[Bug debug/106418] New: '-fcompare-debug' failure w/ -mcpu=e500mc -O2 -fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks -fno-thread-jumps -fno-tree-dce

[Bug debug/106418] New: '-fcompare-debug' failure w/ -mcpu=e500mc -O2 -fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks -fno-thread-jumps -fno-tree-dce

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106418

            Bug ID: 106418
           Summary: '-fcompare-debug' failure w/ -mcpu=e500mc -O2
                    -fnon-call-exceptions -fsched-stalled-insns
                    -fno-reorder-blocks -fno-thread-jumps -fno-tree-dce
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: compare-debug-failure
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-e300c3-linux-gnu

gcc 13.0.0 20220717 snapshot (g:7bcd7f47359b903bf7a193b95d4450d9d69c60ba) fails
-fcompare-debug check when compiling the following testcase w/ -mcpu=e500mc -O2
-fcompare-debug -fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks
-fno-thread-jumps -fno-tree-dce:

int n;

__attribute__ ((noinline)) int
return_zero (void)
{
  return 0;
}

__attribute__ ((noinline)) int
return_one (void)
{
  return 1;
}

__attribute__ ((noinline)) void
empty (int)
{
}

int
foo (int x)
{
  if (x)
    empty (n);
  else if (return_zero () == n)
    empty (return_one ());

  return 0;
}

% powerpc-e300c3-linux-gnu-gcc-13.0.0 -mcpu=e500mc -O2 -fcompare-debug
-fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks
-fno-thread-jumps -fno-tree-dce -c vjbxa62g.c
powerpc-e300c3-linux-gnu-gcc-13.0.0: error: vjbxa62g.c: '-fcompare-debug'
failure

gkd diff:

--- vjbxa62g.c.gkd      2022-07-23 13:54:24.325382258 +0700
+++ vjbxa62g.gk.c.gkd   2022-07-23 13:54:24.350381830 +0700
@@ -188,22 +188,17 @@
 (insn:TI # 0 0 (set (reg/i:SI 3 3)
         (const_int 0 [0])) "vjbxa62g.c":29:1# {*movsi_internal1}
      (nil))
-(insn # 0 0 (unspec_volatile [
+(insn:TI # 0 0 (unspec_volatile [
             (const_int 0 [0])
         ] UNSPECV_BLOCK) "vjbxa62g.c":29:1# {blockage}
      (nil))
+(insn # 0 0 (use (reg/i:SI 3 3)) "vjbxa62g.c":29:1#
+     (nil))
 (note # 0 0 NOTE_INSN_EPILOGUE_BEG)
-(insn:TI # 0 0 (set (reg:SI 0 0)
+(insn # 0 0 (set (reg:SI 0 0)
         (mem/c:SI (plus:SI (reg/f:SI 1 1)
                 (const_int 36 [0x24])) [  S4 A8])) "vjbxa62g.c":29:1#
{*movsi_internal1}
      (nil))
-(insn # 0 0 (use (reg/i:SI 3 3)) "vjbxa62g.c":29:1#
-     (nil))
-(insn/f # 0 0 (set (reg:SI 96 lr)
-        (reg:SI 0 0)) "vjbxa62g.c":29:1# {*movsi_internal1}
-     (expr_list:REG_DEAD (reg:SI 0 0)
-        (expr_list:REG_CFA_RESTORE (reg:SI 96 lr)
-            (nil))))
 (insn:TI # 0 0 (set (reg:SI 31 31)
         (mem/c:SI (plus:SI (reg/f:SI 1 1)
                 (const_int 28 [0x1c])) [  S4 A8])) "vjbxa62g.c":29:1#
{*movsi_internal1}
@@ -218,7 +213,12 @@
      (expr_list:REG_CFA_DEF_CFA (reg/f:SI 1 1)
         (expr_list:REG_CFA_RESTORE (reg:SI 31 31)
             (nil))))
-(jump_insn:TI # 0 0 (simple_return) "vjbxa62g.c":29:1# {simple_return}
+(insn/f:TI # 0 0 (set (reg:SI 96 lr)
+        (reg:SI 0 0)) "vjbxa62g.c":29:1# {*movsi_internal1}
+     (expr_list:REG_DEAD (reg:SI 0 0)
+        (expr_list:REG_CFA_RESTORE (reg:SI 96 lr)
+            (nil))))
+(jump_insn # 0 0 (simple_return) "vjbxa62g.c":29:1# {simple_return}
      (nil)
  -> simple_return)
 (barrier # 0 0)

[Bug rtl-optimization/106418] '-fcompare-debug' failure w/ -mcpu=e500mc -O2 -fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks -fno-thread-jumps -fno-tree-dce

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106418

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bergner at gcc dot gnu.org,
                   |                            |jskumari at gcc dot gnu.org

--- Comment #1 from Peter Bergner <bergner at gcc dot gnu.org> ---
Surya, might this be related to the sched1 -fcompare-debug issue you have a
patch for?  Or is this something new?

[Bug rtl-optimization/106418] '-fcompare-debug' failure w/ -mcpu=e500mc -O2 -fnon-call-exceptions -fsched-stalled-insns -fno-reorder-blocks -fno-thread-jumps -fno-tree-dce

[jskumari at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106418

Surya Kumari Jangala <jskumari at gcc dot gnu.org> changed:

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

--- Comment #2 from Surya Kumari Jangala <jskumari at gcc dot gnu.org> ---
The issue reported here is the same as in bug 105586
The test provided in the description passes with the patch that fixes bug
105586, and fails w/o the patch.
Hence closing this bug.