Hi, This patch implements a small optimization to the code generation of simple array assignments, inlining the array bounds checking code so there is no reliance on the library routine _d_arraycopy(), which also deals with postblit and copy constructors for non-trivial arrays.
Bootstrapped and regression tested on x86_64-linux-gnu, and committed to mainline. Regards Iain --- gcc/d/ChangeLog: * expr.cc (ExprVisitor::visit (AssignExp *)): Inline bounds checking for simple array assignments. gcc/testsuite/ChangeLog: * gdc.dg/array1.d: New test. --- gcc/d/expr.cc | 45 ++++++++++++++++++++++++++++++----- gcc/testsuite/gdc.dg/array1.d | 14 +++++++++++ 2 files changed, 53 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gdc.dg/array1.d diff --git a/gcc/d/expr.cc b/gcc/d/expr.cc index 58d4943ef2b..355561a481e 100644 --- a/gcc/d/expr.cc +++ b/gcc/d/expr.cc @@ -962,14 +962,47 @@ public: /* Perform a memcpy operation. */ gcc_assert (e->e2->type->ty != Tpointer); - if (!postblit && !destructor && !array_bounds_check ()) + if (!postblit && !destructor) { tree t1 = d_save_expr (d_array_convert (e->e1)); - tree t2 = d_array_convert (e->e2); - tree size = size_mult_expr (d_array_length (t1), - size_int (etype->size ())); - tree result = build_memcpy_call (d_array_ptr (t1), - d_array_ptr (t2), size); + tree t2 = d_save_expr (d_array_convert (e->e2)); + + /* References to array data. */ + tree t1ptr = d_array_ptr (t1); + tree t1len = d_array_length (t1); + tree t2ptr = d_array_ptr (t2); + + /* Generate: memcpy(to, from, size) */ + tree size = size_mult_expr (t1len, size_int (etype->size ())); + tree result = build_memcpy_call (t1ptr, t2ptr, size); + + /* Insert check that array lengths match and do not overlap. */ + if (array_bounds_check ()) + { + /* tlencmp = (t1len == t2len) */ + tree t2len = d_array_length (t2); + tree tlencmp = build_boolop (EQ_EXPR, t1len, t2len); + + /* toverlap = (t1ptr + size <= t2ptr + || t2ptr + size <= t1ptr) */ + tree t1ptrcmp = build_boolop (LE_EXPR, + build_offset (t1ptr, size), + t2ptr); + tree t2ptrcmp = build_boolop (LE_EXPR, + build_offset (t2ptr, size), + t1ptr); + tree toverlap = build_boolop (TRUTH_ORIF_EXPR, t1ptrcmp, + t2ptrcmp); + + /* (tlencmp && toverlap) ? memcpy() : _d_arraybounds() */ + tree tassert = build_array_bounds_call (e->loc); + tree tboundscheck = build_boolop (TRUTH_ANDIF_EXPR, + tlencmp, toverlap); + + result = build_condition (void_type_node, tboundscheck, + result, tassert); + } + this->result_ = compound_expr (result, t1); } else if ((postblit || destructor) && e->op != TOKblit) diff --git a/gcc/testsuite/gdc.dg/array1.d b/gcc/testsuite/gdc.dg/array1.d new file mode 100644 index 00000000000..af81813e736 --- /dev/null +++ b/gcc/testsuite/gdc.dg/array1.d @@ -0,0 +1,14 @@ +// { dg-do compile } +// { dg-final { scan-assembler-not "_d_arraycopy" } } + +void test1() +{ + int[10] a1 = void; + int[10] a2 = void; + a1[] = a2[]; +} + +void test2(int[] a1, int[] a2) +{ + a1[] = a2[]; +} -- 2.25.1