new file mode 100644
@@ -0,0 +1,48 @@
+/* PR tree-optimization/80153 */
+
+void check (int, int, int) __attribute__((noinline));
+void check (int c, int c2, int val)
+{
+ if (!val) {
+ __builtin_abort();
+ }
+}
+
+static const char *buf;
+static int l, i;
+
+void _fputs(const char *str) __attribute__((noinline));
+void _fputs(const char *str)
+{
+ buf = str;
+ i = 0;
+ l = __builtin_strlen(buf);
+}
+
+char _fgetc() __attribute__((noinline));
+char _fgetc()
+{
+ char val = buf[i];
+ i++;
+ if (i > l)
+ return -1;
+ else
+ return val;
+}
+
+static const char *string = "oops!\n";
+
+int main(void)
+{
+ int i;
+ int c;
+
+ _fputs(string);
+
+ for (i = 0; i < __builtin_strlen(string); i++) {
+ c = _fgetc();
+ check(c, string[i], c == string[i]);
+ }
+
+ return 0;
+}
@@ -370,66 +370,54 @@ tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
aff_combination_elt (comb, type, expr);
}
-/* Creates EXPR + ELT * SCALE in TYPE. EXPR is taken from affine
+/* Creates EXPR + ELT * SCALE in COMB's type. EXPR is taken from affine
combination COMB. */
static tree
-add_elt_to_tree (tree expr, tree type, tree elt, const widest_int &scale_in,
- aff_tree *comb ATTRIBUTE_UNUSED)
+add_elt_to_tree (tree expr, tree elt, const widest_int &scale_in,
+ aff_tree *comb)
{
enum tree_code code;
- tree type1 = type;
- if (POINTER_TYPE_P (type))
- type1 = sizetype;
-
+ /* Result type for this elt. */
+ tree type = POINTER_TYPE_P (comb->type) ? sizetype : comb->type;
widest_int scale = wide_int_ext_for_comb (scale_in, comb);
- if (scale == -1
- && POINTER_TYPE_P (TREE_TYPE (elt)))
- {
- elt = convert_to_ptrofftype (elt);
- elt = fold_build1 (NEGATE_EXPR, TREE_TYPE (elt), elt);
- scale = 1;
- }
+ /* Preserve elt's pointer type only if below conditions are satisfied:
+ 1) the result expression is of pointer type;
+ 2) scale is 1;
+ 3) expr is not of pointer type.
+ For all other cases, force it to result type. */
+ if (scale != 1
+ || !POINTER_TYPE_P (comb->type)
+ || !POINTER_TYPE_P (TREE_TYPE (elt))
+ || (expr != NULL_TREE && POINTER_TYPE_P (TREE_TYPE (expr))))
+ elt = fold_convert (type, elt);
if (scale == 1)
{
if (!expr)
- {
- if (POINTER_TYPE_P (TREE_TYPE (elt)))
- return elt;
- else
- return fold_convert (type1, elt);
- }
-
+ return elt;
if (POINTER_TYPE_P (TREE_TYPE (expr)))
return fold_build_pointer_plus (expr, elt);
if (POINTER_TYPE_P (TREE_TYPE (elt)))
return fold_build_pointer_plus (elt, expr);
- return fold_build2 (PLUS_EXPR, type1,
- expr, fold_convert (type1, elt));
+
+ return fold_build2 (PLUS_EXPR, type, expr, elt);
}
if (scale == -1)
{
if (!expr)
- return fold_build1 (NEGATE_EXPR, type1,
- fold_convert (type1, elt));
-
+ return fold_build1 (NEGATE_EXPR, type, elt);
if (POINTER_TYPE_P (TREE_TYPE (expr)))
- {
- elt = convert_to_ptrofftype (elt);
- elt = fold_build1 (NEGATE_EXPR, TREE_TYPE (elt), elt);
- return fold_build_pointer_plus (expr, elt);
- }
- return fold_build2 (MINUS_EXPR, type1,
- expr, fold_convert (type1, elt));
+ return fold_build_pointer_plus (expr,
+ fold_build1 (NEGATE_EXPR, type, elt));
+
+ return fold_build2 (MINUS_EXPR, type, expr, elt);
}
- elt = fold_convert (type1, elt);
if (!expr)
- return fold_build2 (MULT_EXPR, type1, elt,
- wide_int_to_tree (type1, scale));
+ return fold_build2 (MULT_EXPR, type, elt, wide_int_to_tree (type, scale));
if (wi::neg_p (scale))
{
@@ -439,15 +427,14 @@ add_elt_to_tree (tree expr, tree type, tree elt, const widest_int &scale_in,
else
code = PLUS_EXPR;
- elt = fold_build2 (MULT_EXPR, type1, elt,
- wide_int_to_tree (type1, scale));
+ elt = fold_build2 (MULT_EXPR, type, elt, wide_int_to_tree (type, scale));
if (POINTER_TYPE_P (TREE_TYPE (expr)))
{
if (code == MINUS_EXPR)
- elt = fold_build1 (NEGATE_EXPR, type1, elt);
+ elt = fold_build1 (NEGATE_EXPR, type, elt);
return fold_build_pointer_plus (expr, elt);
}
- return fold_build2 (code, type1, expr, elt);
+ return fold_build2 (code, type, expr, elt);
}
/* Makes tree from the affine combination COMB. */
@@ -455,22 +442,18 @@ add_elt_to_tree (tree expr, tree type, tree elt, const widest_int &scale_in,
tree
aff_combination_to_tree (aff_tree *comb)
{
- tree type = comb->type;
tree expr = NULL_TREE;
unsigned i;
widest_int off, sgn;
- tree type1 = type;
- if (POINTER_TYPE_P (type))
- type1 = sizetype;
+ tree type = POINTER_TYPE_P (comb->type) ? sizetype : comb->type;
gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE);
for (i = 0; i < comb->n; i++)
- expr = add_elt_to_tree (expr, type, comb->elts[i].val, comb->elts[i].coef,
- comb);
+ expr = add_elt_to_tree (expr, comb->elts[i].val, comb->elts[i].coef, comb);
if (comb->rest)
- expr = add_elt_to_tree (expr, type, comb->rest, 1, comb);
+ expr = add_elt_to_tree (expr, comb->rest, 1, comb);
/* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is
unsigned. */
@@ -484,8 +467,7 @@ aff_combination_to_tree (aff_tree *comb)
off = comb->offset;
sgn = 1;
}
- return add_elt_to_tree (expr, type, wide_int_to_tree (type1, off), sgn,
- comb);
+ return add_elt_to_tree (expr, wide_int_to_tree (type, off), sgn, comb);
}
/* Copies the tree elements of COMB to ensure that they are not shared. */
@@ -37,6 +37,52 @@ struct aff_comb_elt
widest_int coef;
};
+/* This aff_tree represents fully folded expression in a distributed way.
+ For example, tree expression:
+ (unsigned long)(A + ((sizetype)((integer)B + C) + (sizetype)D * 2) * 4)
+ can be represented as aff_tree like:
+ {
+ type = unsigned long
+ offset = 0
+ elts[0] = A * 1
+ elts[1] = B * 4
+ elts[2] = C * 4
+ elts[3] = D * 8
+ }
+ Note aff_tree has (root) type which is type of the original expression,
+ elements can have their own types which are different to aff_tree's. In
+ general, elements' type is type of folded sub-expression, and with NOP
+ type conversion stripped. For example, elts[0] has type of A, which is
+ type of STRIP_NOPS ((sizetype) A).
+
+ Given aff_tree represents folded form of the original tree expression,
+ it lacks ability to track whether the original form is of folded form
+ or non-folded form. For example, both tree expressions:
+ (unsigned)((int)A + (int)B)
+ (unsigned)(int)A + (unsigned)(int)B
+ have the same aff_tree repsentation. This imposes restrictions on this
+ facility, i.e, we need to be conservative and always generate the latter
+ form when converting aff_tree back to tree expression. This implies all
+ elements need to be converted to aff_tree's type before converting.
+
+ Always generating folded expr could lead to information loss because we
+ can no longer know that (int)A + (int)B doesn't overflow. As a result,
+ we should avoid using aff_tree in code generation directly. It should
+ be used when we want to explore CSE opportunities by breaking most
+ associations. It can be then used in code generation if there will be
+ benefit.
+
+ It's possible to represent POINTER_PLUS_EXPR in aff_tree, the aff_tree
+ has pointer type accordingly. Such aff_tree is special in two ways:
+ 1) It has a base element which is the original base pointer. Other
+ elements belong to offset part of the original expression. When
+ converting back to tree, other elements need to be converted to
+ ptr_offtype, rather than pointer type.
+ 2) In aff_tree computation, base element can be eliminated, it's the
+ user's responsibility to convert the rest aff_tree to ptr_offtype.
+ The rest aff_tree stands for offset part expression, no longer the
+ POINTER_PLUS_EXPR. */
+
struct aff_tree
{
/* Type of the result of the combination. */
@@ -1171,7 +1171,7 @@ alloc_iv (struct ivopts_data *data, tree base, tree step,
|| contain_complex_addr_expr (expr))
{
aff_tree comb;
- tree_to_aff_combination (expr, TREE_TYPE (base), &comb);
+ tree_to_aff_combination (expr, TREE_TYPE (expr), &comb);
base = fold_convert (TREE_TYPE (base), aff_combination_to_tree (&comb));
}
@@ -3335,41 +3335,20 @@ add_iv_candidate_for_use (struct ivopts_data *data, struct iv_use *use)
}
/* Record common candidate with base_object removed in base. */
- if (iv->base_object != NULL)
+ base = iv->base;
+ STRIP_NOPS (base);
+ if (iv->base_object != NULL && TREE_CODE (base) == POINTER_PLUS_EXPR)
{
- unsigned i;
- aff_tree aff_base;
- tree step, base_object = iv->base_object;
+ tree step = iv->step;
- base = iv->base;
- step = iv->step;
- STRIP_NOPS (base);
STRIP_NOPS (step);
- STRIP_NOPS (base_object);
- tree_to_aff_combination (base, TREE_TYPE (base), &aff_base);
- for (i = 0; i < aff_base.n; i++)
- {
- if (aff_base.elts[i].coef != 1)
- continue;
-
- if (operand_equal_p (aff_base.elts[i].val, base_object, 0))
- break;
- }
- if (i < aff_base.n)
- {
- aff_combination_remove_elt (&aff_base, i);
- base = aff_combination_to_tree (&aff_base);
- basetype = TREE_TYPE (base);
- if (POINTER_TYPE_P (basetype))
- basetype = sizetype;
-
- step = fold_convert (basetype, step);
- record_common_cand (data, base, step, use);
- /* Also record common candidate with offset stripped. */
- base = strip_offset (base, &offset);
- if (offset)
- record_common_cand (data, base, step, use);
- }
+ base = TREE_OPERAND (base, 1);
+ step = fold_convert (sizetype, step);
+ record_common_cand (data, base, step, use);
+ /* Also record common candidate with offset stripped. */
+ base = strip_offset (base, &offset);
+ if (offset)
+ record_common_cand (data, base, step, use);
}
/* At last, add auto-incremental candidates. Make such variables
@@ -3787,6 +3766,12 @@ get_computation_aff (struct loop *loop,
overflows, as all the arithmetics will in the end be performed in UUTYPE
anyway. */
common_type = determine_common_wider_type (&ubase, &cbase);
+ /* We don't need to compute in UUTYPE if this is the original candidate,
+ and candidate/use have the same (pointer) type. */
+ if (ctype == utype && common_type == utype
+ && POINTER_TYPE_P (utype) && TYPE_UNSIGNED (utype)
+ && cand->pos == IP_ORIGINAL && cand->incremented_at == use->stmt)
+ uutype = utype;
/* use = ubase - ratio * cbase + ratio * var. */
tree_to_aff_combination (ubase, common_type, aff);