def x86_scas(ctx, i, size):
a = ctx.destination
b = r(ctx.accumulator.name, size)
value = ctx.tmp(size)
result = ctx.tmp(size * 2)
address = ctx.tmp(a.size)
if i.mnemonic.startswith('rep'):
rep_prologue(ctx, i)
ctx.emit( str_ (a, address))
# read the value
ctx.emit( ldm_ (address, value))
# do the comparison and set flags
ctx.emit( sub_ (value, b, result))
arithmetic._sub_set_flags(ctx, a, b, result)
# do the increment/decrement
ctx.emit( jcc_ (r('df', 8), 'decrement'))
ctx.emit('increment')
ctx.emit( add_ (address, imm(value.size // 8, ctx.word_size), address))
ctx.emit( jcc_ (imm(1, 8), 'set'))
ctx.emit('decrement')
ctx.emit( sub_ (address, imm(value.size // 8, ctx.word_size), address))
ctx.emit('set')
ctx.emit( str_ (address, ctx.destination))
if i.mnemonic.startswith('rep'):
rep_epilogue(ctx, i)
def x86_cmps(ctx, i, size):
src = ctx.source
dst = ctx.destination
result = ctx.tmp(size * 2)
value1 = ctx.tmp(size)
address1 = ctx.tmp(src.size)
value2 = ctx.tmp(size)
address2 = ctx.tmp(src.size)
if i.mnemonic.startswith('rep'):
rep_prologue(ctx, i)
# read the values
ctx.emit( str_ (src, address1))
ctx.emit( ldm_ (address1, value1))
ctx.emit( str_ (dst, address2))
ctx.emit( ldm_ (address2, value2))
# do the comparison and set flags
ctx.emit( sub_ (value1, value2, result))
arithmetic._sub_set_flags(ctx, value1, value2, result)
# do the increment/decrement
ctx.emit( jcc_ (r('df', 8), 'decrement'))
ctx.emit('increment')
ctx.emit( add_ (address1, imm(size // 8, ctx.word_size), address1))
ctx.emit( add_ (address2, imm(size // 8, ctx.word_size), address2))
ctx.emit( jcc_ (imm(1, 8), 'set'))
ctx.emit('decrement')
ctx.emit( sub_ (address1, imm(size // 8, ctx.word_size), address1))
ctx.emit( sub_ (address2, imm(size // 8, ctx.word_size), address2))
ctx.emit('set')
ctx.emit( str_ (address1, ctx.source))
ctx.emit( str_ (address2, ctx.destination))
if i.mnemonic.startswith('rep'):
rep_epilogue(ctx, i)
