+2007-06-30 Richard Sandiford <richard@codesourcery.com>
+
+ Revert:
+
+ 2007-06-27 Richard Sandiford <richard@codesourcery.com>
+
+ * dce.c (deletable_insn_p_1): New function, split out from...
+ (deletable_insn_p): ...here. Only treat bare USEs and CLOBBERs
+ specially, not those inside PARALLELs. Remove BODY argument
+ and adjust recursive call accordingly.
+ (prescan_insns_for_dce): Update call to delete_insn_p.
+
2007-06-30 Rask Ingemann Lambertsen <rask@sygehus.dk>
* combine.c (combine_validate_cost): New parameter NEWOTHERPAT.
static sbitmap marked = NULL;
-/* A subroutine for which BODY is part of the instruction being tested;
- either the top-level pattern, or an element of a PARALLEL. The
- instruction is known not to be a bare USE or CLOBBER. */
+/* Return true if INSN with BODY is a normal instruction that can be
+ deleted by the DCE pass. */
static bool
-deletable_insn_p_1 (rtx body)
+deletable_insn_p (rtx insn, rtx body, bool fast)
{
+ rtx x;
switch (GET_CODE (body))
{
+ case USE:
case PREFETCH:
case TRAP_IF:
/* The UNSPEC case was added here because the ia-64 claims that
case UNSPEC:
return false;
- default:
- if (volatile_insn_p (body))
- return false;
-
- if (flag_non_call_exceptions && may_trap_p (body))
- return false;
-
- return true;
- }
-}
-
-/* Return true if INSN is a normal instruction that can be deleted by
- the DCE pass. */
-
-static bool
-deletable_insn_p (rtx insn, bool fast)
-{
- rtx body, x;
- int i;
-
- if (!NONJUMP_INSN_P (insn))
- return false;
-
- body = PATTERN (insn);
- switch (GET_CODE (body))
- {
- case USE:
- return false;
-
case CLOBBER:
if (fast)
{
x = XEXP (body, 0);
return REG_P (x) && (!HARD_REGISTER_P (x) || reload_completed);
}
- else
+ else
/* Because of the way that use-def chains are built, it is not
possible to tell if the clobber is dead because it can
never be the target of a use-def chain. */
return false;
case PARALLEL:
- for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
- if (!deletable_insn_p_1 (XVECEXP (body, 0, i)))
- return false;
- return true;
+ {
+ int i;
+ for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
+ if (!deletable_insn_p (insn, XVECEXP (body, 0, i), fast))
+ return false;
+ return true;
+ }
default:
- return deletable_insn_p_1 (body);
+ if (!NONJUMP_INSN_P (insn))
+ return false;
+
+ if (volatile_insn_p (body))
+ return false;
+
+ if (flag_non_call_exceptions && may_trap_p (body))
+ return false;
+
+ return true;
}
}
rtx note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX);
if (note)
mark_libcall (insn, fast);
- else if (deletable_insn_p (insn, fast))
+ else if (deletable_insn_p (insn, PATTERN (insn), fast))
mark_nonreg_stores (PATTERN (insn), insn, fast);
else
mark_insn (insn, fast);