Another minor tweak to the SPARC back-end

[Eric Botcazou <ebotcazou at libertysurf dot fr>]

I've always found UNSPEC_GET_PC and get_pc to be poorly evocative.  Also the 
pattern could be reused for something else than loading the PIC register.

Bootstrapped/regtested on sparc64-sun-solaris2.9 and sparc-sun-solaris2.8.

Applied to mainline.


2004-07-06  Eric Botcazou  <ebotcazou@libertysurf.fr>

	* config/sparc/sparc.c (get_pc_symbol): Rename into
	add_pc_to_pic_symbol.
	(get_pc_symbol_name): Rename into add_pc_to_pic_symbol_name.
	(load_pic_register): Account for previous changes.
	Use reg_names.  Don't create the label twice.
	* config/sparc/sparc.md (UNSPEC_GET_PC): Rename into
	UNSPEC_LOAD_PCREL_SYM.
	(get_pc): Rename into load_pcrel_sym.  Add predicate to
	operands.  Remove condition.


-- 
Eric Botcazou

Index: config/sparc/sparc.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/sparc/sparc.c,v
retrieving revision 1.309
diff -u -p -r1.309 sparc.c
--- config/sparc/sparc.c	4 Jul 2004 21:42:28 -0000	1.309
+++ config/sparc/sparc.c	6 Jul 2004 08:47:07 -0000
@@ -3059,8 +3059,8 @@ sparc_cannot_force_const_mem (rtx x)
 static GTY(()) rtx global_offset_table;
 
 /* The function we use to get at it.  */
-static GTY(()) rtx get_pc_symbol;
-static GTY(()) char get_pc_symbol_name[256];
+static GTY(()) rtx add_pc_to_pic_symbol;
+static GTY(()) char add_pc_to_pic_symbol_name[256];
 
 /* Ensure that we are not using patterns that are not OK with PIC.  */
 
@@ -3643,33 +3643,33 @@ legitimize_address (rtx x, rtx oldx ATTR
 static void
 load_pic_register (void)
 {
-  /* Labels to get the PC in the prologue of this function.  */
   int orig_flag_pic = flag_pic;
 
-  /* If we haven't emitted the special get_pc helper function, do so now.  */
-  if (get_pc_symbol_name[0] == 0)
+  /* If we haven't emitted the special helper function, do so now.  */
+  if (add_pc_to_pic_symbol_name[0] == 0)
     {
+      const char *pic_name = reg_names[REGNO (pic_offset_table_rtx)];
       int align;
 
-      ASM_GENERATE_INTERNAL_LABEL (get_pc_symbol_name, "LGETPC", 0);
+      ASM_GENERATE_INTERNAL_LABEL (add_pc_to_pic_symbol_name, "LADDPC", 0);
       text_section ();
 
       align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
       if (align > 0)
 	ASM_OUTPUT_ALIGN (asm_out_file, align);
-      (*targetm.asm_out.internal_label) (asm_out_file, "LGETPC", 0);
-      fputs ("\tretl\n\tadd\t%o7, %l7, %l7\n", asm_out_file);
+      ASM_OUTPUT_LABEL (asm_out_file, add_pc_to_pic_symbol_name);
+      fprintf (asm_out_file, "\tjmp %%o7+8\n\t add\t%%o7, %s, %s\n",
+	       pic_name, pic_name);
     }
 
   /* Initialize every time through, since we can't easily
      know this to be permanent.  */
   global_offset_table = gen_rtx_SYMBOL_REF (Pmode, "_GLOBAL_OFFSET_TABLE_");
-  get_pc_symbol = gen_rtx_SYMBOL_REF (Pmode, get_pc_symbol_name);
-  flag_pic = 0;
-
-  emit_insn (gen_get_pc (pic_offset_table_rtx, global_offset_table,
-			 get_pc_symbol));
+  add_pc_to_pic_symbol = gen_rtx_SYMBOL_REF (Pmode, add_pc_to_pic_symbol_name);
 
+  flag_pic = 0;
+  emit_insn (gen_load_pcrel_sym (pic_offset_table_rtx, global_offset_table,
+				 add_pc_to_pic_symbol));
   flag_pic = orig_flag_pic;
 
   /* Need to emit this whether or not we obey regdecls,
Index: config/sparc/sparc.md
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/sparc/sparc.md,v
retrieving revision 1.205
diff -u -p -r1.205 sparc.md
--- config/sparc/sparc.md	5 Jul 2004 22:06:09 -0000	1.205
+++ config/sparc/sparc.md	6 Jul 2004 08:47:17 -0000
@@ -27,7 +27,7 @@
 (define_constants
   [(UNSPEC_MOVE_PIC		0)
    (UNSPEC_UPDATE_RETURN	1)
-   (UNSPEC_GET_PC		2)
+   (UNSPEC_LOAD_PCREL_SYM	2)
    (UNSPEC_MOVE_PIC_LABEL	5)
    (UNSPEC_SETH44		6)
    (UNSPEC_SETM44		7)
@@ -1664,17 +1664,19 @@
   [(set_attr "type" "branch")
    (set_attr "branch_type" "reg")])
 
-;; Load program counter insns.
+;; Load in operand 0 the (absolute) address of operand 1, which is a symbolic
+;; value subject to a PC-relative relocation.  Operand 2 is a helper function
+;; that adds the PC value at the call point to operand 0.
 
-(define_insn "get_pc"
-  [(clobber (reg:SI 15))
-   (set (match_operand 0 "register_operand" "=r")
-	(unspec [(match_operand 1 "" "") (match_operand 2 "" "")] UNSPEC_GET_PC))]
-  "flag_pic && REGNO (operands[0]) == 23"
+(define_insn "load_pcrel_sym"
+  [(set (match_operand 0 "register_operand" "=r")
+	(unspec [(match_operand 1 "symbolic_operand" "")
+		 (match_operand 2 "call_operand_address" "")] UNSPEC_LOAD_PCREL_SYM))
+   (clobber (reg:SI 15))]
+  ""
   "sethi\t%%hi(%a1-4), %0\n\tcall\t%a2\n\tadd\t%0, %%lo(%a1+4), %0"
   [(set_attr "type" "multi")
    (set_attr "length" "3")])
-
 
 ;; Move instructions