Hi,
Ignore the previous message.
Attached please find the updated patch.
Bootstrapped on x86_64-suse-linux. Please apply this patch if OK for trunk.
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 215500)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,8 @@
+2014-09-23 Felix Yang <[email protected]>
+
+ * ira.c (update_equiv_regs): Check all definitions for a multiple-set
+ register to make sure that the RHS have the same value.
+
2014-09-23 Ilya Enkovich <[email protected]>
* cfgcleanup.c (try_optimize_cfg): Do not remove label
Index: gcc/ira.c
===================================================================
--- gcc/ira.c (revision 215500)
+++ gcc/ira.c (working copy)
@@ -3467,16 +3467,43 @@ update_equiv_regs (void)
if (note && GET_CODE (XEXP (note, 0)) == EXPR_LIST)
note = NULL_RTX;
- if (DF_REG_DEF_COUNT (regno) != 1
- && (! note
+ if (DF_REG_DEF_COUNT (regno) != 1)
+ {
+ rtx list;
+ bool equal_p = true;
+
+ if (! note
|| rtx_varies_p (XEXP (note, 0), 0)
|| (reg_equiv[regno].replacement
&& ! rtx_equal_p (XEXP (note, 0),
- reg_equiv[regno].replacement))))
- {
- no_equiv (dest, set, NULL);
- continue;
+ reg_equiv[regno].replacement)))
+ {
+ no_equiv (dest, set, NULL);
+ continue;
+ }
+
+ list = reg_equiv[regno].init_insns;
+ for (; list; list = XEXP (list, 1))
+ {
+ rtx note_tmp, insn_tmp;
+ insn_tmp = XEXP (list, 0);
+ note_tmp = find_reg_note (insn_tmp, REG_EQUAL, NULL_RTX);
+
+ if (note_tmp == 0
+ || ! rtx_equal_p (XEXP (note, 0), XEXP (note_tmp, 0)))
+ {
+ equal_p = false;
+ break;
+ }
+ }
+
+ if (! equal_p)
+ {
+ no_equiv (dest, set, NULL);
+ continue;
+ }
}
+
/* Record this insn as initializing this register. */
reg_equiv[regno].init_insns
= gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv[regno].init_insns);
Cheers,
Felix
On Tue, Sep 23, 2014 at 6:45 PM, Felix Yang <[email protected]> wrote:
> Hi,
> Attached please fined the updated patch.
>
> Cheers,
> Felix
>
>
> On Tue, Sep 23, 2014 at 10:48 AM, Yangfei (Felix) <[email protected]>
> wrote:
>>> On 09/22/14 08:40, Felix Yang wrote:
>>> > Hi,
>>> >
>>> > I find that update_equiv_regs in ira.c sets the wrong EQUIV
>>> > reg-note for pseudo with more than one definiton in certain situation.
>>> > Here is a simplified RTL snippet after this function finishs
>>> > handling:
>>> >
>>> > (insn 77 37 78 2 (set (reg:SI 171)
>>> > (const_int 0 [0])) ticket151.c:33 52 {movsi_internal_dsp}
>>> > (expr_list:REG_EQUAL (const_int 0 [0])
>>> > (nil)))
>>> >
>>> > ......
>>> >
>>> > (insn 79 50 53 2 (set (mem/c:SI (reg/f:SI 136) [2 g_728+0 S4 A64])
>>> > (reg:SI 171)) ticket151.c:33 52 {movsi_internal_dsp}
>>> > (expr_list:REG_DEAD (reg:SI 171)
>>> > (nil)))
>>> > (insn 53 79 54 2 (set (mem/c:SI (reg/f:SI 162) [4 g_163+0 S4 A32])
>>> > (reg:SI 163)) 52 {movsi_internal_dsp}
>>> > (expr_list:REG_DEAD (reg:SI 163)
>>> > (expr_list:REG_DEAD (reg/f:SI 162)
>>> > (nil))))
>>> > (insn 54 53 14 2 (set (reg:SI 171)
>>> > (mem/u/c:SI (symbol_ref/u:SI ("*.LC8") [flags 0x2]) [4 S4
>>> > A32])) ticket151.c:49 52 {movsi_internal_dsp}
>>> > (expr_list:REG_EQUIV (mem/u/c:SI (symbol_ref/u:SI ("*.LC8")
>>> > [flags 0x2]) [4 S4 A32])
>>> > (expr_list:REG_EQUAL (mem/u/c:SI (symbol_ref/u:SI ("*.LC8")
>>> > [flags 0x2]) [4 S4 A32])
>>> > (nil))))
>>> >
>>> >
>>> > The REG_EQUIV of insn 54 is not correct as pseudo 171 is defined
>>> > in insn 77 with a differerent value.
>>> > This may causes reload replacing pseudo 171 with mem/u/c:SI
>>> > (symbol_ref/u:SI ("*.LC8"), which is wrong.
>>> > A proposed patch for this issue, please comment:
>>> Is it possible it's the conditional just above this one that is incorrect?
>>>
>>> if (DF_REG_DEF_COUNT (regno) != 1
>>> && (! note
>>> || rtx_varies_p (XEXP (note, 0), 0)
>>> || (reg_equiv[regno].replacement
>>> && ! rtx_equal_p (XEXP (note, 0),
>>>
>>> reg_equiv[regno].replacement))))
>>> {
>>> no_equiv (dest, set, NULL);
>>> continue;
>>> }
>>>
>>>
>>> ISTM the only time a multiply-set register can have a valid REG_EQUIV note
>>> is if
>>> each and every assignment to that pseudo has the same RHS.
>>>
>>> Jeff
>>
>>
>> Thanks Jeff. Yes, I agree that this is a better place to consider. I am
>> thinking of a better way to fix this.
>>
>> Vladimir, can you shed light on this and give me some suggestions? Thank you.
>>
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 215500)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,8 @@
+2014-09-23 Felix Yang <[email protected]>
+
+ * ira.c (update_equiv_regs): Check all definitions for a multiple-set
+ register to make sure that the RHS have the same value.
+
2014-09-23 Ilya Enkovich <[email protected]>
* cfgcleanup.c (try_optimize_cfg): Do not remove label
Index: gcc/ira.c
===================================================================
--- gcc/ira.c (revision 215500)
+++ gcc/ira.c (working copy)
@@ -3467,16 +3467,43 @@ update_equiv_regs (void)
if (note && GET_CODE (XEXP (note, 0)) == EXPR_LIST)
note = NULL_RTX;
- if (DF_REG_DEF_COUNT (regno) != 1
- && (! note
+ if (DF_REG_DEF_COUNT (regno) != 1)
+ {
+ rtx list;
+ bool equal_p = true;
+
+ if (! note
|| rtx_varies_p (XEXP (note, 0), 0)
|| (reg_equiv[regno].replacement
&& ! rtx_equal_p (XEXP (note, 0),
- reg_equiv[regno].replacement))))
- {
- no_equiv (dest, set, NULL);
- continue;
+ reg_equiv[regno].replacement)))
+ {
+ no_equiv (dest, set, NULL);
+ continue;
+ }
+
+ list = reg_equiv[regno].init_insns;
+ for (; list; list = XEXP (list, 1))
+ {
+ rtx note_tmp, insn_tmp;
+ insn_tmp = XEXP (list, 0);
+ note_tmp = find_reg_note (insn_tmp, REG_EQUAL, NULL_RTX);
+
+ if (note_tmp == 0
+ || ! rtx_equal_p (XEXP (note, 0), XEXP (note_tmp, 0)))
+ {
+ equal_p = false;
+ break;
+ }
+ }
+
+ if (! equal_p)
+ {
+ no_equiv (dest, set, NULL);
+ continue;
+ }
}
+
/* Record this insn as initializing this register. */
reg_equiv[regno].init_insns
= gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv[regno].init_insns);
