PGO: preserve branch-weight metadata when simplifying Switch

Hanlde the case when we split the default edge if the default target has "icmp"
and unconditinal branch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164076 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Manman Ren
2012-09-17 23:07:43 +00:00
parent f23ddf54ea
commit b010277b59
2 changed files with 51 additions and 1 deletions

View File

@@ -216,6 +216,40 @@ bees:
ret void
}
; Test edge splitting when the default target has icmp and unconditinal
; branch
define i1 @test9(i32 %x, i32 %y) nounwind {
; CHECK: @test9
entry:
switch i32 %x, label %bees [
i32 0, label %a
i32 1, label %end
i32 2, label %end
], !prof !7
; CHECK: switch i32 %x, label %bees [
; CHECK: i32 0, label %a
; CHECK: i32 1, label %end
; CHECK: i32 2, label %end
; CHECK: i32 92, label %end
; CHECK: ], !prof !7
a:
call void @helper(i32 0) nounwind
%reta = icmp slt i32 %x, %y
ret i1 %reta
bees:
%tmp = icmp eq i32 %x, 92
br label %end
end:
; CHECK: end:
; CHECK: %ret = phi i1 [ true, %entry ], [ false, %bees ], [ true, %entry ], [ true, %entry ]
%ret = phi i1 [ true, %entry ], [%tmp, %bees], [true, %entry]
call void @helper(i32 2) nounwind
ret i1 %ret
}
!0 = metadata !{metadata !"branch_weights", i32 3, i32 5}
!1 = metadata !{metadata !"branch_weights", i32 1, i32 1}
!2 = metadata !{metadata !"branch_weights", i32 1, i32 2}
@@ -232,4 +266,5 @@ bees:
; CHECK: !4 = metadata !{metadata !"branch_weights", i32 11, i32 5}
; CHECK: !5 = metadata !{metadata !"branch_weights", i32 17, i32 15}
; CHECK: !6 = metadata !{metadata !"branch_weights", i32 9, i32 7}
; CHECK-NOT: !7
; CHECK: !7 = metadata !{metadata !"branch_weights", i32 17, i32 9, i32 8, i32 7, i32 17}
; CHECK-NOT: !8