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// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package arm64asm
func extract_bit(value, bit uint32) uint32 {
return (value >> bit) & 1
}
func bfxpreferred_4(sf, opc1, imms, immr uint32) bool {
if imms < immr {
return false
}
if (imms>>5 == sf) && (imms&0x1f == 0x1f) {
return false
}
if immr == 0 {
if sf == 0 && (imms == 7 || imms == 15) {
return false
}
if sf == 1 && opc1 == 0 && (imms == 7 ||
imms == 15 || imms == 31) {
return false
}
}
return true
}
func move_wide_preferred_4(sf, N, imms, immr uint32) bool {
if sf == 1 && N != 1 {
return false
}
if sf == 0 && !(N == 0 && ((imms>>5)&1) == 0) {
return false
}
if imms < 16 {
return (-immr)%16 <= (15 - imms)
}
width := uint32(32)
if sf == 1 {
width = uint32(64)
}
if imms >= (width - 15) {
return (immr % 16) <= (imms - (width - 15))
}
return false
}
type Sys uint8
const (
Sys_AT Sys = iota
Sys_DC
Sys_IC
Sys_TLBI
Sys_SYS
)
func sys_op_4(op1, crn, crm, op2 uint32) Sys {
// TODO: system instruction
return Sys_SYS
}
func is_zero(x uint32) bool {
return x == 0
}
func is_ones_n16(x uint32) bool {
return x == 0xffff
}
func bit_count(x uint32) uint8 {
var count uint8
for count = 0; x > 0; x >>= 1 {
if (x & 1) == 1 {
count++
}
}
return count
}