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1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 use llvm
::{UseRef, ValueRef}
;
13 use trans
::basic_block
::BasicBlock
;
14 use trans
::common
::Block
;
17 #[derive(Copy, Clone)]
18 pub struct Value(pub ValueRef
);
20 macro_rules
! opt_val
{ ($e
:expr
) => (
23 p
if !p
.is_null() => Some(Value(p
)),
29 /// Wrapper for LLVM ValueRef
31 /// Returns the native ValueRef
32 pub fn get(&self) -> ValueRef
{
33 let Value(v
) = *self; v
36 /// Returns the BasicBlock that contains this value
37 pub fn get_parent(self) -> Option
<BasicBlock
> {
39 match llvm
::LLVMGetInstructionParent(self.get()) {
40 p
if !p
.is_null() => Some(BasicBlock(p
)),
46 /// Removes this value from its containing BasicBlock
47 pub fn erase_from_parent(self) {
49 llvm
::LLVMInstructionEraseFromParent(self.get());
53 /// Returns the single dominating store to this value, if any
54 /// This only performs a search for a trivially dominating store. The store
55 /// must be the only user of this value, and there must not be any conditional
56 /// branches between the store and the given block.
57 pub fn get_dominating_store(self, bcx
: Block
) -> Option
<Value
> {
58 match self.get_single_user().and_then(|user
| user
.as_store_inst()) {
60 store
.get_parent().and_then(|store_bb
| {
61 let mut bb
= BasicBlock(bcx
.llbb
);
62 let mut ret
= Some(store
);
63 while bb
.get() != store_bb
.get() {
64 match bb
.get_single_predecessor() {
65 Some(pred
) => bb
= pred
,
66 None
=> { ret = None; break }
76 /// Returns the first use of this value, if any
77 pub fn get_first_use(self) -> Option
<Use
> {
79 match llvm
::LLVMGetFirstUse(self.get()) {
80 u
if !u
.is_null() => Some(Use(u
)),
86 /// Tests if there are no uses of this value
87 pub fn has_no_uses(self) -> bool
{
88 self.get_first_use().is_none()
91 /// Returns the single user of this value
92 /// If there are no users or multiple users, this returns None
93 pub fn get_single_user(self) -> Option
<Value
> {
94 let mut iter
= self.user_iter();
95 match (iter
.next(), iter
.next()) {
96 (Some(first
), None
) => Some(first
),
101 /// Returns an iterator for the users of this value
102 pub fn user_iter(self) -> Users
{
104 next
: self.get_first_use()
108 /// Returns the requested operand of this instruction
109 /// Returns None, if there's no operand at the given index
110 pub fn get_operand(self, i
: usize) -> Option
<Value
> {
111 opt_val
!(llvm
::LLVMGetOperand(self.get(), i
as c_uint
))
114 /// Returns the Store represent by this value, if any
115 pub fn as_store_inst(self) -> Option
<Value
> {
116 opt_val
!(llvm
::LLVMIsAStoreInst(self.get()))
119 /// Tests if this value is a terminator instruction
120 pub fn is_a_terminator_inst(self) -> bool
{
122 !llvm
::LLVMIsATerminatorInst(self.get()).is_null()
127 /// Wrapper for LLVM UseRef
128 #[derive(Copy, Clone)]
129 pub struct Use(UseRef
);
132 pub fn get(&self) -> UseRef
{
133 let Use(v
) = *self; v
136 pub fn get_user(self) -> Value
{
138 Value(llvm
::LLVMGetUser(self.get()))
142 pub fn get_next_use(self) -> Option
<Use
> {
144 match llvm
::LLVMGetNextUse(self.get()) {
145 u
if !u
.is_null() => Some(Use(u
)),
152 /// Iterator for the users of a value
157 impl Iterator
for Users
{
160 fn next(&mut self) -> Option
<Value
> {
161 let current
= self.next
;
163 self.next
= current
.and_then(|u
| u
.get_next_use());
165 current
.map(|u
| u
.get_user())