X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=base-target-features.lisp-expr;h=a116e33e1b7b0592680e0915061939ff2325d126;hb=bee53328c93be3433477821131ab805557476c8b;hp=5f22ccb9beec107402530cca647204b5f3295bce;hpb=81cfdf526490d642c73602ebac9bcacb8af644e1;p=sbcl.git diff --git a/base-target-features.lisp-expr b/base-target-features.lisp-expr index 5f22ccb..a116e33 100644 --- a/base-target-features.lisp-expr +++ b/base-target-features.lisp-expr @@ -64,56 +64,12 @@ ;; the executable I'm running. :sb-doc - ;; When this is set, EVAL is implemented as an "IR1 interpreter": - ;; code is compiled into the compiler's first internal representation, - ;; then the IR1 is interpreted. When this is not set, EVAL is implemented - ;; as a little bit of hackery wrapped around a call to COMPILE, i.e. - ;; the system becomes a "compiler-only implementation" of Common Lisp. - ;; As of sbcl-0.6.7, the compiler-only implementation is prototype code, - ;; and much less mature than the old IR1 interpreter. Thus, the safe - ;; thing is to leave :SB-INTERPRETER set. However, the compiler-only - ;; system is noticeably smaller, so you might want to omit - ;; :SB-INTERPRETER if you have a small machine. - ;; - ;; Probably, the compiler-only implementation will become more - ;; stable someday, and support for the IR1 interpreter will then be - ;; dropped. This will make the system smaller and easier to maintain - ;; not only because we no longer need to support the interpreter, - ;; but because code elsewhere in the system (the dumper, the debugger, - ;; etc.) no longer needs special cases for interpreted code. - :sb-interpreter - ;; Do regression and other tests when building the system. You ;; might or might not want this if you're not a developer, ;; depending on how paranoid you are. You probably do want it if ;; you are a developer. :sb-test - ;; :SB-PROPAGATE-FLOAT-TYPE and :SB-PROPAGATE-FUN-TYPE enable - ;; some numeric optimizer code in the target compiler. They - ;; correspond to the :PROPAGATE-FLOAT-TYPE and :PROPAGATE-FUN-TYPE - ;; features in the original CMU CL code, and while documentation - ;; existed for those, it seemed a little inconsistent. Despite the - ;; name, :SB-PROPAGATE-FLOAT-TYPE seems to control not only - ;; floating point optimizations, but some integer optimizations as - ;; well. - ;; - ;; CROSS-FLOAT-INFINITY-KLUDGE: - ;; * Even when these target features are enabled, the optimizations - ;; aren't enabled in the cross-compiler, because some of them - ;; depend on floating point infinities, which aren't in general - ;; supported on the cross-compilation host. - ;; * This is supported by hacking the features out of the - ;; *SHEBANG-FEATURES* list while we're building the cross-compiler. - ;; This is ugly and confusing and weird, but all the alternatives - ;; that I could think of seem messy and error-prone. That doesn't - ;; mean there's not a better way, though. Suggestions are welcome; - ;; or if you'd like to submit patches to make this code work - ;; without requiring floating point infinities, so that the entire - ;; problem goes away, that might be even better! -- WHN 2001-03-22 - :sb-propagate-float-type - :sb-propagate-fun-type - ;; Make more debugging information available (for debugging SBCL ;; itself). If you aren't hacking or troubleshooting SBCL itself, ;; you probably don't want this set. @@ -204,11 +160,6 @@ ;; affects a lot of floating point code. ; :negative-zero-is-not-zero - ;; It's unclear to me what this does (but it was enabled in the code - ;; that I picked up from Peter Van Eynde, called CONSTRAIN-FLOAT-TYPE - ;; instead of SB-CONSTRAIN-FLOAT-TYPE). -- WHN 19990224 - :sb-constrain-float-type - ;; This is set in classic CMU CL, and presumably there it means ;; that the floating point arithmetic implementation ;; conforms to IEEE's standard. Here it definitely means that the