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separate LA from LI; improve LI logic

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Connor Olding 2015-12-02 10:06:18 -08:00
parent efe3864814
commit c2f436a161
1 changed files with 28 additions and 13 deletions
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41
lips.lua
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@ -972,7 +972,7 @@ function Parser:instruction()
if h == nil then
self:error('undefined instruction')
elseif h == 'LI' or h == 'LA' then
elseif h == 'LI' then
local lui = instructions['LUI']
local ori = instructions['ORI']
local addiu = instructions['ADDIU']
@ -981,32 +981,47 @@ function Parser:instruction()
self:optional_comma()
local im = self:const()
local is_label = im[1] == 'LABELSYM'
-- for us, this is just semantics. for a "real" assembler,
-- LA could add an appropriate RELO directive.
if h == 'LI' and is_label then
if im[1] == 'LABELSYM' then
self:error('use LA for labels')
end
if h == 'LA' and not is_label then
self:error('use LI for immediates')
end
if not is_label then
im[2] = im[2] % 0x100000000
end
if is_label or (im[2] >= 0x8000 and im[2] <= 0xFFFF8000) then
im[2] = im[2] % 0x100000000
if im[2] >= 0x10000 and im[2] <= 0xFFFF8000 then
args.rs = args.rt
args.immediate = {'UPPER', im}
self:format_out(lui[3], lui[1], args, lui[4], lui[5])
if is_label or im[2] % 0x10000 ~= 0 then
if im[2] % 0x10000 ~= 0 then
args.immediate = {'LOWER', im}
self:format_out(ori[3], ori[1], args, ori[4], ori[5])
end
elseif im[2] >= 0x8000 and im[2] < 0x10000 then
args.rs = 'R0'
args.immediate = {'LOWER', im}
self:format_out(ori[3], ori[1], args, ori[4], ori[5])
else
args.rs = 'R0'
args.immediate = {'LOWER', im}
self:format_out(addiu[3], addiu[1], args, addiu[4], addiu[5])
end
elseif h == 'LA' then
local lui = instructions['LUI']
local addiu = instructions['ADDIU']
args.rt = self:register()
self:optional_comma()
local im = self:const()
-- for us, this is just semantics. for a "real" assembler,
-- LA could add appropriate RELO LUI/ADDIU directives.
-- for that reason, we should always use the respective instructions.
if im[1] ~= 'LABELSYM' then
self:error('use LI for immediates')
end
args.rs = args.rt
args.immediate = {'UPPEROFF', im}
self:format_out(lui[3], lui[1], args, lui[4], lui[5])
args.immediate = {'LOWER', im}
self:format_out(addiu[3], addiu[1], args, addiu[4], addiu[5])
elseif h == 'NAND' then
local and_ = instructions['AND']
local nor = instructions['NOR']