[llvm] r216236 - [PeepholeOptimizer] Enable the advanced copy optimization by default.

[Quentin Colombet]

Author: qcolombet
Date: Thu Aug 21 17:23:52 2014
New Revision: 216236

URL: http://llvm.org/viewvc/llvm-project?rev=216236&view=rev
Log:
[PeepholeOptimizer] Enable the advanced copy optimization by default.

The advanced copy optimization does not yield any difference on the whole llvm
test-suite + SPECs, either in compile time or runtime (binaries are identical),
but has a big potential when data go back and forth between register files as
demonstrated with test/CodeGen/ARM/adv-copy-opt.ll.

Note: This was measured for both Os and O3 for armv7s, arm64, and x86_64.

<rdar://problem/12702965>

Modified:
    llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp

Modified: llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp?rev=216236&r1=216235&r2=216236&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp (original)
+++ llvm/trunk/lib/CodeGen/PeepholeOptimizer.cpp Thu Aug 21 17:23:52 2014
@@ -94,7 +94,7 @@ DisablePeephole("disable-peephole", cl::
                 cl::desc("Disable the peephole optimizer"));
 
 static cl::opt<bool>
-DisableAdvCopyOpt("disable-adv-copy-opt", cl::Hidden, cl::init(true),
+DisableAdvCopyOpt("disable-adv-copy-opt", cl::Hidden, cl::init(false),
                   cl::desc("Disable advanced copy optimization"));
 
 STATISTIC(NumReuse,      "Number of extension results reused");