that is constant through the whole function and should never be
eliminated. */
static cselib_val *cfa_base_preserved_val;
-static unsigned int cfa_base_preserved_regno;
+static unsigned int cfa_base_preserved_regno = INVALID_REGNUM;
/* Used to list all values that contain memory reference.
May or may not contain the useless values - the list is compacted
{
n_debug_values--;
l->setting_insn = cselib_current_insn;
- gcc_assert (!l->next);
+ if (cselib_preserve_constants && l->next)
+ {
+ gcc_assert (l->next->setting_insn
+ && DEBUG_INSN_P (l->next->setting_insn)
+ && !l->next->next);
+ l->next->setting_insn = cselib_current_insn;
+ }
+ else
+ gcc_assert (!l->next);
}
}
cselib_reset_table (1);
}
-/* Remove from hash table all VALUEs except constants. */
+/* Remove from hash table all VALUEs except constants
+ and function invariants. */
static int
preserve_only_constants (void **x, void *info ATTRIBUTE_UNUSED)
return 1;
}
}
+ /* Keep around VALUEs that forward function invariant ENTRY_VALUEs
+ to corresponding parameter VALUEs. */
+ if (v->locs != NULL
+ && v->locs->next != NULL
+ && v->locs->next->next == NULL
+ && GET_CODE (v->locs->next->loc) == ENTRY_VALUE
+ && GET_CODE (v->locs->loc) == VALUE)
+ return 1;
htab_clear_slot (cselib_hash_table, x);
return 1;
return DEBUG_IMPLICIT_PTR_DECL (x)
== DEBUG_IMPLICIT_PTR_DECL (y);
+ case DEBUG_PARAMETER_REF:
+ return DEBUG_PARAMETER_REF_DECL (x)
+ == DEBUG_PARAMETER_REF_DECL (y);
+
case ENTRY_VALUE:
- return rtx_equal_for_cselib_1 (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y),
- memmode);
+ /* ENTRY_VALUEs are function invariant, it is thus undesirable to
+ use rtx_equal_for_cselib_1 to compare the operands. */
+ return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y));
case LABEL_REF:
return XEXP (x, 0) == XEXP (y, 0);
+ DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x));
return hash ? hash : (unsigned int) DEBUG_IMPLICIT_PTR;
+ case DEBUG_PARAMETER_REF:
+ hash += ((unsigned) DEBUG_PARAMETER_REF << 7)
+ + DECL_UID (DEBUG_PARAMETER_REF_DECL (x));
+ return hash ? hash : (unsigned int) DEBUG_PARAMETER_REF;
+
case ENTRY_VALUE:
- hash += cselib_hash_rtx (ENTRY_VALUE_EXP (x), create, memmode);
+ /* ENTRY_VALUEs are function invariant, thus try to avoid
+ recursing on argument if ENTRY_VALUE is one of the
+ forms emitted by expand_debug_expr, otherwise
+ ENTRY_VALUE hash would depend on the current value
+ in some register or memory. */
+ if (REG_P (ENTRY_VALUE_EXP (x)))
+ hash += (unsigned int) REG
+ + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x))
+ + (unsigned int) REGNO (ENTRY_VALUE_EXP (x));
+ else if (MEM_P (ENTRY_VALUE_EXP (x))
+ && REG_P (XEXP (ENTRY_VALUE_EXP (x), 0)))
+ hash += (unsigned int) MEM
+ + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x), 0))
+ + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x), 0));
+ else
+ hash += cselib_hash_rtx (ENTRY_VALUE_EXP (x), create, memmode);
return hash ? hash : (unsigned int) ENTRY_VALUE;
case CONST_INT:
if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig))
{
rtx result;
- int regno = REGNO (orig);
+ unsigned regno = REGNO (orig);
/* The only thing that we are not willing to do (this
is requirement of dse and if others potential uses
make the frame assumptions. */
if (regno == STACK_POINTER_REGNUM
|| regno == FRAME_POINTER_REGNUM
- || regno == HARD_FRAME_POINTER_REGNUM)
+ || regno == HARD_FRAME_POINTER_REGNUM
+ || regno == cfa_base_preserved_regno)
return orig;
bitmap_set_bit (evd->regs_active, regno);
}
return e->val_rtx;
+ case ENTRY_VALUE:
+ e = cselib_lookup (x, GET_MODE (x), 0, memmode);
+ if (! e)
+ break;
+ return e->val_rtx;
+
case CONST_DOUBLE:
case CONST_VECTOR:
case CONST_INT:
used_regs[n_used_regs++] = i;
REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL);
}
+ else if (cselib_preserve_constants
+ && GET_MODE_CLASS (mode) == MODE_INT)
+ {
+ /* During var-tracking, try harder to find equivalences
+ for SUBREGs. If a setter sets say a DImode register
+ and user uses that register only in SImode, add a lowpart
+ subreg location. */
+ struct elt_list *lwider = NULL;
+ l = REG_VALUES (i);
+ if (l && l->elt == NULL)
+ l = l->next;
+ for (; l; l = l->next)
+ if (GET_MODE_CLASS (GET_MODE (l->elt->val_rtx)) == MODE_INT
+ && GET_MODE_SIZE (GET_MODE (l->elt->val_rtx))
+ > GET_MODE_SIZE (mode)
+ && (lwider == NULL
+ || GET_MODE_SIZE (GET_MODE (l->elt->val_rtx))
+ < GET_MODE_SIZE (GET_MODE (lwider->elt->val_rtx))))
+ {
+ struct elt_loc_list *el;
+ if (i < FIRST_PSEUDO_REGISTER
+ && hard_regno_nregs[i][GET_MODE (l->elt->val_rtx)] != 1)
+ continue;
+ for (el = l->elt->locs; el; el = el->next)
+ if (!REG_P (el->loc))
+ break;
+ if (el)
+ lwider = l;
+ }
+ if (lwider)
+ {
+ rtx sub = lowpart_subreg (mode, lwider->elt->val_rtx,
+ GET_MODE (lwider->elt->val_rtx));
+ if (sub)
+ e->locs->next = new_elt_loc_list (e->locs->next, sub);
+ }
+ }
REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e);
slot = cselib_find_slot (x, e->hash, INSERT, memmode);
*slot = e;
if (!reg_values || reg_values_size < cselib_nregs
|| (reg_values_size > 10 && reg_values_size > cselib_nregs * 4))
{
- if (reg_values)
- free (reg_values);
+ free (reg_values);
/* Some space for newly emit instructions so we don't end up
reallocating in between passes. */
reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16;
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