diff mbox series

cselib: Skip BImode while keeping track of subvalue relations [PR107088]

Message ID 20221004112849.27678-1-stefansf@linux.ibm.com
State New
Headers show
Series cselib: Skip BImode while keeping track of subvalue relations [PR107088] | expand

Commit Message

Stefan Schulze Frielinghaus Oct. 4, 2022, 11:28 a.m. UTC 
For BImode get_narrowest_mode evaluates to QImode but BImode < QImode.
Thus FOR_EACH_MODE_UNTIL never reaches BImode and iterates until OImode
for which no wider mode exists so we end up with VOIDmode and fail.
Fixed by adding a size guard so we effectively skip BImode.

Bootstrap and regtest are currently running on x64.  Assuming they pass
ok for mainline?

gcc/ChangeLog:

	PR rtl-optimization/107088
	* cselib.cc (new_cselib_val): Skip BImode while keeping track of
	subvalue relations.
---
 gcc/cselib.cc | 1 +
 1 file changed, 1 insertion(+)

Comments

Jeff Law Oct. 6, 2022, 2:48 a.m. UTC | #1 
On 10/4/22 05:28, Stefan Schulze Frielinghaus via Gcc-patches wrote:
> For BImode get_narrowest_mode evaluates to QImode but BImode < QImode.
> Thus FOR_EACH_MODE_UNTIL never reaches BImode and iterates until OImode
> for which no wider mode exists so we end up with VOIDmode and fail.
> Fixed by adding a size guard so we effectively skip BImode.
>
> Bootstrap and regtest are currently running on x64.  Assuming they pass
> ok for mainline?
>
> gcc/ChangeLog:
>
> 	PR rtl-optimization/107088
> 	* cselib.cc (new_cselib_val): Skip BImode while keeping track of
> 	subvalue relations.

OK.  And FWIW, this fixes the various failures I saw in my tester due to 
the cselib patches.


jeff
Stefan Schulze Frielinghaus Oct. 6, 2022, 7:06 a.m. UTC | #2 
On Wed, Oct 05, 2022 at 08:48:13PM -0600, Jeff Law via Gcc-patches wrote:
> 
> On 10/4/22 05:28, Stefan Schulze Frielinghaus via Gcc-patches wrote:
> > For BImode get_narrowest_mode evaluates to QImode but BImode < QImode.
> > Thus FOR_EACH_MODE_UNTIL never reaches BImode and iterates until OImode
> > for which no wider mode exists so we end up with VOIDmode and fail.
> > Fixed by adding a size guard so we effectively skip BImode.
> > 
> > Bootstrap and regtest are currently running on x64.  Assuming they pass
> > ok for mainline?
> > 
> > gcc/ChangeLog:
> > 
> > 	PR rtl-optimization/107088
> > 	* cselib.cc (new_cselib_val): Skip BImode while keeping track of
> > 	subvalue relations.
> 
> OK.  And FWIW, this fixes the various failures I saw in my tester due to the
> cselib patches.

Thanks for testing, too!  Out of curiosity which target is your tester?
I gave it a try on x64 and AArch64 for which bootstrap went fine and
regtest showed no difference, and of course, for s390x regtest went for
the better.
Jeff Law Oct. 7, 2022, 2:15 p.m. UTC | #3 
On 10/6/22 01:06, Stefan Schulze Frielinghaus wrote:
> On Wed, Oct 05, 2022 at 08:48:13PM -0600, Jeff Law via Gcc-patches wrote:
>> On 10/4/22 05:28, Stefan Schulze Frielinghaus via Gcc-patches wrote:
>>> For BImode get_narrowest_mode evaluates to QImode but BImode < QImode.
>>> Thus FOR_EACH_MODE_UNTIL never reaches BImode and iterates until OImode
>>> for which no wider mode exists so we end up with VOIDmode and fail.
>>> Fixed by adding a size guard so we effectively skip BImode.
>>>
>>> Bootstrap and regtest are currently running on x64.  Assuming they pass
>>> ok for mainline?
>>>
>>> gcc/ChangeLog:
>>>
>>> 	PR rtl-optimization/107088
>>> 	* cselib.cc (new_cselib_val): Skip BImode while keeping track of
>>> 	subvalue relations.
>> OK.  And FWIW, this fixes the various failures I saw in my tester due to the
>> cselib patches.
> Thanks for testing, too!  Out of curiosity which target is your tester?
> I gave it a try on x64 and AArch64 for which bootstrap went fine and
> regtest showed no difference, and of course, for s390x regtest went for
> the better.

It's got at least one representative from most of the targets supported 
by gcc.


http://law-sandy.freeddns.org:8080 will get you to the jenkins instance.


Jeff
diff mbox series

Patch

diff --git a/gcc/cselib.cc b/gcc/cselib.cc
index 9b582e5d3d6..2abc763a3f8 100644
--- a/gcc/cselib.cc
+++ b/gcc/cselib.cc
@@ -1571,6 +1571,7 @@  new_cselib_val (unsigned int hash, machine_mode mode, rtx x)
 
   scalar_int_mode int_mode;
   if (REG_P (x) && is_int_mode (mode, &int_mode)
+      && GET_MODE_SIZE (int_mode) > 1
       && REG_VALUES (REGNO (x)) != NULL
       && (!cselib_current_insn || !DEBUG_INSN_P (cselib_current_insn)))
     {