|| !ao_ref_from_mem (&ref2, mem))
return true;
- return refs_may_alias_p_1 (&ref1, &ref2, tbaa_p);
+ return refs_may_alias_p_1 (&ref1, &ref2,
+ tbaa_p
+ && MEM_ALIAS_SET (x) != 0
+ && MEM_ALIAS_SET (mem) != 0);
}
/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
return 0;
}
-static int
-walk_mems_2 (rtx *x, rtx mem)
-{
- if (MEM_P (*x))
- {
- if (alias_sets_conflict_p (MEM_ALIAS_SET(*x), MEM_ALIAS_SET(mem)))
- return 1;
-
- return -1;
- }
- return 0;
-}
-
-static int
-walk_mems_1 (rtx *x, rtx *pat)
-{
- if (MEM_P (*x))
- {
- /* Visit all MEMs in *PAT and check indepedence. */
- if (for_each_rtx (pat, (rtx_function) walk_mems_2, *x))
- /* Indicate that dependence was determined and stop traversal. */
- return 1;
-
- return -1;
- }
- return 0;
-}
-
-/* Return 1 if two specified instructions have mem expr with conflict alias sets*/
-bool
-insn_alias_sets_conflict_p (rtx insn1, rtx insn2)
-{
- /* For each pair of MEMs in INSN1 and INSN2 check their independence. */
- return for_each_rtx (&PATTERN (insn1), (rtx_function) walk_mems_1,
- &PATTERN (insn2));
-}
-
/* Return 1 if the two specified alias sets will always conflict. */
int
}
/* Return nonzero if we can determine the exprs corresponding to memrefs
- X and Y and they do not overlap. */
+ X and Y and they do not overlap.
+ If LOOP_VARIANT is set, skip offset-based disambiguation */
int
-nonoverlapping_memrefs_p (const_rtx x, const_rtx y)
+nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant)
{
tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
rtx rtlx, rtly;
|| (CONSTANT_P (basey) && REG_P (basex)
&& REGNO_PTR_FRAME_P (REGNO (basex))));
+ /* Offset based disambiguation not appropriate for loop invariant */
+ if (loop_invariant)
+ return 0;
+
sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
: MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
: -1);
return sizex >= 0 && offsety >= offsetx + sizex;
}
-/* True dependence: X is read after store in MEM takes place. */
+/* Helper for true_dependence and canon_true_dependence.
+ Checks for true dependence: X is read after store in MEM takes place.
-int
-true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x,
- bool (*varies) (const_rtx, bool))
+ VARIES is the function that should be used as rtx_varies function.
+
+ If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be
+ NULL_RTX, and the canonical addresses of MEM and X are both computed
+ here. If MEM_CANONICALIZED, then MEM must be already canonicalized.
+
+ If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0).
+
+ Returns 1 if there is a true dependence, 0 otherwise. */
+
+static int
+true_dependence_1 (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
+ const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool),
+ bool mem_canonicalized)
{
- rtx x_addr, mem_addr;
rtx base;
int ret;
+ gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX)
+ : (mem_addr == NULL_RTX && x_addr == NULL_RTX));
+
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
return 1;
- if (mem_mode == VOIDmode)
- mem_mode = GET_MODE (mem);
+ if (! mem_addr)
+ {
+ mem_addr = XEXP (mem, 0);
+ if (mem_mode == VOIDmode)
+ mem_mode = GET_MODE (mem);
+ }
- x_addr = XEXP (x, 0);
- mem_addr = XEXP (mem, 0);
- if (!((GET_CODE (x_addr) == VALUE
- && GET_CODE (mem_addr) != VALUE
- && reg_mentioned_p (x_addr, mem_addr))
- || (GET_CODE (x_addr) != VALUE
- && GET_CODE (mem_addr) == VALUE
- && reg_mentioned_p (mem_addr, x_addr))))
+ if (! x_addr)
{
- x_addr = get_addr (x_addr);
- mem_addr = get_addr (mem_addr);
+ x_addr = XEXP (x, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ if (! mem_canonicalized)
+ mem_addr = get_addr (mem_addr);
+ }
}
base = find_base_term (x_addr);
return 0;
x_addr = canon_rtx (x_addr);
- mem_addr = canon_rtx (mem_addr);
+ if (!mem_canonicalized)
+ mem_addr = canon_rtx (mem_addr);
if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
SIZE_FOR_MODE (x), x_addr, 0)) != -1)
if (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
- if (nonoverlapping_memrefs_p (mem, x))
+ if (nonoverlapping_memrefs_p (mem, x, false))
return 0;
if (aliases_everything_p (x))
return 1;
/* We cannot use aliases_everything_p to test MEM, since we must look
- at MEM_MODE, rather than GET_MODE (MEM). */
+ at MEM_ADDR, rather than XEXP (mem, 0). */
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
return 1;
- /* In true_dependence we also allow BLKmode to alias anything. Why
+ /* ??? In true_dependence we also allow BLKmode to alias anything. Why
don't we do this in anti_dependence and output_dependence? */
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
return 1;
return rtx_refs_may_alias_p (x, mem, true);
}
+/* True dependence: X is read after store in MEM takes place. */
+
+int
+true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x,
+ bool (*varies) (const_rtx, bool))
+{
+ return true_dependence_1 (mem, mem_mode, NULL_RTX,
+ x, NULL_RTX, varies,
+ /*mem_canonicalized=*/false);
+}
+
/* Canonical true dependence: X is read after store in MEM takes place.
Variant of true_dependence which assumes MEM has already been
canonicalized (hence we no longer do that here).
- The mem_addr argument has been added, since true_dependence computed
- this value prior to canonicalizing.
- If x_addr is non-NULL, it is used in preference of XEXP (x, 0). */
+ The mem_addr argument has been added, since true_dependence_1 computed
+ this value prior to canonicalizing. */
int
canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool))
{
- int ret;
-
- if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
- return 1;
-
- /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
- This is used in epilogue deallocation functions. */
- if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
- return 1;
- if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
- return 1;
- if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
- || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
- return 1;
-
- /* Read-only memory is by definition never modified, and therefore can't
- conflict with anything. We don't expect to find read-only set on MEM,
- but stupid user tricks can produce them, so don't die. */
- if (MEM_READONLY_P (x))
- return 0;
-
- /* If we have MEMs refering to different address spaces (which can
- potentially overlap), we cannot easily tell from the addresses
- whether the references overlap. */
- if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
- return 1;
-
- if (! x_addr)
- {
- x_addr = XEXP (x, 0);
- if (!((GET_CODE (x_addr) == VALUE
- && GET_CODE (mem_addr) != VALUE
- && reg_mentioned_p (x_addr, mem_addr))
- || (GET_CODE (x_addr) != VALUE
- && GET_CODE (mem_addr) == VALUE
- && reg_mentioned_p (mem_addr, x_addr))))
- x_addr = get_addr (x_addr);
- }
-
- if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
- return 0;
-
- x_addr = canon_rtx (x_addr);
- if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
- SIZE_FOR_MODE (x), x_addr, 0)) != -1)
- return ret;
-
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
- return 0;
-
- if (nonoverlapping_memrefs_p (x, mem))
- return 0;
-
- if (aliases_everything_p (x))
- return 1;
-
- /* We cannot use aliases_everything_p to test MEM, since we must look
- at MEM_MODE, rather than GET_MODE (MEM). */
- if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
- return 1;
-
- /* In true_dependence we also allow BLKmode to alias anything. Why
- don't we do this in anti_dependence and output_dependence? */
- if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
- return 1;
-
- if (fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, varies))
- return 0;
-
- return rtx_refs_may_alias_p (x, mem, true);
+ return true_dependence_1 (mem, mem_mode, mem_addr,
+ x, x_addr, varies,
+ /*mem_canonicalized=*/true);
}
/* Returns nonzero if a write to X might alias a previous read from
SIZE_FOR_MODE (x), x_addr, 0)) != -1)
return ret;
- if (nonoverlapping_memrefs_p (x, mem))
+ if (nonoverlapping_memrefs_p (x, mem, false))
return 0;
fixed_scalar
}
\f
+
+/* Check whether X may be aliased with MEM. Don't do offset-based
+ memory disambiguation & TBAA. */
+int
+may_alias_p (const_rtx mem, const_rtx x)
+{
+ rtx x_addr, mem_addr;
+
+ if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
+ return 1;
+
+ /* ??? In true_dependence we also allow BLKmode to alias anything. */
+ if (GET_MODE (mem) == BLKmode || GET_MODE (x) == BLKmode)
+ return 1;
+
+ if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
+ || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
+ return 1;
+
+ /* Read-only memory is by definition never modified, and therefore can't
+ conflict with anything. We don't expect to find read-only set on MEM,
+ but stupid user tricks can produce them, so don't die. */
+ if (MEM_READONLY_P (x))
+ return 0;
+
+ /* If we have MEMs refering to different address spaces (which can
+ potentially overlap), we cannot easily tell from the addresses
+ whether the references overlap. */
+ if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
+ return 1;
+
+ x_addr = XEXP (x, 0);
+ mem_addr = XEXP (mem, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ mem_addr = get_addr (mem_addr);
+ }
+
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), GET_MODE (mem_addr)))
+ return 0;
+
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
+
+ if (nonoverlapping_memrefs_p (mem, x, true))
+ return 0;
+
+ if (aliases_everything_p (x))
+ return 1;
+
+ /* We cannot use aliases_everything_p to test MEM, since we must look
+ at MEM_ADDR, rather than XEXP (mem, 0). */
+ if (GET_MODE (mem) == QImode || GET_CODE (mem_addr) == AND)
+ return 1;
+
+ if (fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ rtx_addr_varies_p))
+ return 0;
+
+ /* TBAA not valid for loop_invarint */
+ return rtx_refs_may_alias_p (x, mem, false);
+}
+
void
init_alias_target (void)
{
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