gcc/

	* config/i386/i386.c (output_set_got): Add a GOT initialization
	sequence for VxWorks PIC.
	(legitimate_pic_address_disp_p): Allow UNSPEC_GOT wrappers
	around labels as well as symbols.  Use gotoff_operand instead
	of local_symbolic_operand.
	(legitimize_pic_address): Use gotoff_operand instead of
	local_symbolic_operand.  Use @GOT accesses for labels as
	well as symbols.
	(ix86_output_addr_diff_elt): Use PC-relative rather than
	GP-relative offsets for VxWorks PIC.
	(ix86_expand_move): Pass NULL_RTX to legitimize_pic_address unless
	no_new_pseudos.  Check whether the returned register is op0.
	* config/i386/i386.md (tablejump): Use PC-relative rather than
	GP-relative offsets for VxWorks PIC.
	* config/i386/predicates.md (gotoff_operand): New predicate.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@122654 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d23c823..47057a7 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,21 @@
+2007-03-07  Richard Sandiford  <richard@codesourcery.com>
+
+       * config/i386/i386.c (output_set_got): Add a GOT initialization
+       sequence for VxWorks PIC.
+       (legitimate_pic_address_disp_p): Allow UNSPEC_GOT wrappers
+       around labels as well as symbols.  Use gotoff_operand instead
+       of local_symbolic_operand.
+       (legitimize_pic_address): Use gotoff_operand instead of
+       local_symbolic_operand.  Use @GOT accesses for labels as
+       well as symbols.
+       (ix86_output_addr_diff_elt): Use PC-relative rather than
+       GP-relative offsets for VxWorks PIC.
+       (ix86_expand_move): Pass NULL_RTX to legitimize_pic_address unless
+       no_new_pseudos.  Check whether the returned register is op0.
+       * config/i386/i386.md (tablejump): Use PC-relative rather than
+       GP-relative offsets for VxWorks PIC.
+       * config/i386/predicates.md (gotoff_operand): New predicate.
+
 2007-03-06  Richard Sandiford  <richard@codesourcery.com>
 
        * config/vxworks.h (VXWORKS_GOTT_BASE, VXWORKS_GOTT_INDEX): Undefine

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 9cc2144..bd08601 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5371,6 +5371,23 @@ output_set_got (rtx dest, rtx label ATTRIBUTE_UNUSED)
   rtx xops[3];
 
   xops[0] = dest;
+
+  if (TARGET_VXWORKS_RTP && flag_pic)
+    {
+      /* Load (*VXWORKS_GOTT_BASE) into the PIC register.  */
+      xops[2] = gen_rtx_MEM (Pmode,
+                            gen_rtx_SYMBOL_REF (Pmode, VXWORKS_GOTT_BASE));
+      output_asm_insn ("mov{l}\t{%2, %0|%0, %2}", xops);
+
+      /* Load (*VXWORKS_GOTT_BASE)[VXWORKS_GOTT_INDEX] into the PIC register.
+        Use %P and a local symbol in order to print VXWORKS_GOTT_INDEX as
+        an unadorned address.  */
+      xops[2] = gen_rtx_SYMBOL_REF (Pmode, VXWORKS_GOTT_INDEX);
+      SYMBOL_REF_FLAGS (xops[2]) |= SYMBOL_FLAG_LOCAL;
+      output_asm_insn ("mov{l}\t{%P2(%0), %0|%0, DWORD PTR %P2[%0]}", xops);
+      return "";
+    }
+
   xops[1] = gen_rtx_SYMBOL_REF (Pmode, GOT_SYMBOL_NAME);
 
   if (! TARGET_DEEP_BRANCH_PREDICTION || !flag_pic)
@@ -6762,7 +6779,11 @@ legitimate_pic_address_disp_p (rtx disp)
     case UNSPEC_GOT:
       if (saw_plus)
        return false;
-      return GET_CODE (XVECEXP (disp, 0, 0)) == SYMBOL_REF;
+      /* We need to check for both symbols and labels because VxWorks loads
+        text labels with @GOT rather than @GOTOFF.  See gotoff_operand for
+        details.  */
+      return (GET_CODE (XVECEXP (disp, 0, 0)) == SYMBOL_REF
+             || GET_CODE (XVECEXP (disp, 0, 0)) == LABEL_REF);
     case UNSPEC_GOTOFF:
       /* Refuse GOTOFF in 64bit mode since it is always 64bit when used.
         While ABI specify also 32bit relocation but we don't produce it in
@@ -6770,7 +6791,7 @@ legitimate_pic_address_disp_p (rtx disp)
       if ((GET_CODE (XVECEXP (disp, 0, 0)) == SYMBOL_REF
           || GET_CODE (XVECEXP (disp, 0, 0)) == LABEL_REF)
          && !TARGET_64BIT)
-        return local_symbolic_operand (XVECEXP (disp, 0, 0), Pmode);
+        return gotoff_operand (XVECEXP (disp, 0, 0), Pmode);
       return false;
     case UNSPEC_GOTTPOFF:
     case UNSPEC_GOTNTPOFF:
@@ -7091,7 +7112,7 @@ legitimize_pic_address (rtx orig, rtx reg)
     new = addr;
   else if (TARGET_64BIT
           && ix86_cmodel != CM_SMALL_PIC
-          && local_symbolic_operand (addr, Pmode))
+          && gotoff_operand (addr, Pmode))
     {
       rtx tmpreg;
       /* This symbol may be referenced via a displacement from the PIC
@@ -7123,7 +7144,7 @@ legitimize_pic_address (rtx orig, rtx reg)
        }
       else new = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, tmpreg);
     }
-  else if (!TARGET_64BIT && local_symbolic_operand (addr, Pmode))
+  else if (!TARGET_64BIT && gotoff_operand (addr, Pmode))
     {
       /* This symbol may be referenced via a displacement from the PIC
         base address (@GOTOFF).  */
@@ -7148,7 +7169,10 @@ legitimize_pic_address (rtx orig, rtx reg)
          new = reg;
        }
     }
-  else if (GET_CODE (addr) == SYMBOL_REF && SYMBOL_REF_TLS_MODEL (addr) == 0)
+  else if ((GET_CODE (addr) == SYMBOL_REF && SYMBOL_REF_TLS_MODEL (addr) == 0)
+          /* We can't use @GOTOFF for text labels on VxWorks;
+             see gotoff_operand.  */
+          || (TARGET_VXWORKS_RTP && GET_CODE (addr) == LABEL_REF))
     {
       if (TARGET_64BIT && ix86_cmodel != CM_LARGE_PIC)
        {
@@ -7218,7 +7242,7 @@ legitimize_pic_address (rtx orig, rtx reg)
 
          /* Check first to see if this is a constant offset from a @GOTOFF
             symbol reference.  */
-         if (local_symbolic_operand (op0, Pmode)
+         if (gotoff_operand (op0, Pmode)
              && CONST_INT_P (op1))
            {
              if (!TARGET_64BIT)
@@ -9379,7 +9403,8 @@ ix86_output_addr_diff_elt (FILE *file, int value, int rel)
 #else
   gcc_assert (!TARGET_64BIT);
 #endif
-  if (TARGET_64BIT)
+  /* We can't use @GOTOFF for text labels on VxWorks; see gotoff_operand.  */
+  if (TARGET_64BIT || TARGET_VXWORKS_RTP)
     fprintf (file, "%s%s%d-%s%d\n",
             directive, LPREFIX, value, LPREFIX, rel);
   else if (HAVE_AS_GOTOFF_IN_DATA)
@@ -9502,7 +9527,12 @@ ix86_expand_move (enum machine_mode mode, rtx operands[])
          if (MEM_P (op0))
            op1 = force_reg (Pmode, op1);
          else if (!TARGET_64BIT || !x86_64_movabs_operand (op1, Pmode))
-           op1 = legitimize_pic_address (op1, op0);
+           {
+             rtx reg = no_new_pseudos ? op0 : NULL_RTX;
+             op1 = legitimize_pic_address (op1, reg);
+             if (op0 == op1)
+               return;
+           }
        }
     }
   else

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index f66318b..507edd6 100644 (file)
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -14353,7 +14353,9 @@
       rtx op0, op1;
       enum rtx_code code;
 
-      if (TARGET_64BIT)
+      /* We can't use @GOTOFF for text labels on VxWorks;
+        see gotoff_operand.  */
+      if (TARGET_64BIT || TARGET_VXWORKS_RTP)
        {
          code = PLUS;
          op0 = operands[0];

diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index 6ac3622..be2141c 100644 (file)
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -456,6 +456,18 @@
   return 0;
 })
 
+;; Test for a legitimate @GOTOFF operand.
+;;
+;; VxWorks does not impose a fixed gap between segments; the run-time
+;; gap can be different from the object-file gap.  We therefore can't
+;; use @GOTOFF unless we are absolutely sure that the symbol is in the
+;; same segment as the GOT.  Unfortunately, the flexibility of linker
+;; scripts means that we can't be sure of that in general, so assume
+;; that @GOTOFF is never valid on VxWorks.
+(define_predicate "gotoff_operand"
+  (and (match_test "!TARGET_VXWORKS_RTP")
+       (match_operand 0 "local_symbolic_operand")))
+
 ;; Test for various thread-local symbols.
 (define_predicate "tls_symbolic_operand"
   (and (match_code "symbol_ref")