[Bug target/77308] surprisingly large stack usage for sha512 on arm

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77308

--- Comment #31 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
Sure, combine cant help, especially because it runs before split1.

But I wondered why this peephole2 is not enabled:

(define_peephole2 ; ldrd
  [(set (match_operand:SI 0 "arm_general_register_operand" "")
        (match_operand:SI 2 "memory_operand" ""))
   (set (match_operand:SI 1 "arm_general_register_operand" "")
        (match_operand:SI 3 "memory_operand" ""))]
  "TARGET_LDRD
     && current_tune->prefer_ldrd_strd
     && !optimize_function_for_size_p (cfun)"
  [(const_int 0)]


I have -march=armv7-a / -mcpu=cortex-a9 and thus for me
current_tune-> prefer_ldrd_strd is FALSE.

Furthermore, if I want to do -Os the third condition is FALSE too.
But one ldrd must be shorter than two ldr ?

That seems wrong...