1 ; RUN: llc -O2 -o - %s | FileCheck %s 2 target datalayout = "e-m:e-i64:64-n32:64" 3 target triple = "powerpc64le-grtev4-linux-gnu" 4 5 ; Intended layout: 6 ; The code for tail-duplication during layout will produce the layout: 7 ; test1 8 ; test2 9 ; body1 (with copy of test2) 10 ; body2 11 ; exit 12 13 ;CHECK-LABEL: tail_dup_break_cfg: 14 ;CHECK: mr [[TAGREG:[0-9]+]], 3 15 ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1 16 ;CHECK-NEXT: bc 12, 1, [[BODY1LABEL:[._0-9A-Za-z]+]] 17 ;CHECK-NEXT: # %test2 18 ;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30 19 ;CHECK-NEXT: bne 0, [[BODY2LABEL:[._0-9A-Za-z]+]] 20 ;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit 21 ;CHECK: blr 22 ;CHECK-NEXT: [[BODY1LABEL]] 23 ;CHECK: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30 24 ;CHECK-NEXT: beq 0, [[EXITLABEL]] 25 ;CHECK-NEXT: [[BODY2LABEL:[._0-9A-Za-z]+]]: 26 ;CHECK: b [[EXITLABEL]] 27 define void @tail_dup_break_cfg(i32 %tag) { 28 entry: 29 br label %test1 30 test1: 31 %tagbit1 = and i32 %tag, 1 32 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 33 br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely 34 body1: 35 call void @a() 36 call void @a() 37 call void @a() 38 call void @a() 39 br label %test2 40 test2: 41 %tagbit2 = and i32 %tag, 2 42 %tagbit2eq0 = icmp eq i32 %tagbit2, 0 43 br i1 %tagbit2eq0, label %exit, label %body2, !prof !1 ; %exit more likely 44 body2: 45 call void @b() 46 call void @b() 47 call void @b() 48 call void @b() 49 br label %exit 50 exit: 51 ret void 52 } 53 54 ; The branch weights here hint that we shouldn't tail duplicate in this case. 55 ;CHECK-LABEL: tail_dup_dont_break_cfg: 56 ;CHECK: mr [[TAGREG:[0-9]+]], 3 57 ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1 58 ;CHECK-NEXT: bc 4, 1, [[TEST2LABEL:[._0-9A-Za-z]+]] 59 ;CHECK-NEXT: # %body1 60 ;CHECK: [[TEST2LABEL]]: # %test2 61 ;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30 62 ;CHECK-NEXT: beq 0, [[EXITLABEL:[._0-9A-Za-z]+]] 63 ;CHECK-NEXT: # %body2 64 ;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit 65 ;CHECK: blr 66 define void @tail_dup_dont_break_cfg(i32 %tag) { 67 entry: 68 br label %test1 69 test1: 70 %tagbit1 = and i32 %tag, 1 71 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 72 br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely 73 body1: 74 call void @a() 75 call void @a() 76 call void @a() 77 call void @a() 78 br label %test2 79 test2: 80 %tagbit2 = and i32 %tag, 2 81 %tagbit2eq0 = icmp ne i32 %tagbit2, 0 82 br i1 %tagbit2eq0, label %body2, label %exit, !prof !3 ; %body2 more likely 83 body2: 84 call void @b() 85 call void @b() 86 call void @b() 87 call void @b() 88 br label %exit 89 exit: 90 ret void 91 } 92 declare void @a() 93 declare void @b() 94 declare void @c() 95 declare void @d() 96 97 ; This function arranges for the successors of %succ to have already been laid 98 ; out. When we consider whether to lay out succ after bb and to tail-duplicate 99 ; it, v and ret have already been placed, so we tail-duplicate as it removes a 100 ; branch and strictly increases fallthrough 101 ; CHECK-LABEL: tail_dup_no_succ 102 ; CHECK: # %entry 103 ; CHECK: # %v 104 ; CHECK: # %ret 105 ; CHECK: # %bb 106 ; CHECK: # %succ 107 ; CHECK: # %c 108 ; CHECK: bl c 109 ; CHECK: rlwinm. {{[0-9]+}}, {{[0-9]+}}, 0, 29, 29 110 ; CHECK: beq 111 ; CHECK: b 112 define void @tail_dup_no_succ(i32 %tag) { 113 entry: 114 %tagbit1 = and i32 %tag, 1 115 %tagbit1eq0 = icmp eq i32 %tagbit1, 0 116 br i1 %tagbit1eq0, label %v, label %bb, !prof !2 ; %v very much more likely 117 bb: 118 %tagbit2 = and i32 %tag, 2 119 %tagbit2eq0 = icmp eq i32 %tagbit2, 0 120 br i1 %tagbit2eq0, label %succ, label %c, !prof !3 ; %succ more likely 121 c: 122 call void @c() 123 call void @c() 124 br label %succ 125 succ: 126 %tagbit3 = and i32 %tag, 4 127 %tagbit3eq0 = icmp eq i32 %tagbit3, 0 128 br i1 %tagbit3eq0, label %ret, label %v, !prof !1 ; %u more likely 129 v: 130 call void @d() 131 call void @d() 132 br label %ret 133 ret: 134 ret void 135 } 136 137 138 !1 = !{!"branch_weights", i32 5, i32 3} 139 !2 = !{!"branch_weights", i32 95, i32 5} 140 !3 = !{!"branch_weights", i32 8, i32 3} 141
