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Fixed constraint testing in link phase.

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Minimized usage of align offsets during link.
This commit is contained in:
g012 2017-09-20 16:14:48 +02:00
parent 59a2a614ba
commit dbe11c442f
1 changed files with 27 additions and 10 deletions
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37
6502.lua
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@ -70,7 +70,7 @@ M.link = function()
end
table.sort(chunks, function(a,b) return a.size < b.size end)
for chunk_ix,chunk in ipairs(chunks) do
local waste,position = math.maxinteger
local waste,position,position_end = math.maxinteger
local usage_lowest = function(start, finish)
local inc=1
if section.align then
@ -80,20 +80,35 @@ M.link = function()
end
for address=start,finish,inc do
for _,constraint in ipairs(section.constraints) do
local from, to = address+constraint.from, address+constraint.to
if from // 0x100 == to // 0x100 then
local cstart, cfinish = address+constraint.start, address+constraint.finish
if cstart // 0x100 == cfinish // 0x100 then
if constraint.type == 'crosspage' then goto constraints_not_met end
else
if constraint.type == 'samepage' then goto constraints_not_met end
end
end
local w = math.min(address - chunk.start, chunk.size - (address+section.size - chunk.start))
if w < waste then waste=w position=address
elseif w==waste then
-- if waste is the same, keep the one that leaves most aligned addresses for other sections
-- TODO
if position and address>position then waste=w position=address end
local address_end = address+section.size
local w = math.min(address - chunk.start, chunk.size - (address_end - chunk.start))
if w > waste then goto constraints_not_met end
if w==waste then
-- if waste is the same, keep the one that uses the least amount of aligned addresses
local align=0x100
repeat
local cross_count_cur = (position_end+align-1)//align - (position+align-1)//align
if position&(align-1) == 0 then cross_count_cur=cross_count_cur+1 end
local cross_count_new = (address_end+align-1)//align - (address+align-1)//align
if address&(align-1) == 0 then cross_count_new=cross_count_new+1 end
if cross_count_new < cross_count_cur then goto select_pos end
align = align>>1
until align==1
-- if cross count is same, take the one with the most LSB count
local lsb_cur,lsb_new=0,0
for i=0,15 do if position&(1<<i) == 0 then lsb_cur=lsb_cur+1 else break end end
for i=0,15 do if address&(1<<i) == 0 then lsb_new=lsb_new+1 else break end end
if lsb_cur >= lsb_new then goto constraints_not_met end
end
::select_pos::
waste=w position=address position_end=address_end
::constraints_not_met::
end
end
@ -107,6 +122,8 @@ M.link = function()
chunk_reserve(chunk_ix, chunk, position, section.size)
section.org = position
symbols[section.label] = position
--print(section.label, string.format("%04X\t%d", position, section.size))
--for k,v in ipairs(location.chunks) do print(string.format(" %04X %04X %d", v.start, v.size+v.start-1, v.size)) end
goto chunk_located
end
end
@ -242,7 +259,7 @@ M.section = function(t)
local instructions = self.instructions
self.size=0 self.cycles=0
for _,instruction in ipairs(instructions) do
instruction.offset = size
instruction.offset = self.size
local ins_sz = instruction.size or 0
if type(ins_sz) == 'function' then
-- evaluation is needed to get the size (distinguish zpg/abs)