LLVM Value/Use does and MachineRegisterInfo/MachineOperand does.
This allows constant time for all uses list maintenance operations.

The idea was suggested by Chris. Reviewed by Evan and Dan.
Patch is tested and approved by Dan.

On normal use-cases compilation speed is not affected. On very big basic
blocks there are compilation speedups in the range of 15-20% or even better. 

llvm-svn: 48822

llvm-svn: 48819

This fixes Bugzilla #1835 (http://llvm.org/bugs/show_bug.cgi?id=1835).
This patched is reviewed by Tanya and Dan. Dan tested and approved it.

The reason for the bad performance of the old algorithm is that it is very naive and scans every
time all nodes of the DAG in the worst case.

This patch introduces  a new algorithm based on the paper "Online algorithms
for maintaining the topological order of a directed acyclic graph" by
David J.Pearce and Paul H.J.Kelly. This is the MNR algorithm. It has a
linear time worst-case and performs much better in most situations.

The paper can be found here:
http://fano.ics.uci.edu/cites/Document/Online-algorithms-for-maintaining-the-topological-order-of-a-directed-acyclic-graph.html

The main idea of the new algorithm is to compute the topological ordering of the SNodes in the
DAG and to maintain it even after DAG modifications. The topological ordering allows for very fast 
node reachability checks. 

Tests on very big  input files with tens of thousands of instructions in a BB indicate huge 
speed-ups (up to 10x compilation time improvement) compared to the old version.

llvm-svn: 48817

llvm-svn: 48815

llvm-svn: 48811

llvm's output .s files will go through gcc -std=c99
without triggering preprocesser errors.  Approach
suggested by Daveed Vandevoorde.

llvm-svn: 48808

llvm-svn: 48805

llvm-svn: 48804

llvm-svn: 48803

llvm-svn: 48802

llvm-svn: 48801

marked read-write. Use const so that they can be allocated in a
read-only segment.

llvm-svn: 48800

llvm-svn: 48797

llvm-svn: 48794

llvm-svn: 48793

Handle a special case xor undef, undef -> 0. Technically this should be transformed to undef. But this is such a common idiom (misuse) we are going to handle it.

llvm-svn: 48792

Handle a special case xor undef, undef -> 0. Technically this should be transformed to undef. But this is such a common idiom (misuse) we are going to handle it.

llvm-svn: 48791

llvm-svn: 48779

other things, this allows the scheduler to unfold a load operand
in the 2008-01-08-SchedulerCrash.ll testcase, so it now successfully
clones the comparison to avoid a pushf+popf.

llvm-svn: 48777

object directory.

llvm-svn: 48766

llvm-svn: 48759

llvm-svn: 48755

llvm-svn: 48753

If the coalescer commuted a def MI to allow coalescing, it can changed a previously coalesced copy into an non-identity copy.

llvm-svn: 48752

llvm-svn: 48751

mask.

llvm-svn: 48750

- SSE4.1 extractfps extracts a f32 into a gr32 register. Very useful! Not. Fix the instruction specification and teaches lowering code to use it only when the only use is a store instruction.

llvm-svn: 48746

llvm-svn: 48743

llvm-svn: 48739

llvm-svn: 48738

field to store the alignment value instead of haing a
separate field.

llvm-svn: 48727

llvm-svn: 48726

Increasing the inline limit from (overly conservative) 200 to 300. Given each BB costs 20 and each instruction costs 5, 200 means a 4 BB function + 24 instructions (actually less because caller's size also contributes to it).

Furthermore, double the limit when more than 10% of the callee instructions are vector instructions. Multimedia kernels tend to love inlining.

llvm-svn: 48725

llvm-svn: 48720

With this pass, StrongPHIElim can compile very simple testcases correctly.  There's still a ways
to go before it's ready for prime time, though.

llvm-svn: 48719

Transform (zext (or (icmp), (icmp))) to (or (zext (cimp), (zext icmp))) if at least one of the (zext icmp) can be transformed to eliminate an icmp.

llvm-svn: 48715

llvm-svn: 48714

llvm-svn: 48711

llvm-svn: 48710

llvm-svn: 48708