Home | History | Annotate | Download | only in test 
      1 // +build amd64
      2 // errorcheck -0 -d=ssa/likelyadjust/debug=1,ssa/insert_resched_checks/off
      3 // rescheduling check insertion is turend off because the inserted conditional branches perturb the errorcheck
      4 
      5 // Copyright 2016 The Go Authors. All rights reserved.
      6 // Use of this source code is governed by a BSD-style
      7 // license that can be found in the LICENSE file.
      8 
      9 // Test that branches have some prediction properties.
     10 package foo
     11 
     12 func f(x, y, z int) int {
     13 	a := 0
     14 	for i := 0; i < x; i++ { // ERROR "Branch prediction rule stay in loop"
     15 		for j := 0; j < y; j++ { // ERROR "Branch prediction rule stay in loop"
     16 			a += j
     17 		}
     18 		for k := 0; k < z; k++ { // ERROR "Branch prediction rule stay in loop"
     19 			a -= x + y + z
     20 		}
     21 	}
     22 	return a
     23 }
     24 
     25 func g(x, y, z int) int {
     26 	a := 0
     27 	if y == 0 { // ERROR "Branch prediction rule default < call"
     28 		y = g(y, z, x)
     29 	} else {
     30 		y++
     31 	}
     32 	if y == x { // ERROR "Branch prediction rule default < call"
     33 		y = g(y, z, x)
     34 	} else {
     35 	}
     36 	if y == 2 { // ERROR "Branch prediction rule default < call"
     37 		z++
     38 	} else {
     39 		y = g(z, x, y)
     40 	}
     41 	if y+z == 3 { // ERROR "Branch prediction rule call < exit"
     42 		println("ha ha")
     43 	} else {
     44 		panic("help help help")
     45 	}
     46 	if x != 0 { // ERROR "Branch prediction rule default < ret"
     47 		for i := 0; i < x; i++ { // ERROR "Branch prediction rule stay in loop"
     48 			if x == 4 { // ERROR "Branch prediction rule stay in loop"
     49 				return a
     50 			}
     51 			for j := 0; j < y; j++ { // ERROR "Branch prediction rule stay in loop"
     52 				for k := 0; k < z; k++ { // ERROR "Branch prediction rule stay in loop"
     53 					a -= j * i
     54 				}
     55 				a += j
     56 			}
     57 		}
     58 	}
     59 	return a
     60 }
     61 
     62 func h(x, y, z int) int {
     63 	a := 0
     64 	for i := 0; i < x; i++ { // ERROR "Branch prediction rule stay in loop"
     65 		for j := 0; j < y; j++ { // ERROR "Branch prediction rule stay in loop"
     66 			a += j
     67 			if i == j { // ERROR "Branch prediction rule stay in loop"
     68 				break
     69 			}
     70 			a *= j
     71 		}
     72 		for k := 0; k < z; k++ { // ERROR "Branch prediction rule stay in loop"
     73 			a -= k
     74 			if i == k {
     75 				continue
     76 			}
     77 			a *= k
     78 		}
     79 	}
     80 	if a > 0 { // ERROR "Branch prediction rule default < call"
     81 		a = g(x, y, z)
     82 	} else {
     83 		a = -a
     84 	}
     85 	return a
     86 }
     87