Change behavior of -fsched-verbose option

[Nikolai Bozhenov <n dot bozhenov at samsung dot com>]

Hi!

Currently -fsched-verbose option redirects debugging dumps to stderr
if there is no dump_file for the current pass. It would be fine if
there were the only scheduling pass. But for example for AArch64
there are 3 scheduling passes in the default pipeline: sched1,
fusion and sched2. So, when passing options like
-fsched-verbose=7 -fdump-rtl-sched1 to GCC I get a neat dump for
sched1 in the file and a mess of fusion/sched2 logs in the console.

In fact, currently there's no way to tell GCC that I want extremely
verbose logs for sched1 and I want no logs for all other passes.
Especially to the console.

I suggest disabling such redirection in the scheduler and omitting
debugging output for passes without dump_file. I believe a better
way to redirect printing to the stderr is to use options like
-fdump-rtl-sched=stderr. The attached patch implements the
suggestion.

Anyway, the old behavior may be reproduced with options
-fsched-verbose=7 -fdump-rtl-sched1 -fdump-rtl-{sched_fusion,sched2}=stderr
if it is really necessary.

The patch has been bootstrapped and regtested on x86_64.

Thanks,
Nikolai

2015-10-22  Nikolai Bozhenov  <n.bozhenov@samsung.com>

	* haifa-sched.c (setup_sched_dump): Don't redirect output to stderr.
	* common.opt (-fsched-verbose): Set default value to 1.
	* invoke.texi (-fsched-verbose): Update the option's description.

diff --git a/gcc/common.opt b/gcc/common.opt
index 224d3ad..5c23d29 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1973,7 +1973,7 @@ Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
 Allow speculative motion of more loads
 
 fsched-verbose=
-Common RejectNegative Joined UInteger Var(sched_verbose_param)
+Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
 -fsched-verbose=<number>	Set the verbosity level of the scheduler
 
 fsched2-use-superblocks
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 027ce96..d3cb88c 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -7403,12 +7403,7 @@ The @var{number} should be different for every file you compile.
 @item -fsched-verbose=@var{n}
 @opindex fsched-verbose
 On targets that use instruction scheduling, this option controls the
-amount of debugging output the scheduler prints.  This information is
-written to standard error, unless @option{-fdump-rtl-sched1} or
-@option{-fdump-rtl-sched2} is specified, in which case it is output
-to the usual dump listing file, @file{.sched1} or @file{.sched2}
-respectively.  However for @var{n} greater than nine, the output is
-always printed to standard error.
+amount of debugging output the scheduler prints to the dump files.
 
 For @var{n} greater than zero, @option{-fsched-verbose} outputs the
 same information as @option{-fdump-rtl-sched1} and @option{-fdump-rtl-sched2}.
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 46751fe..32506cb 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -206,17 +206,14 @@ static int modulo_last_stage;
 
 /* sched-verbose controls the amount of debugging output the
    scheduler prints.  It is controlled by -fsched-verbose=N:
-   N>0 and no -DSR : the output is directed to stderr.
-   N>=10 will direct the printouts to stderr (regardless of -dSR).
-   N=1: same as -dSR.
+   N=0: no debugging output.
+   N=1: default value.
    N=2: bb's probabilities, detailed ready list info, unit/insn info.
    N=3: rtl at abort point, control-flow, regions info.
    N=5: dependences info.  */
-
 int sched_verbose = 0;
 
-/* Debugging file.  All printouts are sent to dump, which is always set,
-   either to stderr, or to the dump listing file (-dRS).  */
+/* Debugging file.  All printouts are sent to dump. */
 FILE *sched_dump = 0;
 
 /* This is a placeholder for the scheduler parameters common
@@ -7222,17 +7219,14 @@ set_priorities (rtx_insn *head, rtx_insn *tail)
   return n_insn;
 }
 
-/* Set dump and sched_verbose for the desired debugging output.  If no
-   dump-file was specified, but -fsched-verbose=N (any N), print to stderr.
-   For -fsched-verbose=N, N>=10, print everything to stderr.  */
+/* Set sched_dump and sched_verbose for the desired debugging output. */
 void
 setup_sched_dump (void)
 {
   sched_verbose = sched_verbose_param;
-  if (sched_verbose_param == 0 && dump_file)
-    sched_verbose = 1;
-  sched_dump = ((sched_verbose_param >= 10 || !dump_file)
-		? stderr : dump_file);
+  sched_dump = dump_file;
+  if (!dump_file)
+    sched_verbose = 0;
 }
 
 /* Allocate data for register pressure sensitive scheduling.  */