re PR middle-end/91708 ([ARM] Bootstrap fails in gen_movsi, at config/arm/arm.md...

2019-09-13  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR middle-end/91708
        * cse.c (cse_insn): Do not replace anything with a
        MEM.

From-SVN: r275701

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 57a6a67e040af404bf04b558c7b0f3390c0643d7..9bfc0e460a3183c029be5162159bcc99667ac12c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-09-13  Bernd Edlinger  <bernd.edlinger@hotmail.de>
+
+       PR middle-end/91708
+       * cse.c (cse_insn): Do not replace anything with a
+       MEM.
+
 2019-09-13  Ian Lance Taylor  <iant@golang.org>
 
        * doc/invoke.texi (Optimize Options): Fix typo.

diff --git a/gcc/cse.c b/gcc/cse.c
index 098671c035daef5ce87b4c9449dbad14d794a7dd..32b67902451ff1bc6a9c6845868f59b9ca79333b 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -5238,23 +5238,6 @@ cse_insn (rtx_insn *insn)
              src_elt_cost = MAX_COST;
            }
 
-         /* Avoid creation of overlapping memory moves.  */
-         if (MEM_P (trial) && MEM_P (dest) && !rtx_equal_p (trial, dest))
-           {
-             rtx src, dest;
-
-             /* BLKmode moves are not handled by cse anyway.  */
-             if (GET_MODE (trial) == BLKmode)
-               break;
-
-             src = canon_rtx (trial);
-             dest = canon_rtx (SET_DEST (sets[i].rtl));
-
-             if (!MEM_P (src) || !MEM_P (dest)
-                 || !nonoverlapping_memrefs_p (src, dest, false))
-               break;
-           }
-
          /* Try to optimize
             (set (reg:M N) (const_int A))
             (set (reg:M2 O) (const_int B))
@@ -5385,6 +5368,12 @@ cse_insn (rtx_insn *insn)
            /* Do nothing for this case.  */
            ;
 
+         /* Do not replace anything with a MEM, except the replacement
+            is a no-op.  This allows this loop to terminate.  */
+         else if (MEM_P (trial) && !rtx_equal_p (trial, SET_SRC(sets[i].rtl)))
+           /* Do nothing for this case.  */
+           ;
+
          /* Look for a substitution that makes a valid insn.  */
          else if (validate_unshare_change (insn, &SET_SRC (sets[i].rtl),
                                            trial, 0))