modernc.org/gc@v1.0.1-0.20240304020402-f0dba7c97c2b/testdata/errchk/test/fixedbugs/issue15175.go (about)

     1  // run
     2  
     3  // Copyright 2016 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  // Make sure unsigned shift results get sign-extended correctly.
     8  package main
     9  
    10  import "fmt"
    11  
    12  func main() {
    13  	failed := false
    14  	a6 := uint8(253)
    15  	if got := a6 >> 0; got != 253 {
    16  		fmt.Printf("uint8(253)>>0 = %v, wanted 253\n", got)
    17  		failed = true
    18  	}
    19  	if got := f1(0, 2, 1, 0, 0, 1, true); got != 255 {
    20  		fmt.Printf("f1(...) = %v, wanted 255\n", got)
    21  		failed = true
    22  	}
    23  	if got := f2(1); got != 242 {
    24  		fmt.Printf("f2(...) = %v, wanted 242\n", got)
    25  		failed = true
    26  	}
    27  	if got := f3(false, 0, 0); got != 254 {
    28  		fmt.Printf("f3(...) = %v, wanted 254\n", got)
    29  		failed = true
    30  	}
    31  	if failed {
    32  		panic("bad")
    33  	}
    34  }
    35  
    36  func f1(a1 uint, a2 int8, a3 int8, a4 int8, a5 uint8, a6 int, a7 bool) uint8 {
    37  	a5--
    38  	a4 += (a2 << a1 << 2) | (a4 ^ a4<<(a1&a1)) - a3                              // int8
    39  	a6 -= a6 >> (2 + uint32(a2)>>3)                                              // int
    40  	a1 += a1                                                                     // uint
    41  	a3 *= a4 << (a1 | a1) << (uint16(3) >> 2 & (1 - 0) & (uint16(1) << a5 << 3)) // int8
    42  	a7 = a7 || ((a2 == a4) || (a7 && a7) || ((a5 == a5) || (a7 || a7)))          // bool
    43  	return a5 >> a1
    44  }
    45  
    46  func f2(a1 uint8) uint8 {
    47  	a1--
    48  	a1--
    49  	a1 -= a1 + (a1 << 1) - (a1*a1*a1)<<(2-0+(3|3)-1)                // uint8
    50  	v1 := 0 * ((2 * 1) ^ 1) & ((uint(0) >> a1) + (2+0)*(uint(2)+0)) // uint
    51  	_ = v1
    52  	return a1 >> (((2 ^ 2) >> (v1 | 2)) + 0)
    53  }
    54  
    55  func f3(a1 bool, a2 uint, a3 int64) uint8 {
    56  	a3--
    57  	v1 := 1 & (2 & 1 * (1 ^ 2) & (uint8(3*1) >> 0)) // uint8
    58  	_ = v1
    59  	v1 += v1 - (v1 >> a2) + (v1 << (a2 ^ a2) & v1) // uint8
    60  	v1 *= v1                                       // uint8
    61  	a3--
    62  	v1 += v1 & v1 // uint8
    63  	v1--
    64  	v1 = ((v1 << 0) | v1>>0) + v1 // uint8
    65  	return v1 >> 0
    66  }