Hi!
Double arguments passed on the stack on x86_64 (and float too) where
a function is called with a constant is stored using corresponding integer
mode rather than DFmode, so cselib_lookup doesn't find the preserved value
for this. Fixed thusly, bootstrapped/regtested on x86_64-linux and
i686-linux, ok for trunk?
2011-07-26 Jakub Jelinek <ja...@redhat.com>
PR debug/49846
* var-tracking.c (prepare_call_arguments): For non-MODE_INT stack
arguments also check if they aren't initialized with a MODE_INT
mode of the same size.
--- gcc/var-tracking.c.jj 2011-07-22 22:15:02.000000000 +0200
+++ gcc/var-tracking.c 2011-07-26 15:51:35.000000000 +0200
@@ -5777,6 +5777,22 @@ prepare_call_arguments (basic_block bb,
val = cselib_lookup (mem, GET_MODE (mem), 0, VOIDmode);
if (val && cselib_preserved_value_p (val))
item = gen_rtx_CONCAT (GET_MODE (x), copy_rtx (x), val->val_rtx);
+ else if (GET_MODE_CLASS (GET_MODE (mem)) != MODE_INT)
+ {
+ /* For non-integer stack argument see also if they weren't
+ initialized by integers. */
+ enum machine_mode imode = int_mode_for_mode (GET_MODE (mem));
+ if (imode != GET_MODE (mem) && imode != BLKmode)
+ {
+ val = cselib_lookup (adjust_address_nv (mem, imode, 0),
+ imode, 0, VOIDmode);
+ if (val && cselib_preserved_value_p (val))
+ item = gen_rtx_CONCAT (GET_MODE (x), copy_rtx (x),
+ lowpart_subreg (GET_MODE (x),
+ val->val_rtx,
+ imode));
+ }
+ }
}
if (item)
call_arguments = gen_rtx_EXPR_LIST (VOIDmode, item, call_arguments);
Jakub
