Commit Graph

162 Commits

Author SHA1 Message Date
Duncan Sands
cd6636c737 Teach InstructionSimplify about phi nodes. I chose to have it simply
offload the work to hasConstantValue rather than do something more
complicated (such handling mutually recursive phis) because (1) it is
not clear it is worth it; and (2) if it is worth it, maybe such logic
would be better placed in hasConstantValue.  Adjust some GVN tests
which are now cleaned up much further (eg: all phi nodes are removed).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119043 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-14 13:30:18 +00:00
Duncan Sands
dd609e912b Testcase to go along with commit 118923 ("Have GVN simplify instructions
as it goes").  Before -std-compile-opts only got it down to
  %a = tail call i32 @foo(i32 0) readnone
  %x = tail call i32 @foo(i32 %a) readnone
  %y = tail call i32 @foo(i32 %a) readnone
  %z = icmp eq i32 %x, %y
  ret i1 %z
while now -basicaa -gvn alone reduce it to
  %a = call i32 @foo(i32 0) readnone
  %x = call i32 @foo(i32 %a) readnone
  ret i1 true



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119009 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-13 21:33:19 +00:00
Dan Gohman
075fb5d68f Enhance GVN to do more precise alias queries for non-local memory
references. For example, this allows gvn to eliminate the load in
this example:

  void foo(int n, int* p, int *q) {
    p[0] = 0;
    p[1] = 1;
    if (n) {
      *q = p[0];
    }
  }


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118714 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10 20:37:15 +00:00
Dan Gohman
c1be92f3bb Make BasicAliasAnalysis a normal AliasAnalysis implementation which
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.

Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.

Update tests to explicitly request -basicaa.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116720 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-18 18:04:47 +00:00
Owen Anderson
7267e14327 Now that the profitable bits of EnableFullLoadPRE have been enabled by default, rip out the remainder.
Anyone interested in more general PRE would be better served by implementing it separately, to get real
anticipation calculation, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115337 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-01 20:02:55 +00:00
Owen Anderson
722cc1f414 We do want to allow LoadPRE to perform LICM-like transformations: we already consider PHI nodes to be negligible for
code size (making this transform code size neutral), and it allows us to hoist values out of loops, which is always
a good thing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115205 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-30 20:53:04 +00:00
Owen Anderson
b0ba0f4170 LoadPRE was not properly checking that the load it was PRE'ing post-dominated the block it was being hoisted to.
Splitting critical edges at the merge point only addressed part of the issue; it is also possible for non-post-domination
to occur when the path from the load to the merge has branches in it.  Unfortunately, full anticipation analysis is
time-consuming, so for now approximate it.  This is strictly more conservative than real anticipation, so we will miss
some cases that real PRE would allow, but we also no longer insert loads into paths where they didn't exist before. :-)

This is a very slight net positive on SPEC for me (0.5% on average).  Most of the benchmarks are largely unaffected, but
when it pays off it pays off decently: 181.mcf improves by 4.5% on my machine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114785 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-25 05:26:18 +00:00
Duncan Sands
cdd4f8c7cb Correct bogus module triple specifications.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112469 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30 10:48:29 +00:00
Rafael Espindola
1e81966626 Remove arm_apcscc from the test files. It is the default and doing this
matches what llvm-gcc and clang now produce.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106221 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-17 15:18:27 +00:00
Chris Lattner
7944c21cae Fix PR7052, patch by Jakub Staszak!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103347 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-08 20:01:44 +00:00
Nick Lewycky
8e13af309b Fix intrinsic signature in this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101674 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-17 21:12:55 +00:00
Bob Wilson
84bd6b0c31 Re-commit my previous SSAUpdater changes. The previous version naively tried
to determine where to place PHIs by iteratively comparing reaching definitions
at each block.  That was just plain wrong.  This version now computes the
dominator tree within the subset of the CFG where PHIs may need to be placed,
and then places the PHIs in the iterated dominance frontier of each definition.
The rest of the patch is mostly the same, with a few more performance
improvements added in.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101612 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-17 03:08:24 +00:00
Chris Lattner
d2075586c8 add newlines at the end of files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100705 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-07 22:53:17 +00:00
Bob Wilson
49c283fd3f Revert all my SSAUpdater patches. The PHI placement algorithm is not correct
(what was I thinking?) and there's also a problem with LCSSA.  I'll try again
later with fixes.

--- Reverse-merging r100263 into '.':
U    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100177 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100148 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100147 into '.':
U    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100131 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100130 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100126 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100050 into '.':
D    test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
--- Reverse-merging r100047 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100264 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 03:50:38 +00:00
Bob Wilson
368454976c Add a redundant PHI testcase for SSAUpdater to go with svn r100047.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100050 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-31 21:38:43 +00:00
Chris Lattner
219d77430b fix PR6642, GVN forwarding from memset to load of the base of the memset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99488 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 05:58:19 +00:00
Devang Patel
09a695e396 Remove tests that checks @llvm.dbg.stoppoint handling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97493 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 20:33:48 +00:00
Chris Lattner
f09999e103 stop using anders-aa
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97492 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 20:24:50 +00:00
Bob Wilson
713bc585ef Testcase for critical edge splitting with load PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96385 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 20:48:55 +00:00
Chris Lattner
5cc25ce17d a testcase that doesn't crash GVN but could someday.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95851 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 05:08:05 +00:00
Bob Wilson
49db68fba0 Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 04:42:39 +00:00
Bob Wilson
e98585eb36 Avoid creating redundant PHIs in SSAUpdater::GetValueInMiddleOfBlock.
This was already being done in SSAUpdater::GetValueAtEndOfBlock so I've
just changed SSAUpdater to check for existing PHIs in both places.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94690 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-27 22:01:02 +00:00
Dan Gohman
aceba31b7a Delete useless trailing semicolons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92740 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 17:55:26 +00:00
Chris Lattner
f648125be9 fix an overly conservative caching issue that caused memdep to
cache a pointer as being unavailable due to phi trans in the
wrong place.  This would cause later queries to fail even when
they didn't involve phi trans.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91787 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-19 21:29:22 +00:00
Chris Lattner
16e7ae42a1 fix inconsistent use of tabs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91783 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-19 20:44:43 +00:00
Chris Lattner
16f244e982 Fix PR5744, a case where we were getting the pointer size instead of the
value size.  This only manifested when memdep inprecisely returns clobber,
which is do to a caching issue in the PR5744 testcase.  We can 'efficiently
emulate' this by using '-no-aa'


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91004 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-10 00:11:45 +00:00
Chris Lattner
af064aeee6 fix hte last remaining known (by me) phi translation bug. When we reanalyze
clobbers to forward pieces of large stores to small loads, we need to consider
the properly phi translated pointer in the store block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90978 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 18:21:46 +00:00
Chris Lattner
4d3a16f81b Add a minor optimization: if we haven't changed the operands of an
add, there is no need to scan the world to find the same add again.
This invalidates the previous testcase, which wasn't wonderful anyway,
because it needed a run of instcombine to permute the use-lists in 
just the right way to before GVN was run (so it was really fragile).
Not a big loss.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90973 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 17:27:45 +00:00
Chris Lattner
eddc65aa0d fix PR5733, a case where we'd replace an add with a lexically identical
binary operator that wasn't an add.  In this case, a xor.  Whoops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90971 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 17:18:49 +00:00
Chris Lattner
1a247f32dd merge crash-2.ll into crash.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90969 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 17:17:26 +00:00
Chris Lattner
55fe79f044 the code in GVN that tries to forward large loads to small
stores is not phi translating, thus it miscompiles really
crazy testcases.  This is from inspection, I haven't seen
this in the wild.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90930 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 02:43:05 +00:00
Chris Lattner
05e15f8897 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90926 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 01:59:31 +00:00
Chris Lattner
bc9a28dd54 constant fold loads from memcpy's from global constants. This is important
because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90698 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 05:29:56 +00:00
Chris Lattner
cb9cbc4949 add support for forwarding mem intrinsic values to non-local loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90697 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 04:54:31 +00:00
Chris Lattner
faf815b938 Handle forwarding local memsets to loads. For example, we optimize this:
short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90695 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 01:57:02 +00:00
Chris Lattner
f616ee2895 merge two tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90691 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 01:47:24 +00:00
Chris Lattner
e4968a4b9d Small and carefully crafted testcase showing a miscompilation by GVN
that I'm working on.  This is manifesting as a miscompile of 255.vortex
on some targets.  No check lines yet because it fails.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90520 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 02:12:12 +00:00
Owen Anderson
c9f2027adb Fix this crasher, and add a FIXME for a missed optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90408 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 03:43:29 +00:00
Chris Lattner
fd82af0f95 add a failing testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90380 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 01:46:18 +00:00
Owen Anderson
9ff5a23186 Cleanup/remove some parts of the lifetime region handling code in memdep and GVN,
per Chris' comments.  Adjust testcases to match.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90304 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-02 07:35:19 +00:00
Chris Lattner
49f5389aae minimize this a bit more.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90216 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 07:30:01 +00:00
Chris Lattner
156cf873e5 merge 2009-11-29-ReverseMap.ll into crash.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90212 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 06:22:10 +00:00
Nick Lewycky
526bc31cee Add a testcase for the current llvm-gcc build failure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90112 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-30 07:02:18 +00:00
Chris Lattner
ff0a883fe9 add PR#
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90049 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-29 01:28:58 +00:00
Chris Lattner
78c6d4fa9c Add a testcase for:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j] = G[j] + G[j+1] + G[j-1];
}

which we now compile to one load in the loop:

LBB1_2:                                                     ## %bb
	movsd	16(%rsi,%rax,8), %xmm2
	incq	%rdx
	addsd	%xmm2, %xmm1
	addsd	%xmm1, %xmm0
	movapd	%xmm2, %xmm1
	movsd	%xmm0, 8(%rsi,%rax,8)
	incq	%rax
	cmpq	%rcx, %rax
	jne	LBB1_2

instead of:

LBB1_2:                                                     ## %bb
	movsd	8(%rsi,%rax,8), %xmm0
	addsd	16(%rsi,%rax,8), %xmm0
	addsd	(%rsi,%rax,8), %xmm0
	movsd	%xmm0, 8(%rsi,%rax,8)
	incq	%rax
	cmpq	%rcx, %rax
	jne	LBB1_2



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90048 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-29 01:15:43 +00:00
Chris Lattner
9fed3c2835 add a testcase for
void test9(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90047 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-29 01:04:40 +00:00
Chris Lattner
0c264b16b0 reenable load address insertion in load pre. This allows us to
handle cases like this:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

where G[1] isn't live into the loop.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90041 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-28 16:08:18 +00:00
Chris Lattner
971fd57f7d disable value insertion for now, I need to figure out how
to inform GVN about the newly inserted values.  This fixes 
PR5631.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90022 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 22:50:07 +00:00
Chris Lattner
253be4ddb2 I accidentally implemented this :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90014 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 19:56:00 +00:00
Chris Lattner
11c6bab704 add support for recursive phi translation and phi
translation of add with immediate.  This allows us
to optimize this function:

void test(int N, double* G) {
  long j;
  G[1] = 1;
    for (j = 1; j < N - 1; j++)
        G[j+1] = G[j] + G[j+1];
}

to only do one load every iteration of the loop.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90013 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 19:11:31 +00:00