Commit Graph

41 Commits

Author SHA1 Message Date
Eli Friedman
5ac7c7da3e Correct grammar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139565 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-13 00:44:16 +00:00
Eli Friedman
2bc3d52b9a Change a bunch of isVolatile() checks to check for atomic load/store as well.
No tests; these changes aren't really interesting in the sense that the logic is the same for volatile and atomic.

I believe this completes all of the changes necessary for the optimizer to handle loads and stores correctly.  I'm going to try and come up with some additional testing, though.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139533 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-12 20:23:13 +00:00
Chris Lattner
db125cfaf5 land David Blaikie's patch to de-constify Type, with a few tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18 04:54:35 +00:00
Chad Rosier
71400b6afa Disable loop idiom recognition of memset/memcpy if the function being compiled
is named after a common idiom (i.e., memset/memcpy).  Otherwise, we can run into 
infinite recursion.  Ideally, the user should use the correct -fno-builtin flag,
but in case they don't we should play nicely.
rdar://9763412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15 18:25:04 +00:00
Andrew Trick
5e7645be4c SCEVExpander: give new insts a name that identifies the reponsible pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133992 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-28 05:07:32 +00:00
Andrew Trick
a5d950f673 whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133991 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-28 05:04:16 +00:00
Chris Lattner
4f81b54192 Fix PR9815: I was trying to get out of "generating code and then
failing to form a memset, then having to delete it" but my approximation
isn't safe for self recurrent loops.  Instead of doign a hack, just
do it the right way.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131858 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-22 17:39:56 +00:00
Devang Patel
af35841f2e preserve line number info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130869 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-04 21:37:05 +00:00
Andrew Trick
3228cc259b Added SCEV::NoWrapFlags to manage unsigned, signed, and self wrap
properties.
Added the self-wrap flag for SCEV::AddRecExpr.
A slew of temporary FIXMEs indicate the intention of the no-self-wrap flag
without changing behavior in this revision.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127590 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-14 16:50:06 +00:00
Andrew Trick
d99b39e43b whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127589 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-14 16:48:10 +00:00
Devang Patel
cd77a50e63 Preserve line no. info.
Radar 9097659


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 22:43:45 +00:00
Chris Lattner
0e68cee62f fix a crasher in disabled code (on variable stride loops)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126125 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-21 17:02:55 +00:00
Chris Lattner
408b534e43 Add some (disabled code) to print out negative strides.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126102 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-21 02:08:54 +00:00
Chris Lattner
80e8b506b8 rewrite the memset_pattern pattern generation stuff to accept any 2/4/8/16-byte
constant, including globals.  This makes us generate much more "pretty" pattern
globals as well because it doesn't break it down to an array of bytes all the
time.

This enables us to handle stores of relocatable globals.  This kicks in about
48 times in 254.gap, giving us stuff like this:

@.memset_pattern40 = internal constant [2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*] [%struct.TypHeader* (%struct.TypHeader*, %struct
.TypHeader*)* @IsFalse, %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)* @IsFalse], align 16

...
  call void @memset_pattern16(i8* %scevgep5859, i8* bitcast ([2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*]* @.memset_pattern40 to i8*
), i64 %tmp75) nounwind



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126044 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-19 19:56:44 +00:00
Chris Lattner
3a393728a6 Implement rdar://9009151, transforming strided loop stores of
unsplatable values into memset_pattern16 when it is available
(recent darwins).  This transforms lots of strided loop stores
of ints for example, like 5 in vpr:

  Formed memset:   call void @memset_pattern16(i8* %4, i8* getelementptr inbounds ([16 x i8]* @.memset_pattern9, i32 0, i32 0), i64 %tmp25)
    from store to: {%3,+,4}<%11> at:   store i32 3, i32* %scevgep, align 4, !tbaa !4




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126040 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-19 19:31:39 +00:00
Chris Lattner
c19175c9d8 Make loop-idiom use TargetLibraryInfo to determine whether it is allowed
to hack on memset, memcpy etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125974 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 22:22:15 +00:00
Duncan Sands
ab4c366274 Spelling fix: consequtive -> consecutive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125563 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-15 09:23:02 +00:00
Chris Lattner
e41d3c015c Teach loop-idiom to turn a loop containing a memset into a larger memset
when safe.

The testcase is basically this nested loop:
void foo(char *X) {
  for (int i = 0; i != 100; ++i) 
    for (int j = 0; j != 100; ++j)
      X[j+i*100] = 0;
}

which gets turned into a single memset now.  clang -O3 doesn't optimize
this yet though due to a phase ordering issue I haven't analyzed yet.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122806 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 07:46:33 +00:00
Chris Lattner
b7e9ef0ed1 restructure this a bit. Initialize the WeakVH with "I", the
instruction *after* the store.  The store will always be deleted
if the transformation kicks in, so we'd do an N^2 scan of every
loop block.  Whoops.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122805 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 07:27:30 +00:00
Chris Lattner
7c90b90f4e use the very-handy getTruncateOrZeroExtend helper function, and
stop setting NSW: signed overflow is possible.  Thanks to Dan
for pointing these out.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122790 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 00:06:55 +00:00
Owen Anderson
6f96b275b6 Fix comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122788 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 23:51:56 +00:00
Chris Lattner
d957c71791 reduce redundancy in the hashing code and other misc cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122720 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 01:10:08 +00:00
Chris Lattner
91139ccd99 add DEBUG and -stats output to earlycse.
Teach it to CSE the rest of the non-side-effecting instructions.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122716 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 23:19:45 +00:00
Chris Lattner
63f9c3c49a fix a miscompilation of tramp3d-v4: when forming a memcpy, we have to make
sure that the loop we're promoting into a memcpy doesn't mutate the input
of the memcpy.  Before we were just checking that the dest of the memcpy
wasn't mod/ref'd by the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122712 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 21:14:18 +00:00
Chris Lattner
8e08e73f0e If a loop iterates exactly once (has backedge count = 0) then don't
mess with it.  We'd rather peel/unroll it than convert all of its 
stores into memsets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122711 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 20:24:21 +00:00
Chris Lattner
62c50fdf69 enhance loop idiom recognition to scan *all* unconditionally executed
blocks in a loop, instead of just the header block.  This makes it more
aggressive, able to handle Duncan's Ada examples.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122704 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 19:01:03 +00:00
Chris Lattner
bdce5720ad add a list of opportunities for future improvement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122701 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 18:32:09 +00:00
Chris Lattner
cf078f2b20 Allow loop-idiom to run on multiple BB loops, but still only scan the loop
header for now for memset/memcpy opportunities.  It turns out that loop-rotate
is successfully rotating loops, but *DOESN'T MERGE THE BLOCKS*, turning "for 
loops" into 2 basic block loops that loop-idiom was ignoring.

With this fix, we form many *many* more memcpy and memsets than before, including
on the "history" loops in the viterbi benchmark, which look like this:

        for (j=0; j<MAX_history; ++j) {
          history_new[i][j+1] = history[2*i][j];
        }

Transforming these loops into memcpy's speeds up the viterbi benchmark from
11.98s to 3.55s on my machine.  Woo.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122685 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:58:36 +00:00
Chris Lattner
6b04160dd8 remove debugging code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122683 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:37:13 +00:00
Chris Lattner
4ce31fb574 add some -stats output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122682 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:36:44 +00:00
Chris Lattner
e2c4392091 teach loop idiom recognition to form memcpy's from simple loops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122678 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 03:37:56 +00:00
Chris Lattner
bafa117e8f add a validity check that was missed, fixing a crash on the
new testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122662 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 20:12:04 +00:00
Chris Lattner
a64cbf067d improve validity check to handle constant-trip-count loops more
aggressively.  In practice, this doesn't help anything though,
see the todo.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122660 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 19:54:22 +00:00
Chris Lattner
30980b6815 implement the "no aliasing accesses in loop" safety check. This pass
should be correct now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122659 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-01 19:39:01 +00:00
Chris Lattner
95ae676bc8 simplify this, isBytewiseValue handles the extra check. We still
check for "multiple of a byte" in size to make it clear that the
>> 3 below is safe.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122604 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-28 18:53:48 +00:00
Duncan Sands
7922d34b60 Silence gcc warning about an unused variable when doing a release build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122593 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-28 09:41:15 +00:00
Chris Lattner
2e12f1ac6e fix some issues Frits noticed, add AliasAnalysis as a dependency
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122585 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 18:39:08 +00:00
Chris Lattner
9f39188def have loop-idiom nuke instructions that feed stores that get removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122574 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 00:03:23 +00:00
Chris Lattner
a92ff91a96 implement enough of the memset inference algorithm to recognize and insert
memsets.  This is still missing one important validity check, but this is enough
to compile stuff like this:

void test0(std::vector<char> &X) {
  for (std::vector<char>::iterator I = X.begin(), E = X.end(); I != E; ++I)
    *I = 0;
}

void test1(std::vector<int> &X) {
  for (long i = 0, e = X.size(); i != e; ++i)
    X[i] = 0x01010101;
}

With:
 $ clang t.cpp -S -o - -O2 -emit-llvm | opt -loop-idiom | opt -O3 | llc 

to:

__Z5test0RSt6vectorIcSaIcEE:            ## @_Z5test0RSt6vectorIcSaIcEE
## BB#0:                                ## %entry
	subq	$8, %rsp
	movq	(%rdi), %rax
	movq	8(%rdi), %rsi
	cmpq	%rsi, %rax
	je	LBB0_2
## BB#1:                                ## %bb.nph
	subq	%rax, %rsi
	movq	%rax, %rdi
	callq	___bzero
LBB0_2:                                 ## %for.end
	addq	$8, %rsp
	ret
...
__Z5test1RSt6vectorIiSaIiEE:            ## @_Z5test1RSt6vectorIiSaIiEE
## BB#0:                                ## %entry
	subq	$8, %rsp
	movq	(%rdi), %rax
	movq	8(%rdi), %rdx
	subq	%rax, %rdx
	cmpq	$4, %rdx
	jb	LBB1_2
## BB#1:                                ## %for.body.preheader
	andq	$-4, %rdx
	movl	$1, %esi
	movq	%rax, %rdi
	callq	_memset
LBB1_2:                                 ## %for.end
	addq	$8, %rsp
	ret



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122573 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 23:42:51 +00:00
Chris Lattner
22920b5986 sketch more of this out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122567 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 20:45:45 +00:00
Chris Lattner
e6bb649ec6 actually add the file...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122563 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-26 19:39:38 +00:00