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@@ -11839,24 +11839,30 @@ block40:
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As discussed earlier in this chapter, the garbage collector needs to
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access all the pointers in the root set, that is, all variables that
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-are vectors. It will be the responsibility of the register allocator
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+are tuple. It will be the responsibility of the register allocator
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to make sure that:
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\begin{enumerate}
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-\item the root stack is used for spilling vector-typed variables, and
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-\item if a vector-typed variable is live during a call to the
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+\item the root stack is used for spilling tuple-typed variables, and
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+\item if a tuple-typed variable is live during a call to the
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collector, it must be spilled to ensure it is visible to the
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collector.
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\end{enumerate}
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The later responsibility can be handled during construction of the
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interference graph, by adding interference edges between the call-live
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-vector-typed variables and all the callee-saved registers. (They
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-already interfere with the caller-saved registers.) The type
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-information for variables is in the \code{Program} form, so we
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-recommend adding another parameter to the \code{build\_interference}
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-function to communicate this alist.
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+tuple-typed variables and all the callee-saved registers. (They
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+already interfere with the caller-saved registers.)
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+%
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+\racket{The type information for variables is in the \code{Program}
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+ form, so we recommend adding another parameter to the
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+ \code{build\_interference} function to communicate this alist.}
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+%
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+\python{The type information for variables is generated by the type
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+ checker for \LangCVec{}, stored a field named \code{var\_types} in
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+ the \code{CProgram} AST mode. You'll need to propagate that
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+ information so that it is available in this pass.}
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-The spilling of vector-typed variables to the root stack can be
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+The spilling of tuple-typed variables to the root stack can be
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handled after graph coloring, when choosing how to assign the colors
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(integers) to registers and stack locations. The \code{Program} output
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of this pass changes to also record the number of spills to the root
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Jeremy Siek