* Makefile.in (LIB2FUNCS_EH): Define. Just "_eh" for now.

        (LIBGCC2_CFLAGS): Remove -fexceptions.
        (LIB2FUNCS): Remove "_eh".
        (libgcc2.a): Iterate over LIB2FUNCS_EH and build everything in
        it with -fexceptions.
        * Makefile.in (local-alloc.o): Depend on insn-attr.h.
        * local-alloc.c (block_alloc): Avoid creating false
        dependencies for targets which use instruction scheduling.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@20370 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 76 insertions, 5 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2637c44161f..734f2e685e5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+Tue Jun  9 12:36:16 1998  Jeffrey A Law  (law@cygnus.com)
+
+	* Makefile.in (LIB2FUNCS_EH): Define.  Just "_eh" for now.
+	(LIBGCC2_CFLAGS): Remove -fexceptions.
+	(LIB2FUNCS): Remove "_eh".
+	(libgcc2.a): Iterate over LIB2FUNCS_EH and build everything in
+	it with -fexceptions.
+
+	* Makefile.in (local-alloc.o): Depend on insn-attr.h.
+	* local-alloc.c (block_alloc): Avoid creating false 
+	dependencies for targets which use instruction scheduling.
+
 Tue Jun  9 02:40:49 1998  Richard Henderson  <rth@cygnus.com>
 
 	* mips/elf.h (ASM_DECLARE_OBJECT_NAME): Define.
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index f6045273019..65b9b7122ee 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -324,10 +324,8 @@ LIBGCC2 = libgcc2.a
 # we use this here because that should be enough, and also
 # so that -g1 will be tested.
 #
-# -fexceptions is necessary for eh.o now that the exceptions are
-# the default for g++ only.
 LIBGCC2_DEBUG_CFLAGS = -g1
-LIBGCC2_CFLAGS = -O2 $(LIBGCC2_INCLUDES) $(GCC_CFLAGS) $(TARGET_LIBGCC2_CFLAGS) $(LIBGCC2_DEBUG_CFLAGS) $(GTHREAD_FLAGS) -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -fexceptions @inhibit_libc@ 
+LIBGCC2_CFLAGS = -O2 $(LIBGCC2_INCLUDES) $(GCC_CFLAGS) $(TARGET_LIBGCC2_CFLAGS) $(LIBGCC2_DEBUG_CFLAGS) $(GTHREAD_FLAGS) -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED @inhibit_libc@ 
 
 # Additional options to use when compiling libgcc2.a.
 # Some targets override this to -Iinclude
@@ -689,7 +687,9 @@ LIB2FUNCS = _muldi3 _divdi3 _moddi3 _udivdi3 _umoddi3 _negdi2 \
     _fixtfdi _fixunstfdi _floatditf \
     __gcc_bcmp _varargs __dummy _eprintf \
     _bb _shtab _clear_cache _trampoline __main _exit \
-    _ctors _eh  _pure
+    _ctors _pure
+
+LIB2FUNCS_EH = _eh
 
 FPBIT_FUNCS = _pack_sf _unpack_sf _addsub_sf _mul_sf _div_sf \
     _fpcmp_parts_sf _compare_sf _eq_sf _ne_sf _gt_sf _ge_sf \
@@ -1020,6 +1020,15 @@ libgcc2.a: libgcc2.c libgcc2.ready $(CONFIG_H) $(FPBIT) $(DPBIT) $(LIB2ADD) \
 	  $(AR) $(AR_FLAGS) tmplibgcc2.a $${name}$(objext); \
 	  rm -f $${name}$(objext); \
 	done
+	for name in $(LIB2FUNCS_EH); \
+	do \
+	  echo $${name}; \
+	  $(GCC_FOR_TARGET) $(LIBGCC2_CFLAGS) -fexceptions $(INCLUDES) -c \
+	      -DL$${name} $(srcdir)/libgcc2.c -o $${name}$(objext); \
+	  if [ $$? -eq 0 ] ; then true; else exit 1; fi; \
+	  $(AR) $(AR_FLAGS) tmplibgcc2.a $${name}$(objext); \
+	  rm -f $${name}$(objext); \
+	done
 	if [ x$(FPBIT) != x ]; then \
 	  for name in $(FPBIT_FUNCS); \
 	  do \
@@ -1431,7 +1440,8 @@ regclass.o : regclass.c $(CONFIG_H) system.h $(RTL_H) hard-reg-set.h flags.h \
    $(BASIC_BLOCK_H) regs.h insn-config.h $(RECOG_H) reload.h real.h toplev.h \
    output.h
 local-alloc.o : local-alloc.c $(CONFIG_H) system.h $(RTL_H) flags.h \
-   $(BASIC_BLOCK_H) regs.h hard-reg-set.h insn-config.h $(RECOG_H) output.h
+   $(BASIC_BLOCK_H) regs.h hard-reg-set.h insn-config.h $(RECOG_H) output.h \
+   insn-attr.h
 bitmap.o : bitmap.c $(CONFIG_H) system.h $(RTL_H) flags.h $(BASIC_BLOCK_H) \
    regs.h
 global.o : global.c $(CONFIG_H) system.h $(RTL_H) flags.h  \
diff --git a/gcc/local-alloc.c b/gcc/local-alloc.c
index a465bb7ffa3..9daf31dda14 100644
--- a/gcc/local-alloc.c
+++ b/gcc/local-alloc.c
@@ -67,6 +67,7 @@ Boston, MA 02111-1307, USA.  */
 #include "regs.h"
 #include "hard-reg-set.h"
 #include "insn-config.h"
+#include "insn-attr.h"
 #include "recog.h"
 #include "output.h"
 
@@ -1414,8 +1415,48 @@ block_alloc (b)
       q = qty_order[i];
       if (qty_phys_reg[q] < 0)
 	{
+#ifdef INSN_SCHEDULING
+	  /* These values represent the adjusted lifetime of a qty so
+	     that it conflicts with qtys which appear near the start/end
+	     of this qty's lifetime.
+
+	     The purpose behind extending the lifetime of this qty is to
+	     discourage the register allocator from creating false
+	     dependencies.
+ 
+	     The adjustment by the value +-3 indicates precisely that
+	     this qty conflicts with qtys in the instructions immediately
+	     before and after the lifetime of this qty.
+
+	     Experiments have shown that higher values tend to hurt
+	     overall code performance.
+
+	     If allocation using the extended lifetime fails we will try
+	     again with the qty's unadjusted lifetime.  */
+	  int fake_birth = MAX (0, qty_birth[q] - 3);
+	  int fake_death = MIN (insn_number * 2 + 1, qty_death[q] + 3);
+#endif
+
 	  if (N_REG_CLASSES > 1)
 	    {
+#ifdef INSN_SCHEDULING
+	      /* We try to avoid using hard registers allocated to qtys which
+		 are born immediately after this qty or die immediately before
+		 this qty.
+
+		 This optimization is only appropriate when we will run
+		 a scheduling pass after reload and we are not optimizing
+		 for code size.  */
+	      if (flag_schedule_insns_after_reload && !optimize_size)
+		{
+		
+		  qty_phys_reg[q] = find_free_reg (qty_min_class[q], 
+						   qty_mode[q], q, 0, 0,
+						   fake_birth, fake_death);
+		  if (qty_phys_reg[q] >= 0)
+		    continue;
+		}
+#endif
 	      qty_phys_reg[q] = find_free_reg (qty_min_class[q], 
 					       qty_mode[q], q, 0, 0,
 					       qty_birth[q], qty_death[q]);
@@ -1423,6 +1464,14 @@ block_alloc (b)
 		continue;
 	    }
 
+#ifdef INSN_SCHEDULING
+	  /* Similarly, avoid false dependencies.  */
+	  if (flag_schedule_insns_after_reload && !optimize_size
+	      && qty_alternate_class[q] != NO_REGS)
+	    qty_phys_reg[q] = find_free_reg (qty_alternate_class[q],
+					     qty_mode[q], q, 0, 0,
+					     fake_birth, fake_death);
+#endif
 	  if (qty_alternate_class[q] != NO_REGS)
 	    qty_phys_reg[q] = find_free_reg (qty_alternate_class[q],
 					     qty_mode[q], q, 0, 0,