On 02/03/15 17:38, Ilya Tocar wrote:
On 02 Mar 15:22, Kyrill Tkachov wrote:
Hi all,
I'm looking at using the define_subst machinery to auto-generate
zero-extended
versions of some patterns, for example having:
(set reg:SI
(xor:SI a:SI b:SI))
generate a pattern of the form:
(set reg:DI
(zero_extend:DI
(xor:SI (a:SI b:SI))))
How do I go about achieving this? From the documentation, I think I need
something like:
(define_subst "add_z_extend"
[(set (match_operand:SI 0 "" "")
(match_operand:SI 1 "" ""))]
""
[(set (match_dup 0)
(zero_extend:DI (match_dup 1)))]
but in the resultant pattern I need operand 0 to be tranfsormed into DImode.
Is there a way to write that?
Can't you just use [(set (match_operand:DI 0 "" "")... instead of
match_dup?
So, something like:
(define_subst "add_z_extend"
[(set (match_operand:SI 0 "" "")
(match_operand:SI 1 "" ""))]
""
[(set (match_operand:DI 0 "" "")
(zero_extend:DI (match_dup 1)))]
?
Are we allowed to match an operand twice?
