* Change signatures of OptimizeCall and ValidateCalledFunction so they are
  non-const, allowing the optimization object to be modified. This is in
  support of caching things used across multiple calls.
* Provide two functions for constructing and caching function types
* Modify the StrCatOptimization to cache Function objects for strlen and
  llvm.memcpy so it doesn't regenerate them on each call site. Make sure
  these are invalidated each time we start the pass.
* Handle both a GEP Instruction and a GEP ConstantExpr
* Add additional checks to make sure we really are dealing with an arary of
  sbyte and that all the element initializers are ConstantInt or
  ConstantExpr that reduce to ConstantInt.
* Make sure the GlobalVariable is constant!
* Don't use ConstantArray::getString as it can fail and it doesn't give us
  the right thing. We must check for null bytes in the middle of the array.
* Use llvm.memcpy instead of memcpy so we can factor alignment into it.
* Don't use void* types in signatures, replace with sbyte* instead.

llvm-svn: 21555

llvm-svn: 21554

llvm-svn: 21553

llvm-svn: 21552

* Don't use std::string for the function names, const char* will suffice
* Allow each CallOptimizer to validate the function signature before
  doing anything
* Repeatedly loop over the functions until an iteration produces
  no more optimizations. This allows one optimization to insert a
  call that is optimized by another optimization.
* Implement the ConstantArray portion of the StrCatOptimization
* Provide a template for the MemCpyOptimization
* Make ExitInMainOptimization split the block, not delete everything
  after the return instruction.
(This covers revision 1.3 and 1.4, as the 1.3 comments were botched)

llvm-svn: 21548

int foo1(int x, int y) {
  int t1 = x >= 0;
  int t2 = y >= 0;
  return t1 & t2;
}
int foo2(int x, int y) {
  int t1 = x == -1;
  int t2 = y == -1;
  return t1 & t2;
}

produces:

_foo1:
        or r2, r4, r3
        srwi r2, r2, 31
        xori r3, r2, 1
        blr
_foo2:
        and r2, r4, r3
        addic r2, r2, 1
        li r2, 0
        addze r3, r2
        blr

instead of:

_foo1:
        srwi r2, r4, 31
        xori r2, r2, 1
        srwi r3, r3, 31
        xori r3, r3, 1
        and r3, r2, r3
        blr
_foo2:
        addic r2, r4, 1
        li r2, 0
        addze r2, r2
        addic r3, r3, 1
        li r3, 0
        addze r3, r3
        and r3, r2, r3
        blr

llvm-svn: 21547

* Use a 

llvm-svn: 21546

the restriction that it is an XFAIL because it now passes.

llvm-svn: 21545

_foo:
        or r2, r4, r3
        srwi r3, r2, 31
        blr

instead of:

_foo:
        srwi r2, r4, 31
        srwi r3, r3, 31
        or r3, r2, r3
        blr

llvm-svn: 21544

Naveen Neelakantam, thanks!

llvm-svn: 21543

llvm-svn: 21542

llvm-svn: 21541

llvm-svn: 21540

llvm-svn: 21539

llvm-svn: 21537

llvm-svn: 21536

llvm-svn: 21535

llvm-svn: 21534

strcat when its called.

llvm-svn: 21533

llvm-svn: 21532

* Fix comments at top of file
* Change algorithm for running the call optimizations from n*n to something
  closer to n.
* Use a hash_map to store and lookup the optimizations since there will
  eventually (or potentially) be a large number of them. This gets lookup
  based on the name of the function to O(1). Each CallOptimizer now has a
  std::string member named func_name that tracks the name of the function
  that it applies to. It is this string that is entered into the hash_map
  for fast comparison against the function names encountered in the module.
* Cleanup some style issues pertaining to iterator invalidation
* Don't pass the Function pointer to the OptimizeCall function because if
  the optimization needs it, it can get it from the CallInst passed in.
* Add the skeleton for a new CallOptimizer, StrCatOptimizer which will
  eventually replace strcat's of constant strings with direct copies.

llvm-svn: 21526

llvm-dis output don't go blind.

llvm-svn: 21525

destructor. Just add the do-nothing virtual destructor.

llvm-svn: 21524

llvm-svn: 21523

calls. The pass visits all external functions in the module and determines
if such function calls can be optimized. The optimizations are specific to
the library calls involved. This initial version only optimizes calls to
exit(3) when they occur in main(): it changes them to ret instructions.

llvm-svn: 21522

llvm-svn: 21521

so we put the destructor in Pass.cpp and make it non-inline.

llvm-svn: 21520

llvm-svn: 21515

instruction is added to the original block, not the new block.

llvm-svn: 21513

destructor.

llvm-svn: 21510

don't have virtual destructors.

llvm-svn: 21507

grammar rules for the English language.

llvm-svn: 21503

llvm-svn: 21501

llvm-svn: 21500

regardless of the tab size/stop settings on the developer side

llvm-svn: 21499

llvm-svn: 21498

llvm-svn: 21497

llvm-svn: 21496

llvm-svn: 21495

llvm-svn: 21494