP/calltest.ll

llvm-svn: 12921
2004-04-13 19:43:54 +00:00
Chris Lattner d0dc6d5295 Constant propagation should remove the dead instructions
llvm-svn: 12917
2004-04-13 19:28:20 +00:00
Chris Lattner 89e959bb1f Fix LoopSimplify/2004-04-13-LoopSimplifyUpdateDomFrontier.ll
LoopSimplify was not updating dominator frontiers correctly in some cases.

llvm-svn: 12890
2004-04-13 16:23:25 +00:00
Chris Lattner a6e22814ab Refactor code a bit to make it simpler and eliminate the goto
llvm-svn: 12888
2004-04-13 15:21:18 +00:00
Chris Lattner 8417052938 This patch addresses PR35: Loop simplify should reconstruct nested loops.
This is fairly straight-forward, but was a real nightmare to get just
perfect.  aarg.  :)

llvm-svn: 12884
2004-04-13 05:05:33 +00:00
Chris Lattner 494a685449 Add support for removing invoke instructions
llvm-svn: 12858
2004-04-12 05:15:13 +00:00
Chris Lattner 24cf0200c7 Fix a bug in my select transformation
llvm-svn: 12826
2004-04-11 01:39:19 +00:00
Chris Lattner f16fe7206c Update the value numbering interface.
llvm-svn: 12824
2004-04-10 22:33:34 +00:00
Chris Lattner 623fba1107 Implement InstCombine/select.ll:test13*
llvm-svn: 12821
2004-04-10 22:21:27 +00:00
Chris Lattner cf4a996cba Implement InstCombine/add.ll:test20
Canonicalize add of sign bit constant into a xor

llvm-svn: 12819
2004-04-10 22:01:55 +00:00
Chris Lattner 69c4900512 Rewrite the GCSE pass to be *substantially* simpler, a bit more efficient,
and a bit more powerful

llvm-svn: 12817
2004-04-10 21:11:11 +00:00
Chris Lattner f9d9665138 Fix spurious warning in release mode
llvm-svn: 12816
2004-04-10 19:15:56 +00:00
Chris Lattner d95ef7eff0 Simplify code a bit, and fix a bug that was breaking perlbmk
llvm-svn: 12814
2004-04-10 18:06:21 +00:00
Chris Lattner 7ebfe61dc1 Fix a bug in my checkin last night that was breaking programs using invoke.
llvm-svn: 12813
2004-04-10 16:53:29 +00:00
Chris Lattner 5093213c40 Fix previous patch
llvm-svn: 12811
2004-04-10 07:27:48 +00:00
Chris Lattner 6149ac8991 Correctly update counters
llvm-svn: 12810
2004-04-10 07:02:02 +00:00
Chris Lattner cfa1adcdb8 Simplify code a bit, and use alias analysis to allow us to delete unused
call and invoke instructions that are known to not write to memory.

llvm-svn: 12807
2004-04-10 06:53:09 +00:00
Chris Lattner 56e4d3d8ad Implement select.ll:test12*
This transforms code like this:

   %C = or %A, %B
   %D = select %cond, %C, %A
into:
   %C = select %cond, %B, 0
   %D = or %A, %C

Since B is often a constant, the select can often be eliminated.  In any case,
this reduces the usage count of A, allowing subsequent optimizations to happen.

This xform applies when the operator is any of:
  add, sub, mul, or, xor, and, shl, shr

llvm-svn: 12800
2004-04-09 23:46:01 +00:00
Chris Lattner 183b336a54 Fold binary operators with a constant operand into select instructions
that have a constant operand.  This implements
add.ll:test19, shift.ll:test15*, and others that are not tested

llvm-svn: 12794
2004-04-09 19:05:30 +00:00
Chris Lattner cf7baf3519 Implement select.ll:test11
llvm-svn: 12793
2004-04-09 18:19:44 +00:00
Chris Lattner e228ee5870 Implement InstCombine/cast-propagate.ll
llvm-svn: 12784
2004-04-08 20:39:49 +00:00
Chris Lattner 1c631e813d Implement InstCombine/select.ll:test[7-10]
llvm-svn: 12769
2004-04-08 04:43:23 +00:00
Chris Lattner 2b2412d0c8 Implement test/Regression/Transforms/InstCombine/getelementptr_index.ll
llvm-svn: 12762
2004-04-07 18:38:20 +00:00
Chris Lattner 4d1fcf1dcd Fix a bug in yesterdays checkins which broke siod. siod is a great testcase! :)
llvm-svn: 12659
2004-04-05 16:02:41 +00:00
Chris Lattner 8953b90aaa Fix InstCombine/2004-04-04-InstCombineReplaceAllUsesWith.ll
llvm-svn: 12658
2004-04-05 02:10:19 +00:00
Chris Lattner 69193f93b6 Support getelementptr instructions which use uint's to index into structure
types and can have arbitrary 32- and 64-bit integer types indexing into
sequential types.

llvm-svn: 12653
2004-04-05 01:30:19 +00:00
Chris Lattner e61b67d7d5 Rewrite the indvars pass to use the ScalarEvolution analysis.
This also implements some new features for the indvars pass, including
linear function test replacement, exit value substitution, and it works with
a much more general class of induction variables and loops.

llvm-svn: 12620
2004-04-02 20:24:31 +00:00
Chris Lattner 59fdf74968 Remove some assertions that are now bogus with the last patch I put in
llvm-svn: 12595
2004-04-01 19:21:46 +00:00
Chris Lattner 146d0df5e4 Fix PR306: Loop simplify incorrectly updates dominator information
Testcase: LoopSimplify/2004-04-01-IncorrectDomUpdate.ll

llvm-svn: 12592
2004-04-01 19:06:07 +00:00
Chris Lattner 61fab1409d Add warning
llvm-svn: 12573
2004-03-31 22:00:30 +00:00
Chris Lattner 533bc49775 Implement select.ll:test[3-6]
llvm-svn: 12544
2004-03-30 19:37:13 +00:00
Chris Lattner 059f390257 Add a simple select instruction lowering pass
llvm-svn: 12540
2004-03-30 18:41:10 +00:00
Chris Lattner 56b5051428 X % -1 == X % 1 == 0
llvm-svn: 12520
2004-03-26 16:11:24 +00:00
Chris Lattner 57c67b06e9 Two changes:
#1 is to unconditionally strip constantpointerrefs out of
instruction operands where they are absolutely pointless and inhibit
optimization.  GRRR!

#2 is to implement InstCombine/getelementptr_const.ll

llvm-svn: 12519
2004-03-25 22:59:29 +00:00
Chris Lattner abb77c9959 Teach the optimizer to delete zero sized alloca's (but not mallocs!)
llvm-svn: 12507
2004-03-19 06:08:10 +00:00
Chris Lattner 684fa5ac64 Be more accurate
llvm-svn: 12464
2004-03-17 01:59:27 +00:00
Chris Lattner a3783a577e Fix bug in previous checkin
llvm-svn: 12458
2004-03-16 23:36:49 +00:00
Chris Lattner 95057f6ad1 Okay, so there is no reasonable way for tail duplication to update SSA form,
as it is making effectively arbitrary modifications to the CFG and we don't
have a domset/domfrontier implementations that can handle the dynamic updates.
Instead of having a bunch of code that doesn't actually work in practice,
just demote any potentially tricky values to the stack (causing the problem
to go away entirely).  Later invocations of mem2reg will rebuild SSA for us.

This fixes all of the major performance regressions with tail duplication
from LLVM 1.1.  For example, this loop:

---
int popcount(int x) {
  int result = 0;
  while (x != 0) {
    result = result + (x & 0x1);
    x = x >> 1;
  }
  return result;
}
---
Used to be compiled into:

int %popcount(int %X) {
entry:
	br label %loopentry

loopentry:		; preds = %entry, %no_exit
	%x.0 = phi int [ %X, %entry ], [ %tmp.9, %no_exit ]		; <int> [#uses=3]
	%result.1.0 = phi int [ 0, %entry ], [ %tmp.6, %no_exit ]		; <int> [#uses=2]
	%tmp.1 = seteq int %x.0, 0		; <bool> [#uses=1]
	br bool %tmp.1, label %loopexit, label %no_exit

no_exit:		; preds = %loopentry
	%tmp.4 = and int %x.0, 1		; <int> [#uses=1]
	%tmp.6 = add int %tmp.4, %result.1.0		; <int> [#uses=1]
	%tmp.9 = shr int %x.0, ubyte 1		; <int> [#uses=1]
	br label %loopentry

loopexit:		; preds = %loopentry
	ret int %result.1.0
}

And is now compiled into:

int %popcount(int %X) {
entry:
        br label %no_exit

no_exit:                ; preds = %entry, %no_exit
        %x.0.0 = phi int [ %X, %entry ], [ %tmp.9, %no_exit ]          ; <int> [#uses=2]
        %result.1.0.0 = phi int [ 0, %entry ], [ %tmp.6, %no_exit ]             ; <int> [#uses=1]
        %tmp.4 = and int %x.0.0, 1              ; <int> [#uses=1]
        %tmp.6 = add int %tmp.4, %result.1.0.0          ; <int> [#uses=2]
        %tmp.9 = shr int %x.0.0, ubyte 1                ; <int> [#uses=2]
        %tmp.1 = seteq int %tmp.9, 0            ; <bool> [#uses=1]
        br bool %tmp.1, label %loopexit, label %no_exit

loopexit:               ; preds = %no_exit
        ret int %tmp.6
}

llvm-svn: 12457
2004-03-16 23:29:09 +00:00
Chris Lattner 7a7b114871 Do not try to optimize PHI nodes with incredibly high degree. This reduces SCCP
time from 615s to 1.49s on a large testcase that has a gigantic switch statement
that all of the blocks in the function go to (an intepreter).

llvm-svn: 12442
2004-03-16 19:49:59 +00:00
Chris Lattner a64923ad26 Do not copy gigantic switch instructions
llvm-svn: 12441
2004-03-16 19:45:22 +00:00
Chris Lattner db5b8f4d6b Fix a regression from this patch:
http://mail.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20040308/013095.html

Basically, this patch only updated the immediate dominatees of the header node
to tell them that the preheader also dominated them.  In practice, ALL
dominatees of the header node are also dominated by the preheader.

This fixes: LoopSimplify/2004-03-15-IncorrectDomUpdate.
and PR293

llvm-svn: 12434
2004-03-16 06:00:15 +00:00
Chris Lattner cd83282df1 Add counters for the number of calls elimianted
llvm-svn: 12420
2004-03-15 05:46:59 +00:00
Chris Lattner 20cda2645e Implement LICM of calls in simple cases. This is sufficient to move around
sin/cos/strlen calls and stuff.  This implements:
  LICM/call_sink_pure_function.ll
  LICM/call_sink_const_function.ll

llvm-svn: 12415
2004-03-15 04:11:30 +00:00
Chris Lattner b68659552a Do not create empty basic blocks when the lowerswitch pass expects blocks to
be non-empty!  This fixes LowerSwitch/2004-03-13-SwitchIsDefaultCrash.ll

llvm-svn: 12384
2004-03-14 04:14:31 +00:00
Chris Lattner d078812f96 If a block is dead, dominators will not be calculated for it. Because of this
loop information won't see it, and we could have unreachable blocks pointing to
the non-header node of blocks in a natural loop.  This isn't tidy, so have the
loopsimplify pass clean it up.

llvm-svn: 12380
2004-03-14 03:59:22 +00:00
Chris Lattner 7d2a539735 Add some debugging output
Fix InstCombine/2004-03-13-InstCombineInfLoop.ll which caused an infinite
loop compiling (I think) povray.

llvm-svn: 12365
2004-03-13 23:54:27 +00:00
Chris Lattner 797cb2f6c1 This little patch speeds up the loop used to update the dominator set analysis.
On the testcase from GCC PR12440, which has a LOT of loops (1392 of which require
preheaders to be inserted), this speeds up the loopsimplify pass from 1.931s to
0.1875s.  The loop in question goes from 1.65s -> 0.0097s, which isn't bad. All of
these times are a debug build.

This adds a dependency on DominatorTree analysis that was not there before, but
we always had dominatortree available anyway, because LICM requires both loop
simplify and DT, so this doesn't add any extra analysis in practice.

llvm-svn: 12362
2004-03-13 22:01:26 +00:00
Chris Lattner 022167f13b Implement sub.ll:test14
llvm-svn: 12355
2004-03-13 00:11:49 +00:00
Chris Lattner 92295c5031 Implement InstCombine/sub.ll:test12 & test13
llvm-svn: 12353
2004-03-12 23:53:13 +00:00
Chris Lattner 59db22dcd4 Add sccp support for select instructions
llvm-svn: 12318
2004-03-12 05:52:44 +00:00
Chris Lattner b909e8b0d4 Add trivial optimizations for select instructions
llvm-svn: 12317
2004-03-12 05:52:32 +00:00
Chris Lattner 538fee7aa2 Since 'load null' is undefined, we can make it do whatever we want. Returning
a zero value is the most likely way to cause further simplification, so we do it.

llvm-svn: 12197
2004-03-07 22:16:24 +00:00
Chris Lattner 7abcc387de Don't emit things like malloc(16*1). Allocation instructions are fixed arity now.
llvm-svn: 12086
2004-03-03 01:40:53 +00:00
Chris Lattner 5cf39339d1 Disable tail duplication in a case that breaks on Olden/tsp
llvm-svn: 12021
2004-03-01 01:12:13 +00:00
Chris Lattner bf2963ef91 Fix PR255: [tailduplication] Single basic block loops are very rare
Note that this is a band-aid put over a band-aid.  This just undisables
tail duplication in on very specific case that it seems to work in.

llvm-svn: 11989
2004-02-29 06:41:20 +00:00
Chris Lattner 772eafa332 if there is already a prototype for malloc/free, use it, even if it's incorrect.
Do not just inject a new prototype.

llvm-svn: 11951
2004-02-28 18:51:45 +00:00
Chris Lattner 51ea127bf3 Rename AddUsesToWorkList -> AddUsersToWorkList, as that is what it does.
Create a new AddUsesToWorkList method
optimize memmove/set/cpy of zero bytes to a noop.

llvm-svn: 11941
2004-02-28 05:22:00 +00:00
Chris Lattner f3a366062c Turn 'free null' into nothing
llvm-svn: 11940
2004-02-28 04:57:37 +00:00
Chris Lattner 4f7accab96 Implement test/Regression/Transforms/InstCombine/canonicalize_branch.ll
This is a really minor thing, but might help out the 'switch statement induction'
code in simplifycfg.

llvm-svn: 11900
2004-02-27 06:27:46 +00:00
Chris Lattner 9c6833c5ca Fix incorrect debug code
llvm-svn: 11821
2004-02-25 15:15:04 +00:00
Chris Lattner 8ee0593f0d Fix a faulty optimization on FP values
llvm-svn: 11801
2004-02-24 18:10:14 +00:00
Chris Lattner ae739aefd7 Generate much more efficient code in programs like pifft
llvm-svn: 11775
2004-02-23 21:46:58 +00:00
Chris Lattner c40b9d7d51 Fix a small typeo in my checkin last night that broke vortex and other programs :(
llvm-svn: 11774
2004-02-23 21:46:42 +00:00
Chris Lattner f5ce254692 Fix InstCombine/2004-02-23-ShiftShiftOverflow.ll
Also, turn 'shr int %X, 1234' into 'shr int %X, 31'

llvm-svn: 11768
2004-02-23 20:30:06 +00:00
Chris Lattner 2b55ea38bc Implement cast.ll::test14/15
llvm-svn: 11742
2004-02-23 07:16:20 +00:00
Chris Lattner e79e854c5c Refactor some code. In the mul - setcc folding case, we really care about
whether this is the sign bit or not, so check unsigned comparisons as well.

llvm-svn: 11740
2004-02-23 06:38:22 +00:00
Chris Lattner c8a10c4b6a Implement mul.ll:test11
llvm-svn: 11737
2004-02-23 06:00:11 +00:00
Chris Lattner 59611149ee Implement "strength reduction" of X <= C and X >= C
llvm-svn: 11735
2004-02-23 05:47:48 +00:00