tests/hard_coded/*.m:
Rename modules as mentioned above.
In a few cases, where the main module's name itself had a suffix,
such as "_mod_a" or "_main", remove that suffix. This entails
renaming the .exp file as well. (In some cases, this meant that
the name of a helper module was "taken over" by the main module
of the test case.)
Update all references to the moved modules.
General updates to programming style, such as
- replacing DCG notation with state var notation
- replacing (C->T;E) with (if C then T else E)
- moving pred/func declarations to just before their code
- replacing io.write/io.nl sequences with io.write_line
- replacing io.print/io.nl sequences with io.print_line
- fixing too-long lines
- fixing grammar errors in comments
tests/hard_coded/Mmakefile:
tests/hard_coded/Mercury.options:
Update all references to the moved modules.
Enable the constant_prop_int test case. The fact that it wasn't enabled
before is probably an accident. (When constant_prop_int.m was created,
the test case was added to a list in the Mmakefile, but that list
was later removed due to never being referenced.)
tests/hard_coded/constant_prop_int.{m,exp}:
Delete the calls to shift operations with negative shift amounts,
since we have added a compile-time error for these since the test
was originally created.
tests/accumulator/*.m:
tests/analysis_*/*.m:
tests/benchmarks*/*.m:
tests/debugger*/*.{m,exp,inp}:
tests/declarative_debugger*/*.{m,exp,inp}:
tests/dppd*/*.m:
tests/exceptions*/*.m:
tests/general*/*.m:
tests/grade_subdirs*/*.m:
tests/hard_coded*/*.m:
Make these tests use four-space indentation, and ensure that
each module is imported on its own line. (I intend to use the latter
to figure out which subdirectories' tests can be executed in parallel.)
These changes usually move code to different lines. For the debugger tests,
specify the new line numbers in .inp files and expect them in .exp files.
Estimated hours taken: 40
Branches: main
Until now, the only indexing we did for switches on strings was using a hash
table containing jump targets (represented as indices into a list of labels).
This diff supplements this with
- binary searches of tables containing jump targets,
- binary searches of tables containing values (lookup tables), and
- hash searches of tables containing values (lookup tables).
For now, the new methods exist in the LLDS backend only.
NEWS:
Mention the new capability.
compiler/string_switch.m:
Add predicates that implement the new indexing methods on strings.
Factor out code from existing predicates as required for this.
compiler/switch_gen.m:
Invoke the new predicates in string_switch.m when relevant.
Avoid passing the constant "no" as the initial value of !MaybeEnd
to predicates where we know this will ALWAYS happen.
compiler/options.m:
doc/user_guide.texi:
Add an option to control when we use binary searches for switches
on strings.
compiler/lookup_switch.m:
This module previously handled lookup switches on integers.
Generalize it so that pieces of it are now also usable to help
implement lookup switches on strings. Rename the predicates specific
to switches on integers to make clear this specificity, and separate
them from the predicates that help implement lookup switches on
variables of all the supported types.
Export some types, predicates and functions for use in string_switch.m.
Fix the code so that it correctly handles det switches, which
can happen e.g. if we know the possible set of values of the
switched-on variable.
Use tail-recursive code to handle the list of switch arms, to allow us
to handle very large switches.
Remove an obsolete comment from the top about a previously implemented
optimization.
compiler/lookup_util.m:
Make set_liveness_and_end_branch update MaybeEnd, to account for the
reservation of stack slots for holding the current and last rows in
later solutions tables for model_non lookup switches.
compiler/switch_util.m:
Make the exported predicates of this module more general, making them
usable for switches on strings as well as ints. Also make them easier
to use. In one case this meant bundling two predicates that were always
used together into one predicate. In another, it meant splitting one
predicate into two, since some of its callers needed an intermediate
result. In the case of a type, it means reordering its fields
to make the order match the order of their use in the implementation.
Add some predicates specifically for switches on strings.
compiler/ml_lookup_switch.m:
compiler/ml_string_switch.m:
compiler/ml_switch_gen.m:
Conform to the changes to switch_util.m.
compiler/jumpopt.m:
If the comment associated with a label ends with "nofulljump", then
inhibit fulljump optimization of jumps to that label. That
optimization would replace the jumps with the code starting at that
label. This is avoids the overhead of jump instructions, and it is a
good idea in the usual case of forward jumps. However, for the few
backward jumps we generate, the block that replaces the jump
instruction can actually END with the same jump instruction (which may
be conditionally executed), which means that our usual repeated
invocation of jumpopt can replace the original jump instruction
with MANY copies of the block it jumps to. In some cases, such as those
in hash switches, you get more copies than can ever be executed in any
actual execution. Lookup switches therefore now mark the labels that
are targets of backward jumps with this marker.
compiler/llds.m:
Document the new behavior of jumpopt.
compiler/code_info.m:
Export a predicate for use in improving the code we generate for lookup
switches.
Make some other predicates simpler and/or more efficient.
compiler/builtin_ops.m:
Add a builtin op for doing string comparisons by calling strcmp.
This is to prevent the need for two traversals of the strings being
compared in each iteration of binary search.
compiler/bytecode.m:
compiler/c_util.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/llds.m:
compiler/llds_to_x86_64.m:
Conform to the change in builtin_ops.m.
compiler/disj_gen.m:
Conform to the change in lookup_util.m
compiler/frameopt.m:
compiler/proc_gen.m:
compiler/unify_gen.m:
Take advantage of the change in fulljump optimization.
compiler/opt_debug.m:
Improve the string representation of rvals by recording the types of
the operands of binary operations, and making the output a bit more
consistent looking.
compiler/dupproc.m:
compiler/var_locn.m:
Minor style fixes.
runtime/mercury_string.h:
Add a version of strcmp for use by our code generator. This version
casts the arguments before calling the real strcmp. We need it since we
usually specify the arguments as r1, r2 etc, which are declared as
MR_Word, not char *.
tests/hard_coded/lookup_disj.{m,exp}:
tests/hard_coded/string_switch.{m,exp}:
Make these existing tests significantly tougher by making them exercise
a wider range of use scenarios.
tests/hard_coded/string_switch{2,3}.{m,exp}:
tests/hard_coded/Mercury.options
While the string_switch test case tests the handling of jump switches,
these two new test cases test the handling of binary search tables and
hash tables respectively. Their code is identical to the code of
the string_switch test case, but Mercury.options causes them to be
compiled with different options.
tests/hard_coded/int_switch.{m,exp}:
A new test case, equivalent in structure to the string switch test
cases, to test the handling of lookup switches on atomic values.
