Trouble understanding reload dump file format..

[Ulrich Weigand]

Dave Korn wrote:

> (define_insn "mulsi3"
>   [(set (match_operand:SI 0 "register_operand" "=d")
>         (mult:SI (match_operand:SI 2 "register_operand" "r")
>                  (match_operand:SI 1 "register_operand" "a")))
>    (clobber (match_scratch:SI 3 "b"))]

You should be using "=b" to designate the operand as *output* only.

Otherwise, reload will attempt (unsuccessfully) to load up "scratch:SI"
as input value ...

B.t.w. if the register class denoted by "b" has just a single 
element, you might just as well use the hard reg directly in
the insn pattern here.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com