contrib/gcc/tree-sra.c

15 GCC is distributed in the hope that it will be useful, but WITHOUT
56    will be scalars.  But a secondary objective is to break up larger
58    bits of the larger aggregate can be deleted as unreferenced.
61    be the purvey of a load-store motion pass.
118      given "a.b.c", this would be incremented for C, but not for A or B.  */
224 /* Return true if TYPE can be decomposed into a set of independent variables.
226    Note that this doesn't imply that all elements of TYPE can be
228    separate pieces that it can be done.  */
247   /* The type must be a non-union aggregate.  */
298 /* Return true if DECL can be decomposed into a set of independent
308   /* The variable must not be aliased.  */
320   /* The variable must not be volatile.  */
332   /* We must be able to decompose the variable's type.  */
339 	  fprintf (dump_file, " because its type cannot be decomposed\n");
347 /* Return true if TYPE can be *completely* decomposed into scalars.  */
394 /* Test whether ELT or some sub-element cannot be scalarized.  */
468      lengths are rarely very long, this should be acceptable.  If we
484   tree ae, be;
490   be = b->element;
492   if (ae == be)
494   if (TREE_CODE (ae) != TREE_CODE (be))
507       return tree_int_cst_equal (ae, be);
511 	tree_int_cst_equal (TREE_OPERAND (ae, 0), TREE_OPERAND (be, 0))
512 	&& tree_int_cst_equal (TREE_OPERAND (ae, 1), TREE_OPERAND (be, 1));
517       if (DECL_FIELD_CONTEXT (ae) == DECL_FIELD_CONTEXT (be))
519       return fields_compatible_p (ae, be);
527    may be null, in which case CHILD must be a DECL.  */
652 /* A set of callbacks for phases 2 and 4.  They'll be invoked for the
669   /* Invoked when ELT is initialized from a constant.  VALUE may be NULL,
670      in which case it should be treated as an empty CONSTRUCTOR.  */
743 	/* Non-constant index means any member may be accessed.  Prevent the
748 	   be avoided by using dynamic usage counts based on BB trip counts
888   /* If it isn't scalarizable, there may be scalarizable variables within, so
930 	 aggregate to be seen as a whole.  Invoke USE.  */
936      whole is not a scalarizable reference.  There may be occurrences of
1009    structures that could be decomposed.  */
1037    the sub-elements needn't be contiguous.  */
1118    All elements to be scalarized have replacement variables made for them.  */
1213       /* ??? We can't generate any warning that would be meaningful.  */
1250 	 than the parent needs to be seen as a complete unit.  */
1388   /* We shouldn't be invoked on groups of sub-elements as they must
1472 	  /* In order to avoid block copy, we have to be able to instantiate
1718    elements under SRC to their counterparts under DST.  There must be a 1-1
1781   /* The replacement can be almost arbitrarily complex.  Gimplify.  */
1802   /* We can be passed DECL_INITIAL of a static variable.  It might have a
1894    has more than one edge, STMT will be replicated for each edge.  Also,
1895    abnormal edges will be ignored.  */
1909 	 be valid through an abnormal edge.  */
1990 	 the values.  We should be able to record the SSA number of the VOP
1995 	 This optimization would be most effective if sra_walk_function
2043 	 both structures to be optimized well.  */
2065       /* Otherwise both sides must be fully instantiated.  In which
2082    COMPLEX_EXPR.  If RHS is NULL, it should be treated as an empty