#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
+#include "langhooks.h"
/* The alias sets assigned to MEMs assist the back-end in determining
which MEMs can alias which other MEMs. In general, two MEMs in
static rtx find_base_term PARAMS ((rtx));
static int base_alias_check PARAMS ((rtx, rtx, enum machine_mode,
enum machine_mode));
-static int handled_component_p PARAMS ((tree));
-static int can_address_p PARAMS ((tree));
static rtx find_base_value PARAMS ((rtx));
static int mems_in_disjoint_alias_sets_p PARAMS ((rtx, rtx));
static int insert_subset_children PARAMS ((splay_tree_node, void*));
static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx,
int (*) (rtx, int)));
static int aliases_everything_p PARAMS ((rtx));
+static bool nonoverlapping_component_refs_p PARAMS ((tree, tree));
+static tree decl_for_component_ref PARAMS ((tree));
+static rtx adjust_offset_for_component_ref PARAMS ((tree, rtx));
+static int nonoverlapping_memrefs_p PARAMS ((rtx, rtx));
static int write_dependence_p PARAMS ((rtx, rtx, int));
+
+static int nonlocal_mentioned_p_1 PARAMS ((rtx *, void *));
static int nonlocal_mentioned_p PARAMS ((rtx));
+static int nonlocal_referenced_p_1 PARAMS ((rtx *, void *));
+static int nonlocal_referenced_p PARAMS ((rtx));
+static int nonlocal_set_p_1 PARAMS ((rtx *, void *));
+static int nonlocal_set_p PARAMS ((rtx));
/* Set up all info needed to perform alias analysis on memory references. */
/* T is an expression with pointer type. Find the DECL on which this
expression is based. (For example, in `a[i]' this would be `a'.)
If there is no such DECL, or a unique decl cannot be determined,
- NULL_TREE is retured. */
+ NULL_TREE is returned. */
static tree
find_base_decl (t)
}
}
-/* Return 1 if T is an expression that get_inner_reference handles. */
-
-static int
-handled_component_p (t)
- tree t;
-{
- switch (TREE_CODE (t))
- {
- case BIT_FIELD_REF:
- case COMPONENT_REF:
- case ARRAY_REF:
- case ARRAY_RANGE_REF:
- case NON_LVALUE_EXPR:
- return 1;
-
- case NOP_EXPR:
- case CONVERT_EXPR:
- return (TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 0))));
-
- default:
- return 0;
- }
-}
-
/* Return 1 if all the nested component references handled by
get_inner_reference in T are such that we can address the object in T. */
-static int
+int
can_address_p (t)
tree t;
{
else if (TREE_CODE (t) == BIT_FIELD_REF)
return 0;
+ /* Fields are addressable unless they are marked as nonaddressable or
+ the containing type has alias set 0. */
else if (TREE_CODE (t) == COMPONENT_REF
&& ! DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))
+ && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0
&& can_address_p (TREE_OPERAND (t, 0)))
return 1;
+ /* Likewise for arrays. */
else if ((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
&& ! TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))
+ && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0
&& can_address_p (TREE_OPERAND (t, 0)))
return 1;
tree inner = t;
tree placeholder_ptr = 0;
+ /* Remove any nops, then give the language a chance to do
+ something with this tree before we look at it. */
+ STRIP_NOPS (t);
+ set = (*lang_hooks.get_alias_set) (t);
+ if (set != -1)
+ return set;
+
/* First see if the actual object referenced is an INDIRECT_REF from a
- restrict-qualified pointer or a "void *". Start by removing nops
- since we care only about the actual object. Also replace
+ restrict-qualified pointer or a "void *". Replace
PLACEHOLDER_EXPRs. */
- while (((TREE_CODE (inner) == NOP_EXPR
- || TREE_CODE (inner) == CONVERT_EXPR)
- && (TYPE_MODE (TREE_TYPE (inner))
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (inner, 0)))))
- || TREE_CODE (inner) == NON_LVALUE_EXPR
- || TREE_CODE (inner) == PLACEHOLDER_EXPR
+ while (TREE_CODE (inner) == PLACEHOLDER_EXPR
|| handled_component_p (inner))
{
if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
inner = find_placeholder (inner, &placeholder_ptr);
else
inner = TREE_OPERAND (inner, 0);
+
+ STRIP_NOPS (inner);
}
/* Check for accesses through restrict-qualified pointers. */
if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
{
- /* If we haven't computed the actual alias set, do it now. */
+ /* If we haven't computed the actual alias set, do it now. */
if (DECL_POINTER_ALIAS_SET (decl) == -2)
{
/* No two restricted pointers can point at the same thing.
/* Otherwise, pick up the outermost object that we could have a pointer
to, processing conversion and PLACEHOLDER_EXPR as above. */
placeholder_ptr = 0;
- while (((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
- && (TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 0)))))
- || TREE_CODE (t) == NON_LVALUE_EXPR
- || TREE_CODE (t) == PLACEHOLDER_EXPR
+ while (TREE_CODE (t) == PLACEHOLDER_EXPR
|| (handled_component_p (t) && ! can_address_p (t)))
{
- /* Give the language a chance to do something with this tree
- before we go inside it. */
- if ((set = lang_get_alias_set (t)) != -1)
- return set;
-
if (TREE_CODE (t) == PLACEHOLDER_EXPR)
t = find_placeholder (t, &placeholder_ptr);
else
t = TREE_OPERAND (t, 0);
- }
- /* Give the language another chance to do something. */
- if ((set = lang_get_alias_set (t)) != -1)
- return set;
+ STRIP_NOPS (t);
+ }
/* If we've already determined the alias set for a decl, just return
it. This is necessary for C++ anonymous unions, whose component
return TYPE_ALIAS_SET (t);
/* See if the language has special handling for this type. */
- if ((set = lang_get_alias_set (t)) != -1)
+ set = (*lang_hooks.get_alias_set) (t);
+ if (set != -1)
return set;
/* There are no objects of FUNCTION_TYPE, so there's no point in
case RECORD_TYPE:
case UNION_TYPE:
case QUAL_UNION_TYPE:
+ /* Recursively record aliases for the base classes, if there are any */
+ if (TYPE_BINFO (type) != NULL && TYPE_BINFO_BASETYPES (type) != NULL)
+ {
+ int i;
+ for (i = 0; i < TREE_VEC_LENGTH (TYPE_BINFO_BASETYPES (type)); i++)
+ {
+ tree binfo = TREE_VEC_ELT (TYPE_BINFO_BASETYPES (type), i);
+ record_alias_subset (superset,
+ get_alias_set (BINFO_TYPE (binfo)));
+ }
+ }
for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
rtx src;
{
unsigned int regno;
+
switch (GET_CODE (src))
{
case SYMBOL_REF:
return new_reg_base_value[regno];
/* If a pseudo has a known base value, return it. Do not do this
- for hard regs since it can result in a circular dependency
- chain for registers which have values at function entry.
+ for non-fixed hard regs since it can result in a circular
+ dependency chain for registers which have values at function entry.
The test above is not sufficient because the scheduler may move
a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */
- if (regno >= FIRST_PSEUDO_REGISTER
+ if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
&& regno < reg_base_value_size
&& reg_base_value[regno])
return reg_base_value[regno];
{
rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1);
+ /* If either operand is a REG that is a known pointer, then it
+ is the base. */
+ if (REG_P (src_0) && REG_POINTER (src_0))
+ return find_base_value (src_0);
+ if (REG_P (src_1) && REG_POINTER (src_1))
+ return find_base_value (src_1);
+
/* If either operand is a REG, then see if we already have
a known value for it. */
- if (GET_CODE (src_0) == REG)
+ if (REG_P (src_0))
{
temp = find_base_value (src_0);
if (temp != 0)
src_0 = temp;
}
- if (GET_CODE (src_1) == REG)
+ if (REG_P (src_1))
{
temp = find_base_value (src_1);
if (temp!= 0)
src_1 = temp;
}
+ /* If either base is named object or a special address
+ (like an argument or stack reference), then use it for the
+ base term. */
+ if (src_0 != 0
+ && (GET_CODE (src_0) == SYMBOL_REF
+ || GET_CODE (src_0) == LABEL_REF
+ || (GET_CODE (src_0) == ADDRESS
+ && GET_MODE (src_0) != VOIDmode)))
+ return src_0;
+
+ if (src_1 != 0
+ && (GET_CODE (src_1) == SYMBOL_REF
+ || GET_CODE (src_1) == LABEL_REF
+ || (GET_CODE (src_1) == ADDRESS
+ && GET_MODE (src_1) != VOIDmode)))
+ return src_1;
+
/* Guess which operand is the base address:
If either operand is a symbol, then it is the base. If
either operand is a CONST_INT, then the other is the base. */
else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1))
return find_base_value (src_1);
- /* This might not be necessary anymore:
- If either operand is a REG that is a known pointer, then it
- is the base. */
- else if (GET_CODE (src_0) == REG && REG_POINTER (src_0))
- return find_base_value (src_0);
- else if (GET_CODE (src_1) == REG && REG_POINTER (src_1))
- return find_base_value (src_1);
-
return 0;
}
if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode))
break;
/* Fall through. */
- case ZERO_EXTEND:
- case SIGN_EXTEND: /* used for NT/Alpha pointers */
case HIGH:
+ case PRE_INC:
+ case PRE_DEC:
+ case POST_INC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
return find_base_value (XEXP (src, 0));
+ case ZERO_EXTEND:
+ case SIGN_EXTEND: /* used for NT/Alpha pointers */
+ {
+ rtx temp = find_base_value (XEXP (src, 0));
+
+#ifdef POINTERS_EXTEND_UNSIGNED
+ if (temp != 0 && CONSTANT_P (temp) && GET_MODE (temp) != Pmode)
+ temp = convert_memory_address (Pmode, temp);
+#endif
+
+ return temp;
+ }
+
default:
break;
}
case REG:
return REG_BASE_VALUE (x);
- case ZERO_EXTEND:
- case SIGN_EXTEND: /* Used for Alpha/NT pointers */
+ case TRUNCATE:
+ if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode))
+ return 0;
+ /* Fall through. */
case HIGH:
case PRE_INC:
case PRE_DEC:
case POST_INC:
case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
return find_base_term (XEXP (x, 0));
+ case ZERO_EXTEND:
+ case SIGN_EXTEND: /* Used for Alpha/NT pointers */
+ {
+ rtx temp = find_base_term (XEXP (x, 0));
+
+#ifdef POINTERS_EXTEND_UNSIGNED
+ if (temp != 0 && CONSTANT_P (temp) && GET_MODE (temp) != Pmode)
+ temp = convert_memory_address (Pmode, temp);
+#endif
+
+ return temp;
+ }
+
case VALUE:
val = CSELIB_VAL_PTR (x);
for (l = val->locs; l; l = l->next)
rtx tmp1 = XEXP (x, 0);
rtx tmp2 = XEXP (x, 1);
- /* This is a litle bit tricky since we have to determine which of
+ /* This is a little bit tricky since we have to determine which of
the two operands represents the real base address. Otherwise this
routine may return the index register instead of the base register.
}
case AND:
- if (GET_CODE (XEXP (x, 0)) == REG && GET_CODE (XEXP (x, 1)) == CONST_INT)
- return REG_BASE_VALUE (XEXP (x, 0));
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0)
+ return find_base_term (XEXP (x, 0));
return 0;
case SYMBOL_REF:
return 0;
}
+/* Return true if we can determine that the fields referenced cannot
+ overlap for any pair of objects. */
+
+static bool
+nonoverlapping_component_refs_p (x, y)
+ tree x, y;
+{
+ tree fieldx, fieldy, typex, typey, orig_y;
+
+ do
+ {
+ /* The comparison has to be done at a common type, since we don't
+ know how the inheritance hierarchy works. */
+ orig_y = y;
+ do
+ {
+ fieldx = TREE_OPERAND (x, 1);
+ typex = DECL_FIELD_CONTEXT (fieldx);
+
+ y = orig_y;
+ do
+ {
+ fieldy = TREE_OPERAND (y, 1);
+ typey = DECL_FIELD_CONTEXT (fieldy);
+
+ if (typex == typey)
+ goto found;
+
+ y = TREE_OPERAND (y, 0);
+ }
+ while (y && TREE_CODE (y) == COMPONENT_REF);
+
+ x = TREE_OPERAND (x, 0);
+ }
+ while (x && TREE_CODE (x) == COMPONENT_REF);
+
+ /* Never found a common type. */
+ return false;
+
+ found:
+ /* If we're left with accessing different fields of a structure,
+ then no overlap. */
+ if (TREE_CODE (typex) == RECORD_TYPE
+ && fieldx != fieldy)
+ return true;
+
+ /* The comparison on the current field failed. If we're accessing
+ a very nested structure, look at the next outer level. */
+ x = TREE_OPERAND (x, 0);
+ y = TREE_OPERAND (y, 0);
+ }
+ while (x && y
+ && TREE_CODE (x) == COMPONENT_REF
+ && TREE_CODE (y) == COMPONENT_REF);
+
+ return false;
+}
+
+/* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */
+
+static tree
+decl_for_component_ref (x)
+ tree x;
+{
+ do
+ {
+ x = TREE_OPERAND (x, 0);
+ }
+ while (x && TREE_CODE (x) == COMPONENT_REF);
+
+ 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. */
+
+static rtx
+adjust_offset_for_component_ref (x, offset)
+ tree x;
+ rtx offset;
+{
+ HOST_WIDE_INT ioffset;
+
+ if (! offset)
+ return NULL_RTX;
+
+ ioffset = INTVAL (offset);
+ do
+ {
+ tree field = TREE_OPERAND (x, 1);
+
+ if (! host_integerp (DECL_FIELD_OFFSET (field), 1))
+ return NULL_RTX;
+ ioffset += (tree_low_cst (DECL_FIELD_OFFSET (field), 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 deterimine the exprs corresponding to memrefs
+ X and Y and they do not overlap. */
+
+static int
+nonoverlapping_memrefs_p (x, y)
+ rtx x, y;
+{
+ tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
+ rtx rtlx, rtly;
+ rtx basex, basey;
+ rtx moffsetx, moffsety;
+ HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem;
+
+ /* Unless both have exprs, we can't tell anything. */
+ if (exprx == 0 || expry == 0)
+ return 0;
+
+ /* If both are field references, we may be able to determine something. */
+ if (TREE_CODE (exprx) == COMPONENT_REF
+ && TREE_CODE (expry) == COMPONENT_REF
+ && nonoverlapping_component_refs_p (exprx, expry))
+ return 1;
+
+ /* If the field reference test failed, look at the DECLs involved. */
+ 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);
+ exprx = t;
+ }
+ 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);
+ expry = t;
+ }
+
+ if (! DECL_P (exprx) || ! DECL_P (expry))
+ return 0;
+
+ rtlx = DECL_RTL (exprx);
+ rtly = DECL_RTL (expry);
+
+ /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they
+ can't overlap unless they are the same because we never reuse that part
+ of the stack frame used for locals for spilled pseudos. */
+ if ((GET_CODE (rtlx) != MEM || GET_CODE (rtly) != MEM)
+ && ! rtx_equal_p (rtlx, rtly))
+ return 1;
+
+ /* Get the base and offsets of both decls. If either is a register, we
+ know both are and are the same, so use that as the base. The only
+ we can avoid overlap is if we can deduce that they are nonoverlapping
+ pieces of that decl, which is very rare. */
+ basex = GET_CODE (rtlx) == MEM ? XEXP (rtlx, 0) : rtlx;
+ if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT)
+ offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0);
+
+ basey = GET_CODE (rtly) == MEM ? XEXP (rtly, 0) : rtly;
+ if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT)
+ offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0);
+
+ /* If the bases are different, we know they do not overlap if both
+ are constants or if one is a constant and the other a pointer into the
+ stack frame. Otherwise a different base means we can't tell if they
+ overlap or not. */
+ if (! rtx_equal_p (basex, basey))
+ return ((CONSTANT_P (basex) && CONSTANT_P (basey))
+ || (CONSTANT_P (basex) && REG_P (basey)
+ && REGNO_PTR_FRAME_P (REGNO (basey)))
+ || (CONSTANT_P (basey) && REG_P (basex)
+ && REGNO_PTR_FRAME_P (REGNO (basex))));
+
+ sizex = (GET_CODE (rtlx) != MEM ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
+ : MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
+ : -1);
+ sizey = (GET_CODE (rtly) != MEM ? (int) GET_MODE_SIZE (GET_MODE (rtly))
+ : MEM_SIZE (rtly) ? INTVAL (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 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));
+
+ /* Put the values of the memref with the lower offset in X's values. */
+ if (offsetx > offsety)
+ {
+ tem = offsetx, offsetx = offsety, offsety = tem;
+ tem = sizex, sizex = sizey, sizey = tem;
+ }
+
+ /* If we don't know the size of the lower-offset value, we can't tell
+ if they conflict. Otherwise, we do the test. */
+ return sizex >= 0 && offsety > offsetx + sizex;
+}
+
/* True dependence: X is read after store in MEM takes place. */
int
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 (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
return 0;
+ if (nonoverlapping_memrefs_p (mem, x))
+ return 0;
+
if (mem_mode == VOIDmode)
mem_mode = GET_MODE (mem);
if (aliases_everything_p (x))
return 1;
- /* We cannot use aliases_everyting_p to test MEM, since we must look
+ /* 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;
}
/* Canonical true dependence: X is read after store in MEM takes place.
- Variant of true_dependece which assumes MEM has already been
+ 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 (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 (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
return 0;
+ if (nonoverlapping_memrefs_p (x, mem))
+ return 0;
+
x_addr = get_addr (XEXP (x, 0));
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
if (aliases_everything_p (x))
return 1;
- /* We cannot use aliases_everyting_p to test MEM, since we must look
+ /* 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;
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 (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
if (! writep && RTX_UNCHANGING_P (mem))
return 0;
+ if (nonoverlapping_memrefs_p (x, mem))
+ return 0;
+
x_addr = get_addr (XEXP (x, 0));
mem_addr = get_addr (XEXP (mem, 0));
{
return write_dependence_p (mem, x, /*writep=*/1);
}
-
-/* Returns non-zero if X mentions something which is not
- local to the function and is not constant. */
+\f
+/* A subroutine of nonlocal_mentioned_p, returns 1 if *LOC mentions
+ something which is not local to the function and is not constant. */
static int
-nonlocal_mentioned_p (x)
- rtx x;
+nonlocal_mentioned_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
{
+ rtx x = *loc;
rtx base;
- RTX_CODE code;
int regno;
- code = GET_CODE (x);
-
- if (GET_RTX_CLASS (code) == 'i')
- {
- /* Constant functions can be constant if they don't use
- scratch memory used to mark function w/o side effects. */
- if (code == CALL_INSN && CONST_OR_PURE_CALL_P (x))
- {
- x = CALL_INSN_FUNCTION_USAGE (x);
- if (x == 0)
- return 0;
- }
- else
- x = PATTERN (x);
- code = GET_CODE (x);
- }
+ if (! x)
+ return 0;
- switch (code)
+ switch (GET_CODE (x))
{
case SUBREG:
if (GET_CODE (SUBREG_REG (x)) == REG)
case CC0:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case CONST:
case LABEL_REF:
return 0;
break;
}
- /* Recursively scan the operands of this expression. */
+ return 0;
+}
- {
- const char *fmt = GET_RTX_FORMAT (code);
- int i;
-
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e' && XEXP (x, i))
- {
- if (nonlocal_mentioned_p (XEXP (x, i)))
- return 1;
- }
- else if (fmt[i] == 'E')
- {
- int j;
- for (j = 0; j < XVECLEN (x, i); j++)
- if (nonlocal_mentioned_p (XVECEXP (x, i, j)))
- return 1;
- }
- }
- }
+/* Returns non-zero if X might mention something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_mentioned_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_mentioned_p_1, NULL);
+}
+
+/* A subroutine of nonlocal_referenced_p, returns 1 if *LOC references
+ something which is not local to the function and is not constant. */
+
+static int
+nonlocal_referenced_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
+{
+ rtx x = *loc;
+
+ if (! x)
+ return 0;
+
+ switch (GET_CODE (x))
+ {
+ case MEM:
+ case REG:
+ case SYMBOL_REF:
+ case SUBREG:
+ return nonlocal_mentioned_p (x);
+
+ case CALL:
+ /* Non-constant calls and recursion are not local. */
+ return 1;
+
+ case SET:
+ if (nonlocal_mentioned_p (SET_SRC (x)))
+ return 1;
+
+ if (GET_CODE (SET_DEST (x)) == MEM)
+ return nonlocal_mentioned_p (XEXP (SET_DEST (x), 0));
+
+ /* If the destination is anything other than a CC0, PC,
+ MEM, REG, or a SUBREG of a REG that occupies all of
+ the REG, then X references nonlocal memory if it is
+ mentioned in the destination. */
+ if (GET_CODE (SET_DEST (x)) != CC0
+ && GET_CODE (SET_DEST (x)) != PC
+ && GET_CODE (SET_DEST (x)) != REG
+ && ! (GET_CODE (SET_DEST (x)) == SUBREG
+ && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG
+ && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (x))))
+ + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
+ == ((GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
+ + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
+ return nonlocal_mentioned_p (SET_DEST (x));
+ return 0;
+
+ case CLOBBER:
+ if (GET_CODE (XEXP (x, 0)) == MEM)
+ return nonlocal_mentioned_p (XEXP (XEXP (x, 0), 0));
+ return 0;
+
+ case USE:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case ASM_INPUT:
+ case UNSPEC_VOLATILE:
+ return 1;
+
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/* Returns non-zero if X might reference something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_referenced_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_referenced_p_1, NULL);
+}
+
+/* A subroutine of nonlocal_set_p, returns 1 if *LOC sets
+ something which is not local to the function and is not constant. */
+
+static int
+nonlocal_set_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
+{
+ rtx x = *loc;
+
+ if (! x)
+ return 0;
+
+ switch (GET_CODE (x))
+ {
+ case CALL:
+ /* Non-constant calls and recursion are not local. */
+ return 1;
+
+ case PRE_INC:
+ case PRE_DEC:
+ case POST_INC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case SET:
+ if (nonlocal_mentioned_p (SET_DEST (x)))
+ return 1;
+ return nonlocal_set_p (SET_SRC (x));
+
+ case CLOBBER:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case USE:
+ return 0;
+
+ case ASM_INPUT:
+ case UNSPEC_VOLATILE:
+ return 1;
+
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
return 0;
}
+/* Returns non-zero if X might set something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_set_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_set_p_1, NULL);
+}
+
/* Mark the function if it is constant. */
void
mark_constant_function ()
{
rtx insn;
- int nonlocal_mentioned;
+ int nonlocal_memory_referenced;
if (TREE_PUBLIC (current_function_decl)
|| TREE_READONLY (current_function_decl)
|| DECL_IS_PURE (current_function_decl)
|| TREE_THIS_VOLATILE (current_function_decl)
- || TYPE_MODE (TREE_TYPE (current_function_decl)) == VOIDmode)
+ || TYPE_MODE (TREE_TYPE (current_function_decl)) == VOIDmode
+ || current_function_has_nonlocal_goto)
return;
/* A loop might not return which counts as a side effect. */
if (mark_dfs_back_edges ())
return;
- nonlocal_mentioned = 0;
+ nonlocal_memory_referenced = 0;
init_alias_analysis ();
- /* Determine if this is a constant function. */
+ /* Determine if this is a constant or pure function. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- if (INSN_P (insn) && nonlocal_mentioned_p (insn))
- {
- nonlocal_mentioned = 1;
- break;
- }
+ {
+ if (! INSN_P (insn))
+ continue;
- end_alias_analysis ();
+ if (nonlocal_set_p (insn) || global_reg_mentioned_p (insn)
+ || volatile_refs_p (PATTERN (insn)))
+ break;
+ if (! nonlocal_memory_referenced)
+ nonlocal_memory_referenced = nonlocal_referenced_p (insn);
+ }
+
+ end_alias_analysis ();
+
/* Mark the function. */
-
- if (! nonlocal_mentioned)
+
+ if (insn)
+ ;
+ else if (nonlocal_memory_referenced)
+ DECL_IS_PURE (current_function_decl) = 1;
+ else
TREE_READONLY (current_function_decl) = 1;
}
-
+\f
static HARD_REG_SET argument_registers;
start counting from zero each iteration of the loop. */
unique_id = 0;
- /* We're at the start of the funtion each iteration through the
+ /* We're at the start of the function each iteration through the
loop, so we're copying arguments. */
copying_arguments = 1;
rtx note, set;
#if defined (HAVE_prologue) || defined (HAVE_epilogue)
- /* The prologue/epilouge insns are not threaded onto the
+ /* The prologue/epilogue insns are not threaded onto the
insn chain until after reload has completed. Thus,
there is no sense wasting time checking if INSN is in
the prologue/epilogue until after reload has completed. */
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