[Bug target/69810] PowerPC64: unrecognizable insn

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69810

--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> ---
The patch introducing the EXTQI stuff did

-(define_insn ""
-  [(set (match_operand:CC 2 "cc_reg_operand" "=x,?y")
-       (compare:CC (sign_extend:HI (match_operand:QI 1 "gpc_reg_operand"
"r,r")
-                   (const_int 0)))
-   (set (match_operand:HI 0 "gpc_reg_operand" "=r,r")
-       (sign_extend:HI (match_dup 1)))]
-  ""
-  "@
-   extsb. %0,%1
-   #"
-  [(set_attr "type" "compare")
-   (set_attr "length" "4,8")])
-
-(define_split
-  [(set (match_operand:CC 2 "cc_reg_not_micro_cr0_operand" "")
-       (compare:CC (sign_extend:HI (match_operand:QI 1 "gpc_reg_operand" ""))
-                   (const_int 0)))
-   (set (match_operand:HI 0 "gpc_reg_operand" "")
-       (sign_extend:HI (match_dup 1)))]
-  "reload_completed"
-  [(set (match_dup 0)
-       (sign_extend:HI (match_dup 1)))
-   (set (match_dup 2)
-       (compare:CC (match_dup 0)
-                   (const_int 0)))]
-  "")

so this problem is older.

Extending _to_ HImode doesn't make much sense (like doing any other
non-memory operation in HImode, and it can always be expressed with
a subreg:SI.  David, I think your patch is just right :-)