output.h (current_function_is_leaf, [...]): Declare.

	* output.h (current_function_is_leaf,
	current_function_uses_only_leaf_regs): Declare.
	* function.c (current_function_is_leaf,
	current_function_uses_only_leaf_regs): Define.
	(init_function_start): Initialize current_function_is_leaf
	and current_function_uses_only_leaf_regs.
	* final.c (leaf_function): Don't define.
	(final_start_function): Replace uses of leaf_function with
	current_function_uses_only_leaf_regs.
	* toplev.c (rest_of_compilation): Set current_function_is_leaf
	prior to invoking local register allocation.
	(rest_of_compilation): Replace uses of leaf_function with
	current_function_uses_only_leaf_regs.
	* dbxout.c (dbxout_symbol, dbxout_parms): Likewise.
	* dwarf2out.c (add_location_or_const_vaule_attribute): Likewise.
	* dwarfout.c (add_location_or_const_value_attribute): Likewise.
	* sdbout.c (sdbout_symbol): Likewise.
	* sparc.h (FUNCTION_PROLOGUE, FUNCTION_EPILOGUE): Likewise.
	* sparc.c (eligible_for_epilogue_delay, output_return,
	sparc_return_peephole_ok): Likewise.
	* sparc.md (leaf_function attribute, untyped_return): Likewise.
	* i386.c (ix86_compute_frame_size): Don't align the stack
	for leaf functions which don't allocate any stack slots.
	* tm.texi: Update documentation.

From-SVN: r26538

14 files changed, 96 insertions, 30 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a092483..37cb3f0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,30 @@
+Sun Apr 18 15:50:33 EDT 1999  John Wehle  (john@feith.com)
+
+	* output.h (current_function_is_leaf,
+	current_function_uses_only_leaf_regs): Declare.
+	* function.c (current_function_is_leaf,
+	current_function_uses_only_leaf_regs): Define.
+	(init_function_start): Initialize current_function_is_leaf
+	and current_function_uses_only_leaf_regs.
+	* final.c (leaf_function): Don't define.
+	(final_start_function): Replace uses of leaf_function with
+	current_function_uses_only_leaf_regs.
+	* toplev.c (rest_of_compilation): Set current_function_is_leaf
+	prior to invoking local register allocation.
+	(rest_of_compilation): Replace uses of leaf_function with
+	current_function_uses_only_leaf_regs.
+	* dbxout.c (dbxout_symbol, dbxout_parms): Likewise.
+	* dwarf2out.c (add_location_or_const_vaule_attribute): Likewise.
+	* dwarfout.c (add_location_or_const_value_attribute): Likewise.
+	* sdbout.c (sdbout_symbol): Likewise.
+	* sparc.h (FUNCTION_PROLOGUE, FUNCTION_EPILOGUE): Likewise.
+	* sparc.c (eligible_for_epilogue_delay, output_return,
+	sparc_return_peephole_ok): Likewise.
+	* sparc.md (leaf_function attribute, untyped_return): Likewise.
+	* i386.c (ix86_compute_frame_size): Don't align the stack
+	for leaf functions which don't allocate any stack slots.
+	* tm.texi: Update documentation.
+
 Sun Apr 18 02:15:09 PDT 1999 Jeff Law  (law@cygnus.com)
 
 	* version.c: Bump for snapshot.
@@ -1150,7 +1177,7 @@ Fri Apr  2 14:12:06 1999  John Wehle  (john@feith.com)
 	* i386.md: Delete floating point compare, add, subtract,
 	multiply, and divide patterns which allowed integer
 	operands.
-	* i386.c (output_386_binary_op): Delete unused code.
+	* i386.c (output_387_binary_op): Delete unused code.
 	(output_float_compare): Likewise.
 
 Fri Apr  2 11:53:37 1999  John Wehle  (john@feith.com)
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index dab0300..4faff7b 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -1990,6 +1990,11 @@ ix86_compute_frame_size (size, nregs_on_stack)
     if (padding < (((offset + preferred_alignment - 1)
 		    & -preferred_alignment) - offset))
       padding += preferred_alignment;
+
+    /* Don't bother aligning the stack of a leaf function
+       which doesn't allocate any stack slots.  */
+    if (size == 0 && current_function_is_leaf)
+      padding = 0;
   }
 #endif
 
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index 05affdd..4950242 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -2230,7 +2230,7 @@ eligible_for_epilogue_delay (trial, slot)
   /* In the case of a true leaf function, anything can go into the delay slot.
      A delay slot only exists however if the frame size is zero, otherwise
      we will put an insn to adjust the stack after the return.  */
-  if (leaf_function)
+  if (current_function_uses_only_leaf_regs)
     {
       if (leaf_return_peephole_ok ())
 	return ((get_attr_in_uncond_branch_delay (trial)
@@ -4686,7 +4686,7 @@ output_return (operands)
       operands[0] = leaf_label;
       return "b%* %l0%(";
     }
-  else if (leaf_function)
+  else if (current_function_uses_only_leaf_regs)
     {
       /* No delay slot in a leaf function.  */
       if (delay)
@@ -7524,7 +7524,7 @@ sparc_return_peephole_ok (dest, src)
 {
   if (! TARGET_V9)
     return 0;
-  if (leaf_function)
+  if (current_function_uses_only_leaf_regs)
     return 0;
   if (GET_CODE (src) != CONST_INT
       && (GET_CODE (src) != REG || ! IN_OR_GLOBAL_P (src)))
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index b37b5e9..a220ce7 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -1838,10 +1838,10 @@ do {									\
    to do a "save" insn.  The decision about whether or not
    to do this is made in regclass.c.  */
 
-extern int leaf_function;
 #define FUNCTION_PROLOGUE(FILE, SIZE) \
   (TARGET_FLAT ? sparc_flat_output_function_prologue (FILE, (int)SIZE) \
-   : output_function_prologue (FILE, (int)SIZE, leaf_function))
+   : output_function_prologue (FILE, (int)SIZE, \
+			       current_function_uses_only_leaf_regs))
 
 /* Output assembler code to FILE to increment profiler label # LABELNO
    for profiling a function entry.
@@ -2216,7 +2216,8 @@ extern union tree_node *current_function_decl;
 
 #define FUNCTION_EPILOGUE(FILE, SIZE) \
   (TARGET_FLAT ? sparc_flat_output_function_epilogue (FILE, (int)SIZE) \
-   : output_function_epilogue (FILE, (int)SIZE, leaf_function))
+   : output_function_epilogue (FILE, (int)SIZE, \
+			       current_function_uses_only_leaf_regs))
 
 #define DELAY_SLOTS_FOR_EPILOGUE \
   (TARGET_FLAT ? sparc_flat_epilogue_delay_slots () : 1)
diff --git a/gcc/config/sparc/sparc.md b/gcc/config/sparc/sparc.md
index c1adf93..025992a 100644
--- a/gcc/config/sparc/sparc.md
+++ b/gcc/config/sparc/sparc.md
@@ -159,7 +159,7 @@
   [(eq_attr "in_call_delay" "true") (nil) (nil)])
 
 (define_attr "leaf_function" "false,true"
-  (const (symbol_ref "leaf_function")))
+  (const (symbol_ref "current_function_uses_only_leaf_regs")))
 
 (define_attr "in_return_delay" "false,true"
   (if_then_else (and (and (and (eq_attr "type" "move,load,sload,store,binary,ialu")
@@ -7618,7 +7618,8 @@
 
   if (! TARGET_ARCH64)
     {
-      rtx rtnreg = gen_rtx_REG (SImode, (leaf_function ? 15 : 31));
+      rtx rtnreg = gen_rtx_REG (SImode, (current_function_uses_only_leaf_regs
+					 ? 15 : 31));
       rtx value = gen_reg_rtx (SImode);
 
       /* Fetch the instruction where we will return to and see if it's an unimp
diff --git a/gcc/dbxout.c b/gcc/dbxout.c
index 07122ec..bc15a4d 100644
--- a/gcc/dbxout.c
+++ b/gcc/dbxout.c
@@ -1937,7 +1937,7 @@ dbxout_symbol (decl, local)
 
       DECL_RTL (decl) = eliminate_regs (DECL_RTL (decl), 0, NULL_RTX);
 #ifdef LEAF_REG_REMAP
-      if (leaf_function)
+      if (current_function_uses_only_leaf_regs)
 	leaf_renumber_regs_insn (DECL_RTL (decl));
 #endif
 
@@ -2259,7 +2259,7 @@ dbxout_parms (parms)
 	  = eliminate_regs (DECL_INCOMING_RTL (parms), 0, NULL_RTX);
 	DECL_RTL (parms) = eliminate_regs (DECL_RTL (parms), 0, NULL_RTX);
 #ifdef LEAF_REG_REMAP
-	if (leaf_function)
+	if (current_function_uses_only_leaf_regs)
 	  {
 	    leaf_renumber_regs_insn (DECL_INCOMING_RTL (parms));
 	    leaf_renumber_regs_insn (DECL_RTL (parms));
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 393dbc5..659b119 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -7207,7 +7207,7 @@ add_location_or_const_value_attribute (die, decl)
 
   rtl = eliminate_regs (rtl, 0, NULL_RTX);
 #ifdef LEAF_REG_REMAP
-  if (leaf_function)
+  if (current_function_uses_only_leaf_regs)
     leaf_renumber_regs_insn (rtl);
 #endif
 
diff --git a/gcc/dwarfout.c b/gcc/dwarfout.c
index 388c4a4..ac17f7f 100644
--- a/gcc/dwarfout.c
+++ b/gcc/dwarfout.c
@@ -2421,7 +2421,7 @@ location_or_const_value_attribute (decl)
 
   rtl = eliminate_regs (rtl, 0, NULL_RTX);
 #ifdef LEAF_REG_REMAP
-  if (leaf_function)
+  if (current_function_uses_only_leaf_regs)
     leaf_renumber_regs_insn (rtl);
 #endif
 
diff --git a/gcc/final.c b/gcc/final.c
index 3cd2e0c..bacc093 100644
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -131,11 +131,6 @@ Boston, MA 02111-1307, USA.  */
 #define JUMP_TABLES_IN_TEXT_SECTION 0
 #endif
 
-/* Nonzero means this function is a leaf function, with no function calls. 
-   This variable exists to be examined in FUNCTION_PROLOGUE
-   and FUNCTION_EPILOGUE.  Always zero, unless set by some action.  */
-int leaf_function;
-
 /* Last insn processed by final_scan_insn.  */
 static rtx debug_insn = 0;
 
@@ -1634,7 +1629,7 @@ final_start_function (first, file, optimize)
 	output_source_line (file, first);
 
 #ifdef LEAF_REG_REMAP
-  if (leaf_function)
+  if (current_function_uses_only_leaf_regs)
     leaf_renumber_regs (first);
 #endif
 
diff --git a/gcc/function.c b/gcc/function.c
index ac55f3a..3035786 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -140,12 +140,25 @@ int current_function_has_nonlocal_goto;
 
 int current_function_contains_functions;
 
+/* Nonzero if function being compiled doesn't contain any calls
+   (ignoring the prologue and epilogue).  This is set prior to
+   local register allocation and is valid for the remaining
+   compiler passes. */
+
+int current_function_is_leaf;
+
 /* Nonzero if function being compiled doesn't modify the stack pointer
    (ignoring the prologue and epilogue).  This is only valid after
    life_analysis has run. */
 
 int current_function_sp_is_unchanging;
 
+/* Nonzero if the function being compiled is a leaf function which only
+   uses leaf registers.  This is valid after reload (specifically after
+   sched2) and is useful only if the port defines LEAF_REGISTERS.  */
+
+int current_function_uses_only_leaf_regs;
+
 /* Nonzero if the function being compiled issues a computed jump.  */
 
 int current_function_has_computed_jump;
@@ -5897,7 +5910,9 @@ init_function_start (subr, filename, line)
   current_function_has_nonlocal_label = 0;
   current_function_has_nonlocal_goto = 0;
   current_function_contains_functions = 0;
+  current_function_is_leaf = 0;
   current_function_sp_is_unchanging = 0;
+  current_function_uses_only_leaf_regs = 0;
   current_function_has_computed_jump = 0;
   current_function_is_thunk = 0;
 
diff --git a/gcc/output.h b/gcc/output.h
index 7e1c28b..e1cf6d8 100644
--- a/gcc/output.h
+++ b/gcc/output.h
@@ -383,12 +383,25 @@ extern int current_function_has_nonlocal_label;
 
 extern int current_function_contains_functions;
 
+/* Nonzero if function being compiled doesn't contain any calls
+   (ignoring the prologue and epilogue).  This is set prior to
+   local register allocation and is valid for the remaining
+   compiler passes. */
+
+extern int current_function_is_leaf;
+
 /* Nonzero if function being compiled doesn't modify the stack pointer
    (ignoring the prologue and epilogue).  This is only valid after
    life_analysis has run. */
 
 extern int current_function_sp_is_unchanging;
 
+/* Nonzero if the function being compiled is a leaf function which only
+   uses leaf registers.  This is valid after reload (specifically after
+   sched2) and is useful only if the port defines LEAF_REGISTERS.  */
+
+extern int current_function_uses_only_leaf_regs;
+
 /* Nonzero if the function being compiled issues a computed jump.  */
 
 extern int current_function_has_computed_jump;
diff --git a/gcc/sdbout.c b/gcc/sdbout.c
index 1f13899..0aebd83 100644
--- a/gcc/sdbout.c
+++ b/gcc/sdbout.c
@@ -811,7 +811,7 @@ sdbout_symbol (decl, local)
 
       DECL_RTL (decl) = eliminate_regs (DECL_RTL (decl), 0, NULL_RTX);
 #ifdef LEAF_REG_REMAP
-      if (leaf_function)
+      if (current_function_uses_only_leaf_regs)
 	leaf_renumber_regs_insn (DECL_RTL (decl));
 #endif
       value = DECL_RTL (decl);
diff --git a/gcc/tm.texi b/gcc/tm.texi
index 8e6797a..ac6e6be 100644
--- a/gcc/tm.texi
+++ b/gcc/tm.texi
@@ -1642,12 +1642,17 @@ treatment of leaf functions, and registers need to be renumbered to do
 this.
 @end table
 
-@findex leaf_function
+@findex current_function_is_leaf
+@findex current_function_uses_only_leaf_regs
 Normally, @code{FUNCTION_PROLOGUE} and @code{FUNCTION_EPILOGUE} must
-treat leaf functions specially.  It can test the C variable
-@code{leaf_function} which is nonzero for leaf functions.  (The variable
-@code{leaf_function} is defined only if @code{LEAF_REGISTERS} is
-defined.)
+treat leaf functions specially.  They can test the C variable
+@code{current_function_is_leaf} which is nonzero for leaf functions.
+@code{current_function_is_leaf} is set prior to local register allocation
+and is valid for the remaining compiler passes.  They can also test the C
+variable @code{current_function_uses_only_leaf_regs} which is nonzero for
+leaf functions which only use leaf registers.
+@code{current_function_uses_only_leaf_regs} is valid after reload and is
+only useful if @code{LEAF_REGISTERS} is defined.
 @c changed this to fix overfull.  ALSO:  why the "it" at the beginning
 @c of the next paragraph?!  --mew 2feb93
 
@@ -3296,7 +3301,7 @@ argument lists of the function.  @xref{Stack Arguments}.
 
 Normally, it is necessary for the macros @code{FUNCTION_PROLOGUE} and
 @code{FUNCTION_EPILOGUE} to treat leaf functions specially.  The C
-variable @code{leaf_function} is nonzero for such a function.
+variable @code{current_function_is_leaf} is nonzero for such a function.
 
 @findex EXIT_IGNORE_STACK
 @item EXIT_IGNORE_STACK
@@ -3346,8 +3351,8 @@ is wanted, the macro can refer to the variable
 a function that needs a frame pointer.
 
 Normally, @code{FUNCTION_PROLOGUE} and @code{FUNCTION_EPILOGUE} must
-treat leaf functions specially.  The C variable @code{leaf_function} is
-nonzero for such a function.  @xref{Leaf Functions}.
+treat leaf functions specially.  The C variable @code{current_function_is_leaf}
+is nonzero for such a function.  @xref{Leaf Functions}.
 
 On some machines, some functions pop their arguments on exit while
 others leave that for the caller to do.  For example, the 68020 when
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 482b956..7b3c31c 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -4089,6 +4089,11 @@ rest_of_compilation (decl)
 	}
     }
 
+  /* Determine if the current function is a leaf before running reload
+     since this can impact optimizations done by the prologue and
+     epilogue thus changing register elimination offsets.  */
+  current_function_is_leaf = leaf_function_p ();
+
   /* Unless we did stupid register allocation,
      allocate pseudo-regs that are used only within 1 basic block. 
 
@@ -4235,9 +4240,8 @@ rest_of_compilation (decl)
     }
 
 #ifdef LEAF_REGISTERS
-  leaf_function = 0;
   if (optimize > 0 && only_leaf_regs_used () && leaf_function_p ())
-    leaf_function = 1;
+    current_function_uses_only_leaf_regs = 1;
 #endif
 
   /* One more attempt to remove jumps to .+1