This bug appears to revolve around whether there is a canonical rtx for
internal_arg_pointer in var-tracking. In vt_add_function_parameter() we
currently have:
static void
vt_add_function_parameter (tree parm)
{
rtx decl_rtl = DECL_RTL_IF_SET (parm);
rtx incoming = DECL_INCOMING_RTL (parm);
tree decl;
machine_mode mode;
poly_int64 offset;
dataflow_set *out;
decl_or_value dv;
if (TREE_CODE (parm) != PARM_DECL)
return;
if (!decl_rtl || !incoming)
return;
if (GET_MODE (decl_rtl) == BLKmode || GET_MODE (incoming) == BLKmode)
return;
/* If there is a DRAP register or a pseudo in internal_arg_pointer,
rewrite the incoming location of parameters passed on the stack
into MEMs based on the argument pointer, so that incoming doesn't
depend on a pseudo. */
if (MEM_P (incoming)
&& (XEXP (incoming, 0) == crtl->args.internal_arg_pointer
|| (GET_CODE (XEXP (incoming, 0)) == PLUS
&& XEXP (XEXP (incoming, 0), 0)
== crtl->args.internal_arg_pointer
&& CONST_INT_P (XEXP (XEXP (incoming, 0), 1)))))
{
HOST_WIDE_INT off = -FIRST_PARM_OFFSET (current_function_decl);
if (GET_CODE (XEXP (incoming, 0)) == PLUS)
off += INTVAL (XEXP (XEXP (incoming, 0), 1));
incoming
= replace_equiv_address_nv (incoming,
plus_constant (Pmode,
arg_pointer_rtx, off));
}
This is looking for crtl->args.internal_arg_pointer within rtx
incoming. The problem I am seeing is that the same rtx is there, just
not as a pointer to the identical rtx objects, so is not found by the
== comparison in the current code. So hence my patch below to switch
from == to rtx_equal_p(). If the expression is not rewritten, then the
pseudo created for the stack pointer is not preserved and later we run
into the assert near the beginning of vt_expand_var_loc_chain().
Bootstrap now passes for languages=c,c++,go on ppc64le. If
bootstrap/regtest is ok on ppc64le and x86_64, ok for trunk?
2018-01-29 Aaron Sawdey <acsaw...@linux.vnet.ibm.com>
* var-tracking.c (vt_add_function_parameter): Fix comparison of rtx.
Index: gcc/var-tracking.c
===================================================================
--- gcc/var-tracking.c (revision 257159)
+++ gcc/var-tracking.c (working copy)
@@ -9668,10 +9668,10 @@
into MEMs based on the argument pointer, so that incoming doesn't
depend on a pseudo. */
if (MEM_P (incoming)
- && (XEXP (incoming, 0) == crtl->args.internal_arg_pointer
+ && (rtx_equal_p (XEXP (incoming, 0), crtl-
>args.internal_arg_pointer)
|| (GET_CODE (XEXP (incoming, 0)) == PLUS
- && XEXP (XEXP (incoming, 0), 0)
- == crtl->args.internal_arg_pointer
+ && rtx_equal_p (XEXP (XEXP (incoming, 0), 0),
+ crtl->args.internal_arg_pointer)
&& CONST_INT_P (XEXP (XEXP (incoming, 0), 1)))))
{
HOST_WIDE_INT off = -FIRST_PARM_OFFSET (current_function_decl);
--
Aaron Sawdey, Ph.D. acsaw...@linux.vnet.ibm.com
050-2/C113 (507) 253-7520 home: 507/263-0782
IBM Linux Technology Center - PPC Toolchain
