re PR rtl-optimization/48542 (unchanged variables in code which calls setjmp may...

	PR rtl-optimization/48542
	* reload.c (find_equiv_reg): Stop looking when finding a
	setjmp-type call.
	* reload1.c (reload_as_needed): Invalidate all reload
	registers when crossing a setjmp-type call.

From-SVN: r175132

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c1620d2eff41ef7c1d0edd82c8853d6466b79d14..26c1f813011b6c1d5017d0f61e23cc8b9e9962af 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2011-06-17  Hans-Peter Nilsson  <hp@axis.com>
+
+       PR rtl-optimization/48542
+       * reload.c (find_equiv_reg): Stop looking when finding a
+       setjmp-type call.
+       * reload1.c (reload_as_needed): Invalidate all reload
+       registers when crossing a setjmp-type call.
+
 2011-06-16  Jeff Law  <law@redhat.com>
 
        * tree-ssa-threadupdate.c (struct redirection_data): New field

diff --git a/gcc/reload.c b/gcc/reload.c
index 27d5787750129779045a17e35f42c78bc3b24e5b..3ad46b991ad3a01878ac8a54af30dc552cf11790 100644 (file)
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -6791,6 +6791,15 @@ find_equiv_reg (rtx goal, rtx insn, enum reg_class rclass, int other,
          || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
        return 0;
 
+      /* Don't reuse register contents from before a setjmp-type
+        function call; on the second return (from the longjmp) it
+        might have been clobbered by a later reuse.  It doesn't
+        seem worthwhile to actually go and see if it is actually
+        reused even if that information would be readily available;
+        just don't reuse it across the setjmp call.  */
+      if (CALL_P (p) && find_reg_note (p, REG_SETJMP, NULL_RTX))
+       return 0;
+
       if (NONJUMP_INSN_P (p)
          /* If we don't want spill regs ...  */
          && (! (reload_reg_p != 0

diff --git a/gcc/reload1.c b/gcc/reload1.c
index e65503b9fa5ce6ec701432a5cc767766035da6d1..a87e6ad08d6f9ba6eb9c3e6d043ceca2d0b688e4 100644 (file)
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -4844,6 +4844,13 @@ reload_as_needed (int live_known)
        {
          AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
          AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
+
+         /* If this is a call to a setjmp-type function, we must not
+            reuse any reload reg contents across the call; that will
+            just be clobbered by other uses of the register in later
+            code, before the longjmp.  */
+         if (find_reg_note (insn, REG_SETJMP, NULL_RTX))
+           CLEAR_HARD_REG_SET (reg_reloaded_valid);
        }
     }