[Chicken-janitors] #1219: read-char could be better optimized

[Chicken Trac]

#1219: read-char could be better optimized
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 Reporter:  sjamaan  |      Owner:
     Type:  defect   |     Status:  new
 Priority:  major    |  Milestone:  someday
Component:  unknown  |    Version:  4.9.x
 Keywords:           |
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 Currently, there are two issues with {{{read-char}}}:

 * It calls {{{##sys#read-char/port}}}, which is itself a CPS procedure
 (consuming needless CPU cycles and stack).  This will get rewritten in
 {{{c-platform.scm}}} to a direct call to {{{##sys#read-char/port}}} with
 fixed argcount. Is omitting argcount check really that much faster? Why
 not rewrite it to the complete body of {{{##sys#read-char/port}}} instead?
 * Equally important, the {{{##sys#check-input-port}}} call in {{{##sys
 #read-char/port}}} is not being specialized, even though there's an entry
 in {{{types.db}}}(!)  This also causes an extra needless CPS call, because
 it can (and should) be inlined.

 Once this is fixed, we should run the {{{slatex}}}, {{{kernwyk-wc}}} and
 {{{kernwyk-cat}}} benchmarks to see how much of an improvement this is.

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Ticket URL: <http://bugs.call-cc.org/ticket/1219>
CHICKEN Scheme <http://www.call-cc.org/>
CHICKEN Scheme is a compiler for the Scheme programming language.