[gcc r10-7685] cselib: Mark the cselib_record_sp_cfa_base_equiv VALUE as preserved [PR94551]

[Jakub Jelinek <jakub@gcc.gnu.org>]

https://gcc.gnu.org/g:a615ea71bc8fbf31b9bc71cb373a7ca5b9cca44a

commit r10-7685-ga615ea71bc8fbf31b9bc71cb373a7ca5b9cca44a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Sat Apr 11 07:32:12 2020 +0200

    cselib: Mark the cselib_record_sp_cfa_base_equiv VALUE as preserved [PR94551]
    
    Sometimes the cselib_record_sp_cfa_base_equiv makes it into the var-tracking
    used VALUEs and needs to be preserved.
    
    2020-04-11  Jakub Jelinek  <jakub@redhat.com>
    
            PR debug/94495
            PR target/94551
            * cselib.c (cselib_record_sp_cfa_base_equiv): Set PRESERVED_VALUE_P on
            val->val_rtx.

Diff:
---
 gcc/ChangeLog | 7 +++++++
 gcc/cselib.c  | 5 ++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 33e980bd977..f1a9568d9c4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-04-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/94495
+	PR target/94551
+	* cselib.c (cselib_record_sp_cfa_base_equiv): Set PRESERVED_VALUE_P on
+	val->val_rtx.
+
 2020-04-10  Thomas Schwinge  <thomas@codesourcery.com>
 
 	PR middle-end/89433
diff --git a/gcc/cselib.c b/gcc/cselib.c
index 3692feb13a2..53e9603868d 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -2695,7 +2695,10 @@ cselib_record_sp_cfa_base_equiv (HOST_WIDE_INT offset, rtx_insn *insn)
     = cselib_lookup_from_insn (plus_constant (Pmode, sp_derived_value, offset),
 			       Pmode, 1, VOIDmode, insn);
   if (val != NULL)
-    cselib_record_set (stack_pointer_rtx, val, NULL);
+    {
+      PRESERVED_VALUE_P (val->val_rtx) = 1;
+      cselib_record_set (stack_pointer_rtx, val, NULL);
+    }
 }
 
 /* Return true if V is SP_DERIVED_VALUE_P (or SP_DERIVED_VALUE_P + CONST_INT)