## solve-register-allocation-problems.api "regor" is a contraction of "register allocator"
#
# The main register allocator API.
#
# This is a low-level register-allocator interface;
# for a higher-level interface see:
#
# src/lib/compiler/back/low/regor/register-allocator.api#
# We accept accept one machcode controlflow graph
# and typically two associated register allocation problems,
# one each for the int and floating-point registers,
# solve the allocation problems, and return the updated graph.
#
# In the interests of being machine-independent, we define the
# register allocation problems somewhat abstractly and accept
# a list of them rather than assuming there will always be
# exactly two.
#
# Comments are mainly in
#
# src/lib/compiler/back/low/regor/solve-register-allocation-problems-by-iterated-coalescing-g.pkg# Compiled by:
# src/lib/compiler/back/low/lib/lowhalf.libstipulate
package cig = codetemp_interference_graph; # codetemp_interference_graph is from src/lib/compiler/back/low/regor/codetemp-interference-graph.pkg package rkj = registerkinds_junk; # registerkinds_junk is from src/lib/compiler/back/low/code/registerkinds-junk.pkg package rwv = rw_vector; # rw_vector is from src/lib/std/src/rw-vector.pkgherein
# This API is implemented (only) in:
#
# src/lib/compiler/back/low/regor/solve-register-allocation-problems-by-iterated-coalescing-g.pkg # src/lib/compiler/back/low/regor/solve-register-allocation-problems-by-recursive-partition-g.pkg #
api Solve_Register_Allocation_Problems {
#
package mcf: Machcode_Form; # Machcode_Form is from src/lib/compiler/back/low/code/machcode-form.api package rgk: Registerkinds; # Registerkinds is from src/lib/compiler/back/low/code/registerkinds.api package flo: Regor_View_Of_Machcode_Controlflow_Graph; # Regor_View_Of_Machcode_Controlflow_Graph is from src/lib/compiler/back/low/regor/regor-view-of-machcode-controlflow-graph.api sharing flo::mcf == mcf; # "mcf" == "machcode_form" (abstract machine code).
sharing mcf::rgk == rgk; # "rgk" == "registerkinds".
Getreg = { preferred_registers: List( rkj::Universal_Register_Id ),
register_is_taken: rwv::Rw_Vector( Int ),
true_value: Int # Speedhack: register is taken iff register_is_taken[ register ] == true_value.
}
->
rkj::Universal_Register_Id;
Mode = Unt;
Spill_To == cig::Spill_To;
# Optimizations/options.
# 'or' them together:
no_optimization: Mode;
dead_copy_elim: Mode;
biased_selection: Mode;
spill_coloring: Mode;
spill_coalescing: Mode;
spill_propagation: Mode;
has_parallel_copies: Mode;
#
# The above MUST be used when spill coloring is used and
# you have parallel copies in the program. Otherwise, phantom
# problems involving copy temporaries may appear.
# Define a register allocation problem.
#
# On today's architectures the integer and floating-point registers
# are usually disjoint, allowing us to allot them separately,
# so we define our interface in the expectation that usually one
# machcode controlflow graph will have two or more associated
# register allocation problems:
#
Register_Allocation_Problem
=
{ registerkind: rkj::Registerkind, # Kind of register.
spill_prohibitions: List( rkj::Codetemp_Info ), # Don't spill these.
ramregs: List( rkj::Codetemp_Info ), # Memory registers.
hardware_registers_we_may_use: Int, # E.g. 6 int regs on intel32. Number of colors for our graph-colorer -- this number is the center of our life during register allocation.
is_globally_allocated_register_or_codetemp: Int -> Bool, # Distinguishes registers globally allocated by hand (e.g., esp and edi on intel32) from those locally allocated by the register allocator.
pick_available_hardware_register: Getreg, # Select among free hardware registers.
# pick_available_hardware_register_by_round_robin_g is from src/lib/compiler/back/low/regor/pick-available-hardware-register-by-round-robin-g.pkg copy_instr: flo::spl::Copy_Instr, # How to make a copy.
spill: flo::spl::Spill, # Spill callback.
spill_src: flo::spl::Spill_Src, # Spill callback.
spill_copy_tmp: flo::spl::Spill_Copy_Tmp, # Spill callback.
reload: flo::spl::Reload, # Reload callback.
reload_dst: flo::spl::Reload_Dst, # Reload callback.
rename_src: flo::spl::Rename_Src, # Rename callback.
mode: Mode # Mode.
};
solve_register_allocation_problems
:
List( Register_Allocation_Problem )
->
flo::Machcode_Controlflow_Graph
->
flo::Machcode_Controlflow_Graph;
};
end;