Commit Graph

195 Commits

Author SHA1 Message Date
Chris Lattner
c1526a9da1 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. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13289 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-30 04:37:52 +00:00
Chris Lattner
6ffe551f65 Changes to fix up the inst_iterator to pass to boost iterator checks. This
patch was graciously contributed by Vladimir Prus.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13185 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-27 15:13:33 +00:00
Chris Lattner
83a2e6e4a1 Instcombine X/-1 --> 0-X
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13172 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-26 14:01:59 +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
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