problem reported on cfe-dev.

llvm-svn: 130661

Luis Felipe Strano Moraes!

llvm-svn: 129558

llvm-svn: 125563

how they should be checked.

llvm-svn: 123999

llvm-svn: 123302

of the bootstrap miscompare issue.

llvm-svn: 123299

the source of the bootstrap problem.

llvm-svn: 123298

llvm-svn: 123149

back to life.

llvm-svn: 123146

llvm-svn: 123144

without informing memdep.  This could cause nondeterminstic weirdness 
based on where instructions happen to get allocated, and will hopefully
breath some life into some broken testers.

llvm-svn: 123124

updating memdep when fusing stores together.  This fixes the crash optimizing
the bullet benchmark.

llvm-svn: 123091

llvm-svn: 123090

larger memsets.  Among other things, this fixes rdar://8760394 and
allows us to handle "Example 2" from http://blog.regehr.org/archives/320,
compiling it into a single 4096-byte memset:

_mad_synth_mute:                        ## @mad_synth_mute
## BB#0:                                ## %entry
	pushq	%rax
	movl	$4096, %esi             ## imm = 0x1000
	callq	___bzero
	popq	%rax
	ret

llvm-svn: 123089

P and P+1 are relative to the same base pointer.

llvm-svn: 123087

memset into a single larger memset.

llvm-svn: 123086

Split memset formation logic out into its own
"tryMergingIntoMemset" helper function.

llvm-svn: 123081

llvm-svn: 122572

llvm-svn: 122565

llvm-svn: 122561

Fix a thinko pointed out by Frits van Bommel: looking through global variables in isBytewiseValue is not safe.

llvm-svn: 122550

This allows us to compile "int cst[] = {-1, -1, -1};" into
  movl  $-1, 16(%rsp)
  movq  $-1, 8(%rsp)
instead of
  movl  _cst+8(%rip), %eax
  movl  %eax, 16(%rsp)
  movq  _cst(%rip), %rax
  movq  %rax, 8(%rsp)

llvm-svn: 122548

new gcc warning that complains on self-assignments and
self-initializations.

llvm-svn: 122458

llvm-svn: 121944

llvm-svn: 121362

substitution because it doesn't actually change the IR.  Patch by
Jakub Staszak!

llvm-svn: 121361

zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

llvm-svn: 121120

20040709-1.c from the gcc testsuite.  I was using the size of a
pointer instead of the pointee.  This fixes rdar://8713376

llvm-svn: 120519

llvm-svn: 120347

llvm-svn: 119948

method in MemDep instead of inserting an instruction, doing a query,
then removing it.  Neither operation is effectively cached.

llvm-svn: 119930

allowing the memcpy to be eliminated.

Unfortunately, the requirements on byval's without explicit 
alignment are really weak and impossible to predict in the 
mid-level optimizer, so this doesn't kick in much with current
frontends.  The fix is to change clang to set alignment on all
byval arguments.

llvm-svn: 119916

llvm-svn: 119908

saying "it would be bad", give an example of what is going on.

llvm-svn: 119695

refusing to optimize two memcpy's like this:

copy A <- B
copy C <- A

if it couldn't prove that noalias(B,C).  We can eliminate
the copy by producing a memmove instead of memcpy.

llvm-svn: 119694

source and dest are known to not overlap.

llvm-svn: 119692

there is no need to check to see if the source and dest of a memcpy are noalias,
behavior is undefined if not.

llvm-svn: 119691

out of processMemCpy into its own function.

llvm-svn: 119687

uint64_t, plus fixes for places I missed before.

llvm-svn: 116875

llvm-svn: 116858