Revert r299536. [AMDGPU] SDWA peephole: enable by default.

Reason: breaks multiple bots:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/3988
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/1173

Original Review URL: https://reviews.llvm.org/D31671

llvm-svn: 299583
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index f03adfc..c6c20b8 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -105,7 +105,7 @@
 static cl::opt<bool> EnableSDWAPeephole(
   "amdgpu-sdwa-peephole",
   cl::desc("Enable SDWA peepholer"),
-  cl::init(true));
+  cl::init(false));
 
 // Enable address space based alias analysis
 static cl::opt<bool> EnableAMDGPUAliasAnalysis("enable-amdgpu-aa", cl::Hidden,