Makefile.in (loop-unroll.o): Add VARRAY_H dependency.

2004-10-18  Revital Eres  <eres@il.ibm.com>

        * Makefile.in (loop-unroll.o): Add VARRAY_H dependency.
        * loop-unroll.c: Include varray.h.
        (struct var_to_expand, struct opt_info): Rename split_ivs_info to
        opt_info and expand it to support variable expansion.
        (analyze_insns_in_loop): Rename analyze_ivs_to_split and
        expand it to support variable expansion.
        (pt_info_start_duplication): Rename si_info_start_duplication.
        (apply_opt_in_copies): Rename split_ivs_in_copies and add support
        to the variable expansion optimization.
        (free_opt_info): Rename free_si_info.
        (analyze_insn_to_expand_var, referenced_in_one_insn_in_loop_p,
        expand_var_during_unrolling, insert_var_expansion_initialization,
        combine_var_copies_in_loop_exit, release_var_copies,
        get_expansion): New functions.
        (peel_loop_completely, unroll_loop_constant_iterations,
        unroll_loop_runtime_iterations, peel_loop_simple,
        unroll_loop_stupid): Change uses of struct si_info
        to struct opt_info
        and add uses of fvariable-expansion-in-unroller flag.
        * params.def: Add parameter to restrict the number of expansions.
        * params.h: (MAX_VARIABLE_EXPANSIONS): New define to restrict
        the number of expansions.
        * common.opt: (fvariable-expansion-in-unroller): New flag.
        * doc/invoke.texi: (fvariable-expansion-in-unroller): Document.

From-SVN: r89197

gcc/ChangeLog

+2004-10-18  Revital Eres  <eres@il.ibm.com>
+
+	* Makefile.in (loop-unroll.o): Add VARRAY_H dependency.
+	* loop-unroll.c: Include varray.h.
+	(struct var_to_expand, struct opt_info): Rename split_ivs_info to
+	opt_info and expand it to support variable expansion.
+	(analyze_insns_in_loop): Rename analyze_ivs_to_split and
+	expand it to support variable expansion.
+	(pt_info_start_duplication): Rename si_info_start_duplication.
+	(apply_opt_in_copies): Rename split_ivs_in_copies and add support
+	to the variable expansion optimization.
+	(free_opt_info): Rename free_si_info.
+	(analyze_insn_to_expand_var, referenced_in_one_insn_in_loop_p,
+	expand_var_during_unrolling, insert_var_expansion_initialization,
+	combine_var_copies_in_loop_exit, release_var_copies,
+	get_expansion): New functions.
+	(peel_loop_completely, unroll_loop_constant_iterations,
+	unroll_loop_runtime_iterations, peel_loop_simple,
+	unroll_loop_stupid): Change uses of struct si_info
+	to struct opt_info
+	and add uses of fvariable-expansion-in-unroller flag.
+	* params.def: Add parameter to restrict the number of expansions.
+	* params.h: (MAX_VARIABLE_EXPANSIONS): New define to restrict
+	the number of expansions.
+	* common.opt: (fvariable-expansion-in-unroller): New flag. 
+	* doc/invoke.texi: (fvariable-expansion-in-unroller): Document.
+
 2004-10-18  Danny Smith  <dannysmith@users.sourceforge.net>
 
 	* config/i386/cygming.h (TARGET_OS_CPP_BUILTINS): Define

gcc/Makefile.in

@@ -2037,7 +2037,7 @@ loop-unswitch.o : loop-unswitch.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TM_H) \
    output.h $(EXPR_H) coretypes.h $(TM_H)
 loop-unroll.o: loop-unroll.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TM_H) \
    $(BASIC_BLOCK_H) hard-reg-set.h $(CFGLOOP_H) $(CFGLAYOUT_H) $(PARAMS_H) \
-   output.h $(EXPR_H) coretypes.h $(TM_H) $(HASHTAB_H) $(RECOG_H)
+   output.h $(EXPR_H) coretypes.h $(TM_H) $(HASHTAB_H) $(RECOG_H) $(VARRAY_H)
 dominance.o : dominance.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
    hard-reg-set.h $(BASIC_BLOCK_H) et-forest.h
 et-forest.o : et-forest.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) et-forest.h alloc-pool.h

gcc/common.opt

@@ -748,6 +748,10 @@ fsplit-ivs-in-unroller
 Common Report Var(flag_split_ivs_in_unroller) Init(1)
 Split lifetimes of induction variables when loops are unrolled.
 
+fvariable-expansion-in-unroller
+Common Report Var(flag_variable_expansion_in_unroller) 
+Apply variable expansion when loops are unrolled.
+
 ; Emit code to probe the stack, to help detect stack overflow; also
 ; may cause large objects to be allocated dynamically.
 fstack-check

gcc/doc/invoke.texi

@@ -316,6 +316,7 @@ Objective-C and Objective-C++ Dialects}.
 -fstrength-reduce  -fstrict-aliasing  -ftracer  -fthread-jumps @gol
 -funroll-all-loops  -funroll-loops  -fpeel-loops @gol
 -fsplit-ivs-in-unroller -funswitch-loops @gol
+-fvariable-expansion-in-unroller @gol
 -ftree-pre  -ftree-ccp  -ftree-dce -ftree-loop-optimize @gol
 -ftree-loop-linear -ftree-loop-im -ftree-loop-ivcanon -fivopts @gol
 -ftree-dominator-opts -ftree-dse -ftree-copyrename @gol
@@ -4728,6 +4729,11 @@ on some of the architectures due to restrictions in the CSE pass.
 
 This optimization is enabled by default.
 
+@item -fvariable-expansion-in-unroller
+@opindex -fvariable-expansion-in-unroller
+With this option, the compiler will create multiple copies of some 
+local variables when unrolling a loop which can result in superior code.
+
 @item -fprefetch-loop-arrays
 @opindex fprefetch-loop-arrays
 If supported by the target machine, generate instructions to prefetch

gcc/params.def

@@ -95,6 +95,15 @@ DEFPARAM (PARAM_MAX_INLINE_INSNS_RTL,
 	  "The maximum number of instructions for the RTL inliner",
 	  600)
 
+/* Limit the number of expansions created by the variable expansion
+   optimization to avoid register pressure.  */
+DEFPARAM (PARAM_MAX_VARIABLE_EXPANSIONS,
+	  "max-variable-expansions-in-unroller",
+	  "If -fvariable-expansion-in-unroller is used, the maximum number of \
+           times that an individual variable will be expanded \
+           during loop unrolling",
+          1)
+     
 /* The maximum number of instructions to consider when looking for an
    instruction to fill a delay slot.  If more than this arbitrary
    number of instructions is searched, the time savings from filling

gcc/params.h

@@ -94,6 +94,8 @@ typedef enum compiler_param
   PARAM_VALUE (PARAM_MAX_INLINE_INSNS_AUTO)
 #define MAX_INLINE_INSNS_RTL \
   PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RTL)
+#define MAX_VARIABLE_EXPANSIONS \
+  PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS)
 #define MAX_DELAY_SLOT_INSN_SEARCH \
   PARAM_VALUE (PARAM_MAX_DELAY_SLOT_INSN_SEARCH)
 #define MAX_DELAY_SLOT_LIVE_SEARCH \