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Update NEWS for Guile 2.9.6
* NEWS: Update, folding in old NEWS entries.
This commit is contained in:
Andy Wingo
parent
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1 changed files with 121 additions and 91 deletions
212
NEWS
212
NEWS
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@ -6,10 +6,93 @@ Please send Guile bug reports to bug-guile@gnu.org.
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Changes in alpha 2.9.5 (since alpha 2.9.4):
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Changes in alpha 2.9.6 (since alpha 2.9.5):
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* Notable changes
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** Add --r6rs, --r7rs options to `guild compile'
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This makes compiling R6RS or R7RS code a bit easier. See "R6RS Support"
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and "R7RS Support" in the manual, for more.
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** Add guile-3, guile-3.0 cond-expand features
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See "SRFI-0" in the manual, for more.
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** Add #:re-export-and-replace argument to `define-module'
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This new keyword specifies a set of bindings to re-export, but also
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marks them as intended to replace core bindings. See "Creating Guile
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Modules" in the manual, for full details.
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Note to make this change, we had to change the way replacement flags are
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stored, to being associated with modules instead of individual variable
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objects. This means that users who #:re-export an imported binding that
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was already marked as #:replace by another module will now see warnings,
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as they need to use #:re-export-and-replace instead.
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** Better optimizations for vector-length et al
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Sometimes the compiler get confused and think it couldn't hoist a
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`vector-length' call out of a loop. This has been fixed.
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* Bug fixes
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** Fix range inference on division in unreachable code
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** Fix frame-call-representation for callees without closures
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** Fix range inference for right-shifts
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** Fix port-position documentation
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** Fix stack overflow if printing a pre-boot error throws an error
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Changes in alpha 2.9.x (since the stable 2.2 series):
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* Notable changes
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** Just-in-time code generation
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Guile programs now run up to 4 times faster, relative to Guile 2.2,
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thanks to just-in-time (JIT) native code generation. Notably, this
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brings the performance of "eval" as written in Scheme back to the level
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of "eval" written in C, as in the days of Guile 1.8.
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See "Just-In-Time Native Code" in the manual, for more information. JIT
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compilation will be enabled automatically and transparently. To disable
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JIT compilation, configure Guile with `--enable-jit=no' or
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`--disable-jit'. The default is `--enable-jit=auto', which enables the
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JIT if it is available. See `./configure --help' for more.
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JIT compilation is enabled by default on x86-64, i686, ARMv7, and
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AArch64 targets.
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** Lower-level bytecode
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Relative to the virtual machine in Guile 2.2, Guile's VM instruction set
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is now more low-level. This allows it to express more advanced
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optimizations, for example type check elision or integer
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devirtualization, and makes the task of JIT code generation easier.
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Note that this change can mean that for a given function, the
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corresponding number of instructions in Guile 3.0 may be higher than
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Guile 2.2, which can lead to slowdowns when the function is interpreted.
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We hope that JIT compilation more than makes up for this slight
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slowdown.
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** Interleaved internal definitions and expressions allowed
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It used to be that internal definitions had to precede all expressions
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in their bodies. This restriction has been relaxed. If an expression
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precedes an internal definition, it is treated as if it were a
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definition of an unreferenced variable. For example, the expression
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`(foo)' transforms to the equivalent of `(define _ (begin (foo) #f))',
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if it precedes other definitions.
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This change improves the readability of Guile programs, as it used to be
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that program indentation tended to increase needlessly to allow nested
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`let' and `letrec' to re-establish definition contexts after initial
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expressions, for example for type-checks on procedure arguments.
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** Record unification
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Guile used to have a number of implementations of structured data types
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@ -67,18 +150,40 @@ via `throw'. These will probably migrate over time to
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See "Exceptions" in the manual, for full details on the new API.
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** More optimization for unexported definitions at -O3
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** Optimization of top-level bindings within a compilation unit
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There is a new optimization pass, `seal-private-bindings', which is
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enabled at the new optimization level -O3. (Prior to this change, -O3
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was the same as -O2.) With this pass, private declarative bindings
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aren't available for access from the first-class module reflection API.
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This allows for better optimization.
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At optimization level 2 and above, Guile's compiler is now allowed to
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inline top-level definitions within a compilation unit. See
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"Declarative Modules" in the manual, for full details. This change can
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improve the performance of programs with many small top-level
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definitions by quite a bit!
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** Better optimization for unboxed int/float conversions
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At optimization level 3 and above, Guile will assume that any top-level
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binding in a declarative compilation unit that isn't exported from a
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module can be completely inlined into its uses. (Prior to this change,
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-O3 was the same as -O2.) Note that with this new
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`seal-private-bindings' pass, private declarative bindings are no longer
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available for access from the first-class module reflection API. The
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optimizations afforded by this pass can be useful when you need a speed
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boost, but having them enabled at optimization level 3 means they are
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not on by default, as they change Guile's behavior in ways that users
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might not expect.
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This improves optimization for "exact->inexact" and integer operands to
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floating-point ops.
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** By default, GOOPS classes are not redefinable
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It used to be that all GOOPS classes were redefinable, at least in
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theory. This facility was supported by an indirection in all "struct"
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instances, even though only a subset of structs would need redefinition.
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We wanted to remove this indirection, in order to speed up Guile
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records, allow immutable Guile records to eventually be described by
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classes, and allow for some optimizations in core GOOPS classes that
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shouldn't be redefined anyway.
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Thus in GOOPS now there are classes that are redefinable and classes
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that aren't. By default, classes created with GOOPS are not
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redefinable. To make a class redefinable, it should be an instance of
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`<redefinable-class>'. See "Redefining a Class" in the manual for more
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information.
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** Define top-level bindings for aux syntax: `else', `=>', `...', `_'
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@ -114,87 +219,6 @@ see "R6RS Support" in the manual, for full details.
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Also as with R6RS, there is an `install-r7rs!' procedure and a `--r7rs'
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command-line option.
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* New deprecations
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** The two-argument form of `record-constructor'
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Calling `record-constructor' with two arguments (the record type and a
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list of field names) is deprecated. Instead, call with just one
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argument, and provide a wrapper around that constructor if needed.
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Changes in alpha 2.9.x (since the stable 2.2 series):
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* Notable changes
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** Just-in-time code generation
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|
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Guile programs now run up to 4 times faster, relative to Guile 2.2,
|
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thanks to just-in-time (JIT) native code generation. Notably, this
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brings the performance of "eval" as written in Scheme back to the level
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of "eval" written in C, as in the days of Guile 1.8.
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See "Just-In-Time Native Code" in the manual, for more information. JIT
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compilation will be enabled automatically and transparently. To disable
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JIT compilation, configure Guile with `--enable-jit=no' or
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`--disable-jit'. The default is `--enable-jit=auto', which enables the
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JIT if it is available. See `./configure --help' for more.
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JIT compilation is enabled by default on x86-64, i686, ARMv7, and
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AArch64 targets.
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** Lower-level bytecode
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Relative to the virtual machine in Guile 2.2, Guile's VM instruction set
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is now more low-level. This allows it to express more advanced
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optimizations, for example type check elision or integer
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devirtualization, and makes the task of JIT code generation easier.
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Note that this change can mean that for a given function, the
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corresponding number of instructions in Guile 3.0 may be higher than
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Guile 2.2, which can lead to slowdowns when the function is interpreted.
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We hope that JIT compilation more than makes up for this slight
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slowdown.
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** Interleaved internal definitions and expressions allowed
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It used to be that internal definitions had to precede all expressions
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in their bodies. This restriction has been relaxed. If an expression
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precedes an internal definition, it is treated as if it were a
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definition of an unreferenced variable. For example, the expression
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`(foo)' transforms to the equivalent of `(define _ (begin (foo) #f))',
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if it precedes other definitions.
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This change improves the readability of Guile programs, as it used to be
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that program indentation tended to increase needlessly to allow nested
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`let' and `letrec' to re-establish definition contexts after initial
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expressions, for example for type-checks on procedure arguments.
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** Optimization of top-level bindings within a compilation unit
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At optimization level 2 and above, Guile's compiler is now allowed to
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inline top-level definitions within a compilation unit. See
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"Declarative Modules" in the manual, for full details. This change can
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improve the performance of programs with many small top-level
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definitions by quite a bit!
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** By default, GOOPS classes are not redefinable
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It used to be that all GOOPS classes were redefinable, at least in
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theory. This facility was supported by an indirection in all "struct"
|
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instances, even though only a subset of structs would need redefinition.
|
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We wanted to remove this indirection, in order to speed up Guile
|
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records, allow immutable Guile records to eventually be described by
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classes, and allow for some optimizations in core GOOPS classes that
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shouldn't be redefined anyway.
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|
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Thus in GOOPS now there are classes that are redefinable and classes
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that aren't. By default, classes created with GOOPS are not
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redefinable. To make a class redefinable, it should be an instance of
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`<redefinable-class>'. See "Redefining a Class" in the manual for more
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information.
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* New deprecations
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** scm_t_uint8, etc deprecated in favor of C99 stdint.h
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@ -208,6 +232,12 @@ and uintN for N in 8, 16, 32, and 64. Guile also now uses ptrdiff_t
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instead of scm_t_ptrdiff, and similarly for intmax_t, uintmax_t,
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intptr_t, and uintptr_t.
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** The two-argument form of `record-constructor'
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Calling `record-constructor' with two arguments (the record type and a
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list of field names) is deprecated. Instead, call with just one
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argument, and provide a wrapper around that constructor if needed.
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* Incompatible changes
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** All deprecated code removed
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