[llvm] r225566 - [PowerPC] Readjust the loop unrolling threshold

[Hal Finkel]

Author: hfinkel
Date: Fri Jan  9 18:31:10 2015
New Revision: 225566

URL: http://llvm.org/viewvc/llvm-project?rev=225566&view=rev
Log:
[PowerPC] Readjust the loop unrolling threshold

Now that the way that the partial unrolling threshold for small loops is used
to compute the unrolling factor as been corrected, a slightly smaller threshold
is preferable. This is expected; other targets may need to re-tune as well.

Modified:
    llvm/trunk/lib/Target/PowerPC/PPCScheduleP7.td
    llvm/trunk/lib/Target/PowerPC/PPCScheduleP8.td
    llvm/trunk/test/Transforms/LoopUnroll/PowerPC/p7-unrolling.ll

Modified: llvm/trunk/lib/Target/PowerPC/PPCScheduleP7.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCScheduleP7.td?rev=225566&r1=225565&r2=225566&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCScheduleP7.td (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCScheduleP7.td Fri Jan  9 18:31:10 2015
@@ -380,8 +380,8 @@ def P7Model : SchedMachineModel {
                        // Itineraries are queried instead.
   let MispredictPenalty = 16;
 
-  // Try to make sure we have at least 10-11 dispatch groups in a loop.
-  let LoopMicroOpBufferSize = 44;
+  // Try to make sure we have at least 10 dispatch groups in a loop.
+  let LoopMicroOpBufferSize = 40;
 
   let Itineraries = P7Itineraries;
 }

Modified: llvm/trunk/lib/Target/PowerPC/PPCScheduleP8.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCScheduleP8.td?rev=225566&r1=225565&r2=225566&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCScheduleP8.td (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCScheduleP8.td Fri Jan  9 18:31:10 2015
@@ -389,8 +389,8 @@ def P8Model : SchedMachineModel {
                        // Itineraries are queried instead.
   let MispredictPenalty = 16;
 
-  // Try to make sure we have at least 10-11 dispatch groups in a loop.
-  let LoopMicroOpBufferSize = 66;
+  // Try to make sure we have at least 10 dispatch groups in a loop.
+  let LoopMicroOpBufferSize = 60;
 
   let Itineraries = P8Itineraries;
 }

Modified: llvm/trunk/test/Transforms/LoopUnroll/PowerPC/p7-unrolling.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/PowerPC/p7-unrolling.ll?rev=225566&r1=225565&r2=225566&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnroll/PowerPC/p7-unrolling.ll (original)
+++ llvm/trunk/test/Transforms/LoopUnroll/PowerPC/p7-unrolling.ll Fri Jan  9 18:31:10 2015
@@ -22,7 +22,31 @@ exit:
 ; CHECK-NEXT: add
 ; CHECK-NEXT: add
 ; CHECK-NEXT: add
-; CHECK: icmp
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: icmp
 
 define void @unroll_default() nounwind {
 entry:
@@ -47,5 +71,29 @@ exit:
 ; CHECK-NEXT: add
 ; CHECK-NEXT: add
 ; CHECK-NEXT: add
-; CHECK: icmp
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: add
+; CHECK-NEXT: icmp