--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1" } */
+
+struct X { int a[256]; };
+
+int foo(struct X *p, __SIZE_TYPE__ i)
+{
+ int *q = &p->a[0];
+ int *q2 = (int *)((void *)q + i*4 + 32);
+ return *q2;
+}
+
+int bar(struct X *p, int i)
+{
+ return *((int *)p + i + 8);
+}
+
+/* We should have propagated the base array address through the
+ address arithmetic into the memory access as an array access. */
+
+/* { dg-final { scan-tree-dump-times "->a\\\[D\\\." 2 "forwprop1" } } */
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
tree def_rhs,
gimple_stmt_iterator *use_stmt_gsi)
{
- tree index;
+ tree index, tunit;
gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);
+ tree tmp;
+
+ tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)));
+ if (!host_integerp (tunit, 1))
+ return false;
/* Get the offset's defining statement. */
offset_def = SSA_NAME_DEF_STMT (offset);
along in case the element size is one. In that case, however, we do not
allow multiplications because they can be computing index to a higher
level dimension (PR 37861). */
- if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)))))
+ if (integer_onep (tunit))
{
if (is_gimple_assign (offset_def)
&& gimple_assign_rhs_code (offset_def) == MULT_EXPR)
multiplication of an object by the size of the array elements.
This implicitly verifies that the size of the array elements
is constant. */
- offset = gimple_assign_rhs1 (offset_def);
- if (gimple_assign_rhs_code (offset_def) != MULT_EXPR
- || TREE_CODE (gimple_assign_rhs2 (offset_def)) != INTEGER_CST
- || !simple_cst_equal (gimple_assign_rhs2 (offset_def),
- TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)))))
+ if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), tunit))
+ {
+ /* The first operand to the MULT_EXPR is the desired index. */
+ index = gimple_assign_rhs1 (offset_def);
+ }
+ /* If we have idx * tunit + CST * tunit re-associate that. */
+ else if ((gimple_assign_rhs_code (offset_def) == PLUS_EXPR
+ || gimple_assign_rhs_code (offset_def) == MINUS_EXPR)
+ && TREE_CODE (gimple_assign_rhs1 (offset_def)) == SSA_NAME
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && (tmp = div_if_zero_remainder (EXACT_DIV_EXPR,
+ gimple_assign_rhs2 (offset_def),
+ tunit)) != NULL_TREE)
+ {
+ gimple offset_def2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (offset_def));
+ if (gimple_assign_rhs_code (offset_def2) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def2)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def2), tunit))
+ {
+ index = fold_build2 (gimple_assign_rhs_code (offset_def),
+ TREE_TYPE (offset),
+ gimple_assign_rhs1 (offset_def2), tmp);
+ }
+ else
+ return false;
+ }
+ else
return false;
-
- /* The first operand to the MULT_EXPR is the desired index. */
- index = offset;
}
/* Replace the pointer addition with array indexing. */
+ index = force_gimple_operand_gsi (use_stmt_gsi, index, true, NULL_TREE,
+ true, GSI_SAME_STMT);
gimple_assign_set_rhs_from_tree (use_stmt_gsi, unshare_expr (def_rhs));
use_stmt = gsi_stmt (*use_stmt_gsi);
TREE_OPERAND (TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0), 1)