[B2-devel] IRIX patches

[Brian J. J. <br...@fr...>]

OK, hopefully this is the last of the patches for IRIX for a while (at
least until I get around to writing an OpenGL video driver or optimizing
the condition code handling in UAE CPU.)

The patch to configure.in tests for the "-Ofast" option to the compiler,
and uses it instead of "-g" if it exists.  This turns on massive
optimizations in the MIPSPro compilers, which do a pretty good job with
the UAE CPU, video blitters, etc.

The patch to main_unix.c uses pthread_cond_timedwait() instead of
nanosleep() to work around a bug in SGI's pthreads library.  With this
fix, the annoying hangs I was experiencing (especially on uniprocessor
machines) are gone.  I've only enabled it for SGI platforms, but it
should work with any pthreads implementation.  Feel free to remove
anything under "#ifdef DEBUG_SLEEP" if you don't like debugging code
clogging up the official sources.

With these changes, BasiliskII configures, builds, and runs very well on
IRIX with no special hand-holding, hacks, or manual edits.  Whew....

Except for one thing:  the recent changes to configure.in to select
among different FPU cores don't work for the "default" core on non-X86
systems.  Perhaps step 1 under "Select appropriate FPU source" needs a
non-X68 case which selects the UAE CPU.  If I specify "--enable-fpe=uae"
on the configure command line, it works fine.

Anyway, here are the patches, and thanks again for a way-cool, portable
(and actually useful!) emulator.

--

                                                Brian J. Johnson

--------------------------------------------------------------------

   "I have discovered that all human evil comes from this, man's being
    unable to sit still in a room."
                                           -- Blaise Pascal

Index: main_unix.cpp
===================================================================
RCS file: /cvs/BasiliskII/src/Unix/main_unix.cpp,v
retrieving revision 1.30
diff -c -r1.30 main_unix.cpp
*** main_unix.cpp 2001/02/02 20:52:57 1.30
--- main_unix.cpp 2001/03/23 18:09:40
***************
*** 869,891 ****
  // Linux select() changes its timeout parameter upon return to contain

  // the remaining time. Most other unixen leave it unchanged or
undefined.
  #define SELECT_SETS_REMAINING
! #elif defined(__FreeBSD__) || defined(__sun__) || defined(sgi)
  #define USE_NANOSLEEP
  #endif

  void Delay_usec(uint32 usec)
  {
   int was_error;

! #ifdef USE_NANOSLEEP
   struct timespec elapsed, tv;
  #else
   struct timeval tv;
  #ifndef SELECT_SETS_REMAINING
   uint64 then, now, elapsed;
  #endif
  #endif

   // Set the timeout interval - Linux only needs to do this once
  #ifdef SELECT_SETS_REMAINING
      tv.tv_sec = 0;
--- 869,912 ----
  // Linux select() changes its timeout parameter upon return to contain

  // the remaining time. Most other unixen leave it unchanged or
undefined.
  #define SELECT_SETS_REMAINING
! #elif defined(__FreeBSD__) || defined(__sun__)
  #define USE_NANOSLEEP
+ #elif defined(HAVE_PTHREADS) && defined(sgi)
+ // SGI pthreads has a bug when using pthreads+signals+nanosleep,
+ // so instead of using nanosleep, wait on a CV which is never
signalled.
+ #define USE_COND_TIMEDWAIT
  #endif

+ #ifdef DEBUG_SLEEP
+ int sleeps = 0;
+ int early = 0;
+ #endif
+
  void Delay_usec(uint32 usec)
  {
   int was_error;

! #if defined(USE_NANOSLEEP)
   struct timespec elapsed, tv;
+ #elif defined(USE_COND_TIMEDWAIT)
+  // Use a local mutex and cv, so threads remain independent
+  pthread_cond_t delay_cond = PTHREAD_COND_INITIALIZER;
+  pthread_mutex_t delay_mutex = PTHREAD_MUTEX_INITIALIZER;
+  struct timespec elapsed;
+  uint64 future;
  #else
   struct timeval tv;
  #ifndef SELECT_SETS_REMAINING
   uint64 then, now, elapsed;
  #endif
  #endif
+ #ifdef DEBUG_SLEEP
+  uint64 stop, end;
+  sleeps++;

+     stop = GetTicks_usec() + usec; // expected stop time
+ #endif
+
   // Set the timeout interval - Linux only needs to do this once
  #ifdef SELECT_SETS_REMAINING
      tv.tv_sec = 0;
***************
*** 893,898 ****
--- 914,928 ----
  #elif defined(USE_NANOSLEEP)
      elapsed.tv_sec = 0;
      elapsed.tv_nsec = usec * 1000;
+ #elif defined(USE_COND_TIMEDWAIT)
+     future = GetTicks_usec() + usec;
+     elapsed.tv_sec = future / 1000000;
+     elapsed.tv_nsec = (future % 1000000) * 1000;
+ #if defined(DEBUG_SLEEP) || 1
+  if (usec > 1000000) {
+   printf(" delay for %u nsec\n", usec);
+  }
+ #endif
  #else
      then = GetTicks_usec();
  #endif
***************
*** 903,908 ****
--- 933,965 ----
    tv.tv_sec = elapsed.tv_sec;
    tv.tv_nsec = elapsed.tv_nsec;
    was_error = nanosleep(&tv, &elapsed);
+ #elif defined(USE_COND_TIMEDWAIT)
+   was_error = pthread_mutex_lock(&delay_mutex);
+ #ifdef DEBUG_SLEEP
+   if (was_error) {
+    // Just for debugging
+    printf("ERROR: pthread_mutex_lock error %d\n", was_error);
+    exit(1);
+   }
+ #endif
+   was_error = pthread_cond_timedwait(&delay_cond,
+              &delay_mutex, &elapsed);
+ #ifdef DEBUG_SLEEP
+   if (was_error != ETIMEDOUT) {
+    // Just for debugging
+    printf("ERROR: pthread_cond_timedwait error %d\n", was_error);
+    exit(1);
+   }
+ #endif
+
+   was_error = pthread_mutex_unlock(&delay_mutex);
+ #ifdef DEBUG_SLEEP
+   if (was_error) {
+    // Just for debugging
+    printf("ERROR: pthread_mutex_unlock error %d\n", was_error);
+    exit(1);
+   }
+ #endif
  #else
  #ifndef SELECT_SETS_REMAINING
    // Calculate the time interval left (in case of interrupt)
***************
*** 918,923 ****
--- 975,988 ----
    was_error = select(0, NULL, NULL, NULL, &tv);
  #endif
   } while (was_error && (errno == EINTR));
+
+ #ifdef DEBUG_SLEEP
+  end = GetTicks_usec(); // actual stop time
+  if (end < stop) {  // we woke up early
+   printf("woke up %ld out of %u usec too early\n", stop - end, usec);
+   early++;
+  }
+ #endif
  }


Index: configure.in
===================================================================
RCS file: /cvs/BasiliskII/src/Unix/configure.in,v
retrieving revision 1.35
diff -c -r1.35 configure.in
*** configure.in 2001/03/20 18:05:35 1.35
--- configure.in 2001/03/23 18:09:40
***************
*** 279,284 ****
--- 279,293 ----
    dnl IRIX headers work fine, but somehow don't define or use
"STDC_HEADERS"
    DEFINES="$DEFINES -DCRTSCTS=CNEW_RTSCTS -DB230400=B115200
-DSTDC_HEADERS"
    LIBS="$LIBS -laudio"
+
+   dnl Check if our compiler supports -Ofast (MIPSPro)
+   HAVE_OFAST=no
+   ocflags="$CFLAGS"
+   CFLAGS=`echo $CFLAGS | sed -e 's/ -g / -Ofast /;s/^-g /-Ofast /;s/
-g$/ -Ofast/;s/^-g$/-Ofast/'`
+   AC_MSG_CHECKING(if "-Ofast" works)
+   dnl Do a test compile of an empty function
+   AC_TRY_COMPILE(,, [AC_MSG_RESULT(yes); HAVE_OFAST=yes],
AC_MSG_RESULT(no))
+   CFLAGS="$ocflags"
    ;;
  esac

***************
*** 662,667 ****
--- 671,684 ----
    dnl gb-- Probably not the cleanest way to take
    CFLAGS=`echo $CFLAGS | sed -e 's/ -g / /;s/^-g / /;s/ -g$/
/;s/^-g$//'`
    CXXFLAGS=`echo $CXXFLAGS | sed -e 's/ -g / /;s/^-g / /;s/ -g$/
/;s/^-g$//'`
+ fi
+
+ dnl Or if we have -Ofast
+ if [[ "x$HAVE_OFAST" = "xyes" ]]; then
+   CFLAGS=`echo $CFLAGS | sed -e 's/ -g / -Ofast /;s/^-g /-Ofast /;s/
-g$/ -Ofast/;s/^-g$/-Ofast/'`
+   CXXFLAGS=`echo $CXXFLAGS | sed -e 's/ -g / -Ofast /;s/^-g /-Ofast
/;s/ -g$/ -Ofast/;s/^-g$/-Ofast/'`
+   CXXFLAGS="-LANG:std $CXXFLAGS"
+   LDFLAGS="$LDFLAGS -Ofast"
  fi

  dnl Generate Makefile.