[PATCH] Prevent frame-related insn from occurring in delay slots of insns that throw

[Tom de Vries]

Richard,

[now cc-ing gcc-patches]

this patch fixes PR50283 in a target-independent way.

it asserts on frame-related insns in the delay slot of insns that can throw,
and prevents the assert by testing for the same condition in
eligible_for_{delay,annul_true,annul_false}.

build and reg-tested on mips64el.

I don't know of any tests currently failing on this, so I think it's not
appropriate for stage4. OK for stage1 ?

Thanks,
- Tom

2012-01-27  Andrew Pinski  <apin...@cavium.com>
            Tom de Vries  <t...@codesourcery.com>

        * dwarf2cfi.c (scan_trace): Add assert that frame-related insns should
        not occur in delay-slots of insns that can throw.
        * genattrtab.c (write_eligible_delay): Prevent frame-related insns from
        occurring in delay-slots of insns that can throw.


Index: gcc/genattrtab.c
===================================================================
--- gcc/genattrtab.c (revision 183557)
+++ gcc/genattrtab.c (working copy)
@@ -4280,6 +4280,12 @@ write_eligible_delay (const char *kind)
   printf ("  if (!INSN_P (candidate_insn))\n");
   printf ("    return 0;\n");
   printf ("\n");
+  /* Frame-related instructions should not be put into delay slots of
+     instructions that can throw.  */
+  printf ("  if (insn_could_throw_p (delay_insn)\n");
+  printf ("      && RTX_FRAME_RELATED_P (candidate_insn))\n");
+  printf ("    return 0;\n");
+  printf ("\n");
 
   /* If more than one delay type, find out which type the delay insn is.  */
 
Index: gcc/dwarf2cfi.c
===================================================================
--- gcc/dwarf2cfi.c (revision 183557)
+++ gcc/dwarf2cfi.c (working copy)
@@ -2474,6 +2474,8 @@ scan_trace (dw_trace_info *trace)
 	  for (i = 1; i < n; ++i)
 	    {
 	      elt = XVECEXP (pat, 0, i);
+	      gcc_assert (!(insn_could_throw_p (control)
+			    && RTX_FRAME_RELATED_P (elt)));
 	      scan_insn_after (elt);
 	    }