libgo/go/internal/bytealg/compare_generic.go

   1 // Copyright 2018 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 // +build ignore_for_gccgo
   6 // +build !386,!amd64,!amd64p32,!s390x,!arm,!arm64,!ppc64,!ppc64le,!mips,!mipsle,!wasm
   7
   8 package bytealg
   9
  10 import _ "unsafe" // for go:linkname
  11
  12 func Compare(a, b []byte) int {
  13         l := len(a)
  14         if len(b) < l {
  15                 l = len(b)
  16         }
  17         if l == 0 || &a[0] == &b[0] {
  18                 goto samebytes
  19         }
  20         for i := 0; i < l; i++ {
  21                 c1, c2 := a[i], b[i]
  22                 if c1 < c2 {
  23                         return -1
  24                 }
  25                 if c1 > c2 {
  26                         return +1
  27                 }
  28         }
  29 samebytes:
  30         if len(a) < len(b) {
  31                 return -1
  32         }
  33         if len(a) > len(b) {
  34                 return +1
  35         }
  36         return 0
  37 }
  38
  39 //go:linkname bytes_Compare bytes.Compare
  40 func bytes_Compare(a, b []byte) int {
  41         l := len(a)
  42         if len(b) < l {
  43                 l = len(b)
  44         }
  45         if l == 0 || &a[0] == &b[0] {
  46                 goto samebytes
  47         }
  48         for i := 0; i < l; i++ {
  49                 c1, c2 := a[i], b[i]
  50                 if c1 < c2 {
  51                         return -1
  52                 }
  53                 if c1 > c2 {
  54                         return +1
  55                 }
  56         }
  57 samebytes:
  58         if len(a) < len(b) {
  59                 return -1
  60         }
  61         if len(a) > len(b) {
  62                 return +1
  63         }
  64         return 0
  65 }
  66
  67 //go:linkname runtime_cmpstring runtime.cmpstring
  68 func runtime_cmpstring(a, b string) int {
  69         l := len(a)
  70         if len(b) < l {
  71                 l = len(b)
  72         }
  73         for i := 0; i < l; i++ {
  74                 c1, c2 := a[i], b[i]
  75                 if c1 < c2 {
  76                         return -1
  77                 }
  78                 if c1 > c2 {
  79                         return +1
  80                 }
  81         }
  82         if len(a) < len(b) {
  83                 return -1
  84         }
  85         if len(a) > len(b) {
  86                 return +1
  87         }
  88         return 0
  89 }