On 19/10/2020 13:53, Henri Cloetens wrote:
> Hello all,
>
> I am building a gcc 9.2.0 custom compiler, and I am running in an issue
> during step 263, combine.
>
> Before combine:
>
> /(insn 2354 2352 1743 175 (set (reg/v:SI 197 [ dig ])//
> // (if_then_else (eq (subreg:QI (reg:SI 632) 1)//
Your problem is likely here, on the input. The SET_SRC (the
if_then_else) of the pattern should have the same mode as the SET_DEST,
unless the SET_SRC is a CONST_INT.
R.
> // (const_int 1 [0x1]))//
> // (reg:SI 708)//
> // (reg/v:SI 197 [ dig ])))
> "/home/henri/blueICe/gcc/newlib/newlib/libc/stdlib/dtoa.c":771:6 35
> {select_internal3}//
> // (expr_list:REG_DEAD (reg:SI 708)//
> // (expr_list:REG_DEAD (reg:SI 632)//
> // (nil))))//
> //(insn 1743 2354 124 175 (set (mem:QI (reg:SI 316 [ ivtmp.118 ]) [0
> *s_304+0 S1 A8])//
> // (subreg:QI (reg/v:SI 197 [ dig ]) 0))
> "/home/henri/blueICe/gcc/newlib/newlib/libc/stdlib/dtoa.c":772:13 6
> {movqi_internal}//
> // (expr_list:REG_DEAD (reg:SI 316 [ ivtmp.118 ])//
> // (expr_list:REG_DEAD (reg/v:SI 197 [ dig ])//
> // (nil))))/
>
> This is during the combine-step transformed into:
>
> /(insn 1743 2354 124 175 (set (mem:QI (reg:SI 316 [ ivtmp.118 ]) [0
> *s_304+0 S1 A8])//
> // (subreg:QI (if_then_else (eq (subreg:QI (reg:SI 632) 1)//
> // (const_int 1 [0x1]))//
> // (reg:SI 708)//
> // (reg/v:SI 197 [ dig ])) 0))
> "/home/henri/blueICe/gcc/newlib/newlib/libc/stdlib/dtoa.c":772:13 6
> {movqi_internal}//
> // (expr_list:REG_DEAD (reg:SI 316 [ ivtmp.118 ])//
> // (expr_list:REG_DEAD (reg/v:SI 197 [ dig ])//
> // (nil))))/
>
> This, of course, is not correct any more. Now, how should I prevent this
> ?, the pattern is defined in the .md-file as:
>
> /(define_insn "movqi_internal" //
> //[(set (match_operand:QI 0 "movqi_operand_0"
> "=r,r,r,r,r,r,u,u,W,t,r,c,*c*l,*h,*h,y")//
> //(match_operand:QI 1 "movqi_operand_1" "O,k,i,r,W,t,W,t,r,r,*h,u, r,
> r, 0,y"))]/
>
> /.../
> and /movqi_operand_1/ is defined as:
>
> /(define_predicate "movqi_operand_1"//
> // (ior (match_operand 0 "gpc_reg_operand")//
> // (ior (match_operand 0
> "quarterword_offset21_memref_operand_or_indirect")//
> // (match_operand 0 "immediate_operand"))))/
>
>
> and /gpc_reg_operand/ as:
>
> /(define_predicate "gpc_reg_operand"//
> // (and (match_operand 0 "register_operand")//
> // (match_test "(GET_CODE (op) != REG && GET_CODE(op) != SUBREG//
> // || (REGNO (op) >= ARG_POINTER_REGNUM//
> // && !CA_REGNO_P (REGNO (op)))//
> // || REGNO (op) == SFP_REGNO//
> // || REGNO (op) == ARG_POINTER_REGNUM//
> // || REGNO (op) <= MAX_REGFILE_REGNO)")))/
>
> Any of you any idea why the combine succeeds ?. I mean, it should fail
> !. After combine, it does not match /movqi_internal/ pattern
> any more, but the compiler seems to think otherwise !.
>
> Best Regards,
>
> Henri.
>
>
