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Re: Vector permutation support for x86
-;; Note the instruction does not allow the value being added to be a memory
-;; operation. However by pretending via the nonimmediate_operand predicate
-;; that it does and splitting it later allows the following to be recognized:
-;; a[i] = b[i] * c[i] + d[i];
(define_insn "xop_pmacsww"
[(set (match_operand:V8HI 0 "register_operand" "=x")
(plus:V8HI
(mult:V8HI
- (match_operand:V8HI 1 "register_operand" "%x")
+ (match_operand:V8HI 1 "nonimmediate_operand" "%x")
(match_operand:V8HI 2 "nonimmediate_operand" "xm"))
- (match_operand:V8HI 3 "register_operand" "x")))]
+ (match_operand:V8HI 3 "nonimmediate_operand" "x")))]
I think the comment is still valuable, minus the subclause about
splitting. Because otherwise I would question the use of
nonimmediate_operand in op3.
However, I do not believe that the same applies to any of the
non-multiply-add patterns. E.g.
(define_insn "xop_pperm"
[(set (match_operand:V16QI 0 "register_operand" "=x,x")
(unspec:V16QI
- [(match_operand:V16QI 1 "register_operand" "x,x")
+ [(match_operand:V16QI 1 "nonimmediate_operand" "x,x")
There's really no reason to accept a memory operand here, AFAICS.
Similarly with all of the patterns that follow.
r~