changes in sbcl-2.5.3 relative to sbcl-2.5.2:
* enhancement: breakpoint debugger commands have been added. Included is a
stepper based on breakpoints requiring no extra instrumentation. However,
it still has less functionality than the existing single stepper. See the
new debugger manual section titled "Breakpoint Commands" for more
information on the new commands.
* minor incompatible change: the behaviour of :save-runtime-options has been
restored to match the documentation. (lp#2096995, reported by Zach Beane)
* minor incompatible change: invoking CHANGE-CLASS from user code no longer
grabs the CLOS world lock. Callers must take responsibility for ordering
execution of CHANGE-CLASS and any changes to the class hierarchy.
* platform support:
** (CAS SAP) is implemented on ARM v8.1 directly with CAS instructions.
** on x86-64, list constructors emit more compact code sequences,
particularly in the presence of multiple references to the same object.
** on x86 and x86-64, fix the stack overflow check to use signed
comparisons.
** on Darwin/arm64 and Linux/x86-64, provide a restart to disable
floating-point exceptions of the type signalled, and another to disable
all floating-point exceptions.
* bug fix: cycle detection in class precedence lists happens before adding
classes to the direct subclasses of the parent.
* bug fix: stack-allocated unaligned cons cells no longer cause errors in
the debugger.
* bug fix: local function type declarations no longer inhibit tail calls in
(SAFETY 0) code. (lp#2039301)
* bug fix: bad or unknown type specifiers in CHECK-TYPE do not crash or slow
down the compiler. (lp#2102644, lp#2102653, lp#2102714, lp#2104048)
* bug fix: numerous bug fixes relating to the type system's handling of
arrays make SUBTYPEP more reliable and less likely to express a
contradiction. (lp#1996980, lp#2100563, lp#2100728, lp#2100779,
lp#2100784, lp#2100812, lp#2100825, lp#2101192, lp#2101215, lp#2101803,
lp#2102684)
* bug fix: improve other aspects of the type system's self-consistency.
(lp#2101073, lp#2101170, lp#2101183, lp#2101189, lp#2101399, lp#2101589)
* bug fix: fix compiler type error when deriving the type of FTRUNCATE.
(lp#2101073)
* bug fix: fix compiler error when deriving constraints for single-floats.
(lp#2102759)
* bug fix: startup tuning for particular microarchitectures no longer
accidentally disables one of the optimizations.
* optimization: ROW-MAJOR-AREF is transformed to use the same array
machinery as one-dimensional array references. (Thanks to Scott Burson
for the suggestion)
* optimization: list constructors emit shorter code sequences on x86-64,
particularly in the presence of multiple references to the same object.
* optimization: FLOOR and CEILING on ratios do not unnecessarily cons.
* optimization: provide specialized CALL-NEXT-METHOD functions for the
no-argument and full-argument cases.