Home | History | Annotate | Download | only in testdata 
      1 // run
      2 
      3 // Copyright 2015 The Go Authors. All rights reserved.
      4 // Use of this source code is governed by a BSD-style
      5 // license that can be found in the LICENSE file.
      6 
      7 // Tests load/store ordering
      8 
      9 package main
     10 
     11 import "fmt"
     12 
     13 // testLoadStoreOrder tests for reordering of stores/loads.
     14 func testLoadStoreOrder() {
     15 	z := uint32(1000)
     16 	if testLoadStoreOrder_ssa(&z, 100) == 0 {
     17 		println("testLoadStoreOrder failed")
     18 		failed = true
     19 	}
     20 }
     21 
     22 //go:noinline
     23 func testLoadStoreOrder_ssa(z *uint32, prec uint) int {
     24 	old := *z         // load
     25 	*z = uint32(prec) // store
     26 	if *z < old {     // load
     27 		return 1
     28 	}
     29 	return 0
     30 }
     31 
     32 func testStoreSize() {
     33 	a := [4]uint16{11, 22, 33, 44}
     34 	testStoreSize_ssa(&a[0], &a[2], 77)
     35 	want := [4]uint16{77, 22, 33, 44}
     36 	if a != want {
     37 		fmt.Println("testStoreSize failed.  want =", want, ", got =", a)
     38 		failed = true
     39 	}
     40 }
     41 
     42 //go:noinline
     43 func testStoreSize_ssa(p *uint16, q *uint16, v uint32) {
     44 	// Test to make sure that (Store ptr (Trunc32to16 val) mem)
     45 	// does not end up as a 32-bit store. It must stay a 16 bit store
     46 	// even when Trunc32to16 is rewritten to be a nop.
     47 	// To ensure that we get rewrite the Trunc32to16 before
     48 	// we rewrite the Store, we force the truncate into an
     49 	// earlier basic block by using it on both branches.
     50 	w := uint16(v)
     51 	if p != nil {
     52 		*p = w
     53 	} else {
     54 		*q = w
     55 	}
     56 }
     57 
     58 var failed = false
     59 
     60 //go:noinline
     61 func testExtStore_ssa(p *byte, b bool) int {
     62 	x := *p
     63 	*p = 7
     64 	if b {
     65 		return int(x)
     66 	}
     67 	return 0
     68 }
     69 
     70 func testExtStore() {
     71 	const start = 8
     72 	var b byte = start
     73 	if got := testExtStore_ssa(&b, true); got != start {
     74 		fmt.Println("testExtStore failed.  want =", start, ", got =", got)
     75 		failed = true
     76 	}
     77 }
     78 
     79 var b int
     80 
     81 // testDeadStorePanic_ssa ensures that we don't optimize away stores
     82 // that could be read by after recover().  Modeled after fixedbugs/issue1304.
     83 //go:noinline
     84 func testDeadStorePanic_ssa(a int) (r int) {
     85 	defer func() {
     86 		recover()
     87 		r = a
     88 	}()
     89 	a = 2      // store
     90 	b := a - a // optimized to zero
     91 	c := 4
     92 	a = c / b // store, but panics
     93 	a = 3     // store
     94 	r = a
     95 	return
     96 }
     97 
     98 func testDeadStorePanic() {
     99 	if want, got := 2, testDeadStorePanic_ssa(1); want != got {
    100 		fmt.Println("testDeadStorePanic failed.  want =", want, ", got =", got)
    101 		failed = true
    102 	}
    103 }
    104 
    105 func main() {
    106 
    107 	testLoadStoreOrder()
    108 	testStoreSize()
    109 	testExtStore()
    110 	testDeadStorePanic()
    111 
    112 	if failed {
    113 		panic("failed")
    114 	}
    115 }
    116