[Bug target/31137] New: missing "break" in switch for MULT in avr_rtx_costs

[Bug target/31137] New: missing "break" in switch for MULT in avr_rtx_costs

[christer at weinigel dot se]

I have just started reading the gcc code a bit, and while looking at the avr
port I noticed that in the function avr_rtx_costs in avr.c there is some code
to calculate the cost of a multiplication:

    case MULT:
      switch (mode)
        {
        case QImode:
          if (AVR_HAVE_MUL)
            *total = COSTS_N_INSNS (optimize_size ? 3 : 4);
          else if (optimize_size)
            *total = COSTS_N_INSNS (AVR_MEGA ? 2 : 1);
          else
            return false;

        case HImode:
          if (AVR_HAVE_MUL)
            *total = COSTS_N_INSNS (optimize_size ? 7 : 10);
          else if (optimize_size)
            *total = COSTS_N_INSNS (AVR_MEGA ? 2 : 1);
          else
            return false;

        default:
          return false;
        }
      *total += avr_operand_rtx_cost (XEXP (x, 0), mode, code);
      *total += avr_operand_rtx_cost (XEXP (x, 1), mode, code);
      return true;

if AVR_HAVE_MUL is true, the above code will be equal to the following:

    case MULT:
      switch (mode)
        {
        case QImode:
          *total = COSTS_N_INSNS (optimize_size ? 3 : 4);

        case HImode:
          *total = COSTS_N_INSNS (optimize_size ? 7 : 10);

        default:
          return false;
        }
      *total += avr_operand_rtx_cost (XEXP (x, 0), mode, code);
      *total += avr_operand_rtx_cost (XEXP (x, 1), mode, code);
      return true;

which I belive is incorrect since it means that the assignments to *total in
the switch statement are useless.  It probably doesn't break anything serious
but might give slightly worse optimizations.


-- 
           Summary: missing "break" in switch for MULT in avr_rtx_costs
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: christer at weinigel dot se
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: avr-unknown-none


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[eweddington at cso dot atmel dot com]

------- Comment #1 from eweddington at cso dot atmel dot com  2007-03-16 21:34 -------
Created an attachment (id=13217)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13217&action=view)
Patch to add in the missing break statements.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[aesok at gcc dot gnu dot org]

------- Comment #2 from aesok at gcc dot gnu dot org  2007-04-02 22:44 -------
Subject: Bug 31137

Author: aesok
Date: Mon Apr  2 22:43:53 2007
New Revision: 123437

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123437
Log:
        PR target/31137
        * config/avr/avr.c (avr_rtx_costs): Add missing 'break' statements.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/avr/avr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[aesok at gcc dot gnu dot org]

------- Comment #3 from aesok at gcc dot gnu dot org  2007-04-02 22:53 -------
Subject: Bug 31137

Author: aesok
Date: Mon Apr  2 22:53:14 2007
New Revision: 123438

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123438
Log:
        PR target/31137
        * config/avr/avr.c (avr_rtx_costs): Add missing 'break' statements.

Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/config/avr/avr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[aesok at gcc dot gnu dot org]

------- Comment #4 from aesok at gcc dot gnu dot org  2007-04-02 23:00 -------
Subject: Bug 31137

Author: aesok
Date: Mon Apr  2 23:00:28 2007
New Revision: 123439

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123439
Log:
        PR target/31137
        * config/avr/avr.c (avr_rtx_costs): Add missing 'break' statements.



Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/config/avr/avr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[aesok at gcc dot gnu dot org]

------- Comment #5 from aesok at gcc dot gnu dot org  2007-04-02 23:03 -------
Fixed.


-- 

aesok at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137

[Bug target/31137] missing "break" in switch for MULT in avr_rtx_costs

[eweddington at cso dot atmel dot com]

-- 

eweddington at cso dot atmel dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31137