account-deduce-tail-call.yaml 1.5 KB
#RUN: llvm-xray account %s -o - -m %S/Inputs/simple-instrmap.yaml -d | FileCheck %s
---
header:
  version: 1
  type: 0
  constant-tsc: true
  nonstop-tsc: true
  cycle-frequency: 0
records:
# Here we reconstruct the following call trace:
#
#   f1()
#     f2()
#       f3()
#
# But we find that we're missing an exit record for f2() because it's
# tail-called f3(). We make sure that if we see a trace like this that we can
# deduce tail calls, and account the time (potentially wrongly) to f2() when
# f1() exits. That is because we don't go back to f3()'s entry record to
# properly do the math on the timing of f2().
#
# Note that by default, tail/sibling call deduction is disabled, and is enabled
# with a flag "-d" or "-deduce-sibling-calls".
#
  - { type: 0, func-id: 1, cpu: 1, thread: 111, kind: function-enter, tsc: 10000 }
  - { type: 0, func-id: 2, cpu: 1, thread: 111, kind: function-enter, tsc: 10001 }
  - { type: 0, func-id: 3, cpu: 1, thread: 111, kind: function-enter, tsc: 10002 }
  - { type: 0, func-id: 3, cpu: 1, thread: 111, kind: function-exit,  tsc: 10003 }
  - { type: 0, func-id: 1, cpu: 1, thread: 111, kind: function-exit,  tsc: 10004 }
...

#CHECK:       Functions with latencies: 3
#CHECK-NEXT:  funcid  count  [ min, med, 90p, 99p, max] sum function
#CHECK-NEXT:  1 1 [ 4.{{.*}}, 4.{{.*}}, 4.{{.*}}, 4.{{.*}}, 4.{{.*}}] {{.*}} {{.*}}
#CHECK-NEXT:  2 1 [ 3.{{.*}}, 3.{{.*}}, 3.{{.*}}, 3.{{.*}}, 3.{{.*}}] {{.*}} {{.*}}
#CHECK-NEXT:  3 1 [ 1.{{.*}}, 1.{{.*}}, 1.{{.*}}, 1.{{.*}}, 1.{{.*}}] {{.*}} {{.*}}