Commit Graph

729 Commits

Author SHA1 Message Date
Chris Lattner c27302c79f Disable a previous patch that was causing indvars to loop infinitely :(
llvm-svn: 13108
2004-04-22 15:12:36 +00:00
Chris Lattner c1a682dda0 Fix an extremely serious thinko I made in revision 1.60 of this file.
llvm-svn: 13106
2004-04-22 14:59:40 +00:00
Chris Lattner af532f27e7 Implement a todo, rewriting all possible scev expressions inside of the
loop.  This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall.  Tommorows test
results will tell. :)

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

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

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

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

instead of:

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

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

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

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

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

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

This was causing a verifier assertion on 252.eon.

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

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

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

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

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

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

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

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

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

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

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

Here's the before code for this function:

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

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

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

loopexit:               ; preds = %entry
        ret int 0
}


Here's the after code:

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

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

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

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

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

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

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

Loop:
  X = phi 0, X2
  ...

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

We now generate code that looks like this:

Loop:
  X = phi 0, X2
  ...

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

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

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

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

To:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

#2 is to implement InstCombine/getelementptr_const.ll

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

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

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

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

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

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

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

And is now compiled into:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

llvm-svn: 11740
2004-02-23 06:38:22 +00:00
Chris Lattner c8a10c4b6a Implement mul.ll:test11
llvm-svn: 11737
2004-02-23 06:00:11 +00:00
Chris Lattner 59611149ee Implement "strength reduction" of X <= C and X >= C
llvm-svn: 11735
2004-02-23 05:47:48 +00:00
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 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 7cbb22abe6 Expose a pass ID that can be 'required'
llvm-svn: 11376
2004-02-13 16:16:16 +00:00
Chris Lattner d4b36cf9bc 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 5add05129e 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 37d46f4815 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
Misha Brukman 3480e935d0 Fix grammar-o.
llvm-svn: 11210
2004-02-08 22:27:33 +00:00
Chris Lattner 3b7f6b2217 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 fae8ab3088 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 108cadc274 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 476488e669 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
Chris Lattner 2dd1c8d8ce Fix another dominator update bug. These bugs keep getting exposed because GCSE
keeps finding more code motion opportunities now that the dominators are correct!

llvm-svn: 11142
2004-02-05 23:20:59 +00:00
Chris Lattner c0c953f0bc Fix bug updating dominators
llvm-svn: 11140
2004-02-05 22:33:26 +00:00
Chris Lattner f978c421e5 Add debug output
llvm-svn: 11139
2004-02-05 22:33:19 +00:00
Chris Lattner 14ab84a483 Fix PR223: Loopsimplify incorrectly updates dominator information
The problem is that the dominator update code didn't "realize" that it's
possible for the newly inserted basic block to dominate anything.  Because
it IS possible, stuff was getting updated wrong.

llvm-svn: 11137
2004-02-05 21:12:24 +00:00
Chris Lattner 8d414ad035 Adjust to the new BasicBlock ctor, which requires a function parameter
llvm-svn: 11114
2004-02-04 03:58:28 +00:00
Chris Lattner c2f0aa58df Disable (x - (y - z)) => (x + (z - y)) optimization for floating point.
llvm-svn: 11083
2004-02-02 20:09:56 +00:00
Chris Lattner cacd30b957 Update comment
llvm-svn: 11082
2004-02-02 20:09:22 +00:00
Chris Lattner ed9b12c31a Disable tail duplication in any "hard" cases, where it might break SSA form.
llvm-svn: 11052
2004-02-01 06:32:28 +00:00
Chris Lattner 7c91a6176c Fix the count of the number of instructions removed
llvm-svn: 11049
2004-02-01 05:15:07 +00:00
Misha Brukman bf43787f33 Hyphenate `target-dependent'
llvm-svn: 11003
2004-01-28 20:43:01 +00:00
Chris Lattner 1f7942fe7d Fix InstCombine/2004-01-13-InstCombineInvokePHI.ll, which also fixes lots
of C++ programs in Shootout-C++, including lists1 and moments, etc

llvm-svn: 10845
2004-01-14 06:06:08 +00:00
Chris Lattner fcf21a75b0 Fix bug in previous checkin
llvm-svn: 10798
2004-01-12 19:47:05 +00:00
Chris Lattner c1e7cc0fbe Eliminate use of ConstantHandling and ConstantExpr::getShift interfaces
llvm-svn: 10796
2004-01-12 19:35:11 +00:00
Chris Lattner d7ccc9e5a5 Add header file I accidentally removed in teh shuffle
llvm-svn: 10795
2004-01-12 19:15:20 +00:00
Chris Lattner c9fb4a3b89 Remove use of the ConstantHandling interfaces
llvm-svn: 10793
2004-01-12 19:12:50 +00:00
Chris Lattner 1b7d4d7b63 Don't use ConstantExpr::getShift anymore
llvm-svn: 10791
2004-01-12 19:08:43 +00:00
Chris Lattner 118a76cb2f Remove unneeded #include
llvm-svn: 10788
2004-01-12 18:33:54 +00:00
Chris Lattner 0fe5b32c01 Use constantexprs for casts. Eliminate use of the ConstantHandling interfaces
llvm-svn: 10779
2004-01-12 17:43:40 +00:00
Chris Lattner fe992d4332 Fix fairly severe bug in my last checking where we treated all unfoldable
constants as being "true" when evaluating branches.  This was introduced
because we now create constantexprs for the constants instead of failing the
fold.

llvm-svn: 10778
2004-01-12 17:40:36 +00:00
Chris Lattner 49f74522ec * Implement minor performance optimization for the getelementptr case
* Implement SCCP of load instructions, implementing Transforms/SCCP/loadtest.ll
  This allows us to fold expressions like "foo"[2], even if the pointer is only
  a conditional constant.

llvm-svn: 10767
2004-01-12 04:29:41 +00:00
Chris Lattner 7e8af38637 Do not hack on volatile loads. I'm not sure what the point of a volatile load
from constant memory is, but lets not take chances.

llvm-svn: 10765
2004-01-12 04:13:56 +00:00
Chris Lattner 05fe6847a8 Implement SCCP/phitest.ll
llvm-svn: 10763
2004-01-12 03:57:30 +00:00
Chris Lattner 3bcecb92f3 Update obsolete comments
Fix iterator invalidation problems which was causing -mstrip to miss some
entries, and read free'd memory.  This shrinks the symbol table of 254.gap
from 333 to 284 bytes!  :)

llvm-svn: 10751
2004-01-10 21:36:49 +00:00
Chris Lattner 49525f8cf4 Finegrainify namespacification
llvm-svn: 10725
2004-01-09 06:02:20 +00:00
Chris Lattner 59d2d7fc33 Improve encapsulation in the Loop and LoopInfo classes by eliminating the
getSubLoops/getTopLevelLoops methods, replacing them with iterator-based
accessors.

llvm-svn: 10714
2004-01-08 00:09:44 +00:00
Chris Lattner 7e755e443f More minor non-functional changes. This now computes the exit condition, though
it doesn't do anything with it.

llvm-svn: 10590
2003-12-23 07:47:09 +00:00
Chris Lattner a02d5aa6ce Don't mind me, I'm just refactoring away. This patch makes room for LFTR, but
contains no functionality changes.

llvm-svn: 10583
2003-12-22 09:53:29 +00:00
Chris Lattner 6449dcefbc Implement IndVarsSimplify/pointer-indvars.ll, transforming pointer
arithmetic into "array subscripts"

llvm-svn: 10580
2003-12-22 05:02:01 +00:00
Chris Lattner d3678bc7c5 Fix PR194
llvm-svn: 10573
2003-12-22 03:58:44 +00:00
Chris Lattner fc7bdac1b3 Fix ADCE/2003-12-19-MergeReturn.llx
llvm-svn: 10539
2003-12-19 09:08:34 +00:00
Chris Lattner 918460190f Remove the wierd "Operands" loop, by traversing basicblocks in reverse order
llvm-svn: 10536
2003-12-19 08:18:16 +00:00
Chris Lattner 547192d688 Implement LICM/sink_multiple.ll, by sinking all possible instructions in the
loop before hoisting any.

llvm-svn: 10534
2003-12-19 07:22:45 +00:00
Chris Lattner 031a3f8cc7 Generalize a special case to fix PR187
llvm-svn: 10531
2003-12-19 06:27:08 +00:00
Chris Lattner 91daeb5431 Factor code out into the Utils library
llvm-svn: 10530
2003-12-19 05:58:40 +00:00
John Criswell b22e9b4b35 Reverted back to previous revision - this was previously merged
according to the CVS log messages.

llvm-svn: 10517
2003-12-18 17:19:19 +00:00
John Criswell 86a3a48697 Merged in RELEASE_11.
llvm-svn: 10516
2003-12-18 16:43:17 +00:00
Chris Lattner 9e2b42a0c8 When we delete instructions from the loop, make sure to remove them from the
AliasSetTracker as well.

llvm-svn: 10507
2003-12-18 08:12:32 +00:00
Chris Lattner 6c08bb8b8e Fix for PR185 & IndVarsSimplify/2003-12-15-Crash.llx
llvm-svn: 10473
2003-12-15 17:34:02 +00:00
Chris Lattner 884e824534 Refactor code just a little bit, allowing us to implement TailCallElim/return_constant.ll
llvm-svn: 10467
2003-12-14 23:57:39 +00:00