Commit Graph

342 Commits

Author SHA1 Message Date
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
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
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
fbede52af4 Fix a bug in my select transformation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12826 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-11 01:39:19 +00:00
Chris Lattner
d76956d444 Implement InstCombine/select.ll:test13*
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12821 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 22:21:27 +00:00
Chris Lattner
66331a4e33 Implement InstCombine/add.ll:test20
Canonicalize add of sign bit constant into a xor


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12819 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 22:01:55 +00:00
Chris Lattner
326c0f3013 Fix spurious warning in release mode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12816 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 19:15:56 +00:00
Chris Lattner
e576b91948 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12800 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-09 23:46:01 +00:00
Chris Lattner
2eefe518de 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12794 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-09 19:05:30 +00:00
Chris Lattner
82e14fe168 Implement select.ll:test11
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12793 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-09 18:19:44 +00:00
Chris Lattner
f499eaca36 Implement InstCombine/cast-propagate.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12784 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-08 20:39:49 +00:00
Chris Lattner
0c199a7628 Implement InstCombine/select.ll:test[7-10]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12769 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-08 04:43:23 +00:00
Chris Lattner
cb69a4ed64 Implement test/Regression/Transforms/InstCombine/getelementptr_index.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12762 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-07 18:38:20 +00:00
Chris Lattner
548f47efb0 Fix a bug in yesterdays checkins which broke siod. siod is a great testcase! :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12659 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-05 16:02:41 +00:00
Chris Lattner
15a76c0b35 Fix InstCombine/2004-04-04-InstCombineReplaceAllUsesWith.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12658 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-05 02:10:19 +00:00
Chris Lattner
28977af72a 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12653 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-05 01:30:19 +00:00
Chris Lattner
c32b30a429 Implement select.ll:test[3-6]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12544 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-30 19:37:13 +00:00
Chris Lattner
4df1b8aa26 X % -1 == X % 1 == 0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12520 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-26 16:11:24 +00:00
Chris Lattner
ebd985cb87 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12519 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-25 22:59:29 +00:00
Chris Lattner
7c881dffc9 Teach the optimizer to delete zero sized alloca's (but not mallocs!)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12507 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-19 06:08:10 +00:00
Chris Lattner
0cea42a560 Add some debugging output
Fix InstCombine/2004-03-13-InstCombineInfLoop.ll which caused an infinite
loop compiling (I think) povray.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12365 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-13 23:54:27 +00:00
Chris Lattner
bfe492b5c2 Implement sub.ll:test14
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12355 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-13 00:11:49 +00:00
Chris Lattner
9c2906744a Implement InstCombine/sub.ll:test12 & test13
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12353 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-12 23:53:13 +00:00
Chris Lattner
3d69f46d64 Add trivial optimizations for select instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12317 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-12 05:52:32 +00:00
Chris Lattner
7bcc0e7fff Rename AddUsesToWorkList -> AddUsersToWorkList, as that is what it does.
Create a new AddUsesToWorkList method
optimize memmove/set/cpy of zero bytes to a noop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11941 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-28 05:22:00 +00:00
Chris Lattner
6160e85201 Turn 'free null' into nothing
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11940 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-28 04:57:37 +00:00
Chris Lattner
a0ebcebc06 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11900 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-27 06:27:46 +00:00
Chris Lattner
d38f208cd9 Fix a faulty optimization on FP values
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11801 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-24 18:10:14 +00:00
Chris Lattner
d8864ce766 Generate much more efficient code in programs like pifft
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11775 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 21:46:58 +00:00
Chris Lattner
077a373791 Fix a small typeo in my checkin last night that broke vortex and other programs :(
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11774 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 21:46:42 +00:00
Chris Lattner
8adac75298 Fix InstCombine/2004-02-23-ShiftShiftOverflow.ll
Also, turn 'shr int %X, 1234' into 'shr int %X, 31'


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11768 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 20:30:06 +00:00
Chris Lattner
c5943fb186 Implement cast.ll::test14/15
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11742 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 07:16:20 +00:00
Chris Lattner
4cb170cc6e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11740 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 06:38:22 +00:00
Chris Lattner
fed58fd72e Implement mul.ll:test11
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11737 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 06:00:11 +00:00
Chris Lattner
45aaafef49 Implement "strength reduction" of X <= C and X >= C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11735 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 05:47:48 +00:00
Chris Lattner
fb54b2b744 Implement InstCombine/mul.ll:test10, which is a case that occurs when dealing
with "predication"


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11734 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-23 05:39:21 +00:00
Chris Lattner
c6bd195336 Implement Transforms/InstCombine/cast.ll:test13, a case which occurs in a
hot 164.gzip loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11702 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-22 05:25:17 +00:00
Chris Lattner
7059f2e76b Fold PHI nodes of constants which are only used by a single cast. This implements
phi.ll:test4


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11494 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-16 05:07:08 +00:00
Chris Lattner
26ca7e145e Teach LLVM to unravel the "swap idiom". This implements:
Regression/Transforms/InstCombine/xor.ll:test20


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11492 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-16 03:54:20 +00:00
Chris Lattner
c317d39887 Implement Transforms/InstCombine/xor.ll:test19
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11490 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-16 01:20:27 +00:00
Chris Lattner
de512b5b2e Adjustments to support the new ConstantAggregateZero class
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11474 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-15 05:55:15 +00:00
Chris Lattner
aeb2a1d708 rename the "exceptional" destination of an invoke instruction to the 'unwind' dest
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11202 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-08 21:44:31 +00:00
Chris Lattner
0517e72096 Disable (x - (y - z)) => (x + (z - y)) optimization for floating point.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11083 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-02 20:09:56 +00:00
Chris Lattner
f78616b339 Fix InstCombine/2004-01-13-InstCombineInvokePHI.ll, which also fixes lots
of C++ programs in Shootout-C++, including lists1 and moments, etc


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10845 91177308-0d34-0410-b5e6-96231b3b80d8
2004-01-14 06:06:08 +00:00
Chris Lattner
76f7fe25d9 Fix bug in previous checkin
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10798 91177308-0d34-0410-b5e6-96231b3b80d8
2004-01-12 19:47:05 +00:00
Chris Lattner
7c4049c5a0 Eliminate use of ConstantHandling and ConstantExpr::getShift interfaces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10796 91177308-0d34-0410-b5e6-96231b3b80d8
2004-01-12 19:35:11 +00:00
Chris Lattner
5f16a13896 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10765 91177308-0d34-0410-b5e6-96231b3b80d8
2004-01-12 04:13:56 +00:00
Chris Lattner
60921c9aa1 Factor code out into the Utils library
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10530 91177308-0d34-0410-b5e6-96231b3b80d8
2003-12-19 05:58:40 +00:00
Chris Lattner
67b1e1b89f * Finegrainify namespacification
* Transform: free <ty>* (cast <ty2>* X to <ty>*) into free <ty2>* X


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10303 91177308-0d34-0410-b5e6-96231b3b80d8
2003-12-07 01:24:23 +00:00
Chris Lattner
917e804253 Implement feature: InstCombine/2003-11-13-ConstExprCastCall.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9981 91177308-0d34-0410-b5e6-96231b3b80d8
2003-11-13 19:17:02 +00:00