[Bug tree-optimization/102752] New: [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[Bug tree-optimization/102752] New: [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

            Bug ID: 102752
           Summary: [12 Regression] Recent change to ldist causing ICE on
                    msp430-elf, rl78-elf, and xstormy16-elf
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: law at gcc dot gnu.org
  Target Milestone: ---

After this change:


msp430-elf, rl78-elf and xstormy16-elf are all getting an ICE on
gcc.c-torture/execute/

>From the msp430-elf gcc.log file:

/home/jlaw/jenkins/workspace/msp430-elf/gcc/gcc/testsuite/gcc.c-torture/execute/20100827-1.c:
In function 'foo':^M
/home/jlaw/jenkins/workspace/msp430-elf/gcc/gcc/testsuite/gcc.c-torture/execute/20100827-1.c:3:1:
internal compiler error: tree check: expected class 'type', have 'exceptional'
(ssa_name) in transform_reduction_loop, at tree-loop-distribution.c:3684^M
0x1532ceb tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)^M
        ../../..//gcc/gcc/tree.c:8739^M
0x861c29 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)^M
        ../../..//gcc/gcc/tree.h:3556^M
0x12006d9 loop_distribution::transform_reduction_loop(loop*)^M
        ../../..//gcc/gcc/tree-loop-distribution.c:3684^M
0x1200d92 loop_distribution::execute(function*)^M
        ../../..//gcc/gcc/tree-loop-distribution.c:3776^M
0x12012bd execute^M
        ../../..//gcc/gcc/tree-loop-distribution.c:3901^M
Please submit a full bug report,^M

You should be able to reproduce this with just a cross compiler.  No assembler
or target libraries should be needed.

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

--- Comment #1 from Jeffrey A. Law <law at gcc dot gnu.org> ---
gcc.dg/tree-ssa/pr45427.c shows the same issue.

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[stefansf at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

--- Comment #2 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com> ---
It looks like I missed to take the TREE_TYPE of reduction_var. I just did a
quick test with

diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index fb9250031b5..0559b9c47d7 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -3430,7 +3430,7 @@ generate_strlen_builtin_using_rawmemchr (loop_p loop,
tree reduction_var,
 static bool
 reduction_var_overflows_first (tree reduction_var, tree load_type)
 {
-  widest_int n2 = wi::lshift (1, TYPE_PRECISION (reduction_var));;
+  widest_int n2 = wi::lshift (1, TYPE_PRECISION (TREE_TYPE (reduction_var)));;
   widest_int m2 = wi::lshift (1, TYPE_PRECISION (ptrdiff_type_node) - 1);
   widest_int s = wi::to_widest (TYPE_SIZE_UNIT (load_type));
   return wi::ltu_p (n2, wi::udiv_trunc (m2, s));
@@ -3681,7 +3681,7 @@ loop_distribution::transform_reduction_loop (loop_p loop)
          && ((TYPE_PRECISION (sizetype) >= TYPE_PRECISION (ptr_type_node) - 1
               && TYPE_PRECISION (ptr_type_node) >= 32)
              || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (reduction_var))
-                 && TYPE_PRECISION (reduction_var) <= TYPE_PRECISION
(sizetype)))
+                 && TYPE_PRECISION (TREE_TYPE (reduction_var)) <=
TYPE_PRECISION (sizetype)))
          && builtin_decl_implicit (BUILT_IN_STRLEN))
        generate_strlen_builtin (loop, reduction_var, load_iv.base,
                                 reduction_iv.base, loc);

successfully. It's getting late here. I will come back to this tomorrow
morning. Sorry for the inconvenience.

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

--- Comment #3 from Jeffrey A. Law <law at gcc dot gnu.org> ---
No worries.  This is why we have testing systems.

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-10-14
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #4 from Jeffrey A. Law <law at gcc dot gnu.org> ---
And just an FYI.  That patch fixes the problem on all three affected platforms.
 Assuming it bootstraps and regression tests, consider it pre-approved for the
trunk.

Thanks

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
   Target Milestone|---                         |12.0
           Keywords|                            |ice-on-valid-code

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[stefansf at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

--- Comment #5 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com> ---
Created attachment 51606
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51606&action=edit
Fix determining precission of reduction_var

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[stefansf at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

--- Comment #6 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com> ---
Thanks for confirmation! Bootstrap and regtest are still running on x86 as well
as IBM Z. I will commit the attached patch assuming successful runs.

[Bug tree-optimization/102752] [12 Regression] Recent change to ldist causing ICE on msp430-elf, rl78-elf, and xstormy16-elf

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102752

Jeffrey A. Law <law at gcc dot gnu.org> changed:

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

--- Comment #7 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Fixed on the trunk.