Home | History | Annotate | Download | only in testdata 
      1 // Copyright 2016 The Go Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style
      3 // license that can be found in the LICENSE file.
      4 
      5 package main
      6 
      7 // Test to make sure spills of cast-shortened values
      8 // don't end up spilling the pre-shortened size instead
      9 // of the post-shortened size.
     10 
     11 import (
     12 	"fmt"
     13 	"runtime"
     14 )
     15 
     16 // unfoldable true
     17 var true_ = true
     18 
     19 var data1 [26]int32
     20 var data2 [26]int64
     21 
     22 func init() {
     23 	for i := 0; i < 26; i++ {
     24 		// If we spill all 8 bytes of this datum, the 1 in the high-order 4 bytes
     25 		// will overwrite some other variable in the stack frame.
     26 		data2[i] = 0x100000000
     27 	}
     28 }
     29 
     30 func foo() int32 {
     31 	var a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z int32
     32 	if true_ {
     33 		a = data1[0]
     34 		b = data1[1]
     35 		c = data1[2]
     36 		d = data1[3]
     37 		e = data1[4]
     38 		f = data1[5]
     39 		g = data1[6]
     40 		h = data1[7]
     41 		i = data1[8]
     42 		j = data1[9]
     43 		k = data1[10]
     44 		l = data1[11]
     45 		m = data1[12]
     46 		n = data1[13]
     47 		o = data1[14]
     48 		p = data1[15]
     49 		q = data1[16]
     50 		r = data1[17]
     51 		s = data1[18]
     52 		t = data1[19]
     53 		u = data1[20]
     54 		v = data1[21]
     55 		w = data1[22]
     56 		x = data1[23]
     57 		y = data1[24]
     58 		z = data1[25]
     59 	} else {
     60 		a = int32(data2[0])
     61 		b = int32(data2[1])
     62 		c = int32(data2[2])
     63 		d = int32(data2[3])
     64 		e = int32(data2[4])
     65 		f = int32(data2[5])
     66 		g = int32(data2[6])
     67 		h = int32(data2[7])
     68 		i = int32(data2[8])
     69 		j = int32(data2[9])
     70 		k = int32(data2[10])
     71 		l = int32(data2[11])
     72 		m = int32(data2[12])
     73 		n = int32(data2[13])
     74 		o = int32(data2[14])
     75 		p = int32(data2[15])
     76 		q = int32(data2[16])
     77 		r = int32(data2[17])
     78 		s = int32(data2[18])
     79 		t = int32(data2[19])
     80 		u = int32(data2[20])
     81 		v = int32(data2[21])
     82 		w = int32(data2[22])
     83 		x = int32(data2[23])
     84 		y = int32(data2[24])
     85 		z = int32(data2[25])
     86 	}
     87 	// Lots of phis of the form phi(int32,int64) of type int32 happen here.
     88 	// Some will be stack phis. For those stack phis, make sure the spill
     89 	// of the second argument uses the phi's width (4 bytes), not its width
     90 	// (8 bytes).  Otherwise, a random stack slot gets clobbered.
     91 
     92 	runtime.Gosched()
     93 	return a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p + q + r + s + t + u + v + w + x + y + z
     94 }
     95 
     96 func main() {
     97 	want := int32(0)
     98 	got := foo()
     99 	if got != want {
    100 		fmt.Printf("want %d, got %d\n", want, got)
    101 		panic("bad")
    102 	}
    103 }
    104