* flags.h (flag_move_all_movables): Declare.

        (flag_reduce_all_givs): Likewise.
        * loop.c (move_movables): Handle flag_move_all_movables.
        (strength_reduce): Handle flag_reduce_all_givs.
        * toplev.c (flag_move_all_movables): Define.
        (flag_reduce_all_givs): Likewise.
        (f_options): Add -fmove-all-movables and -freduce-all-givs.
        * invoke.texi: Document new options, including alias stuff that
        wasn't included last time.
Two of the "Tooning" options :-)

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@14987 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8bd67b9..10aa03a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+Wed Aug 27 21:32:20 1997  Jeffrey A Law  (law@cygnus.com)
+
+       * flags.h (flag_move_all_movables): Declare.
+       (flag_reduce_all_givs): Likewise.
+       * loop.c (move_movables): Handle flag_move_all_movables.
+       (strength_reduce): Handle flag_reduce_all_givs.
+       * toplev.c (flag_move_all_movables): Define.
+       (flag_reduce_all_givs): Likewise.
+       (f_options): Add -fmove-all-movables and -freduce-all-givs.
+       * invoke.texi: Document new options, including alias stuff that
+       wasn't included last time.
+
 Wed Aug 27 18:08:51 1997  Bob Manson  (manson@cygnus.com)
 
        * t-h8300: Use TARGET_LIBGCC2_CFLAGS instead of LIBGCC2_CFLAGS.

diff --git a/gcc/flags.h b/gcc/flags.h
index 58f5bc0..5b3c763 100644 (file)
--- a/gcc/flags.h
+++ b/gcc/flags.h
@@ -216,6 +216,16 @@ extern int flag_unroll_loops;
 
 extern int flag_unroll_all_loops;
 
+/* Nonzero forces all invariant computations in loops to be moved
+   outside the loop. */
+
+extern int flag_move_all_movables;
+
+/* Nonzero forces all general induction variables in loops to be
+   strength reduced. */
+
+extern int flag_reduce_all_givs;
+
 /* Nonzero for -fcse-follow-jumps:
    have cse follow jumps to do a more extensive job.  */
 

diff --git a/gcc/invoke.texi b/gcc/invoke.texi
index 2c7ae54..68b21ac 100644 (file)
--- a/gcc/invoke.texi
+++ b/gcc/invoke.texi
@@ -151,6 +151,7 @@ in the following sections.
 -frerun-cse-after-loop  -fschedule-insns
 -fschedule-insns2  -fstrength-reduce  -fthread-jumps
 -funroll-all-loops  -funroll-loops
+-fmove-all-movables  -freduce-all-givs
 -O  -O0  -O1  -O2  -O3
 @end smallexample
 
@@ -354,6 +355,8 @@ in the following sections.
 -freg-struct-return  -fshared-data  -fshort-enums
 -fshort-double  -fvolatile  -fvolatile-global
 -fverbose-asm -fpack-struct  -fstack-check  +e0  +e1
+-fargument-alias  -fargument-noalias
+-fargument-noalias-global
 @end smallexample
 @end table
 
@@ -2176,6 +2179,31 @@ Perform the optimization of loop unrolling.  This is done for all loops
 and usually makes programs run more slowly.  @samp{-funroll-all-loops}
 implies @samp{-fstrength-reduce} as well as @samp{-frerun-cse-after-loop}.
 
+@item -fmove-all-movables
+Forces all invariant computations in loops to be moved
+outside the loop.
+
+@item -freduce-all-givs
+Forces all general-induction variables in loops to be
+strength-reduced.
+
+@emph{Note:} When compiling programs written in Fortran,
+@samp{-fmove-all-moveables} and @samp{-freduce-all-givs} are enabled
+by default when you use the optimizer.
+
+These options may generate better or worse code; results are highly
+dependent on the structure of loops within the source code.
+
+These two options are intended to be removed someday, once
+they have helped determine the efficacy of various
+approaches to improving loop optimizations.
+
+Please let us (@code{egcs@cygnus.com and fortran@@gnu.ai.mit.edu})
+know how use of these options affects
+the performance of your production code.
+We're very interested in code that runs @emph{slower}
+when these options are @emph{enabled}.
+
 @item -fno-peephole
 Disable any machine-specific peephole optimizations.
 
@@ -5138,6 +5166,24 @@ compilation).
 
 With @samp{+e1}, G++ actually generates the code implementing virtual
 functions defined in the code, and makes them publicly visible.
+
+@cindex aliasing of parameters
+@cindex parameters, aliased
+@item -fargument-alias
+@item -fargument-noalias
+@item -fargument-noalias-global
+Specify the possible relationships among parameters and between
+parameters and global data.
+
+@samp{-fargument-alias} specifies that arguments (parameters) may
+alias each other and may alias global storage.
+@samp{-fargument-noalias} specifies that arguments do not alias
+each other, but may alias global storage.
+@samp{-fargument-noalias-global} specifies that arguments do not
+alias each other and do not alias global storage.
+
+Each language will automatically use whatever option is required by
+the language standard.  You should not need to use these options yourself.
 @end table
 
 @node Environment Variables

diff --git a/gcc/loop.c b/gcc/loop.c
index 5e0d1d1..2b4af61 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -1722,6 +1722,7 @@ move_movables (movables, threshold, insn_count, loop_start, end, nregs)
             extra cost because something else was already moved.  */
 
          if (already_moved[regno]
+             || flag_move_all_movables
              || (threshold * savings * m->lifetime) >= insn_count
              || (m->forces && m->forces->done
                  && n_times_used[m->forces->regno] == 1))
@@ -3991,8 +3992,8 @@ strength_reduce (scan_start, end, loop_top, insn_count,
             of such giv's whether or not we know they are used after the loop
             exit.  */
 
-         if (v->lifetime * threshold * benefit < insn_count
-             && ! bl->reversed)
+         if ( ! flag_reduce_all_givs && v->lifetime * threshold * benefit < insn_count
+             && ! bl->reversed )
            {
              if (loop_dump_stream)
                fprintf (loop_dump_stream,

diff --git a/gcc/toplev.c b/gcc/toplev.c
index 821dab6..bd22ff0 100644 (file)
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -446,6 +446,16 @@ int flag_unroll_loops;
 
 int flag_unroll_all_loops;
 
+/* Nonzero forces all invariant computations in loops to be moved
+   outside the loop. */
+
+int flag_move_all_movables = 0;
+
+/* Nonzero forces all general induction variables in loops to be
+   strength reduced. */
+
+int flag_reduce_all_givs = 0;
+
 /* Nonzero for -fwritable-strings:
    store string constants in data segment and don't uniquize them.  */
 
@@ -679,6 +689,8 @@ struct { char *string; int *variable; int on_value;} f_options[] =
   {"strength-reduce", &flag_strength_reduce, 1},
   {"unroll-loops", &flag_unroll_loops, 1},
   {"unroll-all-loops", &flag_unroll_all_loops, 1},
+  {"move-all-movables", &flag_move_all_movables, 1},
+  {"reduce-all-givs", &flag_reduce_all_givs, 1},
   {"writable-strings", &flag_writable_strings, 1},
   {"peephole", &flag_no_peephole, 0},
   {"force-mem", &flag_force_mem, 1},