compiler: compact D registers.

We now have some constant folding in the optimizer too, not
just in the front end compiler pass. This is leaving behind
dead D registers that are not referenced in the code.
Let's compact the D register table to close the gap.

* stdlib/compiler.tl (compiler get-dreg): In this function
we no longer check that we have allocated too many D
registers.  We let the counter blow past %lev-size%.
Because this creates the fighting chance that the compaction
of D regs will reduce their number to %lev-size% or less.
By doing this, we allow code to be compilable that otherwise
would not be: code that allocates too many D regs which
are then optimized away.
(compiler compact-dregs): New function. Does all the work.
(compiler optimize): Compact the D regs at optimization
level 5 or higher.
(compile-toplevel): Check for an overflowing D reg count
here, after optimization.

* stdlib/optimize.tl (basic-blocks null-unused-data):
Here, we no longer have to do anything with the D registers.

0 files changed, 0 insertions, 0 deletions