[LoopUnroll] Switch the default value of -unroll-runtime-epilog back to its original value.

As agreed in post-commit review of r265388, I'm switching the flag to
its original value until the 90% runtime performance regression on
SingleSource/Benchmarks/Stanford/Bubblesort is addressed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277524 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/LoopUnroll.cpp

@@ -46,7 +46,7 @@ STATISTIC(NumCompletelyUnrolled, "Number of loops completely unrolled");
 STATISTIC(NumUnrolled, "Number of loops unrolled (completely or otherwise)");
 
 static cl::opt<bool>
-UnrollRuntimeEpilog("unroll-runtime-epilog", cl::init(true), cl::Hidden,
+UnrollRuntimeEpilog("unroll-runtime-epilog", cl::init(false), cl::Hidden,
                     cl::desc("Allow runtime unrolled loops to be unrolled "
                              "with epilog instead of prolog."));
 

test/Transforms/LoopUnroll/AArch64/runtime-loop.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57 | FileCheck %s -check-prefix=EPILOG
+; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57 -unroll-runtime-epilog=true  | FileCheck %s -check-prefix=EPILOG
 ; RUN: opt < %s -S -loop-unroll -mtriple aarch64 -mcpu=cortex-a57 -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 
 ; Tests for unrolling loops with run-time trip counts

test/Transforms/LoopUnroll/runtime-loop.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -loop-unroll -unroll-runtime=true | FileCheck %s -check-prefix=EPILOG
+; RUN: opt < %s -S -loop-unroll -unroll-runtime=true -unroll-runtime-epilog=true  | FileCheck %s -check-prefix=EPILOG
 ; RUN: opt < %s -S -loop-unroll -unroll-runtime=true -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"

test/Transforms/LoopUnroll/runtime-loop1.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2 | FileCheck %s -check-prefix=EPILOG
+; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2 -unroll-runtime-epilog=true | FileCheck %s -check-prefix=EPILOG
 ; RUN: opt < %s -S -loop-unroll -unroll-runtime -unroll-count=2 -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 
 ; This tests that setting the unroll count works

test/Transforms/LoopUnroll/runtime-loop2.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime -unroll-count=8 | FileCheck %s  -check-prefix=EPILOG
+; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime -unroll-runtime-epilog=true  -unroll-count=8 | FileCheck %s  -check-prefix=EPILOG
 ; RUN: opt < %s -S -loop-unroll -unroll-threshold=25 -unroll-runtime -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 
 ; Choose a smaller, power-of-two, unroll count if the loop is too large.

test/Transforms/LoopUnroll/runtime-loop4.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -O2 -unroll-runtime=true | FileCheck %s -check-prefix=EPILOG
+; RUN: opt < %s -S -O2 -unroll-runtime=true -unroll-runtime-epilog=true  | FileCheck %s -check-prefix=EPILOG
 ; RUN: opt < %s -S -O2 -unroll-runtime=true -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 
 ; Check runtime unrolling prologue can be promoted by LICM pass.

test/Transforms/LoopUnroll/runtime-loop5.ll

@@ -11,6 +11,9 @@ entry:
   %cmp1 = icmp eq i3 %n, 0
   br i1 %cmp1, label %for.end, label %for.body
 
+; UNROLL-16-NOT: for.body.prol:
+; UNROLL-4: for.body.prol:
+
 for.body:                                         ; preds = %for.body, %entry
 ; UNROLL-16-LABEL: for.body:
 ; UNROLL-4-LABEL: for.body:
@@ -36,10 +39,6 @@ for.body:                                         ; preds = %for.body, %entry
 
 ; UNROLL-16-LABEL: for.end
 ; UNROLL-4-LABEL: for.end
-
-; UNROLL-16-NOT: for.body.epil:
-; UNROLL-4: for.body.epil:
-
 for.end:                                          ; preds = %for.body, %entry
   %sum.0.lcssa = phi i3 [ 0, %entry ], [ %add, %for.body ]
   ret i3 %sum.0.lcssa

test/Transforms/LoopUnroll/tripcount-overflow.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -unroll-runtime -unroll-count=2 -loop-unroll | FileCheck %s -check-prefix=EPILOG
+; RUN: opt < %s -S -unroll-runtime -unroll-count=2 -loop-unroll -unroll-runtime-epilog=true  | FileCheck %s -check-prefix=EPILOG
 ; RUN: opt < %s -S -unroll-runtime -unroll-count=2 -loop-unroll -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 

test/Transforms/LoopUnroll/unroll-cleanup.ll

@@ -4,14 +4,14 @@
 ; RUN: opt < %s -O2 -S | FileCheck %s
 
 ; After loop unroll:
-;       %niter.nsub = add nsw i32 %niter, -1
+;       %dec18 = add nsw i32 %dec18.in, -1
 ;       ...
-;       %niter.nsub.1 = add nsw i32 %niter.nsub, -1
+;       %dec18.1 = add nsw i32 %dec18, -1
 ; should be merged to:
-;       %dec18.1 = add nsw i32 %niter, -2
+;       %dec18.1 = add nsw i32 %dec18.in, -2
 ;
 ; CHECK-LABEL: @_Z3fn1v(
-; CHECK: %niter.nsub.1 = add i32 %niter, -2
+; CHECK: %dec18.1 = add nsw i32 %dec18.in, -2
 
 ; ModuleID = '<stdin>'
 target triple = "x86_64-unknown-linux-gnu"

test/Transforms/LoopUnroll/unroll-pragmas.ll

@@ -108,29 +108,6 @@ for.end:                                          ; preds = %for.body
 !3 = !{!3, !4}
 !4 = !{!"llvm.loop.unroll.full"}
 
-; #pragma clang loop unroll(full)
-; Loop should be fully unrolled, even for optsize.
-;
-; CHECK-LABEL: @loop64_with_full_optsize(
-; CHECK-NOT: br i1
-define void @loop64_with_full_optsize(i32* nocapture %a) optsize {
-entry:
-  br label %for.body
-
-for.body:                                         ; preds = %for.body, %entry
-  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
-  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
-  %0 = load i32, i32* %arrayidx, align 4
-  %inc = add nsw i32 %0, 1
-  store i32 %inc, i32* %arrayidx, align 4
-  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
-  %exitcond = icmp eq i64 %indvars.iv.next, 64
-  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !3
-
-for.end:                                          ; preds = %for.body
-  ret void
-}
-
 ; #pragma clang loop unroll_count(4)
 ; Loop should be unrolled 4 times.
 ;
@@ -194,6 +171,10 @@ for.end:                                          ; preds = %for.body, %entry
 ; should be duplicated (original and 4x unrolled).
 ;
 ; CHECK-LABEL: @runtime_loop_with_count4(
+; CHECK: for.body.prol:
+; CHECK: store
+; CHECK-NOT: store
+; CHECK: br i1
 ; CHECK: for.body
 ; CHECK: store
 ; CHECK: store
@@ -201,10 +182,6 @@ for.end:                                          ; preds = %for.body, %entry
 ; CHECK: store
 ; CHECK-NOT: store
 ; CHECK: br i1
-; CHECK: for.body.epil:
-; CHECK: store
-; CHECK-NOT: store
-; CHECK: br i1
 define void @runtime_loop_with_count4(i32* nocapture %a, i32 %b) {
 entry:
   %cmp3 = icmp sgt i32 %b, 0
@@ -310,6 +287,10 @@ for.end:                                          ; preds = %for.body
 ; (original and 8x).
 ;
 ; CHECK-LABEL: @runtime_loop_with_enable(
+; CHECK: for.body.prol:
+; CHECK: store
+; CHECK-NOT: store
+; CHECK: br i1
 ; CHECK: for.body:
 ; CHECK: store i32
 ; CHECK: store i32
@@ -321,10 +302,6 @@ for.end:                                          ; preds = %for.body
 ; CHECK: store i32
 ; CHECK-NOT: store i32
 ; CHECK: br i1
-; CHECK: for.body.epil:
-; CHECK: store
-; CHECK-NOT: store
-; CHECK: br i1
 define void @runtime_loop_with_enable(i32* nocapture %a, i32 %b) {
 entry:
   %cmp3 = icmp sgt i32 %b, 0
@@ -351,13 +328,13 @@ for.end:                                          ; preds = %for.body, %entry
 ; should be duplicated (original and 3x unrolled).
 ;
 ; CHECK-LABEL: @runtime_loop_with_count3(
-; CHECK: for.body
+; CHECK: for.body.prol:
-; CHECK: store
-; CHECK: store
 ; CHECK: store
 ; CHECK-NOT: store
 ; CHECK: br i1
-; CHECK: for.body.epil:
+; CHECK: for.body
+; CHECK: store
+; CHECK: store
 ; CHECK: store
 ; CHECK-NOT: store
 ; CHECK: br i1