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Bug in expr.c and minor bug in toplev.c
- To: gcc-patches at gcc dot gnu dot org
- Subject: Bug in expr.c and minor bug in toplev.c
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- Date: Sat, 6 May 00 07:31:39 EDT
These were tested on Alpha.
(1) You can't use a readonly pseudo as a subtarget because it will
get set more than one, in violation of what "readonly" means.
(2) If there's no filename, toplev.c blows up.
Sat May 6 06:25:56 2000 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
* expr.c (get_subtarget): New function.
(force_operand, expand_expr, do_store_flag): Use it.
* toplev.c (compile_file): Don't take strlen of NAME if null.
*** expr.c 2000/05/04 21:15:03 1.236
--- expr.c 2000/05/06 02:18:10
*************** static void clear_by_pieces_1 PARAMS ((r
*** 156,159 ****
--- 156,160 ----
enum machine_mode,
struct clear_by_pieces *));
+ static rtx get_subtarget PARAMS ((rtx));
static int is_zeros_p PARAMS ((tree));
static int mostly_zeros_p PARAMS ((tree));
*************** free_expr_status (f)
*** 336,339 ****
--- 337,341 ----
/* Small sanity check that the queue is empty at the end of a function. */
+
void
finish_expr_for_function ()
*************** copy_blkmode_from_reg (tgtblk, srcreg, t
*** 2178,2182 ****
}
-
/* Add a USE expression for REG to the (possibly empty) list pointed
to by CALL_FUSAGE. REG must denote a hard register. */
--- 2180,2183 ----
*************** emit_push_insn (x, mode, type, size, ali
*** 3325,3328 ****
--- 3326,3349 ----
}
+ /* Return X if X can be used as a subtarget in a sequence of arithmetic
+ operations. */
+
+ static rtx
+ get_subtarget (x)
+ rtx x;
+ {
+ return ((x == 0
+ /* Only registers can be subtargets. */
+ || GET_CODE (x) != REG
+ /* If the register is readonly, it can't be set more than once. */
+ || RTX_UNCHANGING_P (x)
+ /* Don't use hard regs to avoid extending their life. */
+ || REGNO (x) < FIRST_PSEUDO_REGISTER
+ /* Avoid subtargets inside loops,
+ since they hide some invariant expressions. */
+ || preserve_subexpressions_p ())
+ ? 0 : x);
+ }
+
/* Expand an assignment that stores the value of FROM into TO.
If WANT_VALUE is nonzero, return an rtx for the value of TO.
*************** force_operand (value, target)
*** 5165,5169 ****
register rtx op2;
/* Use subtarget as the target for operand 0 of a binary operation. */
! register rtx subtarget = (target != 0 && GET_CODE (target) == REG ? target : 0);
/* Check for a PIC address load. */
--- 5186,5190 ----
register rtx op2;
/* Use subtarget as the target for operand 0 of a binary operation. */
! register rtx subtarget = get_subtarget (target);
/* Check for a PIC address load. */
*************** expand_expr (exp, target, tmode, modifie
*** 5708,5712 ****
mode = TYPE_MODE (type);
/* Use subtarget as the target for operand 0 of a binary operation. */
! subtarget = (target != 0 && GET_CODE (target) == REG ? target : 0);
original_target = target;
ignore = (target == const0_rtx
--- 5729,5733 ----
mode = TYPE_MODE (type);
/* Use subtarget as the target for operand 0 of a binary operation. */
! subtarget = get_subtarget (target);
original_target = target;
ignore = (target == const0_rtx
*************** expand_expr (exp, target, tmode, modifie
*** 5723,5735 ****
ro_modifier = EXPAND_NORMAL;
- /* Don't use hard regs as subtargets, because the combiner
- can only handle pseudo regs. */
- if (subtarget && REGNO (subtarget) < FIRST_PSEUDO_REGISTER)
- subtarget = 0;
- /* Avoid subtargets inside loops,
- since they hide some invariant expressions. */
- if (preserve_subexpressions_p ())
- subtarget = 0;
-
/* If we are going to ignore this result, we need only do something
if there is a side-effect somewhere in the expression. If there
--- 5744,5747 ----
*************** do_store_flag (exp, target, mode, only_c
*** 10245,10250 ****
);
! if (subtarget == 0 || GET_CODE (subtarget) != REG
! || GET_MODE (subtarget) != operand_mode
|| ! safe_from_p (subtarget, inner, 1))
subtarget = 0;
--- 10257,10261 ----
);
! if (! get_subtarget (subtarget)
|| ! safe_from_p (subtarget, inner, 1))
subtarget = 0;
*************** do_store_flag (exp, target, mode, only_c
*** 10296,10301 ****
preexpand_calls (exp);
! if (subtarget == 0 || GET_CODE (subtarget) != REG
! || GET_MODE (subtarget) != operand_mode
|| ! safe_from_p (subtarget, arg1, 1))
subtarget = 0;
--- 10307,10311 ----
preexpand_calls (exp);
! if (! get_subtarget (target)
|| ! safe_from_p (subtarget, arg1, 1))
subtarget = 0;
*** toplev.c 2000/05/02 20:43:23 1.330
--- toplev.c 2000/05/06 02:18:41
*************** compile_file (name)
*** 2129,2134 ****
}
! if (ggc_p)
name = ggc_alloc_string (name, strlen (name));
input_filename = name;
--- 2129,2135 ----
}
! if (ggc_p && name != 0)
name = ggc_alloc_string (name, strlen (name));
+
input_filename = name;