vm/asm/compiler: parametrize display parameters.

In this patch we replace some hard-coded constants related to
the dimensions of the frame display, which will make it
easier to experiment with changes to the configuration:
to set up wider frames at the cost of max display depth.

The encoding of small operands needs to be abstracted because
games can be played here. A 10 bit small operand can be
configured in various ways: for instance a 5:5 split
would mean that the first 32 entries in the first 32 levels
can be small operands. That's independent of the display
configuration.

* share/txr/stdlib/asm.tl: Load vm-param to get some
fundamental constants.
(small-op-p): New macro.
(assembler parse-args, parse-compound-operand, parse-operand,
operand-to-sym): Use constants.
(enc-small-oip, small-op-to-sym): New macros.
(op-frame asm): Use constants. Small range check problem
fixed here: a frame level of 1 mustn't be allowed.
(op-movrs, op-movsr, op-mov-pseudo, op-movsmi, op-movrbi,
op-movi-pseudo, op-retsr, op-retrs, op-retrr, op-ret-pseudo,
op-getv, op-setv): Deal with small operand via functions.
(op-close): Use constants. Off-by-one problem: frame size
of 256 must be allowed.

* share/txr/stdlib/compiler.tl: Load vm-param to get
constants.
(compiler get-dreg, compiler get-funvec): Use constant for max
frame size.
(compiler new-env): Check for maximum levels being exceeded.
(compiler comp-atom): Use constant for maximum immediate
integer operand width.

* share/txr/stdlib/vm-param.tl: New file.

* vm.c (vm_insn_extra_dec_small): New macro.
(VM_LEV_BITS, VM_LEV_MASK, VM_SM_LEV_BITS, VM_SM_LEV_MASK):
New preprocessor constants.
(vm_lev, vm_idx, vm_sm_lev, vm_sm_idx): New macros.
(vm_get, vm_set): Use macros instead of literals.
(vm_sm_get, vm_sm_set): New inline functions.
(vm_movrs, vm_movsr, vm_movsmi, vm_retsr, vm_retrs,
vm_abscsr, vm_get_binding, vm_bindv): Use
vm_sm_get or vm_sm_set to access the display using
the small operand.
(vm_close): Use preprocessor symbols instead  of hard-coded
literals.

0 files changed, 0 insertions, 0 deletions