<b>bit</b> isReMaterializable = 0;
<b>bit</b> isPredicable = 0;
<b>bit</b> hasDelaySlot = 0;
- <b>bit</b> usesCustomDAGSchedInserter = 0;
+ <b>bit</b> usesCustomInserter = 0;
<b>bit</b> hasCtrlDep = 0;
<b>bit</b> isNotDuplicable = 0;
<b>bit</b> hasSideEffects = 0;
- <b>bit</b> mayHaveSideEffects = 0;
<b>bit</b> neverHasSideEffects = 0;
InstrItinClass Itinerary = NoItinerary;
<b>string</b> Constraints = "";
<p>As you can see, a lot of information is needed for every instruction
supported by the code generator, and specifying it all manually would be
-unmaintainble, prone to bugs, and tiring to do in the first place. Because we
+unmaintainable, prone to bugs, and tiring to do in the first place. Because we
are using TableGen, all of the information was derived from the following
definition:</p>
<dd>This type represents a nestable directed graph of elements.</dd>
<dt><tt><b>code</b></tt></dt>
- <dd>This represents a big hunk of text. NOTE: I don't remember why this is
- distinct from string!</dd>
+ <dd>This represents a big hunk of text. This is lexically distinct from
+ string values because it doesn't require escapeing double quotes and other
+ common characters that occur in code.</dd>
</dl>
<p>To date, these types have been sufficient for describing things that
<dd>a dag value. The first element is required to be a record definition, the
remaining elements in the list may be arbitrary other values, including nested
`<tt>dag</tt>' values.</dd>
-<dt><tt>(implicit a)</tt></dt>
- <dd>an implicitly defined physical register. This tells the dag instruction
- selection emitter the input pattern's extra definitions matches implicit
- physical register definitions.</dd>
-<dt><tt>(parallel (a), (b))</tt></dt>
- <dd>a list of dags specifying parallel operations which map to the same
- instruction.</dd>
<dt><tt>!strconcat(a, b)</tt></dt>
<dd>A string value that is the result of concatenating the 'a' and 'b'
strings.</dd>
<dd>An integer {0,1} indicating whether list 'a' is empty.</dd>
<dt><tt>!if(a,b,c)</tt></dt>
<dd>'b' if the result of integer operator 'a' is nonzero, 'c' otherwise.</dd>
+<dt><tt>!eq(a,b)</tt></dt>
+ <dd>Integer one if string a is equal to string b, zero otherwise. This
+ only operates on string objects. Use !cast<string> to compare other
+ types of objects.</dd>
</dl>
<p>Note that all of the values have rules specifying how they convert to values
</div>
+<!-- *********************************************************************** -->
+<div class="doc_section"><a name="codegen">Code Generator backend info</a></div>
+<!-- *********************************************************************** -->
+
+<p>Expressions used by code generator to describe instructions and isel
+patterns:</p>
+
+<div class="doc_text">
+
+<dt><tt>(implicit a)</tt></dt>
+ <dd>an implicitly defined physical register. This tells the dag instruction
+ selection emitter the input pattern's extra definitions matches implicit
+ physical register definitions.</dd>
+
+</div>
+
<!-- *********************************************************************** -->
<div class="doc_section"><a name="backends">TableGen backends</a></div>
<!-- *********************************************************************** -->