llvm-svn: 9225

llvm-svn: 9195

llvm-svn: 9171

llvm-svn: 9156

Rewrite code to work with use_lists what are either random access or bidirectional

llvm-svn: 9155

llvm-svn: 9135

llvm-svn: 9133

break dominance relationships, and is otherwise bad.  This fixes bug:
Inline/2003-10-13-AllocaDominanceProblem.ll.  This also fixes miscompilation
of 3 176.gcc source files (reload1.c, global.c, flow.c)

llvm-svn: 9109

llvm-svn: 9094

multiple setjmp calls.

llvm-svn: 9093

llvm-svn: 9073

llvm-svn: 9071

llvm-svn: 9069

llvm-svn: 9067

Only transform call sites in a setjmp'ing function which are reachable from
the setjmp.  If the call dominates the setjmp (for example), the called
function cannot longjmp to the setjmp.

This dramatically reduces the number of invoke instructions created in some
large testcases.

llvm-svn: 9066

have a SINGLE backedge.  This is useful to, for example, the -indvars pass.

This implements testcase LoopSimplify/single-backedge.ll and closes PR#34

llvm-svn: 9065

llvm-svn: 9061

llvm-svn: 9059

llvm-svn: 9058

allows GCCAS to only run it once.

llvm-svn: 9056

llvm-svn: 9032

llvm-svn: 9031

llvm-svn: 9027

llvm-svn: 9009

llvm-svn: 8965

to avoid reprocessing PHI nodes needlessly.  This speeds up the big bad PHI
testcase 43%: from 104.9826 to 73.5157s

llvm-svn: 8964

llvm-svn: 8963

of a test that Bill Wendling sent me from 228.5s to 105s.  Obviously there is
more improvement to be had, but this is a nice speedup which should be "felt"
by many programs.

llvm-svn: 8962

llvm-svn: 8955

llvm-svn: 8954

llvm-svn: 8952

llvm-svn: 8930

logarithmic conditional branch sequences instead of linear sequences.  Thanks Bill!

llvm-svn: 8928

llvm-svn: 8922

llvm-svn: 8894

of callees between executions.

On eon, in release mode, this changes the inliner from taking 11.5712s
to taking 2.2066s.  In debug mode, it went from taking 14.4148s to
taking 7.0745s.  In release mode, this is a 24.7% speedup of gccas, in
debug mode, it's a total speedup of 11.7%.

This also makes it slightly more aggressive.  This could be because we
are not judging the size of the functions quite as accurately as before.
When we start looking at the performance of the generated code, this can
be investigated further.

llvm-svn: 8893

Running the inliner on 252.eon used to take 48.4763s, now it takes 14.4148s.

In release mode, it went from taking 25.8741s to taking 11.5712s.

This also fixes a FIXME.

llvm-svn: 8890

"minimal" SSA form (in other words, it doesn't insert dead PHIs).  This
speeds up the mem2reg pass very significantly because it doesn't have to
do a lot of frivolous work in many common cases.

In the 252.eon function I have been playing with, this doesn't even insert
the 120 PHI nodes that it used to which were trivially dead (in the process
of promoting 356 alloca instructions overall).  This speeds up the mem2reg
pass from 1.2459s to 0.1284s.  More significantly, the DCE pass used to take
2.4138s to remove the 120 dead PHI nodes that mem2reg constructed, now it
takes 0.0134s (which is the time to scan the function and decide that there
is nothing dead).  So overall, on this one function, we speed things up a
total of 3.5179s, which is a 24.8x speedup!  :)

This change is tested by the Mem2Reg/2003-10-05-DeadPHIInsertion.ll test,
which now passes.

llvm-svn: 8884

llvm-svn: 8883

basic block.  This is amazingly common in code generated by the C/C++ front-ends.
This change makes it not have to insert ANY phi nodes, whereas before it would insert
a ton of dead ones which DCE would have to clean up.

Thus, this fix improves compile-time performance of these trivial allocas in two ways:
  1. It doesn't have to do the walking and book-keeping for renaming
  2. It does not insert dead phi nodes for them which would have to
     subsequently be cleaned up.

On my favorite testcase from 252.eon, this special case handles 305 out of
356 promoted allocas in the function.  It speeds up the mem2reg pass from 7.5256s
to 1.2505s.  It inserts 677 fewer dead PHI nodes, which speeds up a subsequent
-dce pass from 18.7524s to 2.4806s.

There are still 120 trivially dead PHI nodes being inserted for variables used
in multiple basic blocks, but they are not handled by this patch.

llvm-svn: 8881