Minimize precision loss when computing cyclic probabilities.

Allow block frequencies to exceed 32 bits by using the new
BlockFrequency division function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185236 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 42 insertions, 0 deletions

diff --git a/test/Analysis/BlockFrequencyInfo/basic.ll b/test/Analysis/BlockFrequencyInfo/basic.ll
index 43dd264402..ce29fb5ce1 100644
--- a/test/Analysis/BlockFrequencyInfo/basic.ll
+++ b/test/Analysis/BlockFrequencyInfo/basic.ll
@@ -90,3 +90,45 @@ exit:
 }
 
 !1 = metadata !{metadata !"branch_weights", i32 4, i32 4, i32 64, i32 4, i32 4}
+
+; CHECK: Printing analysis {{.*}} for function 'nested_loops'
+; CHECK: entry = 1.0
+; This test doesn't seem to be assigning sensible frequencies to nested loops.
+define void @nested_loops(i32 %a) {
+entry:
+  br label %for.cond1.preheader
+
+for.cond1.preheader:
+  %x.024 = phi i32 [ 0, %entry ], [ %inc12, %for.inc11 ]
+  br label %for.cond4.preheader
+
+for.cond4.preheader:
+  %y.023 = phi i32 [ 0, %for.cond1.preheader ], [ %inc9, %for.inc8 ]
+  %add = add i32 %y.023, %x.024
+  br label %for.body6
+
+for.body6:
+  %z.022 = phi i32 [ 0, %for.cond4.preheader ], [ %inc, %for.body6 ]
+  %add7 = add i32 %add, %z.022
+  tail call void @g(i32 %add7) #2
+  %inc = add i32 %z.022, 1
+  %cmp5 = icmp ugt i32 %inc, %a
+  br i1 %cmp5, label %for.inc8, label %for.body6, !prof !2
+
+for.inc8:
+  %inc9 = add i32 %y.023, 1
+  %cmp2 = icmp ugt i32 %inc9, %a
+  br i1 %cmp2, label %for.inc11, label %for.cond4.preheader, !prof !2
+
+for.inc11:
+  %inc12 = add i32 %x.024, 1
+  %cmp = icmp ugt i32 %inc12, %a
+  br i1 %cmp, label %for.end13, label %for.cond1.preheader, !prof !2
+
+for.end13:
+  ret void
+}
+
+declare void @g(i32) #1
+
+!2 = metadata !{metadata !"branch_weights", i32 1, i32 4000}