Hello,
Thanks for the quick ok. Yes, I ran into this with out of tree patches
(my new delay slot scheduling pass, based on cfg, DF, and sched-deps).
The problem only happens with hard regs and I think that of the
existing users of these functions only the mips.c ones maybe are
buggy.
Ciao!
Steven
On 4/11/13, Paolo Bonzini <bonz...@gnu.org> wrote:
> Il 10/04/2013 21:33, Steven Bosscher ha scritto:
>> Hello,
>>
>> df_find_def and df_find_use do not work properly for hard registers
>> because rtx_equal_p returns false for the case where
>> REGNO(x)==REGNO(y) but the modes are different. This happened as
>> follows in my case:
>>
>> Breakpoint 9, df_reg_used (insn=0x3fffb6083c50, reg=0x3fffb5eb72e0) at
>> ../../trunk/gcc/df-core.c:1856
>> 1856 return df_find_use (insn, reg) != NULL;
>> (gdb) p debug_rtx(reg)
>> (reg:CCX 100 %icc)
>> $37 = void
>> (gdb) p debug_rtx(insn)
>> (jump_insn 34 33 35 3 (set (pc)
>> (if_then_else (le (reg:CCX 100 %icc)
>> (const_int 0 [0]))
>> (label_ref 44)
>> (pc))) t.c:25 48 {*normal_branch}
>> (expr_list:REG_DEAD (reg:CCX 100 %icc)
>> (expr_list:REG_BR_PROB (const_int 3900 [0xf3c])
>> (nil)))
>> -> 44)
>> $38 = void
>> (gdb) step
>> df_find_use (insn=0x3fffb6083c50, reg=0x3fffb5eb72e0) at
>> ../../trunk/gcc/df-core.c:1829
>> ...
>> 1837 if (rtx_equal_p (DF_REF_REAL_REG (use), reg))
>> (gdb) p debug_rtx(reg)
>> (reg:CCX 100 %icc)
>> $39 = void
>> (gdb) p debug_rtx(DF_REF_REAL_REG(use))
>> (reg:CC 100 %icc)
>> $40 = void
>> (gdb) p rtx_equal_p (DF_REF_REAL_REG (use), reg)
>> $41 = 0
>>
>>
>> I think we should just compare REGNO instead of going through
>> rtx_equal_p.
>>
>> Bootstrapped&tested on x86_64-unknown-linux-gnu.
>> OK for trunk?
>
> Ok. Was this with out-of-tree patches?
>
> Paolo
>
>> Ciao!
>> Steven
>>
>>
>>
>> * df-core.c (df_find_def): Compare register numbers.
>> (df_find_use): Compare register numbers.
>>
>> Index: df-core.c
>> ===================================================================
>> --- df-core.c (revision 197610)
>> +++ df-core.c (working copy)
>> @@ -1800,7 +1800,7 @@ df_find_def (rtx insn, rtx reg)
>> for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
>> {
>> df_ref def = *def_rec;
>> - if (rtx_equal_p (DF_REF_REAL_REG (def), reg))
>> + if (DF_REF_REGNO (def) == REGNO (reg))
>> return def;
>> }
>>
>> @@ -1834,14 +1834,14 @@ df_find_use (rtx insn, rtx reg)
>> for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
>> {
>> df_ref use = *use_rec;
>> - if (rtx_equal_p (DF_REF_REAL_REG (use), reg))
>> + if (DF_REF_REGNO (use) == REGNO (reg))
>> return use;
>> }
>> if (df->changeable_flags & DF_EQ_NOTES)
>> for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++)
>> {
>> df_ref use = *use_rec;
>> - if (rtx_equal_p (DF_REF_REAL_REG (use), reg))
>> + if (DF_REF_REGNO (use) == REGNO (reg))
>> return use;
>> }
>> return NULL;
>>
>
>
