mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-18 12:29:21 +00:00
Finished instruction replacement section, etc. Need better example for replaceAllUsesWith().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3806 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
e6fe6713da
commit
9dd1ad62ab
@ -669,8 +669,7 @@ pb->getInstList().insert(pi, newInst); // inserts newInst before pi in pb
|
||||
</p>
|
||||
|
||||
<li>Insertion into an implicit instruction list
|
||||
<p>
|
||||
<tt>Instruction</tt> instances that are already in
|
||||
<p><tt>Instruction</tt> instances that are already in
|
||||
<tt>BasicBlock</tt>s are implicitly associated with an existing
|
||||
instruction list: the instruction list of the enclosing basic block.
|
||||
Thus, we could have accomplished the same thing as the above code
|
||||
@ -695,7 +694,7 @@ Instruction* newInst = new Instruction(..., pi);
|
||||
</pre>
|
||||
which is much cleaner, especially if you're creating a lot of
|
||||
instructions and adding them to <tt>BasicBlock</tt>s.
|
||||
</p>
|
||||
</p>
|
||||
</p>
|
||||
</ul>
|
||||
|
||||
@ -718,17 +717,59 @@ For example:<p>
|
||||
BB->getInstList().erase(I);
|
||||
</pre><p>
|
||||
|
||||
|
||||
<!--_______________________________________________________________________-->
|
||||
</ul><h4><a name="schanges_replacing"><hr size=0>Replacing an
|
||||
<tt>Instruction</tt> with another <tt>Value</tt></h4><ul>
|
||||
|
||||
<!-- Value::replaceAllUsesWith
|
||||
User::replaceUsesOfWith
|
||||
Point out: include/llvm/Transforms/Utils/
|
||||
especially BasicBlockUtils.h with:
|
||||
ReplaceInstWithValue, ReplaceInstWithInst
|
||||
<p><i>Replacing individual instructions</i></p>
|
||||
<p>
|
||||
Including "<a
|
||||
href="/doxygen/BasicBlock_8h-source.html">llvm/Transforms/Utils/BasicBlock.h
|
||||
</a>" permits use of two very useful replace functions:
|
||||
<tt>ReplaceInstWithValue</tt> and <tt>ReplaceInstWithInst</tt>.
|
||||
|
||||
<ul>
|
||||
|
||||
<li>ReplaceInstWithValue
|
||||
|
||||
<p>This function replaces all uses (within a basic block) of a given
|
||||
instruction with a value, and then removes the original instruction.
|
||||
The following example illustrates the replacement of the result of a
|
||||
particular <tt>AllocaInst</tt> that allocates memory for a single
|
||||
integer with an null pointer to an integer.</p>
|
||||
|
||||
<pre>
|
||||
AllocaInst* instToReplace = ...;
|
||||
ReplaceInstWithValue(*instToReplace->getParent(), instToReplace,
|
||||
Constant::getNullValue(PointerType::get(Type::IntTy)));
|
||||
</pre>
|
||||
|
||||
<li>ReplaceInstWithInst
|
||||
|
||||
<p>This function replaces a particular instruction with another
|
||||
instruction. The following example illustrates the replacement of one
|
||||
<tt>AllocaInst</tt> with another.<p>
|
||||
|
||||
<pre>
|
||||
AllocaInst* instToReplace = ...;
|
||||
ReplaceInstWithInst(*instToReplace->getParent(), instToReplace,
|
||||
new AllocaInst(Type::IntTy, 0, "ptrToReplacedInt");
|
||||
</pre>
|
||||
|
||||
</ul>
|
||||
<p><i>Replacing multiple uses of <tt>User</tt>s and
|
||||
<tt>Value</tt>s</i></p>
|
||||
|
||||
You can use <tt>Value::replaceAllUsesWith</tt> and
|
||||
<tt>User::replaceUsesOfWith</tt> to change more than one use at a
|
||||
time. See the doxygen documentation for the <a
|
||||
href="/doxygen/classValue.html">Value Class</a> and <a
|
||||
href="/doxygen/classUser.html">User Class</a>, respectively, for more
|
||||
information.
|
||||
|
||||
<!-- Value::replaceAllUsesWith User::replaceUsesOfWith Point out:
|
||||
include/llvm/Transforms/Utils/ especially BasicBlockUtils.h with:
|
||||
ReplaceInstWithValue, ReplaceInstWithInst
|
||||
-->
|
||||
|
||||
<!-- *********************************************************************** -->
|
||||
@ -1575,6 +1616,6 @@ pointer to the parent Function.
|
||||
<a href="mailto:sabre@nondot.org">Chris Lattner</a></address>
|
||||
<!-- Created: Tue Aug 6 15:00:33 CDT 2002 -->
|
||||
<!-- hhmts start -->
|
||||
Last modified: Tue Sep 17 17:41:54 CDT 2002
|
||||
Last modified: Tue Sep 17 22:16:24 CDT 2002
|
||||
<!-- hhmts end -->
|
||||
</font></body></html>
|
||||
|
Loading…
Reference in New Issue
Block a user