[Bug rtl-optimization/87874] [8/9 Regression] ICE in simplify_subreg, at simplify-rtx.c:6396

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87874

--- Comment #5 from Alexandre Oliva  ---
Author: aoliva
Date: Wed Nov  7 06:25:30 2018
New Revision: 265860

URL: https://gcc.gnu.org/viewcvs?rev=265860=gcc=rev
Log:
[PR87874] avoid const-wide-int subreg in LRA

Just like CONST_INT, CONST_WIDE_INT is VOIDmode, so LRA might be
tempted to build a SUBREG to "convert" it to the wanted mode.  That's
no use.  Test for CONST_SCALAR_INT_P instead of CONST_INT_P so that we
skip the subreg creation for both.

for  gcc/ChangeLog

PR rtl-optimization/87874
* lra.c (lra_substitute_pseudo): Do not create a subreg for
const wide ints.

for  gcc/testsuite/ChangeLog

PR rtl-optimization/87874
* gcc.dg/pr87874.c: New.

Added:
trunk/gcc/testsuite/gcc.dg/pr87874.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/lra.c
trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/87874] [8/9 Regression] ICE in simplify_subreg, at simplify-rtx.c:6396

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87874

--- Comment #4 from Alexandre Oliva  ---
https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00332.html

[Bug rtl-optimization/87874] [8/9 Regression] ICE in simplify_subreg, at simplify-rtx.c:6396

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87874

--- Comment #3 from Alexandre Oliva  ---
Created attachment 44961
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44961=edit
candidate patch

[Bug rtl-optimization/87874] [8/9 Regression] ICE in simplify_subreg, at simplify-rtx.c:6396

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87874

Alexandre Oliva  changed:

   What|Removed |Added

 CC||aoliva at gcc dot gnu.org
   Assignee|unassigned at gcc dot gnu.org  |aoliva at gcc dot 
gnu.org

--- Comment #2 from Alexandre Oliva  ---
Mine

[Bug rtl-optimization/87874] [8/9 Regression] ICE in simplify_subreg, at simplify-rtx.c:6396

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87874

Martin Liška  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2018-11-05
 CC||marxin at gcc dot gnu.org
  Known to work||7.2.0
   Target Milestone|--- |8.3
 Ever confirmed|0   |1
  Known to fail||8.2.0, 9.0

--- Comment #1 from Martin Liška  ---
Confirmed, started with my commit r256888, but it was a latent issue before
that.