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Code Issues Releases Wiki Activity

use LI for remaining CALL functionality

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This commit is contained in:
Connor Olding 2016-05-18 02:18:25 -07:00
parent dcdfc22f0a
commit 115bae0689
1 changed files with 65 additions and 44 deletions
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109
lips/overrides.lua
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@ -12,6 +12,40 @@ local function name_pop(name, character)
end
end
local function li(self, buffer, dest, im)
if im.tt == 'LABELSYM' then
local im = self:token(im):set('portion', 'upperoff')
insert(buffer, {'LUI', dest, im})
im = self:token(im):set('portion', 'lower')
insert(buffer, {'ADDIU', dest, dest, im})
return
end
if im.portion then
-- FIXME: use appropriate instruction based on portion?
insert(buffer, {'ADDIU', dest, 'R0', im})
return
end
im.tok = im.tok % 0x100000000
if im.tok >= 0x10000 and im.tok <= 0xFFFF8000 then
local temp = self:token(im):set('portion', 'upper')
insert(buffer, {'LUI', dest, temp})
if im.tok % 0x10000 ~= 0 then
local temp = self:token(im):set('portion', 'lower')
insert(buffer, {'ORI', dest, dest, temp})
end
elseif im.tok >= 0x8000 and im.tok < 0x10000 then
local temp = self:token(im):set('portion', 'lower')
insert(buffer, {'ORI', dest, 'R0', temp})
else
local temp = self:token(im):set('portion', 'lower')
insert(buffer, {'ADDIU', dest, 'R0', temp})
end
return buffer
end
local overrides = {}
-- note: "self" is an instance of Preproc
@ -75,26 +109,9 @@ function overrides:LI(name)
self:error('use LA for labels')
end
if im.portion then
-- FIXME: use appropriate instruction based on portion?
self:push_new('ADDIU', dest, 'R0', im)
return
end
im.tok = im.tok % 0x100000000
if im.tok >= 0x10000 and im.tok <= 0xFFFF8000 then
local temp = self:token(im):set('portion', 'upper')
self:push_new('LUI', dest, temp)
if im.tok % 0x10000 ~= 0 then
local temp = self:token(im):set('portion', 'lower')
self:push_new('ORI', dest, dest, temp)
end
elseif im.tok >= 0x8000 and im.tok < 0x10000 then
local temp = self:token(im):set('portion', 'lower')
self:push_new('ORI', dest, 'R0', temp)
else
local temp = self:token(im):set('portion', 'lower')
self:push_new('ADDIU', dest, 'R0', temp)
local buffer = li(self, {}, dest, im)
for i, v in ipairs(buffer) do
self:push_new(unpack(v))
end
end
@ -102,9 +119,9 @@ function overrides:LA(name)
local dest = self:pop('CPU')
local im = self:pop('CONST')
local im = self:token(im):set('portion', 'upperoff')
im = self:token(im):set('portion', 'upperoff')
self:push_new('LUI', dest, im)
local im = self:token(im):set('portion', 'lower')
im = self:token(im):set('portion', 'lower')
self:push_new('ADDIU', dest, dest, im)
end
@ -154,15 +171,11 @@ function overrides:CALL(name)
local stack = {}
for i, t in ipairs(self.s) do
if i == 1 then
if t.tt == 'LABELSYM' then
func = self:pop()
else
self:error("expected a function to call", t.tok)
end
elseif t.tt == 'NUM' then
insert(stack, self:pop())
else
func = self:pop()
elseif t.tt == 'REG' then
insert(stack, self:pop('CPU'))
else
insert(stack, self:pop())
end
end
if func == nil then
@ -170,45 +183,53 @@ function overrides:CALL(name)
end
local buffer = {}
-- one for each An register
-- keep track of An registers used so that
-- we don't use an overwritten value by mistake.
-- in theory, we could set up something to swap
-- An registers around with the minimum use of AT,
-- but that's more complexity than we need for an edge case.
local used = {false, false, false, false}
local need = {false, false, false, false}
local deref_sp = self:token('DEREF', 'SP')
for i, t in ipairs(stack) do
if t.tt == 'NUM' then
error('TODO')
elseif t.tt == 'REG' then
if t.tt == 'REG' then
if i == 1 and t.tok == 'A0' then -- A0 is already A0, noop.
elseif i == 2 and t.tok == 'A1' then -- etc.
elseif i == 3 and t.tok == 'A2' then
elseif i == 4 and t.tok == 'A3' then
elseif i <= 4 then
-- keep track of An registers used so that
-- we don't use an overwritten value by mistake.
-- in theory, we could set up something to swap
-- An registers around with the minimum use of AT,
-- but that's more complexity than we need for an edge case.
if t.tok:sub(1, 1) == 'A' then
local n = tonumber(t.tok:sub(2, 2))
if used[n + 1] then
self:error("cannot use overwritten register A"..tostring(n), t.tok)
end
end
local reg = 'A'..tostring(i - 1)
insert(buffer, {'MOV', reg, t})
local dest = 'A'..tostring(i - 1)
insert(buffer, {'MOV', dest, t})
used[i] = true
else
local offset = (i - 1) * 4
insert(buffer, {'SW', t, offset, deref_sp})
end
else
if i <= 4 then
local dest = 'A'..tostring(i - 1)
li(self, buffer, dest, t)
used[i] = true
else
local dest = 'AT'
li(self, buffer, dest, t)
local offset = (i - 1) * 4
insert(buffer, {'SW', dest, offset, deref_sp})
end
end
end
-- if there was just one argument (the function/label),
-- then push a NOP to fill the delay slot.
-- (if the user wants to be efficient, they should be using JAL directly)
if #stack == 0 then
if #buffer == 0 then
insert(buffer, {'NOP'})
end
@ -217,8 +238,8 @@ function overrides:CALL(name)
insert(buffer, #buffer, {'JAL', func})
-- finally, write everything out
for i, t in ipairs(buffer) do
self:push_new(unpack(t))
for i, v in ipairs(buffer) do
self:push_new(unpack(v))
end
end