[Bug rtl-optimization/106078] RTL PRE with non-call-exceptions

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106078

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Invalid loop invariant      |RTL PRE with
                   |motion with                 |non-call-exceptions
                   |non-call-exceptions         |
           Assignee|rguenth at gcc dot gnu.org         |unassigned at gcc dot 
gnu.org
          Component|middle-end                  |rtl-optimization
             Status|ASSIGNED                    |NEW

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note it is RTL PRE hoisting the load from b, not invariant motion.  On the
testcase w/o -fnon-call-exceptions it's tree PRE (or if disabled, RTL PRE
again)
doing the hoisting.

For some reason for the non-call-exception PRE case the following does not
help.

diff --git a/gcc/gcse-common.cc b/gcc/gcse-common.cc
index e86d4c4f477..16f804d13f9 100644
--- a/gcc/gcse-common.cc
+++ b/gcc/gcse-common.cc
@@ -82,7 +82,8 @@ record_last_mem_set_info_common (rtx_insn *insn,
   modify_mem_list[bb].safe_push (insn);
   bitmap_set_bit (modify_mem_list_set, bb);

-  if (CALL_P (insn))
+  if (CALL_P (insn)
+      || can_throw_external (insn))
     bitmap_set_bit (blocks_with_calls, bb);
   else
     {
diff --git a/gcc/gcse.cc b/gcc/gcse.cc
index f06278a5534..b138e1e501c 100644
--- a/gcc/gcse.cc
+++ b/gcc/gcse.cc
@@ -1535,13 +1535,14 @@ compute_hash_table_work (struct gcse_hash_table_d
*table)
                = insn_callee_abi (insn).full_and_partial_reg_clobbers ();
              EXECUTE_IF_SET_IN_HARD_REG_SET (callee_clobbers, 0, regno, hrsi)
                record_last_reg_set_info (insn, regno);
-
-             if (! RTL_CONST_OR_PURE_CALL_P (insn)
-                 || RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)
-                 || can_throw_external (insn))
-               record_last_mem_set_info (insn);
            }

+         if ((CALL_P (insn)
+              && (! RTL_CONST_OR_PURE_CALL_P (insn)
+                  || RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)))
+             || can_throw_external (insn))
+           record_last_mem_set_info (insn);
+
          note_stores (insn, record_last_set_info, insn);
        }