Patch for performing interprocedural bitwise constant propagation.

2016-08-26  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
	    Martin Jambhor  <mjambor@suse.cz>

	* common.opt: New option -fipa-bit-cp.
	* doc/invoke.texi: Document -fipa-bit-cp.
	* opts.c (default_options_table): Add entry for -fipa-bit-cp.
	(enable_fdo_optimizations): Check for flag_ipa_bit_cp.
	* tree-ssa-ccp.h: New header file.
	* tree-ssa-ccp.c: Include tree-ssa-ccp.h
	(bit_value_binop_1): Change to bit_value_binop_1 and export it.
	Replace all occurences of tree parameter by two new params: signop, int.
	(bit_value_unop_1): Change to bit_value_unop and export it.
	Replace all occurences of tree parameter by two new params: signop,
	int.
	(bit_value_binop): Change call from bit_value_binop_1 to
	bit_value_binop.
	(bit_value_assume_aligned): Likewise.
	(bit_value_unop): Change call from bit_value_unop_1 to bit_value_unop.
	(do_ssa_ccp): Pass nonzero_p || flag_ipa_cp_bit instead of nonzero_p
	to ccp_finalize.
	(ccp_finalize): Skip processing if val->mask == 0.
	* ipa-cp.c: Include tree-ssa-ccp.h
	(ipcp_bits_lattice): New class.
	(ipcp_param_lattice (bits_lattice): New member.
	(print_all_lattices): Call ipcp_bits_lattice::print.
	(set_all_contains_variable): Call ipcp_bits_lattice::set_to_bottom. 
	(initialize_node_lattices): Likewise.
	(propagate_bits_accross_jump_function): New function.
	(propagate_constants_accross_call): Call
	propagate_bits_accross_jump_function.
	(ipcp_propagate_stage): Store parameter types when in_lto_p is true.
	(ipcp_store_bits_results): New function.
	(ipcp_driver): Call ipcp_store_bits_results.
	* ipa-prop.h (ipa_bits): New struct.
	(ipa_jump_func): Add new member bits of type ipa_bits.
	(ipa_param_descriptor): Change decl to decl_or_type.
	(ipa_get_param): Change decl to decl_or_type and assert on
	PARM_DECL.
	(ipa_get_type): New function.
	(ipcp_transformation_summary): New member bits.
	* ipa-prop.c (ipa_get_param_decl_index_1): s/decl/decl_or_type.
	(ipa_populate_param_decls): Likewise.
	(ipa_dump_param): Likewise.
	(ipa_print_node_jump_functions_for_edge): Pretty-print ipa_bits jump
	function.
	(ipa_set_jf_unknown): Set ipa_bits::known to false.
	(ipa_compute_jump_functions_for_edge): Compute jump function for bits
	propagation.
	(ipa_node_params_t::duplicate): Copy src->bits into dst->bits.
	(ipa_write_jump_function): Add streaming for ipa_bits.
	(ipa_read_jump_function): Add support for reading streamed ipa_bits.
	(write_ipcp_transformation_info): Add streaming for ipa_bits
	summary for ltrans.
	(read_ipcp_transfomration_info): Add support for reading streamed ipa_bits.
	(ipcp_update_bits): New function.
	(ipcp_transform_function): Call ipcp_update_bits.

testsuite/
	* gcc.dg/ipa/propbits-1.c: New test-case.
	* gcc.dg/ipa/propbits-2.c: Likewise.
	* gcc.dg/ipa/propbits-3.c: Likewise.

Co-Authored-By: Martin Jambor <mjambor@suse.cz>

From-SVN: r239769

1 files changed, 43 insertions, 4 deletions

diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h
index e32d078edb3..e5a56daeced 100644
--- a/gcc/ipa-prop.h
+++ b/gcc/ipa-prop.h
@@ -154,6 +154,19 @@ struct GTY(()) ipa_alignment
   unsigned misalign;
 };
 
+/* Information about zero/non-zero bits.  */
+struct GTY(()) ipa_bits
+{
+  /* The propagated value.  */
+  widest_int value;
+  /* Mask corresponding to the value.
+     Similar to ccp_lattice_t, if xth bit of mask is 0,
+     implies xth bit of value is constant.  */
+  widest_int mask;
+  /* True if jump function is known.  */
+  bool known;
+};
+
 /* A jump function for a callsite represents the values passed as actual
    arguments of the callsite. See enum jump_func_type for the various
    types of jump functions supported.  */
@@ -166,6 +179,9 @@ struct GTY (()) ipa_jump_func
   /* Information about alignment of pointers. */
   struct ipa_alignment alignment;
 
+  /* Information about zero/non-zero bits.  */
+  struct ipa_bits bits;
+
   enum jump_func_type type;
   /* Represents a value of a jump function.  pass_through is used only in jump
      function context.  constant represents the actual constant in constant jump
@@ -283,8 +299,11 @@ ipa_get_jf_ancestor_type_preserved (struct ipa_jump_func *jfunc)
 
 struct ipa_param_descriptor
 {
-  /* PARAM_DECL of this parameter.  */
-  tree decl;
+  /* In analysis and modification phase, this is the PARAM_DECL of this
+     parameter, in IPA LTO phase, this is the type of the the described
+     parameter or NULL if not known.  Do not read this field directly but
+     through ipa_get_param and ipa_get_type as appropriate.  */
+  tree decl_or_type;
   /* If all uses of the parameter are described by ipa-prop structures, this
      says how many there are.  If any use could not be described by means of
      ipa-prop structures, this is IPA_UNDESCRIBED_USE.  */
@@ -402,13 +421,31 @@ ipa_get_param_count (struct ipa_node_params *info)
 
 /* Return the declaration of Ith formal parameter of the function corresponding
    to INFO.  Note there is no setter function as this array is built just once
-   using ipa_initialize_node_params. */
+   using ipa_initialize_node_params.  This function should not be called in
+   WPA.  */
 
 static inline tree
 ipa_get_param (struct ipa_node_params *info, int i)
 {
   gcc_checking_assert (!flag_wpa);
-  return info->descriptors[i].decl;
+  tree t = info->descriptors[i].decl_or_type;
+  gcc_checking_assert (TREE_CODE (t) == PARM_DECL);
+  return t;
+}
+
+/* Return the type of Ith formal parameter of the function corresponding
+   to INFO if it is known or NULL if not.  */
+
+static inline tree
+ipa_get_type (struct ipa_node_params *info, int i)
+{
+  tree t = info->descriptors[i].decl_or_type;
+  if (!t)
+    return NULL;
+  if (TYPE_P (t))
+    return t;
+  gcc_checking_assert (TREE_CODE (t) == PARM_DECL);
+  return TREE_TYPE (t);
 }
 
 /* Return the move cost of Ith formal parameter of the function corresponding
@@ -482,6 +519,8 @@ struct GTY(()) ipcp_transformation_summary
   ipa_agg_replacement_value *agg_values;
   /* Alignment information for pointers.  */
   vec<ipa_alignment, va_gc> *alignments;
+  /* Known bits information.  */
+  vec<ipa_bits, va_gc> *bits;
 };
 
 void ipa_set_node_agg_value_chain (struct cgraph_node *node,