[Bug tree-optimization/94166] [10 Regression] random -fcompare-debug failures since r10-1913

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94166

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This fixes it, but will try to find a testcase that fails more reliably:
--- gcc/tree-ssa-reassoc.c.jj   2020-01-12 11:54:38.510381771 +0100
+++ gcc/tree-ssa-reassoc.c      2020-03-13 14:06:32.358085863 +0100
@@ -1793,8 +1793,11 @@ sort_by_mach_mode (const void *p_i, cons
     return 1;
   else if (mode1 < mode2)
     return -1;
-  else
-    return 0;
+  if (SSA_NAME_VERSION (tr1) < SSA_NAME_VERSION (tr2))
+    return -1;
+  else if (SSA_NAME_VERSION (tr1) > SSA_NAME_VERSION (tr2))
+    return 1;
+  return 0;
 }

 /* Cleanup hash map for VECTOR information.  */