Commit Graph

15 Commits

Author SHA1 Message Date
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
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
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
Chris Lattner
9a5c22cc5e add two simple test cases we now optimize (to one load in the loop each) and one we don't (corresponding to the fixme I added yesterday).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90012 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 18:08:30 +00:00
Chris Lattner
616613d7a4 teach GVN's load PRE to insert computations of the address in predecessors
where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89997 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 08:25:10 +00:00
Chris Lattner
d280d85791 add some tests for memdep phi translation + PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89996 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 06:42:42 +00:00
Chris Lattner
8dca876ab7 filecheckize
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89994 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 06:33:09 +00:00
Chris Lattner
9b15d60c7a rename test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89993 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 06:31:55 +00:00
Chris Lattner
4f118f0a20 rename some tests to be more uniform in naming convention.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60988 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 18:47:40 +00:00
Chris Lattner
7f7c736682 Fix test/Transforms/GVN/pre-load.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60594 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-05 17:04:12 +00:00
Chris Lattner
c89c6a964c Implement PRE of loads in the GVN pass with a pretty cheap and
straight-forward implementation.  This does not require any extra
alias analysis queries beyond what we already do for non-local loads.

Some programs really really like load PRE.  For example, SPASS triggers
this ~1000 times, ~300 times in 255.vortex, and ~1500 times on 403.gcc.

The biggest limitation to the implementation is that it does not split
critical edges.  This is a huge killer on many programs and should be
addressed after the initial patch is enabled by default.

The implementation of this should incidentally speed up rejection of 
non-local loads because it avoids creating the repl densemap in cases 
when it won't be used for fully redundant loads.

This is currently disabled by default.
Before I turn this on, I need to fix a couple of miscompilations in
the testsuite, look at compile time performance numbers, and look at
perf impact.  This is pretty close to ready though.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60408 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-02 08:16:11 +00:00