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<a href="./Home">MLton 20130715</a>
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<h1>PolyHash</h1>
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<div class="paragraph"><p><a href="PolyHash">PolyHash</a> is an optimization pass for the <a href="SSA">SSA</a>
<a href="IntermediateLanguage">IntermediateLanguage</a>, invoked from <a href="SSASimplify">SSASimplify</a>.</p></div>
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<h2 id="_description">Description</h2>
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<div class="paragraph"><p>This pass implements polymorphic, structural hashing.</p></div>
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<h2 id="_implementation">Implementation</h2>
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<a href="https://github.com/MLton/mlton/blob/master/mlton/ssa/poly-hash.fun"><span class="monospaced">poly-hash.fun</span></a>
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<h2 id="_details_and_notes">Details and Notes</h2>
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<div class="paragraph"><p>For each datatype, tycon, and vector type, it builds and equality
function and translates calls to <span class="monospaced">MLton_hash</span> into calls to that
function.</p></div>
<div class="paragraph"><p>For tuples, it does the equality test inline; i.e., it does not create
a separate equality function for each tuple type.</p></div>
<div class="paragraph"><p>All equality functions are created only if necessary, i.e., if
equality is actually used at a type.</p></div>
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