Commit Graph

2184 Commits

Author SHA1 Message Date
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 192cd18f53 Fix (hopefully the last) issue where LSR is nondeterminstic. When pulling
out CSE's of base expressions it could build a result whose order was
nondet.

llvm-svn: 23698
2005-10-11 18:41:04 +00:00
Chris Lattner 5c9d63da31 Fix another problem where LSR was being nondeterminstic. Also remove elements
from the end of a vector instead of the beginning

llvm-svn: 23697
2005-10-11 18:30:57 +00:00
Chris Lattner b7a3894e7c Fix another lsr-is-nondeterministic case
llvm-svn: 23695
2005-10-11 18:17:57 +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
Chris Lattner eb4be8b942 Hrm, you didn't see this.
llvm-svn: 23673
2005-10-09 06:24:02 +00:00
Chris Lattner 4ea0a3eaac Fix a source of non-determinism in the backend: the order of processing
IV strides dependend on the pointer order of the strides in memory.
Non-determinism is bad.

llvm-svn: 23672
2005-10-09 06:20:55 +00:00
Jeff Cohen 572910c9a2 Remove useless variable.
llvm-svn: 23656
2005-10-07 05:28:29 +00:00
Chris Lattner 20b0754c41 Fix DemoteRegToStack on an invoke. This fixes PR634.
llvm-svn: 23618
2005-10-04 00:44:01 +00:00
Chris Lattner 4c3b2b536c Clean up the code a bit. Use isInstructionTriviallyDead to be more aggressive
and more correct than use_empty().  This fixes PR635 and
SimplifyCFG/2005-10-02-InvokeSimplify.ll

llvm-svn: 23616
2005-10-03 23:43:43 +00:00
Chris Lattner f07a587c79 Make IVUseShouldUsePostIncValue more aggressive when the use is a PHI. In
particular, it should realize that phi's use their values in the pred block
not the phi block itself.  This change turns our em3d loop from this:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r2, 0
        b LBB_test_6    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        or r2, r6, r6
        lwz r6, 0(r3)
        cmpw cr0, r6, r5
        beq cr0, LBB_test_6     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r2, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; endif.loopexit.loopexit_crit_edge
        addi r3, r2, 1
        blr
LBB_test_6:     ; loopexit
        or r3, r2, r2
        blr

into:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r2, 0
        b LBB_test_5    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        or r2, r6, r6
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        or r2, r6, r6
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; loopexit
        or r3, r2, r2
        blr


Unfortunately, this is actually worse code, because the register coallescer
is getting confused somehow.  If it were doing its job right, it could turn the
code into this:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r6, 0
        b LBB_test_5    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; loopexit
        or r3, r6, r6
        blr

... which I'll work on next. :)

llvm-svn: 23604
2005-10-03 02:50:05 +00:00
Chris Lattner e4ed42a426 Refactor some code into a function
llvm-svn: 23603
2005-10-03 01:04:44 +00:00
Chris Lattner 360928dbed This break is bogus and I have no idea why it was there. Basically it prevents
memoizing code when IV's are used by phinodes outside of loops.  In a simple
example, we were getting this code before (note that r6 and r7 are isomorphic
IV's):

        li r6, 0
        or r7, r6, r6
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        or r2, r7, r7
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r2, r7, 1
        addi r7, r7, 1
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit

Now we get:

        li r6, 0
LBB_test_3:     ; no_exit
        or r2, r6, r6
        lwz r6, 0(r3)
        cmpw cr0, r6, r5
        beq cr0, LBB_test_6     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r2, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit

this was noticed in em3d.

llvm-svn: 23602
2005-10-03 00:37:33 +00:00
Chris Lattner 8fcce170cf when checking if we should move a split edge block outside of a loop,
check the presplit pred, not the post-split pred.  This was causing us
to make the wrong decision in some cases, leaving the critical edge block
in the loop.

llvm-svn: 23601
2005-10-03 00:31:52 +00:00
Jeff Cohen f8a5e5ae6e Fix VC++ warnings.
llvm-svn: 23579
2005-10-01 03:57:14 +00:00
Chris Lattner a554c9470b Insert stores after phi nodes in the normal dest. This fixes
LowerInvoke/2005-08-03-InvokeWithPHI.ll

llvm-svn: 23525
2005-09-29 17:44:20 +00:00
Chris Lattner 87ef943a4c Fold isascii into a simple comparison. This speeds up 197.parser by 7.4%,
bringing the LLC time down to the CBE time.

llvm-svn: 23521
2005-09-29 06:17:27 +00:00
Chris Lattner 5f6035feb0 remove a bunch of unneeded stuff, or self evident comments
llvm-svn: 23519
2005-09-29 06:16:11 +00:00
Chris Lattner c244e7c178 Implement a couple of memcmp folds from the todo list
llvm-svn: 23517
2005-09-29 04:54:20 +00:00
Chris Lattner ea7214b23d Constant fold llvm.sqrt
llvm-svn: 23487
2005-09-28 01:34:32 +00:00
Chris Lattner 3b63bb375c add a note about a way to improve this code further, that I won't be getting
to right now.

llvm-svn: 23485
2005-09-27 22:44:59 +00:00
Chris Lattner eb953f0ef8 Fix a regression in my previous patch, fixing GlobalOpt/2005-09-27-Crash.ll
and PR632.

llvm-svn: 23484
2005-09-27 22:28:11 +00:00
Chris Lattner e285f5ed8f Avoid spilling stack slots... to stack slots.
llvm-svn: 23478
2005-09-27 21:33:12 +00:00
Chris Lattner 87eb249300 Completely rewrite 'correct' eh support. This changes how setjmp insertion
is performed so it is only at most once per function that contains an invoke
instead of once per invoke in the function.  This patch has the following perks:

1. It fixes PR631, which complains about slowness.
2. If fixes PR240, which complains about non-volatile vars being live across
   setjmp/longjmps.
3. It improves (but does not fix) the jmpbuf alignment issue on itanium by not
   forcing the jmpbufs to always be 8-bytes off the alignment of the structure.
4. It speeds up 253.perlbmk from 338s to 13.70s (a 25x improvement!), making us
   now about 4% faster than GCC.

Further improvements are also possible.

llvm-svn: 23477
2005-09-27 21:18:17 +00:00
Chris Lattner 92233d2175 Make the pass name simpler
llvm-svn: 23476
2005-09-27 21:10:32 +00:00
Chris Lattner 16cd356fb2 allow demotion to volatile values, add support for invoke
llvm-svn: 23473
2005-09-27 19:39:00 +00:00
Chris Lattner 3d27e7f27f Add support for external calls that we know how to constant fold. This implements
ctor-list-opt.ll:CTOR8

llvm-svn: 23465
2005-09-27 05:02:43 +00:00
Chris Lattner 29b2780c8a Fix a bug where we would evaluate stores into linkonce objects which could be
potentially replaced at link-time.

llvm-svn: 23463
2005-09-27 04:50:03 +00:00
Chris Lattner 65a3a0918f Implement support for static constructors with calls in them. This is useful
because gccas runs globalopt before inlining.

This implements ctor-list-opt.ll:CTOR7

llvm-svn: 23462
2005-09-27 04:45:34 +00:00
Chris Lattner da1889b778 Refactor this code a bit, no functionality changes.
llvm-svn: 23460
2005-09-27 04:27:01 +00:00
Chris Lattner f2f89af69a Remove some dead code. ctor evaluation subsumes empty ctor elim
llvm-svn: 23453
2005-09-26 20:38:20 +00:00
Chris Lattner 6bf2cd5735 Add support for alloca, implementing ctor-list-opt.ll:CTOR6
llvm-svn: 23452
2005-09-26 17:07:09 +00:00
Chris Lattner 46d9ff081d Add a debug printout, fix a crash on kc++
llvm-svn: 23450
2005-09-26 07:34:35 +00:00
Chris Lattner 46af55e0e4 Implement loads/stores through GEP's of globals. This implements
ctor-list-opt.ll:CTOR5.

llvm-svn: 23449
2005-09-26 06:52:44 +00:00
Chris Lattner 61ff32cd70 Replace TraverseGEPInitializer with ConstantFoldLoadThroughGEPConstantExpr
llvm-svn: 23447
2005-09-26 05:34:07 +00:00
Chris Lattner 02ae21e1e0 Eliminate GetGEPGlobalInitializer in favor of the more powerful
ConstantFoldLoadThroughGEPConstantExpr function in the utils lib.

llvm-svn: 23446
2005-09-26 05:28:52 +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 c13c7b9376 Move the ConstantFoldLoadThroughGEPConstantExpr function out of the InstCombine
pass.

llvm-svn: 23444
2005-09-26 05:27:10 +00:00
Chris Lattner b009663e27 add a comment
llvm-svn: 23442
2005-09-26 05:16:34 +00:00
Chris Lattner 4b05c322d5 Add support for getelementptr, load, and correctly reject volatile stores.
llvm-svn: 23441
2005-09-26 05:15:37 +00:00
Chris Lattner 3e9ea5ffec Add support for br/brcond/switch and phi
llvm-svn: 23439
2005-09-26 04:57:38 +00:00
Chris Lattner 99e23fa74c Add a simple interpreter to this code, allowing us to statically evaluate
global ctors that are simple enough.  This implements ctor-list-opt.ll:CTOR2.

llvm-svn: 23437
2005-09-26 04:44:35 +00:00
Chris Lattner 696beefabb factor some code into a InstallGlobalCtors method, add comments. No functionality change.
llvm-svn: 23435
2005-09-26 02:31:18 +00:00
Chris Lattner 838bdc1836 Make the global opt optimizer work on modules with a null terminator, by
accepting the null even with a non-65535 init prio

llvm-svn: 23434
2005-09-26 02:19:27 +00:00
Chris Lattner 41b6a5a693 Factor this code out into a few methods.
Implement the start of global ctor optimization.  It is currently smart
enough to remove the global ctor for cases like this:

struct foo {
  foo() {}
} x;

... saving a bit of startup time for the program.

llvm-svn: 23433
2005-09-26 01:43:45 +00:00
Chris Lattner f487768062 Fix some logic I broke that caused a regression on
SimplifyLibCalls/2005-05-20-sprintf-crash.ll

llvm-svn: 23430
2005-09-25 07:06:48 +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 175463a165 Simplify this code a bit by relying on recursive simplification. Support
sprintf("%s", P)'s that have uses.

s/hasNUses(0)/use_empty()/

llvm-svn: 23425
2005-09-24 22:17:06 +00:00
Chris Lattner 499e33646e remove some debugging code
llvm-svn: 23411
2005-09-23 18:49:09 +00:00
Chris Lattner c59a371d45 Fold two consequtive branches that share a common destination between them.
This implements SimplifyCFG/branch-fold.ll, and is useful on ?:/min/max heavy
code

llvm-svn: 23410
2005-09-23 18:47:20 +00:00
Chris Lattner 3a978bf66d simplify some logic further
llvm-svn: 23408
2005-09-23 07:23:18 +00:00
Chris Lattner cc14ebc17b pull a bunch of logic out of SimplifyCFG into a helper fn
llvm-svn: 23407
2005-09-23 06:39:30 +00:00
Chris Lattner 6c70106053 Start threading across blocks with code in them, so long as the code does
not define a value that is used outside of it's block.  This catches many
more simplifications, e.g. 854 in 176.gcc, 137 in vpr, etc.

This implements branch-phi-thread.ll:test3.ll

llvm-svn: 23397
2005-09-20 01:48:40 +00:00
Chris Lattner f0bd8d0107 Implement merging of blocks with the same condition if the block has multiple
predecessors.  This implements branch-phi-thread.ll::test1

llvm-svn: 23395
2005-09-20 00:43:16 +00:00
Chris Lattner 049cb4482f Reject a case we don't handle yet
llvm-svn: 23393
2005-09-19 23:57:04 +00:00
Chris Lattner a160924d57 remove debugging code :-/
llvm-svn: 23392
2005-09-19 23:50:15 +00:00
Chris Lattner 748f903046 Implement SimplifyCFG/branch-phi-thread.ll, the most trivial case of threading
control across branches with determined outcomes.  More generality to follow.
This triggers a couple thousand times in specint.

llvm-svn: 23391
2005-09-19 23:49:37 +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 fd018c8dfe Fix an issue where LSR would miss rewriting a use of an IV expression by a PHI node that is not the original PHI.
This fixes up a dot-product loop in galgel, speeding it up from 18.47s to
16.13s.

llvm-svn: 23327
2005-09-13 02:09:55 +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 8048b85e8f Fix a regression from last night, which caused this pass to create invalid
code for IV uses outside of loops that are not dominated by the latch block.
We should only convert these uses to use the post-inc value if they ARE
dominated by the latch block.

Also use a new LoopInfo method to simplify some code.

This fixes Transforms/LoopStrengthReduce/2005-09-12-UsesOutOutsideOfLoop.ll

llvm-svn: 23318
2005-09-12 17:11:27 +00:00
Chris Lattner a67648396a _test:
li r2, 0
LBB_test_1:     ; no_exit.2
        li r5, 0
        stw r5, 0(r3)
        addi r2, r2, 1
        addi r3, r3, 4
        cmpwi cr0, r2, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r2, 1
        stw r2, 0(r4)
        blr
[zion ~/llvm]$ cat > ~/xx
Uses of IV's outside of the loop should use hte post-incremented version
of the IV, not the preincremented version.  This helps many loops (e.g. in sixtrack)
which used to generate code like this (this is the code from the
dont-hoist-simple-loop-constants.ll testcase):

_test:
        li r2, 0                 **** IV starts at 0
LBB_test_1:     ; no_exit.2
        or r5, r2, r2            **** Copy for loop exit
        li r2, 0
        stw r2, 0(r3)
        addi r3, r3, 4
        addi r2, r5, 1
        addi r6, r5, 2           **** IV+2
        cmpwi cr0, r6, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r5, 2       ****  IV+2
        stw r2, 0(r4)
        blr

And now generated code like this:

_test:
        li r2, 1               *** IV starts at 1
LBB_test_1:     ; no_exit.2
        li r5, 0
        stw r5, 0(r3)
        addi r2, r2, 1
        addi r3, r3, 4
        cmpwi cr0, r2, 701     *** IV.postinc + 0
        blt cr0, LBB_test_1
LBB_test_2:     ; loopexit.2.loopexit
        stw r2, 0(r4)          *** IV.postinc + 0
        blr

llvm-svn: 23313
2005-09-12 06:04:47 +00:00
Chris Lattner 530fe6ab30 implement Transforms/LoopStrengthReduce/dont-hoist-simple-loop-constants.ll.
We used to emit this code for it:

_test:
        li r2, 1     ;; Value tying up a register for the whole loop
        li r5, 0
LBB_test_1:     ; no_exit.2
        or r6, r5, r5
        li r5, 0
        stw r5, 0(r3)
        addi r5, r6, 1
        addi r3, r3, 4
        add r7, r2, r5  ;; should be addi r7, r5, 1
        cmpwi cr0, r7, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r6, 2
        stw r2, 0(r4)
        blr

now we emit this:

_test:
        li r2, 0
LBB_test_1:     ; no_exit.2
        or r5, r2, r2
        li r2, 0
        stw r2, 0(r3)
        addi r3, r3, 4
        addi r2, r5, 1
        addi r6, r5, 2   ;; whoa, fold those adds!
        cmpwi cr0, r6, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r5, 2
        stw r2, 0(r4)
        blr

more improvement coming.

llvm-svn: 23306
2005-09-10 01:18:45 +00:00
Chris Lattner b5e381a8cf Fix a problem that Dan Berlin noticed, where reassociation would not succeed
in building maximal expressions before simplifying them.  In particular, i
cases like this:

X-(A+B+X)

the code would consider A+B+X to be a maximal expression (not understanding
that the single use '-' would be turned into a + later), simplify it (a noop)
then later get simplified again.

Each of these simplify steps is where the cost of reassociation comes from,
so this patch should speed up the already fast pass a bit.

Thanks to Dan for noticing this!

llvm-svn: 23214
2005-09-02 07:07:58 +00:00
Chris Lattner 9fe263aa75 Avoid creating garbage instructions, just move the old add instruction
to where we need it when converting -(A+B+C) -> -A + -B + -C.

llvm-svn: 23213
2005-09-02 06:38:04 +00:00
Chris Lattner d1325da091 add some assertions and fix problems where reassociate could access the
Ops vector out of range

llvm-svn: 23211
2005-09-02 05:23:22 +00:00
Chris Lattner 8ca5b2a6d2 Fix Regression/Transforms/Reassociate/2005-08-24-Crash.ll
llvm-svn: 23019
2005-08-24 17:55:32 +00:00
Chris Lattner 4201cd1bbc Transform floor((double)FLT) -> (double)floorf(FLT), implementing
Regression/Transforms/SimplifyLibCalls/floor.ll.  This triggers 19 times in
177.mesa.

llvm-svn: 23017
2005-08-24 17:22:17 +00:00
Chris Lattner ea7dfd53d6 Fix Transforms/LoopStrengthReduce/2005-08-17-OutOfLoopVariant.ll, a crash
on 177.mesa

llvm-svn: 22843
2005-08-17 21:22:41 +00:00
Chris Lattner 2bf7cb5213 Use a new helper to split critical edges, making the code simpler.
Do not claim to not change the CFG.  We do change the cfg to split critical
edges.  This isn't causing us a problem now, but could likely do so in the
future.

llvm-svn: 22824
2005-08-17 06:35:16 +00:00
Chris Lattner 5cf983ee0f Fix a bad case in gzip where we put lots of things in registers across the
loop, because a IV-dependent value was used outside of the loop and didn't
have immediate-folding capability

llvm-svn: 22798
2005-08-16 00:38:11 +00:00
Chris Lattner 47d3ec3525 Ooops, don't forget to clear this. The real inner loop is now:
.LBB_foo_3:     ; no_exit.1
        lfd f2, 0(r9)
        lfd f3, 8(r9)
        fmul f4, f1, f2
        fmadd f4, f0, f3, f4
        stfd f4, 8(r9)
        fmul f3, f1, f3
        fmsub f2, f0, f2, f3
        stfd f2, 0(r9)
        addi r9, r9, 16
        addi r8, r8, 1
        cmpw cr0, r8, r4
        ble .LBB_foo_3  ; no_exit.1

llvm-svn: 22782
2005-08-13 07:42:01 +00:00
Chris Lattner 5949d49032 Recursively scan scev expressions for common subexpressions. This allows us
to handle nested loops much better, for example, by being able to tell that
these two expressions:

{( 8 + ( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp 12)}<loopentry.1>

{(( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp12)}<loopentry.1>

Have the following common part that can be shared:
{(( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp12)}<loopentry.1>

This allows us to codegen an important inner loop in 168.wupwise as:

.LBB_foo_4:     ; no_exit.1
        lfd f2, 16(r9)
        fmul f3, f0, f2
        fmul f2, f1, f2
        fadd f4, f3, f2
        stfd f4, 8(r9)
        fsub f2, f3, f2
        stfd f2, 16(r9)
        addi r8, r8, 1
        addi r9, r9, 16
        cmpw cr0, r8, r4
        ble .LBB_foo_4  ; no_exit.1

instead of:

.LBB_foo_3:     ; no_exit.1
        lfdx f2, r6, r9
        add r10, r6, r9
        lfd f3, 8(r10)
        fmul f4, f1, f2
        fmadd f4, f0, f3, f4
        stfd f4, 8(r10)
        fmul f3, f1, f3
        fmsub f2, f0, f2, f3
        stfdx f2, r6, r9
        addi r9, r9, 16
        addi r8, r8, 1
        cmpw cr0, r8, r4
        ble .LBB_foo_3  ; no_exit.1

llvm-svn: 22781
2005-08-13 07:27:18 +00:00
Chris Lattner 89c1dfc733 Teach SplitCriticalEdge to update LoopInfo if it is alive. This fixes
a problem in LoopStrengthReduction, where it would split critical edges
then confused itself with outdated loop information.

llvm-svn: 22776
2005-08-13 01:38:43 +00:00
Chris Lattner 79396539d3 remove dead code. The exit block list is computed on demand, thus does not
need to be updated.  This code is a relic from when it did.

llvm-svn: 22775
2005-08-13 01:30:36 +00:00
Chris Lattner 8447b49526 When splitting critical edges, make sure not to leave the new block in the
middle of the loop.  This turns a critical loop in gzip into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_8 ; loopentry.loopexit_crit_edge
.LBB_test_2:    ; shortcirc_next.0
        add r28, r3, r27
        lhz r28, 5(r28)
        add r26, r4, r27
        lhz r26, 5(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_7 ; shortcirc_next.0.loopexit_crit_edge
.LBB_test_3:    ; shortcirc_next.1
        add r28, r3, r27
        lhz r28, 7(r28)
        add r26, r4, r27
        lhz r26, 7(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_6 ; shortcirc_next.1.loopexit_crit_edge
.LBB_test_4:    ; shortcirc_next.2
        add r28, r3, r27
        lhz r26, 9(r28)
        add r28, r4, r27
        lhz r25, 9(r28)
        addi r28, r27, 8
        cmpw cr7, r26, r25
        mfcr r26, 1
        rlwinm r26, r26, 31, 31, 31
        add r25, r8, r27
        cmpw cr7, r25, r7
        mfcr r25, 1
        rlwinm r25, r25, 29, 31, 31
        and. r26, r26, r25
        bne .LBB_test_1 ; loopentry

instead of this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_test_9   ; loopexit
.LBB_test_3:    ; shortcirc_next.0
        add r28, r3, r27
        lhz r28, 5(r28)
        add r26, r4, r27
        lhz r26, 5(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_5 ; shortcirc_next.1
.LBB_test_4:    ; shortcirc_next.0.loopexit_crit_edge
        add r2, r11, r27
        add r8, r12, r27
        b .LBB_test_9   ; loopexit
.LBB_test_5:    ; shortcirc_next.1
        add r28, r3, r27
        lhz r28, 7(r28)
        add r26, r4, r27
        lhz r26, 7(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_7 ; shortcirc_next.2
.LBB_test_6:    ; shortcirc_next.1.loopexit_crit_edge
        add r2, r9, r27
        add r8, r10, r27
        b .LBB_test_9   ; loopexit
.LBB_test_7:    ; shortcirc_next.2
        add r28, r3, r27
        lhz r26, 9(r28)
        add r28, r4, r27
        lhz r25, 9(r28)
        addi r28, r27, 8
        cmpw cr7, r26, r25
        mfcr r26, 1
        rlwinm r26, r26, 31, 31, 31
        add r25, r8, r27
        cmpw cr7, r25, r7
        mfcr r25, 1
        rlwinm r25, r25, 29, 31, 31
        and. r26, r26, r25
        bne .LBB_test_1 ; loopentry

Next up, improve the code for the loop.

llvm-svn: 22769
2005-08-12 22:22:17 +00:00
Chris Lattner 4fec86d348 Fix a FIXME: if we are inserting code for a PHI argument, split the critical
edge so that the code is not always executed for both operands.  This
prevents LSR from inserting code into loops whose exit blocks contain
PHI uses of IV expressions (which are outside of loops).  On gzip, for
example, we turn this ugly code:

.LBB_test_1:    ; loopentry
        add r27, r3, r28
        lhz r27, 3(r27)
        add r26, r4, r28
        lhz r26, 3(r26)
        add r25, r30, r28    ;; Only live if exiting the loop
        add r24, r29, r28    ;; Only live if exiting the loop
        cmpw cr0, r27, r26
        bne .LBB_test_5 ; loopexit

into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_test_9   ; loopexit
.LBB_test_2:    ; shortcirc_next.0
        ...
        blt .LBB_test_1


into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_t_3:    ; shortcirc_next.0
.LBB_test_3:    ; shortcirc_next.0
        ...
        blt .LBB_test_1


Next step: get the block out of the loop so that the loop is all
fall-throughs again.

llvm-svn: 22766
2005-08-12 22:06:11 +00:00
Chris Lattner b7ebe65c56 Change break critical edges to not remove, then insert, PHI node entries.
Instead, just update the BB in-place.  This is both faster, and it prevents
split-critical-edges from shuffling the PHI argument list unneccesarily.

llvm-svn: 22765
2005-08-12 21:58:07 +00:00
Chris Lattner 62df798919 remove some trickiness that broke yacr2 and some other programs last night
llvm-svn: 22751
2005-08-10 17:15:20 +00:00
Chris Lattner f83ce5faee Make loop-simplify produce better loops by turning PHI nodes like X = phi [X, Y]
into just Y.  This often occurs when it seperates loops that have collapsed loop
headers.  This implements LoopSimplify/phi-node-simplify.ll

llvm-svn: 22746
2005-08-10 02:07:32 +00:00
Chris Lattner 677d85784a Allow indvar simplify to canonicalize ANY affine IV, not just affine IVs with
constant stride.  This implements Transforms/IndVarsSimplify/variable-stride-ivs.ll

llvm-svn: 22744
2005-08-10 01:12:06 +00:00
Chris Lattner edff91a49a Teach LSR to strength reduce IVs that have a loop-invariant but non-constant stride.
For code like this:

void foo(float *a, float *b, int n, int stride_a, int stride_b) {
  int i;
  for (i=0; i<n; i++)
      a[i*stride_a] = b[i*stride_b];
}

we now emit:

.LBB_foo2_2:    ; no_exit
        lfs f0, 0(r4)
        stfs f0, 0(r3)
        addi r7, r7, 1
        add r4, r2, r4
        add r3, r6, r3
        cmpw cr0, r7, r5
        blt .LBB_foo2_2 ; no_exit

instead of:

.LBB_foo_2:     ; no_exit
        mullw r8, r2, r7     ;; multiply!
        slwi r8, r8, 2
        lfsx f0, r4, r8
        mullw r8, r2, r6     ;; multiply!
        slwi r8, r8, 2
        stfsx f0, r3, r8
        addi r2, r2, 1
        cmpw cr0, r2, r5
        blt .LBB_foo_2  ; no_exit

loops with variable strides occur pretty often.  For example, in SPECFP2K
there are 317 variable strides in 177.mesa, 3 in 179.art, 14 in 188.ammp,
56 in 168.wupwise, 36 in 172.mgrid.

Now we can allow indvars to turn functions written like this:

void foo2(float *a, float *b, int n, int stride_a, int stride_b) {
  int i, ai = 0, bi = 0;
  for (i=0; i<n; i++)
    {
      a[ai] = b[bi];
      ai += stride_a;
      bi += stride_b;
    }
}

into code like the above for better analysis.  With this patch, they generate
identical code.

llvm-svn: 22740
2005-08-10 00:45:21 +00:00
Chris Lattner dde7dc525e Fix Regression/Transforms/LoopStrengthReduce/phi_node_update_multiple_preds.ll
by being more careful about updating PHI nodes

llvm-svn: 22739
2005-08-10 00:35:32 +00:00
Chris Lattner c6c4d99a21 Fix some 80 column violations.
Once we compute the evolution for a GEP, tell SE about it.  This allows users
of the GEP to know it, if the users are not direct.  This allows us to compile
this testcase:

void fbSolidFillmmx(int w, unsigned char *d) {
    while (w >= 64) {
        *(unsigned long long *) (d +  0) = 0;
        *(unsigned long long *) (d +  8) = 0;
        *(unsigned long long *) (d + 16) = 0;
        *(unsigned long long *) (d + 24) = 0;
        *(unsigned long long *) (d + 32) = 0;
        *(unsigned long long *) (d + 40) = 0;
        *(unsigned long long *) (d + 48) = 0;
        *(unsigned long long *) (d + 56) = 0;
        w -= 64;
        d += 64;
    }
}

into:

.LBB_fbSolidFillmmx_2:  ; no_exit
        li r2, 0
        stw r2, 0(r4)
        stw r2, 4(r4)
        stw r2, 8(r4)
        stw r2, 12(r4)
        stw r2, 16(r4)
        stw r2, 20(r4)
        stw r2, 24(r4)
        stw r2, 28(r4)
        stw r2, 32(r4)
        stw r2, 36(r4)
        stw r2, 40(r4)
        stw r2, 44(r4)
        stw r2, 48(r4)
        stw r2, 52(r4)
        stw r2, 56(r4)
        stw r2, 60(r4)
        addi r4, r4, 64
        addi r3, r3, -64
        cmpwi cr0, r3, 63
        bgt .LBB_fbSolidFillmmx_2       ; no_exit

instead of:

.LBB_fbSolidFillmmx_2:  ; no_exit
        li r11, 0
        stw r11, 0(r4)
        stw r11, 4(r4)
        stwx r11, r10, r4
        add r12, r10, r4
        stw r11, 4(r12)
        stwx r11, r9, r4
        add r12, r9, r4
        stw r11, 4(r12)
        stwx r11, r8, r4
        add r12, r8, r4
        stw r11, 4(r12)
        stwx r11, r7, r4
        add r12, r7, r4
        stw r11, 4(r12)
        stwx r11, r6, r4
        add r12, r6, r4
        stw r11, 4(r12)
        stwx r11, r5, r4
        add r12, r5, r4
        stw r11, 4(r12)
        stwx r11, r2, r4
        add r12, r2, r4
        stw r11, 4(r12)
        addi r4, r4, 64
        addi r3, r3, -64
        cmpwi cr0, r3, 63
        bgt .LBB_fbSolidFillmmx_2       ; no_exit

llvm-svn: 22737
2005-08-09 23:39:36 +00:00