deploy: 2e6c250

design/decoder/main.html

@@ -193,6 +193,7 @@ <h2 id="program-execution"><a class="header" href="#program-execution">Program e
 <tr><td><code>REPEAT</code></td><td>Initiates a new iteration of an executing loop.</td></tr>
 <tr><td><code>SPAN</code></td><td>Initiates processing of a new <a href="../programs.html#span-block">Span block</a>.</td></tr>
 <tr><td><code>RESPAN</code></td><td>Initiates processing of a new operation batch within a span block.</td></tr>
+<tr><td><code>DYN</code></td><td>Initiates processing of a new <a href="../programs.html#dyn-block">Dyn block</a>.</td></tr>
 <tr><td><code>CALL</code></td><td>Initiates processing of a new <a href="../programs.html#call-block">Call block</a>.</td></tr>
 <tr><td><code>SYSCALL</code></td><td>Initiates processing ofa new  <a href="../programs.html#syscall-block">Syscall block</a>.</td></tr>
 <tr><td><code>END</code></td><td>Marks the end of a program block.</td></tr>
@@ -402,6 +403,17 @@ <h4 id="span-operation"><a class="header" href="#span-operation">SPAN operation<
 <li>Decrements <code>group_count</code> register by <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span></span></span></span>.</li>
 <li>Sets the <code>op_index</code> register to <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>.</li>
 </ol>
+<h4 id="dyn-operation"><a class="header" href="#dyn-operation">DYN operation</a></h4>
+<p>Before a <code>DYN</code> operation is executed by the VM, the prover populates <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">...</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">7</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> registers with <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span> as shown in the diagram below.</p>
+<p><img src="../../assets/design/decoder/decoder_dyn_operation.png" alt="decoder_dyn_operation" /></p>
+<p>In the above diagram, <code>blk</code> is the ID of the <em>dyn</em> block which is about to be executed. <code>blk</code> is also the address of the hasher row in the auxiliary hasher table. <code>prnt</code> is the ID of the block's parent.</p>
+<p>When the VM executes a <code>DYN</code> operation, it does the following:</p>
+<ol>
+<li>Adds a tuple <code>(blk, prnt, 0)</code> to the block stack table.</li>
+<li>Gets the hash of the dynamic code block <code>dynamic_block_hash</code> from the top four elements of the stack.</li>
+<li>Adds the tuple <code>(blk, dynamic_block_hash, 0, 0)</code> to the block hash table.</li>
+<li>Initiates a 2-to-1 hash computation in the hash chiplet (as described <a href="#simple-2-to-1-hash">here</a>) using <code>blk</code> as row address in the auxiliary hashing table and <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">...</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">7</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> as input values.</li>
+</ol>
 <h4 id="end-operation"><a class="header" href="#end-operation">END operation</a></h4>
 <p>Before an <code>END</code> operation is executed by the VM, the prover populates <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">...</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">3</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> registers with the hash of the block which is about to end. The prover also sets values in <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8444em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">4</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> and <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8444em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal">h</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">5</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> registers as follows:</p>
 <ul>
@@ -482,6 +494,10 @@ <h4 id="skipping-the-loop"><a class="header" href="#skipping-the-loop">Skipping
 <p>If the top of the stack is <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>, the VM still executes the <code>LOOP</code> operation. But unlike in the case when we need to enter the loop, the VM sets <code>is_loop</code> flag to <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span> in the block stack table, and does not add any rows to the block hash table. The last point means that the only possible operation to be executed after the <code>LOOP</code> operation is the <code>END</code> operation. This is illustrated in the diagram below.</p>
 <p><img src="../../assets/design/decoder/decoder_loop_skipping.png" alt="decoder_loop_skipping" /></p>
 <p>Moreover, since we've set the <code>is_loop</code> flag to <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>, executing the <code>END</code> operation does not remove any items from the stack.</p>
+<h3 id="dyn-block-decoding"><a class="header" href="#dyn-block-decoding">DYN block decoding</a></h3>
+<p>When decoding a <em>dyn</em> bock, the VM first executes a <code>DYN</code> operation, then executes the child block dynamically specified by the top of the stack. Once the child of the <em>dyn</em> block has been executed, the VM executes an <code>END</code> operation. This is illustrated in the diagram below.</p>
+<p><img src="../../assets/design/decoder/decoder_dyn_block_decoding.png" alt="decoder_dyn_block_decoding" /></p>
+<p>As described previously, when the VM executes a <code>DYN</code> operation, the hash of the child is added to the block hash table. This hash is removed only when the <code>END</code> operation for the child block is executed. Thus, until the child block corresponding to the dynamically specified target is executed, the block hash table is not cleared.</p>
 <h3 id="span-block-decoding"><a class="header" href="#span-block-decoding">SPAN block decoding</a></h3>
 <p>As described <a href="../programs.html#span-block">here</a>, a <em>span</em> block can contain one or more operation batches, each batch containing up to <span class="katex"><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">8</span></span></span></span> operation groups. At the high level, decoding of a span block is done as follows:</p>
 <ol>