; RUN: llc -O2 -o - %s | FileCheck %s target datalayout = "e-m:e-i64:64-n32:64" target triple = "powerpc64le-grtev4-linux-gnu" ; Intended layout: ; The code for tail-duplication during layout will produce the layout: ; test1 ; test2 ; body1 (with copy of test2) ; body2 ; exit ;CHECK-LABEL: tail_dup_break_cfg: ;CHECK: mr [[TAGREG:[0-9]+]], 3 ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1 ;CHECK-NEXT: bc 12, 1, [[BODY1LABEL:[._0-9A-Za-z]+]] ;CHECK-NEXT: # %test2 ;CHECK-NEXT: andi. {{[0-9]+}}, [[TAGREG]], 2 ;CHECK-NEXT: bne 0, [[BODY2LABEL:[._0-9A-Za-z]+]] ;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit ;CHECK: blr ;CHECK-NEXT: [[BODY1LABEL]] ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 2 ;CHECK-NEXT: beq 0, [[EXITLABEL]] ;CHECK-NEXT: [[BODY2LABEL:[._0-9A-Za-z]+]]: ;CHECK: b [[EXITLABEL]] define void @tail_dup_break_cfg(i32 %tag) { entry: br label %test1 test1: %tagbit1 = and i32 %tag, 1 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely body1: call void @a() call void @a() call void @a() call void @a() br label %test2 test2: %tagbit2 = and i32 %tag, 2 %tagbit2eq0 = icmp eq i32 %tagbit2, 0 br i1 %tagbit2eq0, label %exit, label %body2, !prof !1 ; %exit more likely body2: call void @b() call void @b() call void @b() call void @b() br label %exit exit: ret void } ; The branch weights here hint that we shouldn't tail duplicate in this case. ;CHECK-LABEL: tail_dup_dont_break_cfg: ;CHECK: mr [[TAGREG:[0-9]+]], 3 ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1 ;CHECK-NEXT: bc 4, 1, [[TEST2LABEL:[._0-9A-Za-z]+]] ;CHECK-NEXT: # %body1 ;CHECK: [[TEST2LABEL]]: # %test2 ;CHECK-NEXT: andi. {{[0-9]+}}, [[TAGREG]], 2 ;CHECK-NEXT: beq 0, [[EXITLABEL:[._0-9A-Za-z]+]] ;CHECK-NEXT: # %body2 ;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit ;CHECK: blr define void @tail_dup_dont_break_cfg(i32 %tag) { entry: br label %test1 test1: %tagbit1 = and i32 %tag, 1 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely body1: call void @a() call void @a() call void @a() call void @a() br label %test2 test2: %tagbit2 = and i32 %tag, 2 %tagbit2eq0 = icmp ne i32 %tagbit2, 0 br i1 %tagbit2eq0, label %body2, label %exit, !prof !3 ; %body2 more likely body2: call void @b() call void @b() call void @b() call void @b() br label %exit exit: ret void } declare void @a() declare void @b() declare void @c() declare void @d() ; This function arranges for the successors of %succ to have already been laid ; out. When we consider whether to lay out succ after bb and to tail-duplicate ; it, v and ret have already been placed, so we tail-duplicate as it removes a ; branch and strictly increases fallthrough ; CHECK-LABEL: tail_dup_no_succ ; CHECK: # %entry ; CHECK: # %v ; CHECK: # %ret ; CHECK: # %bb ; CHECK: # %succ ; CHECK: # %c ; CHECK: bl c ; CHECK: andi. {{[0-9]+}}, {{[0-9]+}}, 4 ; CHECK: beq ; CHECK: b define void @tail_dup_no_succ(i32 %tag) { entry: %tagbit1 = and i32 %tag, 1 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 br i1 %tagbit1eq0, label %v, label %bb, !prof !2 ; %v very much more likely bb: %tagbit2 = and i32 %tag, 2 %tagbit2eq0 = icmp eq i32 %tagbit2, 0 br i1 %tagbit2eq0, label %succ, label %c, !prof !3 ; %succ more likely c: call void @c() call void @c() br label %succ succ: %tagbit3 = and i32 %tag, 4 %tagbit3eq0 = icmp eq i32 %tagbit3, 0 br i1 %tagbit3eq0, label %ret, label %v, !prof !1 ; %u more likely v: call void @d() call void @d() br label %ret ret: ret void } !1 = !{!"branch_weights", i32 5, i32 3} !2 = !{!"branch_weights", i32 95, i32 5} !3 = !{!"branch_weights", i32 8, i32 3}