Remove unroll pragma metadata after it is used.

llvm-svn: 213412
diff --git a/llvm/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll b/llvm/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll
new file mode 100644
index 0000000..39da7fa
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll
@@ -0,0 +1,69 @@
+; RUN: opt < %s -loop-unroll -S | FileCheck %s
+;
+; Verify that the unrolling pass removes existing loop unrolling metadata
+; and adds a disable unrolling node after unrolling is complete.
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; #pragma clang loop  vectorize(enable) unroll(enable) unroll_count(4) vectorize_width(8)
+;
+; Unroll metadata should be replaces with unroll(disable).  Vectorize
+; metadata should be untouched.
+;
+; CHECK-LABEL: @loop1(
+; CHECK: br i1 {{.*}}, label {{.*}}, label {{.*}}, !llvm.loop ![[LOOP_1:.*]]
+define void @loop1(i32* nocapture %a) {
+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* %a, i64 %indvars.iv
+  %0 = load 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 !1
+
+for.end:                                          ; preds = %for.body
+  ret void
+}
+!1 = metadata !{metadata !1, metadata !2, metadata !3, metadata !4, metadata !5}
+!2 = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true}
+!3 = metadata !{metadata !"llvm.loop.unroll.enable", i1 true}
+!4 = metadata !{metadata !"llvm.loop.unroll.count", i32 4}
+!5 = metadata !{metadata !"llvm.loop.vectorize.width", i32 8}
+
+; #pragma clang loop unroll(disable)
+;
+; Unroll metadata should not change.
+;
+; CHECK-LABEL: @loop2(
+; CHECK: br i1 {{.*}}, label {{.*}}, label {{.*}}, !llvm.loop ![[LOOP_2:.*]]
+define void @loop2(i32* nocapture %a) {
+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* %a, i64 %indvars.iv
+  %0 = load 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 !6
+
+for.end:                                          ; preds = %for.body
+  ret void
+}
+!6 = metadata !{metadata !6, metadata !7}
+!7 = metadata !{metadata !"llvm.loop.unroll.enable", i1 false}
+
+; CHECK: ![[LOOP_1]] = metadata !{metadata ![[LOOP_1]], metadata ![[VEC_ENABLE:.*]], metadata ![[WIDTH_8:.*]], metadata ![[UNROLL_DISABLE:.*]]}
+; CHECK: ![[VEC_ENABLE]] = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true}
+; CHECK: ![[WIDTH_8]] = metadata !{metadata !"llvm.loop.vectorize.width", i32 8}
+; CHECK: ![[UNROLL_DISABLE]] = metadata !{metadata !"llvm.loop.unroll.enable", i1 false}
+; CHECK: ![[LOOP_2]] = metadata !{metadata ![[LOOP_2]], metadata ![[UNROLL_DISABLE:.*]]}