Revert [MBP] Disable aggressive loop rotate in plain mode

This reverts r369664 (git commit 51f48295cbe8fa3a44db263b528dd9f7bae7bf9a)

It causes many benchmark regressions, internally and in llvm's benchmark suite.

llvm-svn: 370398
diff --git a/llvm/test/CodeGen/AMDGPU/i1-copy-from-loop.ll b/llvm/test/CodeGen/AMDGPU/i1-copy-from-loop.ll
index ae78a1e..a050bfe 100644
--- a/llvm/test/CodeGen/AMDGPU/i1-copy-from-loop.ll
+++ b/llvm/test/CodeGen/AMDGPU/i1-copy-from-loop.ll
@@ -3,20 +3,20 @@
 
 ; SI-LABEL: {{^}}i1_copy_from_loop:
 ;
+; SI: ; %Flow
+; SI-DAG:  s_andn2_b64       [[LCSSA_ACCUM:s\[[0-9]+:[0-9]+\]]], [[LCSSA_ACCUM]], exec
+; SI-DAG:  s_and_b64         [[CC_MASK2:s\[[0-9]+:[0-9]+\]]], [[CC_ACCUM:s\[[0-9]+:[0-9]+\]]], exec
+; SI:      s_or_b64          [[LCSSA_ACCUM]], [[LCSSA_ACCUM]], [[CC_MASK2]]
+
 ; SI: ; %for.body
 ; SI:      v_cmp_gt_u32_e64  [[CC_SREG:s\[[0-9]+:[0-9]+\]]], 4,
-; SI-DAG:  s_andn2_b64       [[CC_ACCUM:s\[[0-9]+:[0-9]+\]]], [[CC_ACCUM]], exec
+; SI-DAG:  s_andn2_b64       [[CC_ACCUM]], [[CC_ACCUM]], exec
 ; SI-DAG:  s_and_b64         [[CC_MASK:s\[[0-9]+:[0-9]+\]]], [[CC_SREG]], exec
 ; SI:      s_or_b64          [[CC_ACCUM]], [[CC_ACCUM]], [[CC_MASK]]
 
 ; SI: ; %Flow1
 ; SI:      s_or_b64          [[CC_ACCUM]], [[CC_ACCUM]], exec
 
-; SI: ; %Flow
-; SI-DAG:  s_andn2_b64       [[LCSSA_ACCUM:s\[[0-9]+:[0-9]+\]]], [[LCSSA_ACCUM]], exec
-; SI-DAG:  s_and_b64         [[CC_MASK2:s\[[0-9]+:[0-9]+\]]], [[CC_ACCUM]], exec
-; SI:      s_or_b64          [[LCSSA_ACCUM]], [[LCSSA_ACCUM]], [[CC_MASK2]]
-
 ; SI: ; %for.end
 ; SI:      s_and_saveexec_b64 {{s\[[0-9]+:[0-9]+\]}}, [[LCSSA_ACCUM]]