; RUN: llc -O3 -o - %s | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" declare void @effect(i32); ; After the loop gets laid out, loop.end is the only successor, but can't be ; laid out because of the CFG dependency from top.fakephi. The calculations show ; that it isn't profitable to tail-duplicate in this case, because of the ; effects on fallthrough from %loop.end ; CHECK-LABEL: {{^}}no_successor_still_no_taildup: ; CHECK: %entry ; CHECK: %loop.top ; CHECK: %loop.latch ; CHECK: %top.fakephi ; CHECK: %loop.end ; CHECK: %false ; CHECK: %ret define void @no_successor_still_no_taildup (i32 %count, i32 %key) { entry: br label %loop.top loop.top: %i.loop.top = phi i32 [ %count, %entry ], [ %i.latch, %loop.latch ] %cmp.top = icmp eq i32 %i.loop.top, %key call void @effect(i32 0) br i1 %cmp.top, label %top.fakephi, label %loop.latch, !prof !1 loop.latch: %i.latch = sub i32 %i.loop.top, 1 %cmp.latch = icmp eq i32 %i.latch, 0 call void @effect(i32 1) br i1 %cmp.top, label %loop.top, label %loop.end, !prof !2 top.fakephi: call void @effect(i32 2) br label %loop.end loop.end: %cmp.end = icmp eq i32 %count, 0 br i1 %cmp.end, label %ret, label %false, !prof !3 false: call void @effect(i32 4) br label %ret ret: ret void } !1 = !{!"branch_weights", i32 1, i32 1} !2 = !{!"branch_weights", i32 5, i32 1} !3 = !{!"branch_weights", i32 1, i32 2}