Commit Graph

499 Commits

Author SHA1 Message Date
Chris Lattner b9d3ca5c3c Fix a bit of backwards logic that broke exptree and smg2000
llvm-svn: 24056
2005-10-28 16:27:35 +00:00
Chris Lattner c4f67e67d2 Do not sink any instruction with side effects, including vaarg. This fixes
PR640

llvm-svn: 24046
2005-10-27 17:13:11 +00:00
Chris Lattner c6372cca78 Fix typo
llvm-svn: 24033
2005-10-27 06:26:26 +00:00
Chris Lattner 0fe7551bc0 Teach instcombine to promote stuff like (cast (malloc sbyte, 8*X) to int*)
into: malloc int, (2*X)

llvm-svn: 24032
2005-10-27 06:24:46 +00:00
Chris Lattner b3ecf96900 Promote cases like cast (malloc sbyte, 100) to int* into
(malloc [25 x int]) directly without having to convert to
(malloc [100 x sbyte]) first.

llvm-svn: 24031
2005-10-27 06:12:00 +00:00
Chris Lattner bb17180a23 Minor change to this file to support obscure cases with constant array amounts
llvm-svn: 24030
2005-10-27 05:53:56 +00:00
Chris Lattner 38a1b00a0f fold nested and's early to avoid inefficiencies in MaskedValueIsZero. This
fixes a very slow compile in PR639.

llvm-svn: 24011
2005-10-26 17:18:16 +00:00
Chris Lattner 46705b2f2d Handle allocations that, even after removing dead uses, still have more than
one use (but one is a cast).  This handles the very common case of:

 X = alloc [n x byte]
 Y = cast X to somethingbetter
 seteq X, null

In order to avoid infinite looping when there are multiple casts, we only
allow this if the xform is strictly increasing the alignment of the
allocation.

llvm-svn: 23961
2005-10-24 06:35:18 +00:00
Chris Lattner 355ecc09f8 Fix a bug where we would 'promote' an allocation from one type to another
where the second has less alignment required.  If we had explicit alignment
support in the IR, we could handle this case, but we can't until we do.

llvm-svn: 23960
2005-10-24 06:26:18 +00:00
Chris Lattner ac87beb03a Before promoting a malloc type, remove dead uses. This makes instcombine
more effective at promoting these allocations, catching them earlier in the
compile process.

llvm-svn: 23959
2005-10-24 06:22:12 +00:00
Chris Lattner 216be91817 Pull some code out into a function, no functionality change
llvm-svn: 23958
2005-10-24 06:03:58 +00:00
Chris Lattner da1b152c43 Make this work for FP constantexprs
llvm-svn: 23773
2005-10-17 20:18:38 +00:00
Chris Lattner 7fde91e365 Oops, X+0.0 isn't foldable, but X+-0.0 is.
llvm-svn: 23772
2005-10-17 17:56:38 +00:00
Chris Lattner 32979336a7 relax this a bit, as we only support the default rounding mode
llvm-svn: 23771
2005-10-17 17:49:32 +00:00
Chris Lattner 03b9eb506c Make MaskedValueIsZero a bit more aggressive
llvm-svn: 23677
2005-10-09 22:08:50 +00:00
Chris Lattner 62010c450f Fix funky xcode indentation
llvm-svn: 23674
2005-10-09 06:36:35 +00:00
Jeff Cohen 572910c9a2 Remove useless variable.
llvm-svn: 23656
2005-10-07 05:28:29 +00:00
Chris Lattner 0b011ec8e2 Factor the GetGEPGlobalInitializer out of this pass and into Transforms/Utils
as ConstantFoldLoadThroughGEPConstantExpr.

llvm-svn: 23445
2005-09-26 05:28:06 +00:00
Chris Lattner 0b3557f54a Move MaskedValueIsZero up.
Match a bunch of idioms for sign extensions, implementing InstCombine/signext.ll

llvm-svn: 23428
2005-09-24 23:43:33 +00:00
Chris Lattner b4b2530a1a Refactor this code a bit and make it more general. This now compiles:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus2 (unsigned int x) { b.j += x; }

To:

_plus2:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        slwi r3, r3, 6
        add r3, r4, r3
        rlwimi r3, r4, 0, 26, 14
        stw r3, 0(r2)
        blr


instead of:

_plus2:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        rlwinm r5, r4, 26, 21, 31
        add r3, r5, r3
        rlwimi r4, r3, 6, 15, 25
        stw r4, 0(r2)
        blr

by eliminating an 'and'.

I'm pretty sure this is as small as we can go :)

llvm-svn: 23386
2005-09-18 07:22:02 +00:00
Chris Lattner 797dee7705 Compile
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus2 (unsigned int x) {
  b.j += x;
}

to:

plus2:
        mov %EAX, DWORD PTR [b]
        mov %ECX, %EAX
        and %ECX, 131008
        mov %EDX, DWORD PTR [%ESP + 4]
        shl %EDX, 6
        add %EDX, %ECX
        and %EDX, 131008
        and %EAX, -131009
        or %EDX, %EAX
        mov DWORD PTR [b], %EDX
        ret

instead of:

plus2:
        mov %EAX, DWORD PTR [b]
        mov %ECX, %EAX
        shr %ECX, 6
        and %ECX, 2047
        add %ECX, DWORD PTR [%ESP + 4]
        shl %ECX, 6
        and %ECX, 131008
        and %EAX, -131009
        or %ECX, %EAX
        mov DWORD PTR [b], %ECX
        ret

llvm-svn: 23385
2005-09-18 06:30:59 +00:00
Chris Lattner 01f56c68e9 Generalize this transform, using MaskedValueIsZero, allowing us to compile:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus3 (unsigned int x) { b.k += x; }

To:

plus3:
        mov %EAX, DWORD PTR [%ESP + 4]
        shl %EAX, 17
        add DWORD PTR [b], %EAX
        ret

instead of:

plus3:
        mov %EAX, DWORD PTR [%ESP + 4]
        shl %EAX, 17
        mov %ECX, DWORD PTR [b]
        add %EAX, %ECX
        and %EAX, -131072
        and %ECX, 131071
        or %ECX, %EAX
        mov DWORD PTR [b], %ECX
        ret

llvm-svn: 23384
2005-09-18 06:02:59 +00:00
Chris Lattner 4ebc8ab4e0 fix typeo
llvm-svn: 23383
2005-09-18 05:25:20 +00:00
Chris Lattner e5b23a6d67 Remove unintentionally committed code
llvm-svn: 23382
2005-09-18 05:12:51 +00:00
Chris Lattner 27cb9dbd35 implement shift.ll:test25. This compiles:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus3 (unsigned int x) {
  b.k += x;
}

to:

_plus3:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r3, 0(r2)
        rlwinm r4, r3, 0, 0, 14
        add r4, r4, r3
        rlwimi r4, r3, 0, 15, 31
        stw r4, 0(r2)
        blr

instead of:

_plus3:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        srwi r5, r4, 17
        add r3, r5, r3
        slwi r3, r3, 17
        rlwimi r3, r4, 0, 15, 31
        stw r3, 0(r2)
        blr

llvm-svn: 23381
2005-09-18 05:12:10 +00:00
Chris Lattner af517574ce Implement add.ll:test29. Codegening:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus1 (unsigned int x) {
  b.i += x;
}

as:
_plus1:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        add r3, r4, r3
        rlwimi r3, r4, 0, 0, 25
        stw r3, 0(r2)
        blr

instead of:

_plus1:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        rlwinm r5, r4, 0, 26, 31
        add r3, r5, r3
        rlwimi r3, r4, 0, 0, 25
        stw r3, 0(r2)
        blr

llvm-svn: 23379
2005-09-18 04:24:45 +00:00
Chris Lattner 027eaf01cf remove debug output
llvm-svn: 23377
2005-09-18 03:50:25 +00:00
Chris Lattner 1521298993 Implement or.ll:test21. This teaches instcombine to be able to turn this:
struct {
   unsigned int bit0:1;
   unsigned int ubyte:31;
} sdata;

void foo() {
  sdata.ubyte++;
}

into this:

foo:
        add DWORD PTR [sdata], 2
        ret

instead of this:

foo:
        mov %EAX, DWORD PTR [sdata]
        mov %ECX, %EAX
        add %ECX, 2
        and %ECX, -2
        and %EAX, 1
        or %EAX, %ECX
        mov DWORD PTR [sdata], %EAX
        ret

llvm-svn: 23376
2005-09-18 03:42:07 +00:00
Chris Lattner a393e4d4b3 Fix the regression last night compiling povray
llvm-svn: 23348
2005-09-14 17:32:56 +00:00
Chris Lattner 2a8932960d Add a simple xform to simplify array accesses with casts in the way.
This is useful for 178.galgel where resolution of dope vectors (by the
optimizer) causes the scales to become apparent.

llvm-svn: 23328
2005-09-13 18:36:04 +00:00
Chris Lattner 567b81f0d2 Add a helper function, allowing us to simplify some code a bit, changing
indentation, no functionality change

llvm-svn: 23325
2005-09-13 00:40:14 +00:00
Chris Lattner 219175c84d Implement a simple xform to turn code like this:
if () { store A -> P; } else { store B -> P; }

into a PHI node with one store, in the most trival case.  This implements
load.ll:test10.

llvm-svn: 23324
2005-09-12 23:23:25 +00:00
Chris Lattner e0bfdf1485 Another load-peephole optimization: do gcse when two loads are next to
each other.  This implements InstCombine/load.ll:test9

llvm-svn: 23322
2005-09-12 22:21:03 +00:00
Chris Lattner b990f7d8ed Implement a trivial form of store->load forwarding where the store and the
load are exactly consequtive.  This is picked up by other passes, but this
triggers thousands of times in fortran programs that use static locals
(and is thus a compile-time speedup).

llvm-svn: 23320
2005-09-12 22:00:15 +00:00
Chris Lattner 9f269e40c9 Use the new 'moveBefore' method to simplify some code. Really, which is
easier to understand?  :)

llvm-svn: 22706
2005-08-08 19:11:57 +00:00
Chris Lattner 2c14cf7b74 Add some simple folds that occur in bitfield cases. Fix a minor bug in
isHighOnes, where it would consider 0 to have high ones.

llvm-svn: 22693
2005-08-07 07:03:10 +00:00
Chris Lattner 9f9c260b8c now that hasConstantValue defaults to only returning values that dominate
the PHI node, this ugly code can vanish.

llvm-svn: 22672
2005-08-05 01:04:30 +00:00
Nate Begeman b392321cae Fix a fixme in CondPropagate.cpp by moving a PhiNode optimization into
BasicBlock's removePredecessor routine.  This requires shuffling around
the definition and implementation of hasContantValue from Utils.h,cpp into
Instructions.h,cpp

llvm-svn: 22664
2005-08-04 23:24:19 +00:00
Chris Lattner 22d00a8e90 Update to use the new MathExtras.h support for log2 computation.
Patch contributed by Jim Laskey!

llvm-svn: 22592
2005-08-02 19:16:58 +00:00
Jeff Cohen 5f4ef3c5a8 Eliminate all remaining tabs and trailing spaces.
llvm-svn: 22523
2005-07-27 06:12:32 +00:00
Chris Lattner 18aa4d8196 Do not let MaskedValueIsZero consider undef to be zero, for reasons
explained in the comment.

This fixes UnitTests/2003-09-18-BitFieldTest on darwin

llvm-svn: 22483
2005-07-20 18:49:28 +00:00
Chris Lattner 247aef884c When transforming &A[i] < &A[j] -> i < j, make sure to perform the comparison
as a signed compare.  This patch may fix PR597, but is correct in any case.

llvm-svn: 22465
2005-07-18 23:07:33 +00:00
Chris Lattner 4ed40f7c6f Fix a problem that instcombine would hit when dealing with unreachable code.
Because the instcombine has to scan the entire function when it starts up
to begin with, we might as well do it in DFO so we can nuke unreachable code.

This fixes: Transforms/InstCombine/2005-07-07-DeadPHILoop.ll

llvm-svn: 22348
2005-07-07 20:40:38 +00:00
Reid Spencer 4fdd96c4e0 Clean up some uninitialized variables and missing return statements that
GCC 4.0.0 compiler (sometimes incorrectly) warns about under release build.

llvm-svn: 22249
2005-06-18 17:37:34 +00:00
Chris Lattner 2ceb6ee576 This is not true: (X != 13 | X < 15) -> X < 15
It is actually always true.  This fixes PR586 and
Transforms/InstCombine/2005-06-16-SetCCOrSetCCMiscompile.ll

llvm-svn: 22236
2005-06-17 03:59:17 +00:00
Chris Lattner 73bcba5f61 Don't crash when dealing with INTMIN. This fixes PR585 and
Transforms/InstCombine/2005-06-16-RangeCrash.ll

llvm-svn: 22234
2005-06-17 02:05:55 +00:00
Chris Lattner c53cb9d3ff avoid constructing out of range shift amounts.
llvm-svn: 22230
2005-06-17 01:29:28 +00:00
Chris Lattner 89dc4f16f5 Fix PR583 and testcase Transforms/InstCombine/2005-06-15-DivSelectCrash.ll
llvm-svn: 22227
2005-06-16 04:55:52 +00:00
Chris Lattner 252a845e30 Fix PR571, removing code that does just the WRONG thing :)
llvm-svn: 22225
2005-06-16 03:00:08 +00:00
Chris Lattner 104002bee3 Fix a bug in my previous patch. Do not get the shift amount type (which
is always ubyte, get the type being shifted).  This unbreaks espresso

llvm-svn: 22224
2005-06-16 01:52:07 +00:00
Chris Lattner 19b57f55aa Fix PR577 and testcase InstCombine/2005-06-15-ShiftSetCCCrash.ll.
Do not perform undefined out of range shifts.

llvm-svn: 22217
2005-06-15 20:53:31 +00:00
Reid Spencer a299d6f701 Put the hack back in that removes features, causes regressions to fail, but
allows test programs to succeed. Actual fix for this is forthcoming.

llvm-svn: 22213
2005-06-15 18:25:30 +00:00
Reid Spencer 6d231e55fa Unbreak several InstCombine regression checks introduced by a hack to
fix the bzip2 test. A better hack is needed.

llvm-svn: 22209
2005-06-13 06:41:26 +00:00
Andrew Lenharth ffe65458e7 hack to fix bzip2 (bug 571)
llvm-svn: 22192
2005-06-04 12:43:56 +00:00
Chris Lattner 05c703ea85 preserve calling conventions when hacking on code
llvm-svn: 22024
2005-05-14 12:25:32 +00:00
Chris Lattner 61d9d81770 calling a function with the wrong CC is undefined, turn it into an unreachable
instruction.  This is useful for catching optimizers that don't preserve
calling conventions

llvm-svn: 21928
2005-05-13 07:09:09 +00:00
Chris Lattner b62f5082c5 implement and.ll:test33
llvm-svn: 21809
2005-05-09 04:58:36 +00:00
Chris Lattner b18dbbfff5 Strength reduce SAR into SHR if there is no way sign bits could be shifted
in.  This tends to get cases like this:

  X = cast ubyte to int
  Y = shr int X, ...

Tested by: shift.ll:test24

llvm-svn: 21775
2005-05-08 17:34:56 +00:00
Chris Lattner 4294cec0f1 Fix a miscompilation of crafty by clobbering the "A" variable.
llvm-svn: 21770
2005-05-07 23:49:08 +00:00
Chris Lattner 6aacb0f9da Preserve tail marker
llvm-svn: 21737
2005-05-06 06:48:21 +00:00
Chris Lattner ef298a3b8a Teach instcombine propagate zeroness through shl instructions, implementing
and.ll:test31

llvm-svn: 21717
2005-05-06 04:53:20 +00:00
Chris Lattner 873804168e Implement shift.ll:test23. If we are shifting right then immediately truncating
the result, turn signed shift rights into unsigned shift rights if possible.

This leads to later simplification and happens *often* in 176.gcc.  For example,
this testcase:

struct xxx { unsigned int code : 8; };
enum codes { A, B, C, D, E, F };
int foo(struct xxx *P) {
  if ((enum codes)P->code == A)
     bar();
}

used to be compiled to:

int %foo(%struct.xxx* %P) {
        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.3 = cast uint %tmp.2 to int                ; <int> [#uses=1]
        %tmp.4 = shl int %tmp.3, ubyte 24               ; <int> [#uses=1]
        %tmp.5 = shr int %tmp.4, ubyte 24               ; <int> [#uses=1]
        %tmp.6 = cast int %tmp.5 to sbyte               ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.6, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

Now it is compiled to:

        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.2 = cast uint %tmp.2 to sbyte              ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.2, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

which is the difference between this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        shll $24, %eax
        sarl $24, %eax
        testb %al, %al
        jne .LBBfoo_2

and this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        testb %al, %al
        jne .LBBfoo_2

This occurs 3243 times total in the External tests, 215x in povray,
6x in each f2c'd program, 1451x in 176.gcc, 7x in crafty, 20x in perl,
25x in gap, 3x in m88ksim, 25x in ijpeg.

Maybe this will cause a little jump on gcc tommorow :)

llvm-svn: 21715
2005-05-06 04:18:52 +00:00
Chris Lattner 7208616ec0 Implement xor.ll:test22
llvm-svn: 21713
2005-05-06 02:07:39 +00:00
Chris Lattner 4c2d3781aa implement and.ll:test30 and set.ll:test21
llvm-svn: 21712
2005-05-06 01:53:19 +00:00
Chris Lattner dd1e562ec3 implement or.ll:test20
llvm-svn: 21709
2005-05-06 00:58:50 +00:00
Chris Lattner 809dfac421 Instcombine: cast (X != 0) to int, cast (X == 1) to int -> X iff X has only the low bit set.
This implements set.ll:test20.

This triggers 2x on povray, 9x on mesa, 11x on gcc, 2x on crafty, 1x on eon,
6x on perlbmk and 11x on m88ksim.

It allows us to compile these two functions into the same code:

struct s { unsigned int bit : 1; };
unsigned foo(struct s *p) {
  if (p->bit)
    return 1;
  else
    return 0;
}
unsigned bar(struct s *p) { return p->bit; }

llvm-svn: 21690
2005-05-04 19:10:26 +00:00
Chris Lattner a816eee427 Implement getelementptr.ll:test11
llvm-svn: 21647
2005-05-01 04:42:15 +00:00
Chris Lattner a9d84e3388 Check for volatile loads only once.
Implement load.ll:test7

llvm-svn: 21645
2005-05-01 04:24:53 +00:00
Chris Lattner bd43b9db9d Fix the compile failures from last night.
llvm-svn: 21565
2005-04-26 14:40:41 +00:00
Chris Lattner a21bf8d1be implement getelementptr.ll:test10
llvm-svn: 21541
2005-04-25 20:17:30 +00:00
Chris Lattner 2f1457fd83 Eliminate cases where we could << by 64, which is undefined in C.
llvm-svn: 21500
2005-04-24 17:46:05 +00:00
Chris Lattner d6f636a340 Implement xor.ll:test21: select (not C), A, B -> select C, B, A
llvm-svn: 21495
2005-04-24 07:30:14 +00:00
Chris Lattner d1f46d3bf9 Use getPrimitiveSizeInBits() instead of getPrimitiveSize()*8
Completely rework the 'setcc (cast x to larger), y' code.  This code has
the advantage of implementing setcc.ll:test19 (being more general than
the previous code) and being correct in all cases.

This allows us to unxfail 2004-11-27-SetCCForCastLargerAndConstant.ll,
and close PR454.

llvm-svn: 21491
2005-04-24 06:59:08 +00:00
Jeff Cohen 82639853c0 Eliminate tabs and trailing spaces
llvm-svn: 21480
2005-04-23 21:38:35 +00:00
Chris Lattner 77c32c34d7 Generalize the setcc -> PHI and Select folding optimizations to work with
any constant RHS, not just a constant integer RHS.  This implements
select.ll:test17

llvm-svn: 21470
2005-04-23 15:31:55 +00:00
Misha Brukman b1c9317bb4 Remove trailing whitespace
llvm-svn: 21427
2005-04-21 23:48:37 +00:00
Chris Lattner 374e659466 Instcombine this:
%shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4             ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

into this:

        %shortcirc_val = or bool %tmp.1, %tmp.4         ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

not this:

        %tmp.4.cast = cast bool %tmp.4 to int           ; <int> [#uses=1]
        %tmp.6 = select bool %tmp.1, int 1, int %tmp.4.cast             ; <int> [#uses=1]

llvm-svn: 21389
2005-04-21 05:43:13 +00:00
Chris Lattner 5c219469a0 Eliminate a broken transformation, fixing PR548
llvm-svn: 21354
2005-04-19 06:04:18 +00:00
Chris Lattner 4236261930 Fix bug: InstCombine/2005-05-07-UDivSelectCrash.ll
llvm-svn: 21152
2005-04-08 04:03:26 +00:00
Chris Lattner 4706046e68 Implement the following xforms:
(X-Y)-X --> -Y
A + (B - A) --> B
(B - A) + A --> B

llvm-svn: 21138
2005-04-07 17:14:51 +00:00
Chris Lattner c7f3c1a00e Implement InstCombine/add.ll:test28, transforming C1-(X+C2) --> (C1-C2)-X.
This occurs several dozen times in specint2k, particularly in crafty and gcc
apparently.

llvm-svn: 21136
2005-04-07 16:28:01 +00:00
Chris Lattner a9be4490d8 Transform X-(X+Y) == -Y and X-(Y+X) == -Y
llvm-svn: 21134
2005-04-07 16:15:25 +00:00
Chris Lattner ecfa9b5810 disable this transformation in the one obscure case that really pessimizes
pointer analysis.

llvm-svn: 20916
2005-03-29 06:37:47 +00:00
Chris Lattner cfe2822cdf Do not compute 1ULL << 64, which is undefined. This fixes Ptrdist/ks on the
sparc, and testcase Regression/Transforms/InstCombine/2005-03-04-ShiftOverflow.ll

llvm-svn: 20445
2005-03-04 23:21:33 +00:00
Chris Lattner 72684fecf8 Implement InstCombine/cast.ll:test25, a case that occurs many times
in spec

llvm-svn: 19953
2005-01-31 05:51:45 +00:00
Chris Lattner 31f486c775 Implement the trivial cases in InstCombine/store.ll
llvm-svn: 19950
2005-01-31 05:36:43 +00:00
Chris Lattner fe1b0b8b24 Implement Transforms/InstCombine/cast-load-gep.ll, which allows us to devirtualize
11 indirect calls in perlbmk.

llvm-svn: 19947
2005-01-31 04:50:46 +00:00
Chris Lattner d8e20188c6 Adjust to changes in instruction interfaces.
llvm-svn: 19900
2005-01-29 00:39:08 +00:00
Chris Lattner cd517ff0c7 * add some DEBUG statements
* Properly compile this:

struct a {};
int test() {
  struct a b[2];
  if (&b[0] != &b[1])
    abort ();
  return 0;
}

to 'return 0', not abort().

llvm-svn: 19875
2005-01-28 19:32:01 +00:00
Chris Lattner 9e2c7facb2 Get rid of a several dozen more and instructions in specint.
llvm-svn: 19786
2005-01-23 20:26:55 +00:00
Chris Lattner fc4429e7c1 Handle comparisons of gep instructions that have different typed indices
as long as they are the same size.

llvm-svn: 19734
2005-01-21 23:06:49 +00:00
Chris Lattner 411336fe04 Add two optimizations. The first folds (X+Y)-X -> Y
The second folds operations into selects, e.g. (select C, (X+Y), (Y+Z))
-> (Y+(select C, X, Z)

This occurs a few times across spec, e.g.

         select    add/sub
mesa:    83        0
povray:  5         2
gcc      4         2
parser   0         22
perlbmk  13        30
twolf    0         3

llvm-svn: 19706
2005-01-19 21:50:18 +00:00
Chris Lattner 715364364b Delete PHI nodes that are not dead but are locked in a cycle of single
useness.

llvm-svn: 19629
2005-01-17 05:10:15 +00:00
Chris Lattner 03f06f11aa Move code out of indentation one level to make it easier to read.
Disable the xform for < > cases.  It turns out that the following is being
miscompiled:

bool %test(sbyte %S) {
        %T = cast sbyte %S to uint
        %V = setgt uint %T, 255
        ret bool %V
}

llvm-svn: 19628
2005-01-17 03:20:02 +00:00
Chris Lattner 51726c47fe Fix some bugs in an xform added yesterday. This fixes Prolangs-C/allroots.
llvm-svn: 19553
2005-01-14 17:35:12 +00:00
Chris Lattner 7aa41cfa88 Fix a compile crash on spiff
llvm-svn: 19552
2005-01-14 17:17:59 +00:00
Chris Lattner 4fa89827e2 if two gep comparisons only differ by one index, compare that index directly.
This allows us to better optimize begin() -> end() comparisons in common cases.

llvm-svn: 19542
2005-01-14 00:20:05 +00:00
Chris Lattner d35d210ea0 Do not overrun iterators. This fixes a 176.gcc crash
llvm-svn: 19541
2005-01-13 23:26:48 +00:00
Chris Lattner a04c904c4c Turn select C, (X+Y), (X-Y) --> (X+(select C, Y, (-Y))). This occurs in
the 'sim' program and probably elsewhere.  In sim, it comes up for cases
like this:

#define round(x) ((x)>0.0 ? (x)+0.5 : (x)-0.5)
double G;
void T(double X) { G = round(X); }

(it uses the round macro a lot).  This changes the LLVM code from:

        %tmp.1 = setgt double %X, 0.000000e+00          ; <bool> [#uses=1]
        %tmp.4 = add double %X, 5.000000e-01            ; <double> [#uses=1]
        %tmp.6 = sub double %X, 5.000000e-01            ; <double> [#uses=1]
        %mem_tmp.0 = select bool %tmp.1, double %tmp.4, double %tmp.6
        store double %mem_tmp.0, double* %G

to:

        %tmp.1 = setgt double %X, 0.000000e+00          ; <bool> [#uses=1]
        %mem_tmp.0.p = select bool %tmp.1, double 5.000000e-01, double -5.000000e-01
        %mem_tmp.0 = add double %mem_tmp.0.p, %X
        store double %mem_tmp.0, double* %G
        ret void

llvm-svn: 19537
2005-01-13 22:52:24 +00:00
Chris Lattner 81e8417614 Implement an optimization for == and != comparisons like this:
_Bool test2(int X, int Y) {
  return &arr[X][Y] == arr;
}

instead of generating this:

bool %test2(int %X, int %Y) {
        %tmp.3.idx = mul int %X, 160            ; <int> [#uses=1]
        %tmp.3.idx1 = shl int %Y, ubyte 2               ; <int> [#uses=1]
        %tmp.3.offs2 = sub int 0, %tmp.3.idx            ; <int> [#uses=1]
        %tmp.7 = seteq int %tmp.3.idx1, %tmp.3.offs2            ; <bool> [#uses=1]
        ret bool %tmp.7
}


generate this:

bool %test2(int %X, int %Y) {
        seteq int %X, 0         ; <bool>:0 [#uses=1]
        seteq int %Y, 0         ; <bool>:1 [#uses=1]
        %tmp.7 = and bool %0, %1                ; <bool> [#uses=1]
        ret bool %tmp.7
}

This idiom occurs in C++ programs when iterating from begin() to end(),
in a vector or array.  For example, we now compile this:

void test(int X, int Y) {
  for (int *i = arr; i != arr+100; ++i)
    foo(*i);
}

to this:

no_exit:                ; preds = %entry, %no_exit
	...
        %exitcond = seteq uint %indvar.next, 100                ; <bool> [#uses=1]
        br bool %exitcond, label %return, label %no_exit



instead of this:

no_exit:                ; preds = %entry, %no_exit
	...
        %inc5 = getelementptr [100 x [40 x int]]* %arr, int 0, int 0, int %inc.rec              ; <int*> [#uses=1]
        %tmp.8 = seteq int* %inc5, getelementptr ([100 x [40 x int]]* %arr, int 0, int 100, int 0)              ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.8, label %return, label %no_exit

llvm-svn: 19536
2005-01-13 22:25:21 +00:00
Chris Lattner 4cb9fa373b Fix some bugs in code I didn't mean to check in.
llvm-svn: 19534
2005-01-13 20:40:58 +00:00
Chris Lattner 0798af33a5 Fix a crash compiling 129.compress
llvm-svn: 19533
2005-01-13 20:14:25 +00:00
Chris Lattner fdfe3e49fe Fix uint64_t -> unsigned VS warnings.
llvm-svn: 19381
2005-01-08 19:42:22 +00:00
Chris Lattner 86102b8ad5 This is a bulk commit that implements the following primary improvements:
* We can now fold cast instructions into select instructions that
    have at least one constant operand.
  * We now optimize expressions more aggressively based on bits that are
    known to be zero.  These optimizations occur a lot in code that uses
    bitfields even in simple ways.
  * We now turn more cast-cast sequences into AND instructions.  Before we
    would only do this if it if all types were unsigned.  Now only the
    middle type needs to be unsigned (guaranteeing a zero extend).
  * We transform sign extensions into zero extensions in several cases.

This corresponds to these test/Regression/Transforms/InstCombine testcases:
  2004-11-22-Missed-and-fold.ll
  and.ll: test28-29
  cast.ll: test21-24
  and-or-and.ll
  cast-cast-to-and.ll
  zeroext-and-reduce.ll

llvm-svn: 19220
2005-01-01 16:22:27 +00:00
Chris Lattner 9ad0d55025 Constant exprs are not efficiently negatable in practice. This disables
turning X - (constantexpr) into X + (-constantexpr) among other things.

llvm-svn: 18935
2004-12-14 20:08:06 +00:00
Chris Lattner bf5b7cf638 Optimize div/rem + select combinations more.
In particular, implement div.ll:test10 and rem.ll:test4.

llvm-svn: 18838
2004-12-12 21:48:58 +00:00
Chris Lattner 36d39cecb4 note to self: Do not check in debugging code!
llvm-svn: 18693
2004-12-09 07:15:52 +00:00
Chris Lattner f17a2fb849 Implement trivial sinking for load instructions. This causes us to sink 567 loads in spec
llvm-svn: 18692
2004-12-09 07:14:34 +00:00
Chris Lattner 39c98bb31c Do extremely simple sinking of instructions when they are only used in a
successor block.  This turns cases like this:

x = a op b
if (c) {
  use x
}

into:

if (c) {
  x = a op b
  use x
}

This triggers 3965 times in spec, and is tested by
Regression/Transforms/InstCombine/sink_instruction.ll

This appears to expose a bug in the X86 backend for 177.mesa, which I'm
looking in to.

llvm-svn: 18677
2004-12-08 23:43:58 +00:00
Alkis Evlogimenos a1291a0679 Fix this regression and remove the XFAIL from this test.
llvm-svn: 18674
2004-12-08 23:10:30 +00:00
Chris Lattner 8f30caf549 Fix Transforms/InstCombine/2004-12-08-RemInfiniteLoop.ll
llvm-svn: 18670
2004-12-08 22:20:34 +00:00
Reid Spencer 279fa256a2 Fix for PR454:
* Make sure we handle signed to unsigned conversion correctly
* Move this visitSetCondInst case to its own method.

llvm-svn: 18312
2004-11-28 21:31:15 +00:00
Chris Lattner 14f3cdc227 Implement Regression/Transforms/InstCombine/getelementptr_cast.ll, which
occurs many times in crafty

llvm-svn: 18273
2004-11-27 17:55:46 +00:00
Chris Lattner 953075442d Delete stoppoints that occur for the same source line.
llvm-svn: 17970
2004-11-18 21:41:39 +00:00
Chris Lattner 97013636cd Quiet warnings on the persephone tester
llvm-svn: 17821
2004-11-15 05:54:07 +00:00
Chris Lattner 46dd5a6304 This optimization makes MANY phi nodes that all have the same incoming value.
If this happens, detect it early instead of relying on instcombine to notice
it later.  This can be a big speedup, because PHI nodes can have many
incoming values.

llvm-svn: 17741
2004-11-14 19:29:34 +00:00
Chris Lattner 7515cabe2a Implement instcombine/phi.ll:test6 - pulling operations through PHI nodes.
This exposes subsequent optimization possiblities and reduces code size.
This triggers 1423 times in spec.

llvm-svn: 17740
2004-11-14 19:13:23 +00:00
Chris Lattner 15ff1e1885 Transform this:
%X = alloca ...
  %Y = alloca ...
    X == Y

into false.  This allows us to simplify some stuff in eon (and probably
many other C++ programs) where operator= was checking for self assignment.
Folding this allows us to SROA several additional structs.

llvm-svn: 17735
2004-11-14 07:33:16 +00:00
Chris Lattner 8c3e7b92af Simplify handling of shifts to be the same as we do for adds. Add support
for (X * C1) + (X * C2) (where * can be mul or shl), allowing us to fold:

   Y+Y+Y+Y+Y+Y+Y+Y

into
         %tmp.8 = shl long %Y, ubyte 3           ; <long> [#uses=1]

instead of

        %tmp.4 = shl long %Y, ubyte 2           ; <long> [#uses=1]
        %tmp.12 = shl long %Y, ubyte 2          ; <long> [#uses=1]
        %tmp.8 = add long %tmp.4, %tmp.12               ; <long> [#uses=1]

This implements add.ll:test25

Also add support for (X*C1)-(X*C2) -> X*(C1-C2), implementing sub.ll:test18

llvm-svn: 17704
2004-11-13 19:50:12 +00:00
Chris Lattner 4efe20a103 Fold:
(X + (X << C2)) --> X * ((1 << C2) + 1)
   ((X << C2) + X) --> X * ((1 << C2) + 1)

This means that we now canonicalize "Y+Y+Y" into:

        %tmp.2 = mul long %Y, 3         ; <long> [#uses=1]

instead of:

        %tmp.10 = shl long %Y, ubyte 1          ; <long> [#uses=1]
        %tmp.6 = add long %Y, %tmp.10               ; <long> [#uses=1]

llvm-svn: 17701
2004-11-13 19:31:40 +00:00
Chris Lattner 33eb909939 Fix some warnings on VC++
llvm-svn: 17481
2004-11-05 04:45:43 +00:00
Chris Lattner 96f6616479 * Rearrange code slightly
* Disable broken transforms for simplifying (setcc (cast X to larger), CI)
  where CC is not != or ==

llvm-svn: 17422
2004-11-02 03:50:32 +00:00
Chris Lattner 70c2039b39 Hrm, this code was severely botched. As it turns out, this patch:
http://mail.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20041018/019708.html

exposed ANOTHER latent bug in this xform, which caused Prolangs-C/bison to fill
the zion nightly tester disk up and make the tester barf.

This is obviously not a good thing, so lets fix this bug shall we? :)

llvm-svn: 17276
2004-10-27 05:57:15 +00:00
Chris Lattner 5c3c21e10a Fix a bug Nate noticed, where we miscompiled a simple testcase
llvm-svn: 17157
2004-10-22 04:53:16 +00:00
Chris Lattner 8ba9ec9bbb Turn things with obviously undefined semantics into 'store -> null'
llvm-svn: 17110
2004-10-18 02:59:09 +00:00
Chris Lattner 3b92f17165 My friend the invoke instruction does not dominate all basic blocks if it
occurs in the entry node of a function

llvm-svn: 17109
2004-10-18 01:48:31 +00:00
Chris Lattner 107c15c33d Remove printout, realize that instructions in the entry block dominate all
other blocks.

llvm-svn: 17099
2004-10-17 21:31:34 +00:00
Chris Lattner e29d634a94 hasConstantValue will soon return instructions that don't dominate the PHI node,
so prepare for this.

llvm-svn: 17095
2004-10-17 21:22:38 +00:00
Chris Lattner 67f0545daf Fix a type violation
llvm-svn: 17069
2004-10-16 23:28:04 +00:00
Chris Lattner 684c5c6587 Kill the bogon that slipped into my buffer before I committed.
llvm-svn: 17067
2004-10-16 19:46:33 +00:00
Chris Lattner 6580e09fef Implement InstCombine/getelementptr.ll:test9, which is the source of many
ugly and giant constnat exprs in some programs.

llvm-svn: 17066
2004-10-16 19:44:59 +00:00
Chris Lattner 81a7a23494 Optimize instructions involving undef values. For example X+undef == undef.
llvm-svn: 17047
2004-10-16 18:11:37 +00:00
Chris Lattner 00648e1f86 Transform memmove -> memcpy when the source is obviously constant memory.
llvm-svn: 16932
2004-10-12 04:52:52 +00:00
Chris Lattner a92af96c56 Reenable the transform, turning X/-10 < 1 into X > -10
llvm-svn: 16918
2004-10-11 19:40:04 +00:00
Chris Lattner 4ad08352b4 Implement sub.ll:test17, -X/C -> X/-C
llvm-svn: 16863
2004-10-09 02:50:40 +00:00
Chris Lattner 0b41e861b6 Temporarily disable a buggy transformation until it can be fixed. This fixes
254.gap.

llvm-svn: 16853
2004-10-08 19:15:44 +00:00
Chris Lattner bff91d9a2e Instcombine (X & FF00) + xx00 -> (X+xx00) & FF00, implementing and.ll:test27
This comes up when doing adds to bitfield elements.

llvm-svn: 16836
2004-10-08 05:07:56 +00:00
Chris Lattner 44bd392cbf Little patch to turn (shl (add X, 123), 4) -> (add (shl X, 4), 123 << 4)
This triggers in cases of bitfield additions, opening opportunities for
future improvements.

llvm-svn: 16834
2004-10-08 03:46:20 +00:00
Chris Lattner 0aee4b7947 Instcombine: -(X sdiv C) -> (X sdiv -C), tested by sub.ll:test16
llvm-svn: 16769
2004-10-06 15:08:25 +00:00
Chris Lattner abae776b18 Hrm, debugging printouts do not need to be in here
llvm-svn: 16598
2004-09-29 21:21:14 +00:00
Chris Lattner 6862fbd2cf * Pull range optimization code out into new InsertRangeTest function.
* SubOne/AddOne functions always return ConstantInt, declare them as such
* Pull code for handling setcc X, cst, where cst is at the end of the range,
  or cc is LE or GE up earlier in visitSetCondInst.  This reduces #iterations
  in some cases.
* Fold: (div X, C1) op C2 -> range check, implementing div.ll:test6 - test9.

llvm-svn: 16588
2004-09-29 17:40:11 +00:00
Chris Lattner 6a4adcda4c Fold binary expressions and casts into PHI nodes that have all constant inputs.
This takes something like this:

%A = phi int [ 3, %cond_false.0 ], [ 2, %endif.0.i ], [ 2, %endif.1.i ]
%B = div int %tmp.243, 4

and turns it into:

%A = phi int [ 3/4, %cond_false.0 ], [ 2/4, %endif.0.i ], [ 2/4, %endif.1.i ]

which is later simplified (in this case) into %A = 0.

This triggers thousands of times in spec, for example, 269 times in 176.gcc.

This is tested by InstCombine/add.ll:test23 and set.ll:test18.

llvm-svn: 16582
2004-09-29 05:07:12 +00:00
Chris Lattner c949128b2f Hrm, really, all tests passed without this, but it is scary to think how...
llvm-svn: 16568
2004-09-29 03:16:24 +00:00
Chris Lattner be7a69ebd8 Remove debugging printout
Instcombine (setcc (truncate X), C1).

This occurs THOUSANDS of times in many benchmarks.  Particularlly common
seem to be things like (seteq (cast bool X to int), int 0)

This turns it into (seteq bool %X, false), which then becomes (not %X).

llvm-svn: 16567
2004-09-29 03:09:18 +00:00
Chris Lattner dcf756ec22 Fold (X setcc C1) | (X setcc C2)
This implements or.ll:test1[89]

llvm-svn: 16561
2004-09-28 22:33:08 +00:00
Chris Lattner 623826c888 Fold (and (setcc X, C1), (setcc X, C2))
This is important for several reasons:

1. Benchmarks have lots of code that looks like this (perlbmk in particular):

  %tmp.2.i = setne int %tmp.0.i, 128              ; <bool> [#uses=1]
  %tmp.6343 = seteq int %tmp.0.i, 1               ; <bool> [#uses=1]
  %tmp.63 = and bool %tmp.2.i, %tmp.6343          ; <bool> [#uses=1]

   we now fold away the setne, a clear improvement.

2. In the more important cases, such as (X >= 10) & (X < 20), we now produce
   smaller code: (X-10) < 10.

3. Perhaps the nicest effect of this patch is that it really helps out the
   code generators.  In particular, for a 'range test' like the above,
   instead of generating this on X86 (the difference on PPC is even more
   pronounced):

        cmp %EAX, 50
        setge %CL
        cmp %EAX, 100
        setl %AL
        and %CL, %AL
        cmp %CL, 0

   we now generate this:

        add %EAX, -50
        cmp %EAX, 50

   Furthermore, this causes setcc's to be folded into branches more often.

These combinations trigger dozens of times in the spec benchmarks, particularly
in 176.gcc, 186.crafty, 253.perlbmk, 254.gap, & 099.go.

llvm-svn: 16559
2004-09-28 21:48:02 +00:00
Chris Lattner 272d5ca9e0 Implement X / C1 / C2 folding
Implement (setcc (shl X, C1), C2) folding.

The second one occurs several dozen times in spec.  The first was added
just in case.  :)

These are tested by shift.ll:test2[12], and div.ll:test5

llvm-svn: 16549
2004-09-28 18:22:15 +00:00
Chris Lattner 6afc02f816 shl is always zero extending, so always use a zero extending shift right.
This latent bug was exposed by recent changes, and is tested as:
llvm/test/Regression/Transforms/InstCombine/2004-09-28-BadShiftAndSetCC.llx

llvm-svn: 16546
2004-09-28 17:54:07 +00:00
Chris Lattner bfff18a869 Fix two bugs: one where a condition was mistakenly swapped, and another
where we folded (X & 254) -> X < 1 instead of X < 2.  These problems were
latent problems exposed by the latest patch.

llvm-svn: 16528
2004-09-27 19:29:18 +00:00
Chris Lattner 1023b8726e Fold: (setcc (shr X, ShAmt), CI), where 'cc' is eq or ne. This xform
triggers often, for example:

6x in povray, 1x in gzip, 279x in gcc, 1x in crafty, 8x in eon, 11x in perlbmk,
362x in gap, 4x in vortex, 14 in m88ksim, 211x in 126.gcc, 1x in compress,
11x in ijpeg, and 4x in 147.vortex.

llvm-svn: 16521
2004-09-27 16:18:50 +00:00