Commit Graph

1543 Commits

Author SHA1 Message Date
Chris Lattner dd1a86d858 Minor efficiency tweak, suggested by Patrick Meredith
llvm-svn: 13341
2004-05-04 15:19:33 +00:00
Brian Gaeke 5237476f75 Fix typo
llvm-svn: 13340
2004-05-03 23:52:07 +00:00
Brian Gaeke e96196081e In InsertProfilingInitCall(), make it legal to pass in a null array, in
which case you'll get a null array and zero passed to the profiling function.

llvm-svn: 13336
2004-05-03 22:06:33 +00:00
Brian Gaeke 088dd3e121 Add initial implementation of basic-block tracing instrumentation pass.
llvm-svn: 13335
2004-05-03 22:06:32 +00:00
Chris Lattner be6f06818c Do not clone arbitrary condition instructions.
llvm-svn: 13316
2004-05-02 05:19:36 +00:00
Chris Lattner 51a6dbcb65 Do not infinitely "unroll" single BB loops.
llvm-svn: 13315
2004-05-02 05:02:03 +00:00
Chris Lattner 1e94ed606e Dont' merge terminators that are needed to select PHI node values.
llvm-svn: 13312
2004-05-02 01:00:44 +00:00
Chris Lattner 2e93c4275e Implement SimplifyCFG/branch-cond-merge.ll
Turning "if (A < B && B < C)" into "if (A < B & B < C)"

llvm-svn: 13311
2004-05-01 23:35:43 +00:00
Chris Lattner 63d75af920 Make sure to reprocess instructions used by deleted instructions to avoid
missing opportunities for combination.

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

llvm-svn: 13308
2004-05-01 23:19:52 +00:00
Chris Lattner 4cbd160b45 Fix my missing parens
llvm-svn: 13307
2004-05-01 22:41:51 +00:00
Chris Lattner 88da6f7b52 Implement SimplifyCFG/branch-cond-prop.ll
llvm-svn: 13306
2004-05-01 22:36:37 +00:00
Chris Lattner 652064e3b8 Fix a major pessimization in the instcombiner. If an allocation instruction
is only used by a cast, and the casted type is the same size as the original
allocation, it would eliminate the cast by folding it into the allocation.

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

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

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

llvm-svn: 13185
2004-04-27 15:13:33 +00:00
Chris Lattner e20c334e65 Instcombine X/-1 --> 0-X
llvm-svn: 13172
2004-04-26 14:01:59 +00:00
Misha Brukman 3596f0a180 * Allow aggregating extracted function arguments (controlled by flag)
* Commandline option (for now) controls that flag that is passed in

llvm-svn: 13141
2004-04-23 23:54:17 +00:00
Chris Lattner 83cd87efcd Move the scev expansion code into this pass, where it belongs. There is
still room for cleanup, but at least the code modification is out of the
analysis now.

llvm-svn: 13135
2004-04-23 21:29:48 +00:00
Misha Brukman 98aa516a9c Clarify the logic: the flag is renamed to `deleteFn' to signify it will delete
the function instead of isolating it. This also means the condition is reversed.

llvm-svn: 13112
2004-04-22 23:00:51 +00:00
Misha Brukman e0682426f0 Add a flag to choose between isolating a function or deleting the function from
the Module. The default behavior keeps functionality as before: the chosen
function is the one that remains.

llvm-svn: 13111
2004-04-22 22:52:22 +00:00
Chris Lattner c27302c79f Disable a previous patch that was causing indvars to loop infinitely :(
llvm-svn: 13108
2004-04-22 15:12:36 +00:00
Chris Lattner c1a682dda0 Fix an extremely serious thinko I made in revision 1.60 of this file.
llvm-svn: 13106
2004-04-22 14:59:40 +00:00
Chris Lattner af532f27e7 Implement a todo, rewriting all possible scev expressions inside of the
loop.  This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall.  Tommorows test
results will tell. :)

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

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

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

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

instead of:

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

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

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

llvm-svn: 13101
2004-04-21 22:22:01 +00:00
Chris Lattner be8bb804c5 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 f68f40ea42 Include cerrno (gcc-3.4 fix)
llvm-svn: 13091
2004-04-21 16:11:40 +00:00
Chris Lattner a9691fe70d Fix typeo
llvm-svn: 13089
2004-04-21 14:23:18 +00:00
Chris Lattner c87784f1fc 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 c1aa21f5a7 Fix PR325
llvm-svn: 13081
2004-04-20 20:26:03 +00:00
Chris Lattner 514934051a Fix PR324 and testcase: Inline/2004-04-20-InlineLinkOnce.llx
llvm-svn: 13080
2004-04-20 20:20:59 +00:00
Chris Lattner f48f777d4c Initial checkin of a simple loop unswitching pass. It still needs work,
but it's a start, and seems to do it's basic job.

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

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

This was causing a verifier assertion on 252.eon.

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

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

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

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

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

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

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

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

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

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

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

Here's the before code for this function:

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

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

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

loopexit:               ; preds = %entry
        ret int 0
}


Here's the after code:

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

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

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

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

llvm-svn: 13015
2004-04-17 18:08:33 +00:00
Chris Lattner a43312d30b Add support for evaluation of exp/log/log10/pow
llvm-svn: 13011
2004-04-16 22:35:33 +00:00
Chris Lattner 284d3b0311 Fix some really nasty dominance bugs that were exposed by my patch to
make the verifier more strict.  This fixes building zlib

llvm-svn: 13002
2004-04-16 18:08:07 +00:00
Brian Gaeke 174633b078 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 9e9b2b7474 Fix some of the strange CBE-only failures that happened last night.
llvm-svn: 12980
2004-04-16 06:03:17 +00:00
Chris Lattner 0328d75c83 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 d7a559e353 Fix a bug in the previous checkin: if the exit block is not the same as
the back-edge block, we must check the preincremented value.

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

Loop:
  X = phi 0, X2
  ...

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

We now generate code that looks like this:

Loop:
  X = phi 0, X2
  ...

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

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

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

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

To:

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

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

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

llvm-svn: 12921
2004-04-13 19:43:54 +00:00
Chris Lattner ca52d0468e Add a simple call constant propagation interface.
llvm-svn: 12919
2004-04-13 19:28:52 +00:00
Chris Lattner d0dc6d5295 Constant propagation should remove the dead instructions
llvm-svn: 12917
2004-04-13 19:28:20 +00:00
Chris Lattner 89e959bb1f Fix LoopSimplify/2004-04-13-LoopSimplifyUpdateDomFrontier.ll
LoopSimplify was not updating dominator frontiers correctly in some cases.

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

llvm-svn: 12884
2004-04-13 05:05:33 +00:00
Chris Lattner be43544429 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 494a685449 Add support for removing invoke instructions
llvm-svn: 12858
2004-04-12 05:15:13 +00:00
Chris Lattner 08f201bee5 Stop printing Function*
llvm-svn: 12857
2004-04-12 04:06:56 +00:00
Chris Lattner d041dcd92f 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 24cf0200c7 Fix a bug in my select transformation
llvm-svn: 12826
2004-04-11 01:39:19 +00:00
Chris Lattner f16fe7206c Update the value numbering interface.
llvm-svn: 12824
2004-04-10 22:33:34 +00:00
Chris Lattner 623fba1107 Implement InstCombine/select.ll:test13*
llvm-svn: 12821
2004-04-10 22:21:27 +00:00
Chris Lattner cf4a996cba Implement InstCombine/add.ll:test20
Canonicalize add of sign bit constant into a xor

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

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

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

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

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

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

llvm-svn: 12800
2004-04-09 23:46:01 +00:00
Chris Lattner 0aa565647c 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 183b336a54 Fold binary operators with a constant operand into select instructions
that have a constant operand.  This implements
add.ll:test19, shift.ll:test15*, and others that are not tested

llvm-svn: 12794
2004-04-09 19:05:30 +00:00
Chris Lattner cf7baf3519 Implement select.ll:test11
llvm-svn: 12793
2004-04-09 18:19:44 +00:00
Chris Lattner e228ee5870 Implement InstCombine/cast-propagate.ll
llvm-svn: 12784
2004-04-08 20:39:49 +00:00
Chris Lattner 3b3861d305 Implement ScalarRepl/select_promote.ll
llvm-svn: 12779
2004-04-08 19:59:34 +00:00
Chris Lattner 4d25c86b52 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 1c631e813d Implement InstCombine/select.ll:test[7-10]
llvm-svn: 12769
2004-04-08 04:43:23 +00:00
Chris Lattner 2b2412d0c8 Implement test/Regression/Transforms/InstCombine/getelementptr_index.ll
llvm-svn: 12762
2004-04-07 18:38:20 +00:00
Chris Lattner 4d1fcf1dcd Fix a bug in yesterdays checkins which broke siod. siod is a great testcase! :)
llvm-svn: 12659
2004-04-05 16:02:41 +00:00
Chris Lattner 8953b90aaa Fix InstCombine/2004-04-04-InstCombineReplaceAllUsesWith.ll
llvm-svn: 12658
2004-04-05 02:10:19 +00:00
Chris Lattner 69193f93b6 Support getelementptr instructions which use uint's to index into structure
types and can have arbitrary 32- and 64-bit integer types indexing into
sequential types.

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

llvm-svn: 12620
2004-04-02 20:24:31 +00:00
Chris Lattner eed034bcd3 Fix the obvious bug in my previous checkin
llvm-svn: 12618
2004-04-02 18:15:10 +00:00
Chris Lattner 9f0db32625 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 c24019c825 Fix PR310 and TailDup/2004-04-01-DemoteRegToStack.llx
llvm-svn: 12597
2004-04-01 20:28:45 +00:00
Chris Lattner 59fdf74968 Remove some assertions that are now bogus with the last patch I put in
llvm-svn: 12595
2004-04-01 19:21:46 +00:00
Chris Lattner 146d0df5e4 Fix PR306: Loop simplify incorrectly updates dominator information
Testcase: LoopSimplify/2004-04-01-IncorrectDomUpdate.ll

llvm-svn: 12592
2004-04-01 19:06:07 +00:00
Chris Lattner 61fab1409d Add warning
llvm-svn: 12573
2004-03-31 22:00:30 +00:00
Chris Lattner 709f03e2dd 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 ef327be6ed Start cleaning up this pass so that I can debug it.
llvm-svn: 12548
2004-03-30 19:53:46 +00:00
Chris Lattner 81bdcb90ce 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 533bc49775 Implement select.ll:test[3-6]
llvm-svn: 12544
2004-03-30 19:37:13 +00:00
Chris Lattner 059f390257 Add a simple select instruction lowering pass
llvm-svn: 12540
2004-03-30 18:41:10 +00:00
Chris Lattner 56b5051428 X % -1 == X % 1 == 0
llvm-svn: 12520
2004-03-26 16:11:24 +00:00
Chris Lattner 57c67b06e9 Two changes:
#1 is to unconditionally strip constantpointerrefs out of
instruction operands where they are absolutely pointless and inhibit
optimization.  GRRR!

#2 is to implement InstCombine/getelementptr_const.ll

llvm-svn: 12519
2004-03-25 22:59:29 +00:00
Chris Lattner abb77c9959 Teach the optimizer to delete zero sized alloca's (but not mallocs!)
llvm-svn: 12507
2004-03-19 06:08:10 +00:00
Chris Lattner 232155dc1b 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 e83693560a 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 5bce0c807d 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 acd75986ee Fix CodeExtractor/2004-03-17-UpdatePHIsOutsideRegion.ll
llvm-svn: 12489
2004-03-18 05:38:31 +00:00
Chris Lattner 320d59f4cd Seriously simplify and correct the PHI node handling code.
llvm-svn: 12487
2004-03-18 05:28:49 +00:00
Chris Lattner d8017a340d Fix CodeExtractor/2004-03-17-OutputMismatch.ll
llvm-svn: 12486
2004-03-18 04:12:05 +00:00
Chris Lattner 37de257ef0 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 e9235d2dde The code extractor needs dominator info. Provide it
llvm-svn: 12483
2004-03-18 03:48:06 +00:00
Chris Lattner cee3404d0a 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 a078f47b39 Fix compilation of mesa, which I broke earlier today
llvm-svn: 12465
2004-03-17 02:02:47 +00:00
Chris Lattner 684fa5ac64 Be more accurate
llvm-svn: 12464
2004-03-17 01:59:27 +00:00
Chris Lattner a3783a577e Fix bug in previous checkin
llvm-svn: 12458
2004-03-16 23:36:49 +00:00
Chris Lattner 95057f6ad1 Okay, so there is no reasonable way for tail duplication to update SSA form,
as it is making effectively arbitrary modifications to the CFG and we don't
have a domset/domfrontier implementations that can handle the dynamic updates.
Instead of having a bunch of code that doesn't actually work in practice,
just demote any potentially tricky values to the stack (causing the problem
to go away entirely).  Later invocations of mem2reg will rebuild SSA for us.

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

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

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

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

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

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

And is now compiled into:

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

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

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

llvm-svn: 12457
2004-03-16 23:29:09 +00:00
Chris Lattner bb1a2cc7ab This code was both incredibly complex and incredibly broken. Fix it.
llvm-svn: 12456
2004-03-16 23:23:11 +00:00
Chris Lattner fa48edfb7d 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 7a7b114871 Do not try to optimize PHI nodes with incredibly high degree. This reduces SCCP
time from 615s to 1.49s on a large testcase that has a gigantic switch statement
that all of the blocks in the function go to (an intepreter).

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

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

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

llvm-svn: 12434
2004-03-16 06:00:15 +00:00
Chris Lattner 95ce36da0d 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 cd83282df1 Add counters for the number of calls elimianted
llvm-svn: 12420
2004-03-15 05:46:59 +00:00
Chris Lattner 20cda2645e Implement LICM of calls in simple cases. This is sufficient to move around
sin/cos/strlen calls and stuff.  This implements:
  LICM/call_sink_pure_function.ll
  LICM/call_sink_const_function.ll

llvm-svn: 12415
2004-03-15 04:11:30 +00:00
Chris Lattner fb87cdecd8 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 73ab1fa7c8 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 2f155d8734 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 5b2072ecd3 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 b4d8bf365c 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 9c431f6c44 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 a1672c1bd8 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 0137de5ecb Passes don't print stuff!
llvm-svn: 12385
2004-03-14 04:17:53 +00:00
Chris Lattner b68659552a Do not create empty basic blocks when the lowerswitch pass expects blocks to
be non-empty!  This fixes LowerSwitch/2004-03-13-SwitchIsDefaultCrash.ll

llvm-svn: 12384
2004-03-14 04:14:31 +00:00
Chris Lattner 4fca71eb44 Minor random cleanups
llvm-svn: 12382
2004-03-14 04:01:47 +00:00
Chris Lattner 6c3e8c78cf 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 d078812f96 If a block is dead, dominators will not be calculated for it. Because of this
loop information won't see it, and we could have unreachable blocks pointing to
the non-header node of blocks in a natural loop.  This isn't tidy, so have the
loopsimplify pass clean it up.

llvm-svn: 12380
2004-03-14 03:59:22 +00:00
Chris Lattner 3684469326 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 78a996aec4 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 692a47aeb9 Indent anon namespace properly, add copyright block
llvm-svn: 12373
2004-03-14 02:34:07 +00:00
Chris Lattner 41ec709e00 Move to the IPO library. Utils shouldn't contain passes.
llvm-svn: 12372
2004-03-14 02:32:27 +00:00
Chris Lattner 8eebc49884 DemoteRegToStack got moved from DemoteRegToStack.h to Local.h
llvm-svn: 12368
2004-03-14 02:13:38 +00:00
Chris Lattner 7d2a539735 Add some debugging output
Fix InstCombine/2004-03-13-InstCombineInfLoop.ll which caused an infinite
loop compiling (I think) povray.

llvm-svn: 12365
2004-03-13 23:54:27 +00:00
Chris Lattner 2dc85b27e4 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 797cb2f6c1 This little patch speeds up the loop used to update the dominator set analysis.
On the testcase from GCC PR12440, which has a LOT of loops (1392 of which require
preheaders to be inserted), this speeds up the loopsimplify pass from 1.931s to
0.1875s.  The loop in question goes from 1.65s -> 0.0097s, which isn't bad. All of
these times are a debug build.

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

llvm-svn: 12362
2004-03-13 22:01:26 +00:00
Chris Lattner 022167f13b Implement sub.ll:test14
llvm-svn: 12355
2004-03-13 00:11:49 +00:00
Chris Lattner 92295c5031 Implement InstCombine/sub.ll:test12 & test13
llvm-svn: 12353
2004-03-12 23:53:13 +00:00
Chris Lattner cb015ee6c0 Add constant folding wrapper support for select instructions.
llvm-svn: 12319
2004-03-12 05:53:03 +00:00
Chris Lattner 59db22dcd4 Add sccp support for select instructions
llvm-svn: 12318
2004-03-12 05:52:44 +00:00
Chris Lattner b909e8b0d4 Add trivial optimizations for select instructions
llvm-svn: 12317
2004-03-12 05:52:32 +00:00
Chris Lattner 721264aecc Initial support for edge profiling
llvm-svn: 12225
2004-03-08 17:54:34 +00:00
Chris Lattner dae48f93b0 Split utility functions out of BlockProfiling.cpp
llvm-svn: 12224
2004-03-08 17:06:13 +00:00
Chris Lattner d91e676700 finegrainify namespacification
llvm-svn: 12221
2004-03-08 16:45:53 +00:00
Chris Lattner fe6f2e3e80 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 cc544e57f3 Implement: ArgumentPromotion/chained.ll
llvm-svn: 12200
2004-03-07 22:52:53 +00:00
Chris Lattner 64b8d697ad Fix another minor bug, exposed by perlbmk
llvm-svn: 12198
2004-03-07 22:43:27 +00:00
Chris Lattner 538fee7aa2 Since 'load null' is undefined, we can make it do whatever we want. Returning
a zero value is the most likely way to cause further simplification, so we do it.

llvm-svn: 12197
2004-03-07 22:16:24 +00:00
Chris Lattner 6770842b67 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 483ae01c9c 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 7abcc387de Don't emit things like malloc(16*1). Allocation instructions are fixed arity now.
llvm-svn: 12086
2004-03-03 01:40:53 +00:00
Misha Brukman f44acae31e Implement ExtractCodeRegion()
llvm-svn: 12070
2004-03-02 00:20:57 +00:00
Misha Brukman f272f9b3d5 Make a note that this is usually used via bugpoint.
llvm-svn: 12068
2004-03-02 00:19:09 +00:00
Misha Brukman 5af2be7d09 * Add implementation of ExtractBasicBlock()
* Add comments to ExtractLoop()

llvm-svn: 12053
2004-03-01 18:28:34 +00:00
Chris Lattner 5cf39339d1 Disable tail duplication in a case that breaks on Olden/tsp
llvm-svn: 12021
2004-03-01 01:12:13 +00:00
Misha Brukman c91e1ff50d * 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 2de229f31b 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 bf2963ef91 Fix PR255: [tailduplication] Single basic block loops are very rare
Note that this is a band-aid put over a band-aid.  This just undisables
tail duplication in on very specific case that it seems to work in.

llvm-svn: 11989
2004-02-29 06:41:20 +00:00
Chris Lattner d3e6ae263c 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 772eafa332 if there is already a prototype for malloc/free, use it, even if it's incorrect.
Do not just inject a new prototype.

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

llvm-svn: 11941
2004-02-28 05:22:00 +00:00
Chris Lattner f3a366062c Turn 'free null' into nothing
llvm-svn: 11940
2004-02-28 04:57:37 +00:00
Misha Brukman 8a2c28fdda Right, it's really Extractor, not Extraction.
llvm-svn: 11939
2004-02-28 03:37:58 +00:00
Misha Brukman 03a11340ff 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 caa1a5abeb 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 e82c217b2f setcond instructions don't have aliasing implications.
llvm-svn: 11919
2004-02-27 18:09:25 +00:00
Chris Lattner 4f7accab96 Implement test/Regression/Transforms/InstCombine/canonicalize_branch.ll
This is a really minor thing, but might help out the 'switch statement induction'
code in simplifycfg.

llvm-svn: 11900
2004-02-27 06:27:46 +00:00
Chris Lattner 79636d7cd5 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 21e941fbfd 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 8d1da1abee 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 9c6833c5ca Fix incorrect debug code
llvm-svn: 11821
2004-02-25 15:15:04 +00:00
Chris Lattner 8ee0593f0d Fix a faulty optimization on FP values
llvm-svn: 11801
2004-02-24 18:10:14 +00:00
Chris Lattner 90ea78edba 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 a2ab489135 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 3cd98f054a Rearrange code a bit
llvm-svn: 11793
2004-02-24 05:54:22 +00:00
Chris Lattner 6f4b45acf5 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 ae739aefd7 Generate much more efficient code in programs like pifft
llvm-svn: 11775
2004-02-23 21:46:58 +00:00
Chris Lattner c40b9d7d51 Fix a small typeo in my checkin last night that broke vortex and other programs :(
llvm-svn: 11774
2004-02-23 21:46:42 +00:00
Chris Lattner f5ce254692 Fix InstCombine/2004-02-23-ShiftShiftOverflow.ll
Also, turn 'shr int %X, 1234' into 'shr int %X, 31'

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

llvm-svn: 11740
2004-02-23 06:38:22 +00:00
Chris Lattner c8a10c4b6a Implement mul.ll:test11
llvm-svn: 11737
2004-02-23 06:00:11 +00:00
Chris Lattner 59611149ee Implement "strength reduction" of X <= C and X >= C
llvm-svn: 11735
2004-02-23 05:47:48 +00:00
Chris Lattner 2635b52d4e 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 8d0bacbb9e 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 693e393fee 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 e42732e75f 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 4db2d22bea 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 b36d908f7b 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 c207635fd5 Implement Transforms/InstCombine/xor.ll:test19
llvm-svn: 11490
2004-02-16 01:20:27 +00:00
Chris Lattner d85e061575 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 76b2ff4ded Adjustments to support the new ConstantAggregateZero class
llvm-svn: 11474
2004-02-15 05:55:15 +00:00
Chris Lattner 37a716fa80 Remove dependence on return type of ConstantStruct::get
llvm-svn: 11466
2004-02-15 04:07:32 +00:00