Commit Graph

6147 Commits

Author SHA1 Message Date
Chris Lattner
20aa098ba6 If the loop executes a constant number of times, try a bit harder to replace
exit values.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13018 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:44:09 +00:00
Chris Lattner
7980fb9007 Add the ability to compute trip counts that are only controlled by constants
even if the loop is using expressions that we can't compute as a closed-form.
This allows us to calculate that this function always returns 55:

int test() {
  double X;
  int Count = 0;
  for (X = 100; X > 1; X = sqrt(X), ++Count)
    /*empty*/;
  return Count;
}

And allows us to compute trip counts for loops like:

        int h = 1;
         do h = 3 * h + 1; while (h <= 256);

(which occurs in bzip2), and for this function, which occurs after inlining
and other optimizations:

int popcount()
{
   int x = 666;
  int result = 0;
  while (x != 0) {
    result = result + (x & 0x1);
    x = x >> 1;
  }
  return result;
}

We still cannot compute the exit values of result or h in the two loops above,
which means we cannot delete the loop, but we are getting closer.  Being able to
compute a constant trip count for these two loops will allow us to unroll them
completely though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13017 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:36:24 +00:00
Chris Lattner
4f1134e51a 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
}


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13016 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:16:10 +00:00
Chris Lattner
f50af088f1 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13015 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:08:33 +00:00
Chris Lattner
f5b9eb37a9 Add support for evaluation of exp/log/log10/pow
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13011 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 22:35:33 +00:00
Chris Lattner
657253119e Fix some really nasty dominance bugs that were exposed by my patch to
make the verifier more strict.  This fixes building zlib


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13002 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 18:08:07 +00:00
Misha Brukman
ea51deb18a Fix retriving parent Function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13001 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 17:37:12 +00:00
Brian Gaeke
c598517c24 Include <cmath> for compatibility with gcc 3.0.x (the system compiler on
Debian.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12986 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 15:57:32 +00:00
Misha Brukman
98eb6264d4 Assert if deleting BasicBlock before removing it from Function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12983 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 15:47:21 +00:00
Chris Lattner
006118fe8c Fix some of the strange CBE-only failures that happened last night.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12980 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 06:03:17 +00:00
Chris Lattner
e1f0cf179f Make sure to check for a very bad class of errors: an instruction
that does not dominate all of its users, but is in the same basic block as
its users.  This class of error is what caused the mysterious CBE only
failures last night.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12979 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 05:51:47 +00:00
Chris Lattner
bf3d2e2683 Bugpoint was not correctly capturing stderr! This caused it to "find" bugs
that didn't exist, missing the ones that do :(


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12978 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 05:35:58 +00:00
Chris Lattner
cd01ae5c70 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12977 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 05:17:59 +00:00
Chris Lattner
d244057a48 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12968 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 20:26:22 +00:00
Brian Gaeke
b75a316758 Give SparcV9CodeEmitter a head-of-file comment and a PassName.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12967 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 20:23:13 +00:00
Misha Brukman
7a46e4c62b Don't use invalid HTML in a doxygen comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12962 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:23:45 +00:00
Chris Lattner
59fdaeeae8 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12961 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:21:43 +00:00
Chris Lattner
92020faa2c add some helpful methods. Rearrange #includes to proper order
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12960 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:16:02 +00:00
Chris Lattner
0a7f98c80d Factor a bunch of classes out into a public header
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12958 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:07:24 +00:00
Chris Lattner
0aa84fdd04 Unbreak the build
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12956 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 14:17:43 +00:00
Chris Lattner
e9fc96e7cc Implement a FIXME: if we're going to insert a cast, we might as well only
insert it once!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12955 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 22:01:22 +00:00
John Criswell
53b54be5fc Remove code to adjust the iterator for llvm.readio and llvm.writeio.
The iterator is pointing at the next instruction which should not disappear
when doing the load/store replacement.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12954 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 21:27:56 +00:00
Brian Gaeke
8121fcd260 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12953 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 21:21:56 +00:00
Chris Lattner
16011e6201 This is a trivial tweak to the addrec insertion code: insert the increment
at the bottom of the loop instead of the top.  This reduces the number of
overlapping live ranges a lot, for example, eliminating a spill in an important
loop in 183.equake with linear scan.

I still need to make the exit comparison of the loop use the post-incremented
version of this variable, but this is an easy first step.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12952 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 21:11:25 +00:00
Brian Gaeke
50872d5385 Add a TargetData to the PassManager regardless of the TargetMachine.
This should unbreak the Sparc JIT again.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12949 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 17:45:52 +00:00
John Criswell
71c887d688 Remove the return type check for llvm.readio. This check is done for all
functions and is not needed here.
Simplify the pointer type check per Chris's suggestions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12945 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 15:06:48 +00:00
John Criswell
17f64258cf Added code to verify that llvm.readio's pointer argument returns something
that matches its return type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12944 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 14:49:36 +00:00
John Criswell
994a765e5c Finish adding the llvm.readio and llvm.writeio intrinsics.
Sorry these didn't get in yesterday.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12942 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 13:46:52 +00:00
Chris Lattner
d9955aaa61 ADd a trivial instcombine: load null -> null
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12940 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 03:28:36 +00:00
Chris Lattner
098e945fbd This is the real fix for Codegen/X86/2004-04-13-FPCMOV-Crash.llx which works
even when the "optimization" I added before is turned off.  It generates this
extremely pointless code:

test:
        fld QWORD PTR [%ESP + 4]
        mov %AL, 0
        test %AL, %AL
        fcmove %ST(0), %ST(0)
        ret

Good thing the optimizer will have removed this before code generation
anyway.  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12939 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 02:42:32 +00:00
John Criswell
e5a4c15da6 Added support for the llvm.readio and llvm.writeio intrinsics.
On x86, memory operations occur in-order, so these are just lowered into
volatile loads and stores.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12936 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 22:13:14 +00:00
Chris Lattner
82c5a9990f Implement a small optimization, which papers over the problem in
X86/2004-04-13-FPCMOV-Crash.llx

A more robust fix is to follow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12935 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 21:56:09 +00:00
Chris Lattner
58b7b08ad7 Add SCCP support for constant folding calls, implementing:
test/Regression/Transforms/SCCP/calltest.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12921 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:43:54 +00:00
Chris Lattner
25b8390bf2 Add a simple call constant propagation interface.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12919 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:28:52 +00:00
Chris Lattner
4647b7cd69 Constant propagation should remove the dead instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12917 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:28:20 +00:00
Brian Gaeke
ef8e48aae0 I don't think we have to have 4 extra allocated (but unused) bytes on the stack.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12905 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 18:28:37 +00:00
Brian Gaeke
3d11e8a6d3 I started working on casts, but I don't have anything compilable yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12903 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 18:27:46 +00:00
Chris Lattner
87e18deabc Emit the immediate form of in/out when possible.
Fix several bugs in the intrinsics:
  1. Make sure to copy the input registers before the instructions that use them
  2. Make sure to copy the value returned by 'in' out of EAX into the register
     it is supposed to be in.

This fixes assertions when using in/out and linear scan.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12896 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 17:20:37 +00:00
Chris Lattner
440bbc257e Add immediate forms of in/out. Use let to shorten lines
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12895 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 17:19:31 +00:00
Chris Lattner
e47f4ff9f6 Add support for new instruction type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12894 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 17:18:51 +00:00
Chris Lattner
266538350a Add support for the printImplicitDefsBefore flag
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12893 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 17:18:39 +00:00
Chris Lattner
4b66242c54 Fix LoopSimplify/2004-04-13-LoopSimplifyUpdateDomFrontier.ll
LoopSimplify was not updating dominator frontiers correctly in some cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12890 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 16:23:25 +00:00
Chris Lattner
1f62f82b05 Refactor code a bit to make it simpler and eliminate the goto
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12888 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 15:21:18 +00:00
Chris Lattner
529b28da45 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.  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12884 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 05:05:33 +00:00
Brian Gaeke
5f0b51547c We don't need to insert TargetData into the PassManager here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12874 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 21:46:31 +00:00
Alkis Evlogimenos
6e4d0d6546 Fix bug introduced in previous commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12872 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 20:26:39 +00:00
Chris Lattner
46758a894f Add some methods that are useful for updating loop information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12871 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 20:26:17 +00:00
Alkis Evlogimenos
43b61f724e Correctly compute spill weights
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12869 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 17:39:20 +00:00
Alkis Evlogimenos
e633352fd5 Print def lists a bit more compactly
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12866 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 15:57:58 +00:00
Chris Lattner
ce1a3a292d Actually update the call graph as the inliner changes it. This allows us to
execute other CallGraphSCCPasses after the inliner without crashing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12861 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 05:37:29 +00:00