#include "flags.h"
#include "output.h"
#include "diagnostic-core.h"
-#include "toplev.h"
#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
#include "target.h"
#include "cgraph.h"
#include "tree-pass.h"
-#include "ipa-type-escape.h"
#include "df.h"
#include "tree-ssa-alias.h"
#include "pointer-set.h"
static int aliases_everything_p (const_rtx);
static bool nonoverlapping_component_refs_p (const_tree, const_tree);
static tree decl_for_component_ref (tree);
-static rtx adjust_offset_for_component_ref (tree, rtx);
static int write_dependence_p (const_rtx, const_rtx, int);
static void memory_modified_1 (rtx, const_rtx, void *);
|| TREE_CODE (base) == MEM_REF)
&& TREE_CODE (TREE_OPERAND (base, 0)) != SSA_NAME)
return false;
+ if (TREE_CODE (base) == TARGET_MEM_REF
+ && TMR_BASE (base)
+ && TREE_CODE (TMR_BASE (base)) != SSA_NAME)
+ return false;
/* If this is a reference based on a partitioned decl replace the
base with an INDIRECT_REF of the pointer representative we
if (namep)
ref->base = build_simple_mem_ref (*(tree *)namep);
}
+ else if (TREE_CODE (base) == TARGET_MEM_REF
+ && TREE_CODE (TMR_BASE (base)) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (TMR_BASE (base), 0)) == VAR_DECL
+ && ! TREE_STATIC (TREE_OPERAND (TMR_BASE (base), 0))
+ && cfun->gimple_df->decls_to_pointers != NULL)
+ {
+ void *namep;
+ namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers,
+ TREE_OPERAND (TMR_BASE (base), 0));
+ if (namep)
+ ref->base = build_simple_mem_ref (*(tree *)namep);
+ }
ref->ref_alias_set = MEM_ALIAS_SET (mem);
- /* If MEM_OFFSET or MEM_SIZE are NULL we have to punt.
+ /* If MEM_OFFSET or MEM_SIZE are unknown we have to punt.
Keep points-to related information though. */
- if (!MEM_OFFSET (mem)
- || !MEM_SIZE (mem))
+ if (!MEM_OFFSET_KNOWN_P (mem)
+ || !MEM_SIZE_KNOWN_P (mem))
{
ref->ref = NULL_TREE;
ref->offset = 0;
/* If the base decl is a parameter we can have negative MEM_OFFSET in
case of promoted subregs on bigendian targets. Trust the MEM_EXPR
here. */
- if (INTVAL (MEM_OFFSET (mem)) < 0
- && ((INTVAL (MEM_SIZE (mem)) + INTVAL (MEM_OFFSET (mem)))
- * BITS_PER_UNIT) == ref->size)
+ if (MEM_OFFSET (mem) < 0
+ && (MEM_SIZE (mem) + MEM_OFFSET (mem)) * BITS_PER_UNIT == ref->size)
return true;
- ref->offset += INTVAL (MEM_OFFSET (mem)) * BITS_PER_UNIT;
- ref->size = INTVAL (MEM_SIZE (mem)) * BITS_PER_UNIT;
+ ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT;
+ ref->size = MEM_SIZE (mem) * BITS_PER_UNIT;
/* The MEM may extend into adjacent fields, so adjust max_size if
necessary. */
|| !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
if (set != -1)
return set;
- /* Retrieve the original memory reference if needed. */
- if (TREE_CODE (t) == TARGET_MEM_REF)
- t = TMR_ORIGINAL (t);
-
/* Get the base object of the reference. */
inner = t;
while (handled_component_p (inner))
if (set != -1)
return set;
}
+ else if (TREE_CODE (inner) == TARGET_MEM_REF)
+ return get_deref_alias_set (TMR_OFFSET (inner));
else if (TREE_CODE (inner) == MEM_REF)
{
set = get_deref_alias_set_1 (TREE_OPERAND (inner, 1));
t = TYPE_CANONICAL (t);
- /* Canonical types shouldn't form a tree nor should the canonical
- type require structural equality checks. */
- gcc_checking_assert (TYPE_CANONICAL (t) == t
- && !TYPE_STRUCTURAL_EQUALITY_P (t));
+ /* The canonical type should not require structural equality checks. */
+ gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t));
/* If this is a type with a known alias set, return it. */
if (TYPE_ALIAS_SET_KNOWN_P (t))
else if (TREE_CODE (t) == ARRAY_TYPE && !TYPE_NONALIASED_COMPONENT (t))
set = get_alias_set (TREE_TYPE (t));
+ /* From the former common C and C++ langhook implementation:
+
+ Unfortunately, there is no canonical form of a pointer type.
+ In particular, if we have `typedef int I', then `int *', and
+ `I *' are different types. So, we have to pick a canonical
+ representative. We do this below.
+
+ Technically, this approach is actually more conservative that
+ it needs to be. In particular, `const int *' and `int *'
+ should be in different alias sets, according to the C and C++
+ standard, since their types are not the same, and so,
+ technically, an `int **' and `const int **' cannot point at
+ the same thing.
+
+ But, the standard is wrong. In particular, this code is
+ legal C++:
+
+ int *ip;
+ int **ipp = &ip;
+ const int* const* cipp = ipp;
+ And, it doesn't make sense for that to be legal unless you
+ can dereference IPP and CIPP. So, we ignore cv-qualifiers on
+ the pointed-to types. This issue has been reported to the
+ C++ committee.
+
+ In addition to the above canonicalization issue, with LTO
+ we should also canonicalize `T (*)[]' to `T *' avoiding
+ alias issues with pointer-to element types and pointer-to
+ array types.
+
+ Likewise we need to deal with the situation of incomplete
+ pointed-to types and make `*(struct X **)&a' and
+ `*(struct X {} **)&a' alias. Otherwise we will have to
+ guarantee that all pointer-to incomplete type variants
+ will be replaced by pointer-to complete type variants if
+ they are available.
+
+ With LTO the convenient situation of using `void *' to
+ access and store any pointer type will also become
+ more apparent (and `void *' is just another pointer-to
+ incomplete type). Assigning alias-set zero to `void *'
+ and all pointer-to incomplete types is a not appealing
+ solution. Assigning an effective alias-set zero only
+ affecting pointers might be - by recording proper subset
+ relationships of all pointer alias-sets.
+
+ Pointer-to function types are another grey area which
+ needs caution. Globbing them all into one alias-set
+ or the above effective zero set would work.
+
+ For now just assign the same alias-set to all pointers.
+ That's simple and avoids all the above problems. */
+ else if (POINTER_TYPE_P (t)
+ && t != ptr_type_node)
+ set = get_alias_set (ptr_type_node);
+
/* Otherwise make a new alias set for this type. */
else
- set = new_alias_set ();
+ {
+ /* Each canonical type gets its own alias set, so canonical types
+ shouldn't form a tree. It doesn't really matter for types
+ we handle specially above, so only check it where it possibly
+ would result in a bogus alias set. */
+ gcc_checking_assert (TYPE_CANONICAL (t) == t);
+
+ set = new_alias_set ();
+ }
TYPE_ALIAS_SET (t) = set;
reg_seen[regno] = 1;
}
+/* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid
+ using hard registers with non-null REG_BASE_VALUE for renaming. */
+rtx
+get_reg_base_value (unsigned int regno)
+{
+ return VEC_index (rtx, reg_base_value, regno);
+}
+
/* If a value is known for REGNO, return it. */
rtx
find_base_term (rtx x)
{
cselib_val *val;
- struct elt_loc_list *l;
+ struct elt_loc_list *l, *f;
+ rtx ret;
#if defined (FIND_BASE_TERM)
/* Try machine-dependent ways to find the base term. */
case VALUE:
val = CSELIB_VAL_PTR (x);
+ ret = NULL_RTX;
+
if (!val)
- return 0;
- for (l = val->locs; l; l = l->next)
- if ((x = find_base_term (l->loc)) != 0)
- return x;
- return 0;
+ return ret;
+
+ f = val->locs;
+ /* Temporarily reset val->locs to avoid infinite recursion. */
+ val->locs = NULL;
+
+ for (l = f; l; l = l->next)
+ if (GET_CODE (l->loc) == VALUE
+ && CSELIB_VAL_PTR (l->loc)->locs
+ && !CSELIB_VAL_PTR (l->loc)->locs->next
+ && CSELIB_VAL_PTR (l->loc)->locs->loc == x)
+ continue;
+ else if ((ret = find_base_term (l->loc)) != 0)
+ break;
+
+ val->locs = f;
+ return ret;
case LO_SUM:
/* The standard form is (lo_sum reg sym) so look only at the
return x && DECL_P (x) ? x : NULL_TREE;
}
-/* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the
- offset of the field reference. */
+/* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate
+ for the offset of the field reference. *KNOWN_P says whether the
+ offset is known. */
-static rtx
-adjust_offset_for_component_ref (tree x, rtx offset)
+static void
+adjust_offset_for_component_ref (tree x, bool *known_p,
+ HOST_WIDE_INT *offset)
{
- HOST_WIDE_INT ioffset;
-
- if (! offset)
- return NULL_RTX;
-
- ioffset = INTVAL (offset);
+ if (!*known_p)
+ return;
do
{
- tree offset = component_ref_field_offset (x);
+ tree xoffset = component_ref_field_offset (x);
tree field = TREE_OPERAND (x, 1);
- if (! host_integerp (offset, 1))
- return NULL_RTX;
- ioffset += (tree_low_cst (offset, 1)
+ if (! host_integerp (xoffset, 1))
+ {
+ *known_p = false;
+ return;
+ }
+ *offset += (tree_low_cst (xoffset, 1)
+ (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
/ BITS_PER_UNIT));
x = TREE_OPERAND (x, 0);
}
while (x && TREE_CODE (x) == COMPONENT_REF);
-
- return GEN_INT (ioffset);
}
/* 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;
rtx basex, basey;
- rtx moffsetx, moffsety;
+ bool moffsetx_known_p, moffsety_known_p;
+ HOST_WIDE_INT moffsetx = 0, moffsety = 0;
HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem;
/* Unless both have exprs, we can't tell anything. */
/* For spill-slot accesses make sure we have valid offsets. */
if ((exprx == get_spill_slot_decl (false)
- && ! MEM_OFFSET (x))
+ && ! MEM_OFFSET_KNOWN_P (x))
|| (expry == get_spill_slot_decl (false)
- && ! MEM_OFFSET (y)))
+ && ! MEM_OFFSET_KNOWN_P (y)))
return 0;
/* If both are field references, we may be able to determine something. */
/* If the field reference test failed, look at the DECLs involved. */
- moffsetx = MEM_OFFSET (x);
+ moffsetx_known_p = MEM_OFFSET_KNOWN_P (x);
+ if (moffsetx_known_p)
+ moffsetx = MEM_OFFSET (x);
if (TREE_CODE (exprx) == COMPONENT_REF)
{
tree t = decl_for_component_ref (exprx);
if (! t)
return 0;
- moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
+ adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx);
exprx = t;
}
- moffsety = MEM_OFFSET (y);
+ moffsety_known_p = MEM_OFFSET_KNOWN_P (y);
+ if (moffsety_known_p)
+ moffsety = MEM_OFFSET (y);
if (TREE_CODE (expry) == COMPONENT_REF)
{
tree t = decl_for_component_ref (expry);
if (! t)
return 0;
- moffsety = adjust_offset_for_component_ref (expry, moffsety);
+ adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety);
expry = t;
}
|| (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))
+ : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx)
: -1);
sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly))
- : MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) :
- -1);
+ : MEM_SIZE_KNOWN_P (rtly) ? MEM_SIZE (rtly)
+ : -1);
/* If we have an offset for either memref, it can update the values computed
above. */
- if (moffsetx)
- offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx);
- if (moffsety)
- offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety);
+ if (moffsetx_known_p)
+ offsetx += moffsetx, sizex -= moffsetx;
+ if (moffsety_known_p)
+ offsety += moffsety, sizey -= moffsety;
/* If a memref has both a size and an offset, we can use the smaller size.
We can't do this if the offset isn't known because we must view this
memref as being anywhere inside the DECL's MEM. */
- if (MEM_SIZE (x) && moffsetx)
- sizex = INTVAL (MEM_SIZE (x));
- if (MEM_SIZE (y) && moffsety)
- sizey = INTVAL (MEM_SIZE (y));
+ if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p)
+ sizex = MEM_SIZE (x);
+ if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p)
+ sizey = MEM_SIZE (y);
/* Put the values of the memref with the lower offset in X's values. */
if (offsetx > offsety)
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))
/* We cannot use aliases_everything_p to test MEM, since we must look
at MEM_ADDR, rather than XEXP (mem, 0). */
- if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
+ if (GET_CODE (mem_addr) == AND)
return 1;
/* ??? In true_dependence we also allow BLKmode to alias anything. Why
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_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)
{
= gen_rtx_ADDRESS (Pmode, arg_pointer_rtx);
static_reg_base_value[FRAME_POINTER_REGNUM]
= gen_rtx_ADDRESS (Pmode, frame_pointer_rtx);
-#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
+#if !HARD_FRAME_POINTER_IS_FRAME_POINTER
static_reg_base_value[HARD_FRAME_POINTER_REGNUM]
= gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
#endif
timevar_pop (TV_ALIAS_ANALYSIS);
}
+/* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2).
+ Special API for var-tracking pass purposes. */
+
+void
+vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2)
+{
+ VEC_replace (rtx, reg_base_value, REGNO (reg1), REG_BASE_VALUE (reg2));
+}
+
void
end_alias_analysis (void)
{
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