compiler/liveness.m:
The bug was a violation of an invariant required by delay_death_proc_body.
Document the requirement that this invariant places on cse_detection.m,
the requirement whose non-fulfillment caused the bug.
compiler/cse_detection.m:
When hoisting a deconstruction unification and creating new variables
for its arguments, if any of the arguments were named variables holding
type_infos, typeclass_infos or their components, then give a name
to the variable holding the corresponding argument as well. This fixes
the bug by fixing the violation of the above invariant. Add a pointer
to the invariant in liveness.m.
Document the reason why another change that looks like a potential fix
wouldn't actually work.
Give some predicates better names and argument orders.
Update the module qualifier (from : to .) in an example. We haven't used
: in a LONG time.
compiler/continuation_info.m:
Simplify the code where the bug originally caused the compiler to crash.
(This code was not actually in error.)
compiler/simplify_goal_conj.m:
Fix a small performance bug I noted while hunting the bug. When the
excess_assign optimization replaced all occurrences of a variable,
it delete the variable from the varset, but not the vartypes,
leaving lookups on it slower than necessary.
Record the reason why do not choose to fix a potential performance bug
that to the best of my knowledge, we haven't actually seen yet in the wild.
compiler/hlds_goal.m:
Define a type as a shorter and more meaningful synonym for a particular
type used in a predicate (incremental_rename_vars_in_goal) that I thought
would have been useful to implement the change to cse_detection.m
that turned out to be NOT a good fix.
compiler/state_var.m:
Use the new type synonym.
tests/valid/bug50_full.m:
tests/valid/bug50.m:
Two versions of the Mantis test case; the original version (slightly
cleaned up), and the minimal version I actually debugged. The latter
has a detailed description of the bug.
tests/valid/Mercury.options:
tests/valid/Mmakefile:
Enable the new test cases.
