into the 2.3 release branch.

llvm-svn: 51824

llvm-svn: 51819

llvm-svn: 51817

llvm-svn: 51816

we did not truncate the value down to i1 with (x&1).  This caused a problem
when the computation of x was nontrivial, for example, "add i1 1, 1" would 
return 2 instead of 0.

This makes the testcase compile into:

...
  llvm_cbe_t = (((llvm_cbe_r == 0u) + (llvm_cbe_r == 0u))&1);
  llvm_cbe_u = (((unsigned int )(bool )llvm_cbe_t));
...

instead of:

...
  llvm_cbe_t = ((llvm_cbe_r == 0u) + (llvm_cbe_r == 0u));
  llvm_cbe_u = (((unsigned int )(bool )llvm_cbe_t));
...

This fixes a miscompilation of mediabench/adpcm/rawdaudio/rawdaudio and
403.gcc with the CBE, regressions from LLVM 2.2. Tanya, please pull 
this into the release branch.

llvm-svn: 51813

insertvalue and extractvalue to use constant indices instead of
Value* indices. And begin updating LangRef.html.

There's definately more to come here, but I'm checking this 
basic support in now to make it available to people who are
interested.

llvm-svn: 51806

llvm-svn: 51784

llvm-svn: 51750

llvm-svn: 51726

cases due to an isel deficiency already noted in
lib/Target/X86/README.txt, but they can be matched in this fold-call.ll
testcase, for example.

This is interesting mainly because it exposes a tricky tblgen bug;
tblgen was incorrectly computing the starting index for variable_ops
in the case of a complex pattern.

llvm-svn: 51706

memmove to a more plausible value, now that it's actually being used.

llvm-svn: 51696

llvm-svn: 51695

llvm-svn: 51685

the one case that ADCE catches that normal DCE doesn't: non-induction variable
loop computations.

This implementation handles this problem without using postdominators.

llvm-svn: 51668

llvm-svn: 51667

llvm-svn: 51665

llvm-svn: 51648

llvm-svn: 51647

llvm-svn: 51636

llvm-svn: 51600

is specifically what this test depends on.

llvm-svn: 51599

llvm-svn: 51569

sometimes a "mov %ebp, %esp" in the epilogue.

Force these tests that rely on counting 'mov' to use i686-apple-darwin8.8.0
where they were written.

llvm-svn: 51568

llvm-svn: 51561

llvm-svn: 51560

Analysis/ConstantFolding to fold ConstantExpr's, then make instcombine use it
to try to use targetdata to fold constant expressions on void instructions.

Also extend the icmp(inttoptr, inttoptr) folding to handle the case where
int size != ptr size.

llvm-svn: 51559

This fixes PR2359

llvm-svn: 51536

llvm-svn: 51535

llvm-svn: 51533

Eliminate x86.sse2.movs.d, x86.sse2.shuf.pd, x86.sse2.unpckh.pd, and x86.sse2.unpckl.pd intrinsics. These will be lowered into shuffles.

llvm-svn: 51531

llvm-svn: 51525

llvm-svn: 51523

llvm-svn: 51505

llvm-svn: 51501

llvm-svn: 51500

load-folding table entries for PMULDQ and PMULLD.

llvm-svn: 51489

The SimplifyCFG pass looks at basic blocks that contain only phi nodes,
followed by an unconditional branch. In a lot of cases, such a block (BB) can
be merged into their successor (Succ).

This merging is performed by TryToSimplifyUncondBranchFromEmptyBlock. It does
this by taking all phi nodes in the succesor block Succ and expanding them to
include the predecessors of BB. Furthermore, any phi nodes in BB are moved to
Succ and expanded to include the predecessors of Succ as well.

Before attempting this merge, CanPropagatePredecessorsForPHIs checks to see if
all phi nodes can be properly merged. All functional changes are made to
this function, only comments were updated in
TryToSimplifyUncondBranchFromEmptyBlock.

In the original code, CanPropagatePredecessorsForPHIs looks quite convoluted
and more like stack of checks added to handle different kinds of situations
than a comprehensive check. In particular the first check in the function did
some value checking for the case that BB and Succ have a common predecessor,
while the last check in the function simply rejected all cases where BB and
Succ have a common predecessor. The first check was still useful in the case
that BB did not contain any phi nodes at all, though, so it was not completely
useless.

Now, CanPropagatePredecessorsForPHIs is restructured to to look a lot more
similar to the code that actually performs the merge. Both functions now look
at the same phi nodes in about the same order.  Any conflicts (phi nodes with
different values for the same source) that could arise from merging or moving
phi nodes are detected. If no conflicts are found, the merge can happen.

Apart from only restructuring the checks, two main changes in functionality
happened.

Firstly, the old code rejected blocks with common predecessors in most cases.
The new code performs some extra checks so common predecessors can be handled
in a lot of cases. Wherever common predecessors still pose problems, the
blocks are left untouched.

Secondly, the old code rejected the merge when values (phi nodes) from BB were
used in any other place than Succ. However, it does not seem that there is any
situation that would require this check. Even more, this can be proven.

Consider that BB is a block containing of a single phi node "%a" and a branch
to Succ. Now, since the definition of %a will dominate all of its uses, BB
will dominate all blocks that use %a. Furthermore, since the branch from BB to
Succ is unconditional, Succ will also dominate all uses of %a.

Now, assume that one predecessor of Succ is not dominated by BB (and thus not
dominated by Succ). Since at least one use of %a (but in reality all of them)
is reachable from Succ, you could end up at a use of %a without passing
through it's definition in BB (by coming from X through Succ). This is a
contradiction, meaning that our original assumption is wrong. Thus, all
predecessors of Succ must also be dominated by BB (and thus also by Succ).

This means that moving the phi node %a from BB to Succ does not pose any
problems when the two blocks are merged, and any use checks are not needed.

llvm-svn: 51478

llvm-svn: 51476

llvm-svn: 51474

llvm-svn: 51472