llvm-svn: 90929

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.

llvm-svn: 90926

because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.

llvm-svn: 90698

llvm-svn: 90697

short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  

llvm-svn: 90695

llvm-svn: 90408

per Chris' comments.  Adjust testcases to match.

llvm-svn: 90304

llvm-svn: 90299

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.

llvm-svn: 90041

inserted instructions.  No functionality change until someone starts using it.

llvm-svn: 90039

to inform GVN about the newly inserted values.  This fixes 
PR5631.

llvm-svn: 90022

fixes PR5630 and sets the stage for the next phase of goodness (testcase
pending).

llvm-svn: 90019

where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)

llvm-svn: 89997

translation done by memdep, and reenable gep translation 
again.

llvm-svn: 89992

llvm-svn: 88742

This patch forbids implicit conversion of DenseMap::const_iterator to
DenseMap::iterator which was possible because DenseMapIterator inherited
(publicly) from DenseMapConstIterator. Conversion the other way around is now
allowed as one may expect.

The template DenseMapConstIterator is removed and the template parameter
IsConst which specifies whether the iterator is constant is added to
DenseMapIterator.

Actually IsConst parameter is not necessary since the constness can be
determined from KeyT but this is not relevant to the fix and can be addressed
later.

Patch by Victor Zverovich!

llvm-svn: 86636

llvm-svn: 85692

llvm-svn: 85609

purposes for GVN/DSE.

llvm-svn: 85383

llvm-svn: 85286

llvm-svn: 85181

Remove AllocationInst.  Since MallocInst went away, AllocaInst is the only subclass of AllocationInst, so it no longer is necessary.

llvm-svn: 84969

"In the existing code, if the load and the value to replace it with are
of different types *and* target data is available, it tries to use the
target data to coerce the replacement value to the type of the load.
Otherwise, it skips all effort to handle the type mismatch and just
feeds the wrongly-typed replacement value to replaceAllUsesWith, which
triggers an assertion.

The patch replaces it with an outer if checking for type mismatch, and
an inner if-else that checks whether target data is available and, if
not, returns false rather than trying to replace the load."

Patch by Kenneth Uildriks!

llvm-svn: 84739

numbering first class aggregate instructions while we're at it.

llvm-svn: 84547

llvm-svn: 84533

llvm-svn: 84118

from GVN, this also speeds it up, inserts fewer PHI nodes (see the
testcase) and allows it to remove more loads (due to fewer PHI nodes
standing in the way).

llvm-svn: 83746

llvm-svn: 83742

llvm-svn: 83701

llvm-svn: 82936

update all the callers.

llvm-svn: 82889

bootstrap problems.

llvm-svn: 82464

arrays and structs, which cannot be bitcast to integers.

llvm-svn: 82460

This doesn't kick in too much because of phi translation issues,
but this can be resolved in the future.

llvm-svn: 82447

llvm-svn: 82446

llvm-svn: 82444

analysis, one that does the xform.

llvm-svn: 82443

from a piece of a large store when both are in the same block.

This allows clang to compile the testcase in PR4216 to this code:

_test_bitfield:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$-65536, %ecx
	orl	$32962, %eax
	andl	$40186, %eax
	orl	%ecx, %eax
	ret

This is not ideal, but is a whole lot better than the code produced
by llvm-gcc:

_test_bitfield:
	movw	$-32574, %ax
	orw	4(%esp), %ax
	andw	$-25350, %ax
	movw	%ax, 4(%esp)
	movw	7(%esp), %cx
	shlw	$8, %cx
	movzbl	6(%esp), %edx
	orw	%cx, %dx
	movzwl	%dx, %ecx
	shll	$16, %ecx
	movzwl	%ax, %eax
	orl	%ecx, %eax
	ret

and dramatically better than that produced by gcc 4.2:

_test_bitfield:
	pushl	%ebx
	call	L3
"L00000000001$pb":
L3:
	popl	%ebx
	movl	8(%esp), %eax
	leal	0(,%eax,4), %edx
	sarb	$7, %dl
	movl	%eax, %ecx
	andl	$7168, %ecx
	andl	$-7201, %ebx
	movzbl	%dl, %edx
	andl	$1, %edx
	sall	$5, %edx
	orl	%ecx, %ebx
	orl	%edx, %ebx
	andl	$24, %eax
	andl	$-58336, %ebx
	orl	%eax, %ebx
	orl	$32962, %ebx
	movl	%ebx, %eax
	popl	%ebx
	ret

llvm-svn: 82439

llvm-svn: 82426

so that nonlocal and partially redundant loads can use it as well.
The testcase shows examples of craziness this can handle.  This triggers
*many* times in 176.gcc.

llvm-svn: 82403