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Commit Graph

1522 Commits

Author SHA1 Message Date
Chris Lattner
d1906e2ace 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
96752d27f4 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
a3e2004609 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
7d02bae5d8 Fix an incredibly nasty iterator invalidation problem. I am too spoiled by ilists :)
Eventually it would be nice if CallGraph maintained an ilist of CallGraphNode's instead
of a vector of pointers to them, but today is not that day.

llvm-svn: 13100
2004-04-21 20:44:33 +00:00
Alkis Evlogimenos
904f4f9a21 Include cerrno (gcc-3.4 fix)
llvm-svn: 13091
2004-04-21 16:11:40 +00:00
Chris Lattner
ade6ddc694 Fix typeo
llvm-svn: 13089
2004-04-21 14:23:18 +00:00
Chris Lattner
15eb3c1f39 REALLY fix PR324: don't delete linkonce functions until after the SCC traversal
is done, which avoids invalidating iterators in the SCC traversal routines

llvm-svn: 13088
2004-04-20 22:06:53 +00:00
Chris Lattner
602146eea1 Fix PR325
llvm-svn: 13081
2004-04-20 20:26:03 +00:00
Chris Lattner
5a1e3f099f Fix PR324 and testcase: Inline/2004-04-20-InlineLinkOnce.llx
llvm-svn: 13080
2004-04-20 20:20:59 +00:00
Chris Lattner
29f69938e7 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
1849aa8b1f Add #include
llvm-svn: 13057
2004-04-19 03:01:23 +00:00
Chris Lattner
ab6502f058 Move isLoopInvariant to the Loop class
llvm-svn: 13051
2004-04-18 22:46:08 +00:00
Chris Lattner
5a0ed18724 Correct rewriting of exit blocks after my last patch
llvm-svn: 13048
2004-04-18 22:27:10 +00:00
Chris Lattner
8e42c6f409 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
7174acca00 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
13140766df Reduce the unrolling limit
llvm-svn: 13040
2004-04-18 18:06:14 +00:00
Chris Lattner
430968ac2f 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
199b58db3f 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
33ec7f2f9f 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
f2045a8c05 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
b0d23bf99d 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
e0f56972f0 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
740ae78ae6 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
bcb690dc9b 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
5c85946417 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
6d5decd7d4 Add support for evaluation of exp/log/log10/pow
llvm-svn: 13011
2004-04-16 22:35:33 +00:00
Chris Lattner
ed423cc09d 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
Brian Gaeke
4b9f67c638 Include <cmath> for compatibility with gcc 3.0.x (the system compiler on
Debian.)

llvm-svn: 12986
2004-04-16 15:57:32 +00:00
Chris Lattner
bc458be5f9 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
06eda01d1b Fix Inline/2004-04-15-InlineDeletesCall.ll
Basically we were using SimplifyCFG as a huge sledgehammer for a simple
optimization.  Because simplifycfg does so many things, we can't use it
for this purpose.

llvm-svn: 12977
2004-04-16 05:17:59 +00:00
Chris Lattner
ac2b465cb4 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
dcf2ca93e6 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
6fcf8c7402 ADd a trivial instcombine: load null -> null
llvm-svn: 12940
2004-04-14 03:28:36 +00:00
Chris Lattner
545e77c9d5 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
778f09027f Add a simple call constant propagation interface.
llvm-svn: 12919
2004-04-13 19:28:52 +00:00
Chris Lattner
8c0e9c95e9 Constant propagation should remove the dead instructions
llvm-svn: 12917
2004-04-13 19:28:20 +00:00
Chris Lattner
70f6a0ddcf 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
ae63c235f9 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
faf377df58 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
a3d3872a88 Actually update the call graph as the inliner changes it. This allows us to
execute other CallGraphSCCPasses after the inliner without crashing.

llvm-svn: 12861
2004-04-12 05:37:29 +00:00
Chris Lattner
603d821596 Add support for removing invoke instructions
llvm-svn: 12858
2004-04-12 05:15:13 +00:00
Chris Lattner
af22e5f826 Stop printing Function*
llvm-svn: 12857
2004-04-12 04:06:56 +00:00
Chris Lattner
1c83ee0436 Simplify code a bit, and be sure to mark the external node as potentially throwing
llvm-svn: 12856
2004-04-12 04:06:38 +00:00
Chris Lattner
ca1428e01c Fix a bug in my select transformation
llvm-svn: 12826
2004-04-11 01:39:19 +00:00
Chris Lattner
777977bf2e Update the value numbering interface.
llvm-svn: 12824
2004-04-10 22:33:34 +00:00
Chris Lattner
96fca8de3d Implement InstCombine/select.ll:test13*
llvm-svn: 12821
2004-04-10 22:21:27 +00:00
Chris Lattner
618c89d5eb 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
6d569b52ed 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
22c22de2f0 Fix spurious warning in release mode
llvm-svn: 12816
2004-04-10 19:15:56 +00:00
Chris Lattner
924b6c173c 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
f126f03878 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
d4979e2904 Fix previous patch
llvm-svn: 12811
2004-04-10 07:27:48 +00:00
Chris Lattner
3b211f0432 Correctly update counters
llvm-svn: 12810
2004-04-10 07:02:02 +00:00
Chris Lattner
1676188024 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
306540a2f4 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
8ccddbd123 Fold code like:
if (C)
    V1 |= V2;

into:
  Vx = V1 | V2;
  V1 = select C, V1, Vx

when the expression can be evaluated unconditionally and is *cheap* to
execute.  This limited form of if conversion is quite handy in lots of cases.
For example, it turns this testcase into straight-line code:

int in0 ; int in1 ; int in2 ; int in3 ;
int in4 ; int in5 ; int in6 ; int in7 ;
int in8 ; int in9 ; int in10; int in11;
int in12; int in13; int in14; int in15;
long output;

void mux(void) {
  output =
      (in0   ?  0x00000001 : 0) | (in1   ?  0x00000002 : 0) |
      (in2   ?  0x00000004 : 0) | (in3   ?  0x00000008 : 0) |
      (in4   ?  0x00000010 : 0) | (in5   ?  0x00000020 : 0) |
      (in6   ?  0x00000040 : 0) | (in7   ?  0x00000080 : 0) |
      (in8   ?  0x00000100 : 0) | (in9   ?  0x00000200 : 0) |
      (in10  ?  0x00000400 : 0) | (in11  ?  0x00000800 : 0) |
      (in12  ?  0x00001000 : 0) | (in13  ?  0x00002000 : 0) |
      (in14  ?  0x00004000 : 0) | (in15  ?  0x00008000 : 0) ;
}

llvm-svn: 12798
2004-04-09 22:50:22 +00:00
Chris Lattner
3a6e4b9a35 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
0e1f5553df Implement select.ll:test11
llvm-svn: 12793
2004-04-09 18:19:44 +00:00
Chris Lattner
0ca3cbfa5e Implement InstCombine/cast-propagate.ll
llvm-svn: 12784
2004-04-08 20:39:49 +00:00
Chris Lattner
d8efae05fe Implement ScalarRepl/select_promote.ll
llvm-svn: 12779
2004-04-08 19:59:34 +00:00
Chris Lattner
77beb73ce2 Remove the "really gross hacks" that are there to deal with recursive functions.
Now we collect all of the call sites we are interested in inlining, then inline
them.  This entirely avoids issues with trying to inline a call site we got by
inlining another call site.  This also eliminates iterator invalidation issues.

llvm-svn: 12770
2004-04-08 06:34:31 +00:00
Chris Lattner
cf8117ccbd Implement InstCombine/select.ll:test[7-10]
llvm-svn: 12769
2004-04-08 04:43:23 +00:00
Chris Lattner
2e89e48999 Implement test/Regression/Transforms/InstCombine/getelementptr_index.ll
llvm-svn: 12762
2004-04-07 18:38:20 +00:00
Chris Lattner
c92af54ed5 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
6c961339a3 Fix InstCombine/2004-04-04-InstCombineReplaceAllUsesWith.ll
llvm-svn: 12658
2004-04-05 02:10:19 +00:00
Chris Lattner
9236135e8f 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
cf5bd8a9ab 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
3f202e3a54 Fix the obvious bug in my previous checkin
llvm-svn: 12618
2004-04-02 18:15:10 +00:00
Chris Lattner
bca948c99d Implement Transforms/SimplifyCFG/return-merge.ll
This actually causes us to turn code like:

  return C ? A : B;

into a select instruction.

llvm-svn: 12617
2004-04-02 18:13:43 +00:00
Chris Lattner
973cb73b4f Fix PR310 and TailDup/2004-04-01-DemoteRegToStack.llx
llvm-svn: 12597
2004-04-01 20:28:45 +00:00
Chris Lattner
441ab4b903 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
eda638b0be 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
6aaea5f86b Add warning
llvm-svn: 12573
2004-03-31 22:00:30 +00:00
Chris Lattner
1c0ddbfb7d Fix linking of constant expr casts due to type resolution changes. With
this and the other patches 253.perlbmk links again.

llvm-svn: 12565
2004-03-31 02:58:28 +00:00
Brian Gaeke
59c80cfd05 Start cleaning up this pass so that I can debug it.
llvm-svn: 12548
2004-03-30 19:53:46 +00:00
Chris Lattner
145aea5c4c Now that all the code generators support the select instruction, and the instcombine
pass can eliminate many nasty cases of them, start generating them in the optimizers

llvm-svn: 12545
2004-03-30 19:44:05 +00:00
Chris Lattner
b6612acb18 Implement select.ll:test[3-6]
llvm-svn: 12544
2004-03-30 19:37:13 +00:00
Chris Lattner
58a6a4d57a Add a simple select instruction lowering pass
llvm-svn: 12540
2004-03-30 18:41:10 +00:00
Chris Lattner
d191e5625c X % -1 == X % 1 == 0
llvm-svn: 12520
2004-03-26 16:11:24 +00:00
Chris Lattner
e15fb6ac61 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
078f97b50d 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
0f0a253571 Fix bug: CodeExtractor/2004-03-17-MissedLiveIns.ll
With this fix we now successfully extract all 149 loops from 256.bzip2 without
crashing or miscompiling the program!

llvm-svn: 12493
2004-03-18 05:56:32 +00:00
Chris Lattner
521d687d11 Add statistics to the loop extractor. The loop extractor has successfully
extracted all 63 loops for Olden/bh without crashing and without
miscompiling the program!!!

llvm-svn: 12491
2004-03-18 05:46:10 +00:00
Chris Lattner
c835211d82 Fix problem with PHI nodes having multiple predecessors from different
exit nodes

llvm-svn: 12490
2004-03-18 05:43:18 +00:00
Chris Lattner
b1bc514730 Fix CodeExtractor/2004-03-17-UpdatePHIsOutsideRegion.ll
llvm-svn: 12489
2004-03-18 05:38:31 +00:00
Chris Lattner
69fdd9f14a Seriously simplify and correct the PHI node handling code.
llvm-svn: 12487
2004-03-18 05:28:49 +00:00
Chris Lattner
345cf6f177 Fix CodeExtractor/2004-03-17-OutputMismatch.ll
llvm-svn: 12486
2004-03-18 04:12:05 +00:00
Chris Lattner
0d233c03fc Fix several bugs in the extractor:
1. Names were not put on the new arguments created (ok, this just helps sanity :)
2. Fix outgoing pointer values
3. Do not insert stores for values that had not been computed
4. Fix some wierd problems with the outset calculation

This fixes CodeExtractor/2004-03-14-DominanceProblem.ll, making the extractor
work on at least one simple case!

llvm-svn: 12484
2004-03-18 03:49:40 +00:00
Chris Lattner
55114016ea The code extractor needs dominator info. Provide it
llvm-svn: 12483
2004-03-18 03:48:06 +00:00
Chris Lattner
7c0d39dcd6 Prune #includes, moving the module interface to the front. Note that this
exposed the fact that the header was not self-contained.  There is a reason
we do things :)

llvm-svn: 12481
2004-03-18 03:15:29 +00:00
Chris Lattner
849234af99 Fix compilation of mesa, which I broke earlier today
llvm-svn: 12465
2004-03-17 02:02:47 +00:00
Chris Lattner
eccc0e01b2 Be more accurate
llvm-svn: 12464
2004-03-17 01:59:27 +00:00
Chris Lattner
6fdcd7174b Fix bug in previous checkin
llvm-svn: 12458
2004-03-16 23:36:49 +00:00
Chris Lattner
59342a757e 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
e04883605a This code was both incredibly complex and incredibly broken. Fix it.
llvm-svn: 12456
2004-03-16 23:23:11 +00:00
Chris Lattner
c260cfab09 Punt if we see gigantic PHI nodes. This improves a huge interpreter loop
testcase from 32.5s in -raise to take .3s

llvm-svn: 12443
2004-03-16 19:52:53 +00:00
Chris Lattner
dc22f37eb5 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
2175b35b46 Do not copy gigantic switch instructions
llvm-svn: 12441
2004-03-16 19:45:22 +00:00
Chris Lattner
9ae2b6acd7 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
b9c53cdb65 Restore old inlining heuristic. As the comment indicates, this is a nasty
horrible hack.

llvm-svn: 12423
2004-03-15 06:38:14 +00:00
Chris Lattner
d8905ad834 Add counters for the number of calls elimianted
llvm-svn: 12420
2004-03-15 05:46:59 +00:00
Chris Lattner
8a82176edc 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
781ede7382 Mostly cosmetic improvements. Do fix the bug where a global value was considered an input.
llvm-svn: 12406
2004-03-15 01:26:44 +00:00
Chris Lattner
3933f4660f Assert that input blocks meet the invariants we expect
Simplify the input/output finder.  All elements of a basic block are
instructions.  Any used arguments are also inputs.  An instruction can only
be used by another instruction.

llvm-svn: 12405
2004-03-15 01:18:23 +00:00
Chris Lattner
49038b7708 Fix several bugs in the loop extractor. In particular, subloops were never
extracted, and a function that contained a single top-level loop never had
the loop extracted, regardless of how much non-loop code there was.

llvm-svn: 12403
2004-03-15 00:02:02 +00:00
Chris Lattner
cfe9af750b No correctness fixes here, just minor qoi fixes:
* Don't insert a branch to the switch instruction after the call, just
  make it a single block.
* Insert the new alloca instructions in the entry block of the original
  function instead of having them execute dynamically
* Don't make the default edge of the switch instruction go back to the switch.
  The loop extractor shouldn't create new loops!
* Give meaningful names to the alloca slots and the reload instructions
* Some minor code simplifications

llvm-svn: 12402
2004-03-14 23:43:24 +00:00
Chris Lattner
17c2c776c3 Simplify code a bit, and fix bug CodeExtractor/2004-03-14-NoSwitchSupport.ll
This also implements a two minor improvements:
  * Don't insert live-out stores IN the region, insert them on the code path
    that exits the region
  * If the region is exited to the same block from multiple paths, share the
    switch statement entry, live-out store code, and the basic block.

llvm-svn: 12401
2004-03-14 23:05:49 +00:00
Chris Lattner
f8d6c1a252 Simplify the code a bit by making the collection of basic blocks to extract
a member of the class.  While we're at it, turn the collection into a set
instead of a vector to improve efficiency and make queries simpler.

llvm-svn: 12400
2004-03-14 22:34:55 +00:00
Chris Lattner
95c238ef5b Split into two passes. Now there is the general loop extractor, usable on
the command line, and the single loop extractor, usable by bugpoint

llvm-svn: 12390
2004-03-14 20:01:36 +00:00
Chris Lattner
cf5d48e8af Passes don't print stuff!
llvm-svn: 12385
2004-03-14 04:17:53 +00:00
Chris Lattner
7e7c3332b8 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
e52c176a7c Minor random cleanups
llvm-svn: 12382
2004-03-14 04:01:47 +00:00
Chris Lattner
f3b0377169 FunctionPass's should not define their own 'run' method.
Require 'simplified' loops, not just raw natural loops.  This fixes
CodeExtractor/2004-03-13-LoopExtractorCrash.ll

llvm-svn: 12381
2004-03-14 04:01:06 +00:00
Chris Lattner
39b3ae34bd 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
b23b38259a Verify functions as they are produced if -debug is specified. Reduce
curly braceage

llvm-svn: 12378
2004-03-14 03:17:22 +00:00
Chris Lattner
46c006bb19 Move prototype to IPO.h instead of Scalar.h
Make sure that the file interface header (IPO.h) is included first
remove dead #incldue

llvm-svn: 12375
2004-03-14 02:37:16 +00:00
Chris Lattner
3d96322890 Indent anon namespace properly, add copyright block
llvm-svn: 12373
2004-03-14 02:34:07 +00:00
Chris Lattner
1685a3af78 Move to the IPO library. Utils shouldn't contain passes.
llvm-svn: 12372
2004-03-14 02:32:27 +00:00
Chris Lattner
5003f9e473 DemoteRegToStack got moved from DemoteRegToStack.h to Local.h
llvm-svn: 12368
2004-03-14 02:13:38 +00:00
Chris Lattner
52ac108b28 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
763b6c41d4 This change makes two big adjustments.
* Be a lot more accurate about what the effects will be when inlining a call
   to a function when an argument is an alloca.
 * Dramatically reduce the penalty for inlining a call in a large function.
   This heuristic made it almost impossible to inline a function into a large
   function, no matter how small the callee is.

llvm-svn: 12363
2004-03-13 23:15:45 +00:00
Chris Lattner
8d45aeaff1 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
e10c6cd509 Implement sub.ll:test14
llvm-svn: 12355
2004-03-13 00:11:49 +00:00
Chris Lattner
284e9ab607 Implement InstCombine/sub.ll:test12 & test13
llvm-svn: 12353
2004-03-12 23:53:13 +00:00
Chris Lattner
76457c9c13 Add constant folding wrapper support for select instructions.
llvm-svn: 12319
2004-03-12 05:53:03 +00:00
Chris Lattner
6b127ea270 Add sccp support for select instructions
llvm-svn: 12318
2004-03-12 05:52:44 +00:00
Chris Lattner
41801f046e Add trivial optimizations for select instructions
llvm-svn: 12317
2004-03-12 05:52:32 +00:00
Chris Lattner
01062fb636 Initial support for edge profiling
llvm-svn: 12225
2004-03-08 17:54:34 +00:00
Chris Lattner
d40842737b Split utility functions out of BlockProfiling.cpp
llvm-svn: 12224
2004-03-08 17:06:13 +00:00
Chris Lattner
41c4dc98a7 finegrainify namespacification
llvm-svn: 12221
2004-03-08 16:45:53 +00:00
Chris Lattner
933f605592 Implement ArgumentPromotion/aggregate-promote.ll
This allows pointers to aggregate objects, whose elements are only read, to
be promoted and passed in by element instead of by reference.  This can
enable a LOT of subsequent optimizations in the caller function.

It's worth pointing out that this stuff happens a LOT of C++ programs, because
objects in templates are generally passed around by reference.  When these
templates are instantiated on small aggregate or scalar types, however, it is
more efficient to pass them in by value than by reference.

This transformation triggers most on C++ codes (e.g. 334 times on eon), but
does happen on C codes as well.  For example, on mesa it triggers 72 times,
and on gcc it triggers 35 times.  this is amazingly good considering that
we are using 'basicaa' so far.

llvm-svn: 12202
2004-03-08 01:04:36 +00:00
Chris Lattner
ebebe8f4a0 Implement: ArgumentPromotion/chained.ll
llvm-svn: 12200
2004-03-07 22:52:53 +00:00
Chris Lattner
8494ba277f Fix another minor bug, exposed by perlbmk
llvm-svn: 12198
2004-03-07 22:43:27 +00:00
Chris Lattner
ca3b90f308 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
45cf084497 Fix a minor bug and turn debug output into, well, debug output.
llvm-svn: 12195
2004-03-07 21:54:50 +00:00
Chris Lattner
4415950211 New LLVM pass: argument promotion. This version only handles simple scalar
variables.

llvm-svn: 12193
2004-03-07 21:29:54 +00:00
Chris Lattner
2a1d782aee 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
Misha Brukman
c58f772803 Implement ExtractCodeRegion()
llvm-svn: 12070
2004-03-02 00:20:57 +00:00
Misha Brukman
8a60e317f0 Make a note that this is usually used via bugpoint.
llvm-svn: 12068
2004-03-02 00:19:09 +00:00
Misha Brukman
f93e6ab769 * Add implementation of ExtractBasicBlock()
* Add comments to ExtractLoop()

llvm-svn: 12053
2004-03-01 18:28:34 +00:00
Chris Lattner
2749c25a5c Disable tail duplication in a case that breaks on Olden/tsp
llvm-svn: 12021
2004-03-01 01:12:13 +00:00
Misha Brukman
848c759b41 * Remove function to find "main" in a Module, there's a method for that
* Removing extraneous empty space and empty comment lines

llvm-svn: 12014
2004-02-29 23:09:10 +00:00
Chris Lattner
9736130083 Fix bug: test/Regression/Transforms/LowerInvoke/2004-02-29-PHICrash.llx
... which tickled the lowerinvoke pass because it used the BCE routines.

llvm-svn: 12012
2004-02-29 22:24:41 +00:00
Chris Lattner
bcc0df60ef 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
a854ddd528 Implement switch->br and br->switch folding by ripping out the switch->switch
and br->br code and generalizing it.  This allows us to compile code like this:

int test(Instruction *I) {
  if (isa<CastInst>(I))
    return foo(7);
  else if (isa<BranchInst>(I))
    return foo(123);
  else if (isa<UnwindInst>(I))
    return foo(1241);
  else if (isa<SetCondInst>(I))
    return foo(1);
  else if (isa<VAArgInst>(I))
    return foo(42);
  return foo(-1);
}

into:

int %_Z4testPN4llvm11InstructionE("struct.llvm::Instruction"* %I) {
entry:
        %tmp.1.i.i.i.i.i.i.i = getelementptr "struct.llvm::Instruction"* %I, long 0, ubyte 4            ; <uint*> [#uses=1]
        %tmp.2.i.i.i.i.i.i.i = load uint* %tmp.1.i.i.i.i.i.i.i          ; <uint> [#uses=2]
        %tmp.2.i.i.i.i.i.i = seteq uint %tmp.2.i.i.i.i.i.i.i, 27                ; <bool> [#uses=0]
        switch uint %tmp.2.i.i.i.i.i.i.i, label %endif.0 [
                 uint 27, label %then.0
                 uint 2, label %then.1
                 uint 5, label %then.2
                 uint 14, label %then.3
                 uint 15, label %then.3
                 uint 16, label %then.3
                 uint 17, label %then.3
                 uint 18, label %then.3
                 uint 19, label %then.3
                 uint 32, label %then.4
        ]
...

As well as handling the cases in 176.gcc and many other programs more effectively.

llvm-svn: 11964
2004-02-28 21:28:10 +00:00
Chris Lattner
69ab9e0840 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
7872171767 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
192d8413d3 Turn 'free null' into nothing
llvm-svn: 11940
2004-02-28 04:57:37 +00:00
Misha Brukman
0b846ae65c Right, it's really Extractor, not Extraction.
llvm-svn: 11939
2004-02-28 03:37:58 +00:00
Misha Brukman
f14fbb1a0b A pass that uses the generic CodeExtractor to rip out *every* loop in every
function, as long as the loop isn't the only one in that function. This should
help debugging passes easier with BugPoint.

llvm-svn: 11936
2004-02-28 03:33:01 +00:00
Misha Brukman
26e90f8776 A generic code extractor: given a list of BasicBlocks, it will rip them out into
a new function, taking care of inputs and outputs.

llvm-svn: 11935
2004-02-28 03:26:20 +00:00
Chris Lattner
d06b64c941 setcond instructions don't have aliasing implications.
llvm-svn: 11919
2004-02-27 18:09:25 +00:00
Chris Lattner
ffae67bae8 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
07c3941266 Since LLVM uses structure type equivalence, it isn't useful to keep around
multiple type names for the same structural type.  Make DTE eliminate all
but one of the type names

llvm-svn: 11879
2004-02-26 20:02:23 +00:00
Chris Lattner
e07d786aa6 turn things like:
if (X == 0 || X == 2)

...where the comparisons and branches are in different blocks... into a switch
instruction.  This comes up a lot in various programs, and works well with
the switch/switch merging code I checked earlier.  For example, this testcase:

int switchtest(int C) {
  return C == 0 ? f(123) :
         C == 1 ? f(3123) :
         C == 4 ? f(312) :
         C == 5 ? f(1234): f(444);
}

is converted into this:
        switch int %C, label %cond_false.3 [
                 int 0, label %cond_true.0
                 int 1, label %cond_true.1
                 int 4, label %cond_true.2
                 int 5, label %cond_true.3
        ]

instead of a whole bunch of conditional branches.

Admittedly the code is ugly, and incomplete.  To be complete, we need to add
br -> switch merging and switch -> br merging.  For example, this testcase:

struct foo { int Q, R, Z; };
#define A (X->Q+X->R * 123)
int test(struct foo *X) {
  return A  == 123 ? X1() :
        A == 12321 ? X2():
        (A == 111 || A == 222) ? X3() :
        A == 875 ? X4() : X5();
}

Gets compiled to this:
        switch int %tmp.7, label %cond_false.2 [
                 int 123, label %cond_true.0
                 int 12321, label %cond_true.1
                 int 111, label %cond_true.2
                 int 222, label %cond_true.2
        ]
...
cond_false.2:           ; preds = %entry
        %tmp.52 = seteq int %tmp.7, 875         ; <bool> [#uses=1]
        br bool %tmp.52, label %cond_true.3, label %cond_false.3

where the branch could be folded into the switch.

This kind of thing occurs *ALL OF THE TIME*, especially in programs like
176.gcc, which is a horrible mess of code.  It contains stuff like *shudder*:

#define SWITCH_TAKES_ARG(CHAR) \
  (   (CHAR) == 'D' \
   || (CHAR) == 'U' \
   || (CHAR) == 'o' \
   || (CHAR) == 'e' \
   || (CHAR) == 'u' \
   || (CHAR) == 'I' \
   || (CHAR) == 'm' \
   || (CHAR) == 'L' \
   || (CHAR) == 'A' \
   || (CHAR) == 'h' \
   || (CHAR) == 'z')

and

#define CONST_OK_FOR_LETTER_P(VALUE, C)                 \
  ((C) == 'I' ? SMALL_INTVAL (VALUE)                    \
   : (C) == 'J' ? SMALL_INTVAL (-(VALUE))               \
   : (C) == 'K' ? (unsigned)(VALUE) < 32                \
   : (C) == 'L' ? ((VALUE) & 0xffff) == 0               \
   : (C) == 'M' ? integer_ok_for_set (VALUE)            \
   : (C) == 'N' ? (VALUE) < 0                           \
   : (C) == 'O' ? (VALUE) == 0                          \
   : (C) == 'P' ? (VALUE) >= 0                          \
   : 0)

and

#define LEGITIMIZE_ADDRESS(X,OLDX,MODE,WIN)                     \
{                                                               \
  if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 1))) \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 0),                   \
                   copy_to_mode_reg (SImode, XEXP (X, 1)));     \
  if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 0))) \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 1),                   \
                   copy_to_mode_reg (SImode, XEXP (X, 0)));     \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == MULT)   \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 1),                   \
                   force_operand (XEXP (X, 0), 0));             \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == MULT)   \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 0),                   \
                   force_operand (XEXP (X, 1), 0));             \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == PLUS)   \
    (X) = gen_rtx (PLUS, Pmode, force_operand (XEXP (X, 0), NULL_RTX),\
                   XEXP (X, 1));                                \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == PLUS)   \
    (X) = gen_rtx (PLUS, Pmode, XEXP (X, 0),                    \
                   force_operand (XEXP (X, 1), NULL_RTX));      \
  if (GET_CODE (X) == SYMBOL_REF || GET_CODE (X) == CONST       \
           || GET_CODE (X) == LABEL_REF)                        \
    (X) = legitimize_address (flag_pic, X, 0, 0);               \
  if (memory_address_p (MODE, X))                               \
    goto WIN; }

and others.  These macros get used multiple times of course.  These are such
lovely candidates for macros, aren't they?  :)

This code also nicely handles LLVM constructs that look like this:

  if (isa<CastInst>(I))
   ...
  else if (isa<BranchInst>(I))
   ...
  else if (isa<SetCondInst>(I))
   ...
  else if (isa<UnwindInst>(I))
   ...
  else if (isa<VAArgInst>(I))
   ...

where the isa can obviously be a dyn_cast as well.  Switch instructions are a
good thing.

llvm-svn: 11870
2004-02-26 07:13:46 +00:00
Chris Lattner
2a13dd5706 My faith in programmers has been found to be totally misplaced. One would
assume that if they don't intend to write to a global variable, that they
would mark it as constant.  However, there are people that don't understand
that the compiler can do nice things for them if they give it the information
it needs.

This pass looks for blatently obvious globals that are only ever read from.
Though it uses a trivially simple "alias analysis" of sorts, it is still able
to do amazing things to important benchmarks.  253.perlbmk, for example,
contains several ***GIANT*** function pointer tables that are not marked
constant and should be.  Marking them constant allows the optimizer to turn
a whole bunch of indirect calls into direct calls.  Note that only a link-time
optimizer can do this transformation, but perlbmk does have several strings
and other minor globals that can be marked constant by this pass when run
from GCCAS.

176.gcc has a ton of strings and large tables that are marked constant, both
at compile time (38 of them) and at link time (48 more).  Other benchmarks
give similar results, though it seems like big ones have disproportionally
more than small ones.

This pass is extremely quick and does good things.  I'm going to enable it
in gccas & gccld.  Not bad for 50 SLOC.

llvm-svn: 11836
2004-02-25 21:34:36 +00:00
Chris Lattner
04f116953d Fix incorrect debug code
llvm-svn: 11821
2004-02-25 15:15:04 +00:00
Chris Lattner
fc15346b60 Fix a faulty optimization on FP values
llvm-svn: 11801
2004-02-24 18:10:14 +00:00
Chris Lattner
7845e4f7f0 If a block is made dead, make sure to promptly remove it.
llvm-svn: 11799
2004-02-24 16:09:21 +00:00
Chris Lattner
d678669018 Implement SimplifyCFG/switch_switch_fold.ll
This case occurs many times in various benchmarks, especially when combined
with the previous patch.  This allows it to get stuff like:
  if (X == 4 || X == 3)
    if (X == 5 || X == 8)

and

switch (X) {
case 4: case 5: case 6:
  if (X == 4 || X == 5)

llvm-svn: 11797
2004-02-24 07:23:58 +00:00
Chris Lattner
1293e1d00c Rearrange code a bit
llvm-svn: 11793
2004-02-24 05:54:22 +00:00
Chris Lattner
e5db7dc4c6 Implement: test/Regression/Transforms/SimplifyCFG/switch_create.ll
This turns code like this:
  if (X == 4 | X == 7)
and
  if (X != 4 & X != 7)
into switch instructions.

llvm-svn: 11792
2004-02-24 05:38:11 +00:00
Chris Lattner
78800ae270 Generate much more efficient code in programs like pifft
llvm-svn: 11775
2004-02-23 21:46:58 +00:00
Chris Lattner
7fa6519e07 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
253f77f2a7 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
74418a30aa Implement cast.ll::test14/15
llvm-svn: 11742
2004-02-23 07:16:20 +00:00
Chris Lattner
a65e5e3df1 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
9ecc3fc3c1 Implement mul.ll:test11
llvm-svn: 11737
2004-02-23 06:00:11 +00:00
Chris Lattner
51b37305d9 Implement "strength reduction" of X <= C and X >= C
llvm-svn: 11735
2004-02-23 05:47:48 +00:00
Chris Lattner
c31a2e26ab Implement InstCombine/mul.ll:test10, which is a case that occurs when dealing
with "predication"

llvm-svn: 11734
2004-02-23 05:39:21 +00:00
Chris Lattner
69bb1545d1 Implement Transforms/InstCombine/cast.ll:test13, a case which occurs in a
hot 164.gzip loop.

llvm-svn: 11702
2004-02-22 05:25:17 +00:00
Chris Lattner
4fa2e7a67f Fix PR245: Linking weak and strong global variables is dependent on link order
llvm-svn: 11565
2004-02-17 21:56:04 +00:00
Chris Lattner
f51bbb7eec Implement test/Regression/Transforms/SimplifyCFG/UncondBranchToReturn.ll,
see the testcase for the reasoning.

llvm-svn: 11496
2004-02-16 06:35:48 +00:00
Chris Lattner
9affa63dc6 Fold PHI nodes of constants which are only used by a single cast. This implements
phi.ll:test4

llvm-svn: 11494
2004-02-16 05:07:08 +00:00
Chris Lattner
011b98cec4 Teach LLVM to unravel the "swap idiom". This implements:
Regression/Transforms/InstCombine/xor.ll:test20

llvm-svn: 11492
2004-02-16 03:54:20 +00:00
Chris Lattner
71154f0931 Implement Transforms/InstCombine/xor.ll:test19
llvm-svn: 11490
2004-02-16 01:20:27 +00:00
Chris Lattner
c224c03911 Instead of producing calls to setjmp/longjmp, produce uses of the
llvm.setjmp/llvm.longjmp intrinsics.

llvm-svn: 11482
2004-02-15 22:24:27 +00:00
Chris Lattner
28131460da Adjustments to support the new ConstantAggregateZero class
llvm-svn: 11474
2004-02-15 05:55:15 +00:00
Chris Lattner
52cc69f39e Remove dependence on return type of ConstantStruct::get
llvm-svn: 11466
2004-02-15 04:07:32 +00:00
Chris Lattner
3fd2b573f1 Remove dependence on the return type of ConstantArray::get
llvm-svn: 11463
2004-02-15 04:05:58 +00:00
Chris Lattner
2265790f9f Fix compilation of 126.gcc: intrinsic functions cannot throw, so they are not
allowed in invoke instructions.  Thus, if we are inlining a call to an intrinsic
function into an invoke site, we don't need to turn the call into an invoke!

llvm-svn: 11384
2004-02-13 16:47:35 +00:00
Chris Lattner
b0fadd694d Intrinsic functions cannot throw
llvm-svn: 11383
2004-02-13 16:46:46 +00:00
Chris Lattner
f1de565975 Expose a pass ID that can be 'required'
llvm-svn: 11376
2004-02-13 16:16:16 +00:00
Chris Lattner
5730220037 Remove obsolete comment. Unreachable blocks will automatically be left at the
end of the function.

llvm-svn: 11313
2004-02-11 05:20:50 +00:00
Chris Lattner
ca52c22356 Add an _embarassingly simple_ implementation of basic block layout. This is
more of a testcase for profiling information than anything that should reasonably
be used, but it's a starting point.  When I have more time I will whip this into
better shape.

llvm-svn: 11311
2004-02-11 04:53:20 +00:00
Chris Lattner
4418633216 Implement SimplifyCFG/PhiEliminate.ll
Having a proper 'select' instruction would allow the elimination of a lot
of the special case cruft in this patch, but we don't have one yet.

llvm-svn: 11307
2004-02-11 03:36:04 +00:00
Chris Lattner
754914b142 The hasConstantReferences predicate always returns false.
llvm-svn: 11301
2004-02-11 01:17:07 +00:00
Chris Lattner
d2c679e5f6 initialization calls now return argc. If the program uses the argc value
passed into main, make sure they use the return value of the init call
instead of the one passed in.

llvm-svn: 11262
2004-02-10 17:41:01 +00:00
Chris Lattner
e961c1189f Only add the global variable with the abort message if an unwind actually
occurs in the program.

llvm-svn: 11249
2004-02-09 22:48:47 +00:00
Chris Lattner
255269e677 Don't depend on auto data conversion
llvm-svn: 11229
2004-02-09 05:16:30 +00:00
Chris Lattner
16690fad3d Adjust to the changed StructType interface. In particular, getElementTypes() is gone.
llvm-svn: 11228
2004-02-09 04:37:31 +00:00
Chris Lattner
a1757d1d91 Start using the new and improve interface to FunctionType arguments
llvm-svn: 11224
2004-02-09 04:14:01 +00:00
Chris Lattner
6ef23e7e64 The ConstantExpr::getCast call can cause a CPR to be generated. If so,
strip it off.

llvm-svn: 11213
2004-02-09 00:20:55 +00:00
Misha Brukman
58ca173834 Fix grammar-o.
llvm-svn: 11210
2004-02-08 22:27:33 +00:00
Chris Lattner
a9887d33e8 Improve compatibility with programs that already have a prototype for 'write',
even if it is wierd in some way.

llvm-svn: 11207
2004-02-08 22:14:44 +00:00
Chris Lattner
68fdb35576 rename the "exceptional" destination of an invoke instruction to the 'unwind' dest
llvm-svn: 11202
2004-02-08 21:44:31 +00:00
Chris Lattner
70d893a160 Fix PR225: [pruneeh] -pruneeh pass removes invoke instructions it shouldn't
llvm-svn: 11200
2004-02-08 21:15:59 +00:00
Chris Lattner
46c84561b2 splitBasicBlock "does the right thing" now, no reason to reposition it.
llvm-svn: 11199
2004-02-08 20:49:07 +00:00
Chris Lattner
1c646349df Implement proper invoke/unwind lowering.
This fixed PR16 "[lowerinvoke] The -lowerinvoke pass does not insert calls to setjmp/longjmp"

llvm-svn: 11195
2004-02-08 19:53:56 +00:00
Chris Lattner
f549f9473e Add a call to 'write' right before the call to abort() in the unwind path.
This causes the JIT, or LLC'd program to print out a nice message, explaining
WHY the program aborted.

llvm-svn: 11184
2004-02-08 07:30:29 +00:00