Hi,
we're having issues with get_ref_base_and_extent overflowing the offset and
thus returning bogus big negative values on 32-bit hosts. The attached patch
converts it to double ints like get_inner_reference. It also contains a small
fix for build_user_friendly_ref_for_offset that can stop if a field has again
too big an offset.
Tested on x86_64-suse-linux and i586-suse-linux, OK for mainline?
2012-05-30 Eric Botcazou <ebotca...@adacore.com>
* tree-dfa.c (get_ref_base_and_extent): Compute the offset using
double ints throughout.
* tree-sra.c (build_user_friendly_ref_for_offset) <RECORD_TYPE>:
Check that the position of the field is representable as an integer.
--
Eric Botcazou
Index: tree-dfa.c
===================================================================
--- tree-dfa.c (revision 187922)
+++ tree-dfa.c (working copy)
@@ -614,7 +614,8 @@ get_ref_base_and_extent (tree exp, HOST_
HOST_WIDE_INT bitsize = -1;
HOST_WIDE_INT maxsize = -1;
tree size_tree = NULL_TREE;
- HOST_WIDE_INT bit_offset = 0;
+ double_int bit_offset = double_int_zero;
+ HOST_WIDE_INT hbit_offset;
bool seen_variable_array_ref = false;
tree base_type;
@@ -652,7 +653,9 @@ get_ref_base_and_extent (tree exp, HOST_
switch (TREE_CODE (exp))
{
case BIT_FIELD_REF:
- bit_offset += TREE_INT_CST_LOW (TREE_OPERAND (exp, 2));
+ bit_offset
+ = double_int_add (bit_offset,
+ tree_to_double_int (TREE_OPERAND (exp, 2)));
break;
case COMPONENT_REF:
@@ -660,22 +663,23 @@ get_ref_base_and_extent (tree exp, HOST_
tree field = TREE_OPERAND (exp, 1);
tree this_offset = component_ref_field_offset (exp);
- if (this_offset
- && TREE_CODE (this_offset) == INTEGER_CST
- && host_integerp (this_offset, 0))
+ if (this_offset && TREE_CODE (this_offset) == INTEGER_CST)
{
- HOST_WIDE_INT hthis_offset = TREE_INT_CST_LOW (this_offset);
- hthis_offset *= BITS_PER_UNIT;
- hthis_offset
- += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
- bit_offset += hthis_offset;
+ double_int doffset = tree_to_double_int (this_offset);
+ doffset = double_int_lshift (doffset,
+ BITS_PER_UNIT == 8
+ ? 3 : exact_log2 (BITS_PER_UNIT),
+ HOST_BITS_PER_DOUBLE_INT, true);
+ doffset = double_int_add (doffset,
+ tree_to_double_int
+ (DECL_FIELD_BIT_OFFSET (field)));
+ bit_offset = double_int_add (bit_offset, doffset);
/* If we had seen a variable array ref already and we just
referenced the last field of a struct or a union member
then we have to adjust maxsize by the padding at the end
of our field. */
- if (seen_variable_array_ref
- && maxsize != -1)
+ if (seen_variable_array_ref && maxsize != -1)
{
tree stype = TREE_TYPE (TREE_OPERAND (exp, 0));
tree next = DECL_CHAIN (field);
@@ -687,10 +691,12 @@ get_ref_base_and_extent (tree exp, HOST_
tree fsize = DECL_SIZE_UNIT (field);
tree ssize = TYPE_SIZE_UNIT (stype);
if (host_integerp (fsize, 0)
- && host_integerp (ssize, 0))
+ && host_integerp (ssize, 0)
+ && double_int_fits_in_shwi_p (doffset))
maxsize += ((TREE_INT_CST_LOW (ssize)
- TREE_INT_CST_LOW (fsize))
- * BITS_PER_UNIT - hthis_offset);
+ * BITS_PER_UNIT
+ - double_int_to_shwi (doffset));
else
maxsize = -1;
}
@@ -702,8 +708,12 @@ get_ref_base_and_extent (tree exp, HOST_
/* We need to adjust maxsize to the whole structure bitsize.
But we can subtract any constant offset seen so far,
because that would get us out of the structure otherwise. */
- if (maxsize != -1 && csize && host_integerp (csize, 1))
- maxsize = TREE_INT_CST_LOW (csize) - bit_offset;
+ if (maxsize != -1
+ && csize
+ && host_integerp (csize, 1)
+ && double_int_fits_in_shwi_p (bit_offset))
+ maxsize = TREE_INT_CST_LOW (csize)
+ - double_int_to_shwi (bit_offset);
else
maxsize = -1;
}
@@ -715,24 +725,26 @@ get_ref_base_and_extent (tree exp, HOST_
{
tree index = TREE_OPERAND (exp, 1);
tree low_bound, unit_size;
- double_int doffset;
/* If the resulting bit-offset is constant, track it. */
if (TREE_CODE (index) == INTEGER_CST
&& (low_bound = array_ref_low_bound (exp),
TREE_CODE (low_bound) == INTEGER_CST)
&& (unit_size = array_ref_element_size (exp),
- host_integerp (unit_size, 1))
- && (doffset = double_int_sext
- (double_int_sub (TREE_INT_CST (index),
- TREE_INT_CST (low_bound)),
- TYPE_PRECISION (TREE_TYPE (index))),
- double_int_fits_in_shwi_p (doffset)))
+ TREE_CODE (unit_size) == INTEGER_CST))
{
- HOST_WIDE_INT hoffset = double_int_to_shwi (doffset);
- hoffset *= TREE_INT_CST_LOW (unit_size);
- hoffset *= BITS_PER_UNIT;
- bit_offset += hoffset;
+ double_int doffset
+ = double_int_sext
+ (double_int_sub (TREE_INT_CST (index),
+ TREE_INT_CST (low_bound)),
+ TYPE_PRECISION (TREE_TYPE (index)));
+ doffset = double_int_mul (doffset,
+ tree_to_double_int (unit_size));
+ doffset = double_int_lshift (doffset,
+ BITS_PER_UNIT == 8
+ ? 3 : exact_log2 (BITS_PER_UNIT),
+ HOST_BITS_PER_DOUBLE_INT, true);
+ bit_offset = double_int_add (bit_offset, doffset);
/* An array ref with a constant index up in the structure
hierarchy will constrain the size of any variable array ref
@@ -745,8 +757,12 @@ get_ref_base_and_extent (tree exp, HOST_
/* We need to adjust maxsize to the whole array bitsize.
But we can subtract any constant offset seen so far,
because that would get us outside of the array otherwise. */
- if (maxsize != -1 && asize && host_integerp (asize, 1))
- maxsize = TREE_INT_CST_LOW (asize) - bit_offset;
+ if (maxsize != -1
+ && asize
+ && host_integerp (asize, 1)
+ && double_int_fits_in_shwi_p (bit_offset))
+ maxsize = TREE_INT_CST_LOW (asize)
+ - double_int_to_shwi (bit_offset);
else
maxsize = -1;
@@ -761,7 +777,8 @@ get_ref_base_and_extent (tree exp, HOST_
break;
case IMAGPART_EXPR:
- bit_offset += bitsize;
+ bit_offset
+ = double_int_add (bit_offset, uhwi_to_double_int (bitsize));
break;
case VIEW_CONVERT_EXPR:
@@ -780,10 +797,10 @@ get_ref_base_and_extent (tree exp, HOST_
BITS_PER_UNIT == 8
? 3 : exact_log2 (BITS_PER_UNIT),
HOST_BITS_PER_DOUBLE_INT, true);
- off = double_int_add (off, shwi_to_double_int (bit_offset));
+ off = double_int_add (off, bit_offset);
if (double_int_fits_in_shwi_p (off))
{
- bit_offset = double_int_to_shwi (off);
+ bit_offset = off;
exp = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
}
}
@@ -799,7 +816,7 @@ get_ref_base_and_extent (tree exp, HOST_
if (TMR_INDEX (exp) || TMR_INDEX2 (exp))
{
exp = TREE_OPERAND (TMR_BASE (exp), 0);
- bit_offset = 0;
+ bit_offset = double_int_zero;
maxsize = -1;
goto done;
}
@@ -812,10 +829,10 @@ get_ref_base_and_extent (tree exp, HOST_
BITS_PER_UNIT == 8
? 3 : exact_log2 (BITS_PER_UNIT),
HOST_BITS_PER_DOUBLE_INT, true);
- off = double_int_add (off, shwi_to_double_int (bit_offset));
+ off = double_int_add (off, bit_offset);
if (double_int_fits_in_shwi_p (off))
{
- bit_offset = double_int_to_shwi (off);
+ bit_offset = off;
exp = TREE_OPERAND (TMR_BASE (exp), 0);
}
}
@@ -830,6 +847,17 @@ get_ref_base_and_extent (tree exp, HOST_
}
done:
+ if (!double_int_fits_in_shwi_p (bit_offset))
+ {
+ *poffset = 0;
+ *psize = bitsize;
+ *pmax_size = -1;
+
+ return exp;
+ }
+
+ hbit_offset = double_int_to_shwi (bit_offset);
+
/* We need to deal with variable arrays ending structures such as
struct { int length; int a[1]; } x; x.a[d]
struct { struct { int a; int b; } a[1]; } x; x.a[d].a
@@ -844,7 +872,7 @@ get_ref_base_and_extent (tree exp, HOST_
if (seen_variable_array_ref
&& maxsize != -1
&& (!host_integerp (TYPE_SIZE (base_type), 1)
- || (bit_offset + maxsize
+ || (hbit_offset + maxsize
== (signed) TREE_INT_CST_LOW (TYPE_SIZE (base_type)))))
maxsize = -1;
@@ -856,7 +884,7 @@ get_ref_base_and_extent (tree exp, HOST_
base decl. */
if (maxsize == -1
&& host_integerp (DECL_SIZE (exp), 1))
- maxsize = TREE_INT_CST_LOW (DECL_SIZE (exp)) - bit_offset;
+ maxsize = TREE_INT_CST_LOW (DECL_SIZE (exp)) - hbit_offset;
}
else if (CONSTANT_CLASS_P (exp))
{
@@ -864,13 +892,13 @@ get_ref_base_and_extent (tree exp, HOST_
base type constant. */
if (maxsize == -1
&& host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1))
- maxsize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))) - bit_offset;
+ maxsize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))) - hbit_offset;
}
/* ??? Due to negative offsets in ARRAY_REF we can end up with
negative bit_offset here. We might want to store a zero offset
in this case. */
- *poffset = bit_offset;
+ *poffset = hbit_offset;
*psize = bitsize;
*pmax_size = maxsize;
Index: tree-sra.c
===================================================================
--- tree-sra.c (revision 187922)
+++ tree-sra.c (working copy)
@@ -1549,17 +1549,20 @@ build_user_friendly_ref_for_offset (tree
for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
{
HOST_WIDE_INT pos, size;
- tree expr, *expr_ptr;
+ tree tr_pos, expr, *expr_ptr;
if (TREE_CODE (fld) != FIELD_DECL)
continue;
- pos = int_bit_position (fld);
+ tr_pos = bit_position (fld);
+ if (!tr_pos || !host_integerp (tr_pos, 1))
+ continue;
+ pos = TREE_INT_CST_LOW (tr_pos);
gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
tr_size = DECL_SIZE (fld);
if (!tr_size || !host_integerp (tr_size, 1))
continue;
- size = tree_low_cst (tr_size, 1);
+ size = TREE_INT_CST_LOW (tr_size);
if (size == 0)
{
if (pos != offset)
