[BPI] Apply invoke heuristic before loop branch heuristic

Currently the loop branch heuristic is applied before the invoke heuristic which makes us overestimate the probability of the unwind destination of invokes inside loops. This in turn makes us grossly underestimate the frequencies of loops with invokes.

Reviewed By: skatkov, vsk

Differential Revision: https://reviews.llvm.org/D47371

llvm-svn: 334285
diff --git a/llvm/test/Analysis/BlockFrequencyInfo/loop_with_invoke.ll b/llvm/test/Analysis/BlockFrequencyInfo/loop_with_invoke.ll
new file mode 100644
index 0000000..4e554f8
--- /dev/null
+++ b/llvm/test/Analysis/BlockFrequencyInfo/loop_with_invoke.ll
@@ -0,0 +1,35 @@
+; RUN: opt < %s -analyze -block-freq | FileCheck %s
+; RUN: opt < %s -passes='print<block-freq>' -disable-output 2>&1 | FileCheck %s
+
+; CHECK-LABEL: Printing analysis {{.*}} for function 'loop_with_invoke':
+; CHECK-NEXT: block-frequency-info: loop_with_invoke
+define void @loop_with_invoke(i32 %n) personality i8 0 {
+; CHECK-NEXT: entry: float = 1.0, int = [[ENTRY:[0-9]+]]
+entry:
+  br label %loop
+
+; CHECK-NEXT: loop: float = 9905.6
+loop:
+  %i = phi i32 [ 0, %entry ], [ %i.next, %invoke.cont ]
+  invoke void @foo() to label %invoke.cont unwind label %lpad
+
+; CHECK-NEXT: invoke.cont: float = 9905.6
+invoke.cont:
+  %i.next = add i32 %i, 1
+  %cont = icmp ult i32 %i.next, %n
+  br i1 %cont, label %loop, label %exit, !prof !0
+
+; CHECK-NEXT: lpad: float = 0.0094467
+lpad:
+  %ll = landingpad { i8*, i32 }
+          cleanup
+  br label %exit
+
+; CHECK-NEXT: exit: float = 1.0, int = [[ENTRY]]
+exit:
+  ret void
+}
+
+declare void @foo()
+
+!0 = !{!"branch_weights", i32 9999, i32 1}