Re: Why doesn't this pattern match?

[Andras Tantos <andras@tantosonline.com>]

Thanks for the help, that's exactly it!

Andras

On Thu, 2022-01-06 at 20:25 -0800, Andrew Pinski wrote:
> On Thu, Jan 6, 2022 at 8:13 PM Andras Tantos <andras@tantosonline.com
> > wrote:
> > Hello!
> > 
> > My name is Andras Tantos and I just joined this list, so if I'm
> > asking
> > something off-topic or not following the rules of the community,
> > please
> > let me know.
> > 
> > What I'm working on is to port GCC (and Binutils) to a new CPU ISA,
> > I
> > call 'brew'. During developing for this target, I got the following
> > error:
> 
> How are the following constraints defined:
> W,A,B
> 
> Does one include the pc register?
> Otherwise you have a mismatch between the predicate
> brew_general_mov_src_operand (which accepts the pc register) and the
> constraint which does not.
> 
> Thanks,
> Andrew Pinski
> 
> 
> > first.c: In function ‘test_call’:
> > first.c:61:52: error: insn does not satisfy its constraints:
> >    61 | int test_call(int a, int b) { return test_qm(a,b); }
> >       |                                                    ^
> > (insn 25 8 9 (set (reg:SI 6 $r6)
> >         (reg:SI 0 $pc)) "first.c":61:38 17 {*movsi}
> >      (nil))
> > during RTL pass: final
> > first.c:61:52: internal compiler error: in final_scan_insn_1, at
> > final.c:2811
> > 0x6c4c23 _fatal_insn(char const*, rtx_def const*, char const*, int,
> > char const*)
> >         ../../brew-gcc/gcc/rtl-error.c:108
> > 0x6c4c4f _fatal_insn_not_found(rtx_def const*, char const*, int,
> > char
> > const*)
> >         ../../brew-gcc/gcc/rtl-error.c:118
> > 0x643585 final_scan_insn_1
> >         ../../brew-gcc/gcc/final.c:2811
> > 0xb1ef3f final_scan_insn(rtx_insn*, _IO_FILE*, int, int, int*)
> >         ../../brew-gcc/gcc/final.c:2940
> > 0xb1f207 final_1
> >         ../../brew-gcc/gcc/final.c:1997
> > 0xb1fbe6 rest_of_handle_final
> >         ../../brew-gcc/gcc/final.c:4285
> > 0xb1fbe6 execute
> >         ../../brew-gcc/gcc/final.c:4363
> > Please submit a full bug report,
> > with preprocessed source if appropriate.
> > Please include the complete backtrace with any bug report.
> > See <https://gcc.gnu.org/bugs/> for instructions.
> > <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > 
> > Clearly, the compiler couldn't find a rule that works for this
> > register
> > move. The relevant section of the .md file is:
> > 
> > (define_expand "movsi"
> >    [(set (match_operand:SI 0 "general_operand" "")
> >          (match_operand:SI 1 "general_operand" ""))]
> >    ""
> >   "
> > {
> >   /* If this is a store, force the value into a register.  */
> >   if (! (reload_in_progress || reload_completed))
> >   {
> >     if (MEM_P (operands[0]))
> >     {
> >       operands[1] = force_reg (SImode, operands[1]);
> >       if (MEM_P (XEXP (operands[0], 0)))
> >         operands[0] = gen_rtx_MEM (SImode, force_reg (SImode, XEXP
> > (operands[0], 0)));
> >     }
> >     else
> >       if (MEM_P (operands[1])
> >           && MEM_P (XEXP (operands[1], 0)))
> >         operands[1] = gen_rtx_MEM (SImode, force_reg (SImode, XEXP
> > (operands[1], 0)));
> >   }
> > }")
> > 
> > (define_insn "*movsi"
> >   [(set (match_operand:SI 0
> > "nonimmediate_operand"        "=r,r,r,W,A,B,r,r,r")
> >         (match_operand:SI 1 "brew_general_mov_src_operand"
> > "O,r,i,r,r,r,W,A,B"))]
> >   "register_operand (operands[0], SImode)
> >    || register_operand (operands[1], SImode)"
> >   "@
> >    %0 <- %0 - %0
> >    %0 <- %1
> >    %0 <- %1
> >    mem[%0] <- %1
> >    mem[%0] <- %1
> >    mem[%0] <- %1
> >    %0 <- mem[%1]
> >    %0 <- mem[%1]
> >    %0 <- mem[%1]"
> > )
> > <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > 
> > As you can imagine, I'm fairly new to GCC development, so I must be
> > making some rookie mistake here, but I would have thought that the
> > second alternative in the "*movsi" rule above would match the
> > pattern.
> > 
> > brew_general_mov_src_operand is defined as follows:
> > 
> > (define_predicate "brew_general_mov_src_operand"
> >   (match_code
> > "mem,const_int,reg,subreg,symbol_ref,label_ref,const")
> > {
> >   /* Any (MEM LABEL_REF) is OK.  That is a pc-relative load.  */
> >   if (MEM_P (op) && GET_CODE (XEXP (op, 0)) == LABEL_REF)
> >     return 1;
> > 
> >   if (MEM_P (op)
> >       && GET_CODE (XEXP (op, 0)) == PLUS
> >       && GET_CODE (XEXP (XEXP (op, 0), 0)) == REG
> >       && GET_CODE (XEXP (XEXP (op, 0), 1)) == CONST_INT
> >   )
> >     return 1;
> >   /* Any register is good too */
> >   if (REG_P(op))
> >     return 1;
> >   /* PC as source is also acceptable */
> >   if (op == pc_rtx)
> >     return 1;
> >   return general_operand (op, mode);
> > })
> > <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > 
> > Thanks for all the help,
> > Andras
> > 
> >