Makefile.in (OBJS): Added dce.o.

	* Makefile.in (OBJS): Added dce.o.
	(ssa.o): Updated target to include ssa.h.
	(flow.o): Likewise.
	(toplev.o): Likewise.
	(dce.o): Created target.
	* basic-block.h: Added comments.
	(INVALID_BLOCK): Added definition.
	(connect_infinite_loops_to_exit): Added declaration.
	Moved SSA declarations to ssa.h.
	* flow.c: Added inclusion of ssa.h.
	(struct depth_first_search_dsS, depth_first_search_ds):
	Added definitions.
	(compute_immediate_postdominators): Added definition.
	(connect_infinite_loops_to_exit): Likewise.
	(flow_dfs_compute_reverse_init): Likewise.
	(flow_dfs_compute_reverse_add_bb): Likewise.
	(flow_dfs_compute_reverse_execute): Likewise.
	(flow_dfs_compute_reverse_finish): Likewise.
	* rtl.h (rtx/in_struct): Added use to determine insn necessity.
	(LABEL_P): Added definition.
	(JUMP_P): Likewise.
	(NOTE_P): Likewise.
	(BARRIER_P): Likewise.
	(JUMP_TABLE_DATA_P): Likewise.
	(INSN_DEAD_CODE_P): Likewise.
	* ssa.c: Replaced inclusions with ssa.h inclusion.
	(CONVERT_HARD_REGISTER_TO_SSA_P): Moved to ssa.h.
	(rename_registers): Removed unnecessary variables.
	* ssa.h: Created by moving declarations from ssa.c and
	basic-block.h.
	* timevar.def: Defined TV_DEAD_CODE_ELIM.
	* toplev.c: Added ssa.h inclusion.
	(dump_file_index): Added DFI_dce.
	(dump_file): Added "dce" entry.
	Defined flag_ssa.
	(f_options): Added dce entry.
	* invoke.texi: Document -fdce.  Emphasize experimental status of
	-fssa.

Co-Authored-By: Mark Mitchell <mark@codesourcery.com>

From-SVN: r35419

1 files changed, 24 insertions, 3 deletions

diff --git a/gcc/rtl.h b/gcc/rtl.h
index b96c53f..41caa80 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -148,7 +148,9 @@ typedef struct rtx_def
      together with the preceding insn.  Valid only within sched.
      1 in an INSN, JUMP_INSN, or CALL_INSN if insn is in a delay slot and
      from the target of a branch.  Valid from reorg until end of compilation;
-     cleared before used.  */
+     cleared before used.
+     1 in an INSN if this insn is dead code.  Valid only during
+     dead-code elimination phase; cleared before use. */
   unsigned int in_struct : 1;
   /* 1 if this rtx is used.  This is used for copying shared structure.
      See `unshare_all_rtl'.
@@ -202,10 +204,26 @@ typedef struct rtvec_def{
 #define GET_NUM_ELEM(RTVEC)		((RTVEC)->num_elem)
 #define PUT_NUM_ELEM(RTVEC, NUM)	((RTVEC)->num_elem = (NUM))
 
-/* 1 if X is a REG.  */
-
+/* Predicate yielding nonzero iff X is an rtl for a register.  */
 #define REG_P(X) (GET_CODE (X) == REG)
 
+/* Predicate yielding nonzero iff X is a label insn.  */
+#define LABEL_P(X) (GET_CODE (X) == CODE_LABEL)
+
+/* Predicate yielding nonzero iff X is a jump insn.  */
+#define JUMP_P(X) (GET_CODE (X) == JUMP_INSN)
+
+/* Predicate yielding nonzero iff X is a note insn.  */
+#define NOTE_P(X) (GET_CODE (X) == NOTE)
+
+/* Predicate yielding nonzero iff X is a barrier insn.  */
+#define BARRIER_P(X) (GET_CODE (X) == BARRIER)
+
+/* Predicate yielding nonzero iff X is a data for a jump table.  */
+#define JUMP_TABLE_DATA_P(INSN) \
+  (JUMP_P (INSN) && (GET_CODE (PATTERN (INSN)) == ADDR_VEC || \
+		     GET_CODE (PATTERN (INSN)) == ADDR_DIFF_VEC))
+
 /* 1 if X is a constant value that is an integer.  */
 
 #define CONSTANT_P(X)   \
@@ -374,6 +392,9 @@ extern void rtvec_check_failed_bounds PARAMS ((rtvec, int,
    delay slots, i.e., it is an annulled branch.   */
 #define INSN_ANNULLED_BRANCH_P(INSN) ((INSN)->unchanging)
 
+/* 1 if insn is a dead code.  Valid only for dead-code elimination phase. */
+#define INSN_DEAD_CODE_P(INSN) ((INSN)->in_struct)
+
 /* 1 if insn is in a delay slot and is from the target of the branch.  If
    the branch insn has INSN_ANNULLED_BRANCH_P set, this insn should only be
    executed if the branch is taken.  For annulled branches with this bit