Reapply "blockfreq: Rewrite BlockFrequencyInfoImpl" (#2)

This reverts commit r206628, reapplying r206622 (and r206626).

Two tests are failing only on buildbots [1][2]: i.e., I can't reproduce
on Darwin, and Chandler can't reproduce on Linux.  Asan and valgrind
don't tell us anything, but we're hoping the msan bot will catch it.

So, I'm applying this again to get more feedback from the bots.  I'll
leave it in long enough to trigger builds in at least the sanitizer
buildbots (it was failing for reasons unrelated to my commit last time
it was in), and hopefully a few others.... and then I expect to revert a
third time.

[1]: http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/1816
[2]: http://llvm-amd64.freebsd.your.org/b/builders/clang-i386-freebsd/builds/18445

llvm-svn: 206666

1 files changed, 59 insertions, 0 deletions

diff --git a/llvm/test/Analysis/BlockFrequencyInfo/nested_loop_with_branches.ll b/llvm/test/Analysis/BlockFrequencyInfo/nested_loop_with_branches.ll
new file mode 100644
index 00000000000..d93ffceb5fa
--- /dev/null
+++ b/llvm/test/Analysis/BlockFrequencyInfo/nested_loop_with_branches.ll
@@ -0,0 +1,59 @@
+; RUN: opt < %s -analyze -block-freq | FileCheck %s
+
+; CHECK-LABEL: Printing analysis {{.*}} for function 'nested_loop_with_branches'
+; CHECK-NEXT: block-frequency-info: nested_loop_with_branches
+define void @nested_loop_with_branches(i32 %a) {
+; CHECK-NEXT: entry: float = 1.0, int = [[ENTRY:[0-9]+]]
+entry:
+  %v0 = call i1 @foo0(i32 %a)
+  br i1 %v0, label %exit, label %outer, !prof !0
+
+; CHECK-NEXT: outer: float = 12.0,
+outer:
+  %i = phi i32 [ 0, %entry ], [ %i.next, %inner.end ], [ %i.next, %no_inner ]
+  %i.next = add i32 %i, 1
+  %do_inner = call i1 @foo1(i32 %i)
+  br i1 %do_inner, label %no_inner, label %inner, !prof !0
+
+; CHECK-NEXT: inner: float = 36.0,
+inner:
+  %j = phi i32 [ 0, %outer ], [ %j.next, %inner.end ]
+  %side = call i1 @foo3(i32 %j)
+  br i1 %side, label %left, label %right, !prof !0
+
+; CHECK-NEXT: left: float = 9.0,
+left:
+  %v4 = call i1 @foo4(i32 %j)
+  br label %inner.end
+
+; CHECK-NEXT: right: float = 27.0,
+right:
+  %v5 = call i1 @foo5(i32 %j)
+  br label %inner.end
+
+; CHECK-NEXT: inner.end: float = 36.0,
+inner.end:
+  %stay_inner = phi i1 [ %v4, %left ], [ %v5, %right ]
+  %j.next = add i32 %j, 1
+  br i1 %stay_inner, label %inner, label %outer, !prof !1
+
+; CHECK-NEXT: no_inner: float = 3.0,
+no_inner:
+  %continue = call i1 @foo6(i32 %i)
+  br i1 %continue, label %outer, label %exit, !prof !1
+
+; CHECK-NEXT: exit: float = 1.0, int = [[ENTRY]]
+exit:
+  ret void
+}
+
+declare i1 @foo0(i32)
+declare i1 @foo1(i32)
+declare i1 @foo2(i32)
+declare i1 @foo3(i32)
+declare i1 @foo4(i32)
+declare i1 @foo5(i32)
+declare i1 @foo6(i32)
+
+!0 = metadata !{metadata !"branch_weights", i32 1, i32 3}
+!1 = metadata !{metadata !"branch_weights", i32 3, i32 1}