* expr.c (expr): Move code setting "retval" to the end of the loop,

	and rearrange for efficiency.  For "PIC code" subtraction, use
	"rightseg" rather than recalculating.  For "symbol OP symbol"
	subtract, set "retval" to absolute_section if symbols in same
	section.
	* symbols.c (resolve_symbol_value): Resolve "sym +/- expr" to an
	O_symbol.  Simplify a +/- b code.  Allow equality and non-equality
	comparisons on symbols from any section.  Allow other comparison
	operators as for subtraction.
	(symbol_equated_reloc_p): New predicate function.
	* symbols.h (symbol_equated_reloc_p): Declare.
	* write.c (adjust_reloc_syms): Use symbol_equated_reloc_p.
	(write_relocs): Likewise.
	(write_object_file): Likewise.
	(relax_segment <rs_machine_dependent>): Ensure segment for
	expression syms is set correctly.
	* config/tc-mips.c (md_estimate_size_before_relax): Likewise.
	* config/tc-i386.c (md_assemble <Output jumps>): Don't lose part
	of a complex expression when setting up frag_var.

7 files changed, 174 insertions, 76 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 0c27bef..8f25096 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,25 @@
+2001-09-09  Alan Modra  <amodra@bigpond.net.au>
+
+	* expr.c (expr): Move code setting "retval" to the end of the loop,
+	and rearrange for efficiency.  For "PIC code" subtraction, use
+	"rightseg" rather than recalculating.  For "symbol OP symbol"
+	subtract, set "retval" to absolute_section if symbols in same
+	section.
+	* symbols.c (resolve_symbol_value): Resolve "sym +/- expr" to an
+	O_symbol.  Simplify a +/- b code.  Allow equality and non-equality
+	comparisons on symbols from any section.  Allow other comparison
+	operators as for subtraction.
+	(symbol_equated_reloc_p): New predicate function.
+	* symbols.h (symbol_equated_reloc_p): Declare.
+	* write.c (adjust_reloc_syms): Use symbol_equated_reloc_p.
+	(write_relocs): Likewise.
+	(write_object_file): Likewise.
+	(relax_segment <rs_machine_dependent>): Ensure segment for
+	expression syms is set correctly.
+	* config/tc-mips.c (md_estimate_size_before_relax): Likewise.
+	* config/tc-i386.c (md_assemble <Output jumps>): Don't lose part
+	of a complex expression when setting up frag_var.
+
 2001-09-07  Richard Henderson  <rth@redhat.com>
 
 	* config/tc-alpha.c (alpha_reloc_op_tag): Replace need_seq with
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 275b3e6..739ed58 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -2741,6 +2741,9 @@ md_assemble (line)
       {
 	int code16;
 	int prefix;
+	relax_substateT subtype;
+	symbolS *sym;
+	offsetT off;
 
 	code16 = 0;
 	if (flag_code == CODE_16BIT)
@@ -2785,19 +2788,29 @@ md_assemble (line)
 	if (i.prefix[REX_PREFIX])
 	  *p++ = i.prefix[REX_PREFIX];
 	*p = i.tm.base_opcode;
-	/* 1 possible extra opcode + displacement go in var part.
+
+	if ((unsigned char) *p == JUMP_PC_RELATIVE)
+	  subtype = ENCODE_RELAX_STATE (UNCOND_JUMP, SMALL);
+	else if ((cpu_arch_flags & Cpu386) != 0)
+	  subtype = ENCODE_RELAX_STATE (COND_JUMP, SMALL);
+	else
+	  subtype = ENCODE_RELAX_STATE (COND_JUMP86, SMALL);
+	subtype |= code16;
+
+	sym = i.op[0].disps->X_add_symbol;
+	off = i.op[0].disps->X_add_number;
+
+	if (i.op[0].disps->X_op != O_constant
+	    && i.op[0].disps->X_op != O_symbol)
+	  {
+	    /* Handle complex expressions.  */
+	    sym = make_expr_symbol (i.op[0].disps);
+	    off = 0;
+	  }
+
+	/* 1 possible extra opcode + 4 byte displacement go in var part.
 	   Pass reloc in fr_var.  */
-	frag_var (rs_machine_dependent,
-		  1 + 4,
-		  i.reloc[0],
-		  ((unsigned char) *p == JUMP_PC_RELATIVE
-		   ? ENCODE_RELAX_STATE (UNCOND_JUMP, SMALL) | code16
-		   : ((cpu_arch_flags & Cpu386) != 0
-		      ? ENCODE_RELAX_STATE (COND_JUMP, SMALL) | code16
-		      : ENCODE_RELAX_STATE (COND_JUMP86, SMALL) | code16)),
-		  i.op[0].disps->X_add_symbol,
-		  i.op[0].disps->X_add_number,
-		  p);
+	frag_var (rs_machine_dependent, 5, i.reloc[0], subtype, sym, off, p);
       }
     else if (i.tm.opcode_modifier & (JumpByte | JumpDword))
       {
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 0855af0..f9b5811 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -11143,8 +11143,7 @@ md_estimate_size_before_relax (fragp, segtype)
       sym = fragp->fr_symbol;
 
       /* Handle the case of a symbol equated to another symbol.  */
-      while (symbol_equated_p (sym)
-	     && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
+      while (symbol_equated_reloc_p (sym))
 	{
 	  symbolS *n;
 
diff --git a/gas/expr.c b/gas/expr.c
index 4258868..4f7f225 100644
--- a/gas/expr.c
+++ b/gas/expr.c
@@ -1699,21 +1699,6 @@ expr (rankarg, resultP)
 	    }
 	}
 
-      if (retval == undefined_section)
-	{
-	  if (SEG_NORMAL (rightseg))
-	    retval = rightseg;
-	}
-      else if (! SEG_NORMAL (retval))
-	retval = rightseg;
-      else if (SEG_NORMAL (rightseg)
-	       && retval != rightseg
-#ifdef DIFF_EXPR_OK
-	       && op_left != O_subtract
-#endif
-	       )
-	as_bad (_("operation combines symbols in different segments"));
-
       op_right = operator (&op_chars);
 
       know (op_right == O_illegal
@@ -1769,8 +1754,7 @@ expr (rankarg, resultP)
 	       && resultP->X_op == O_symbol
 	       && (symbol_get_frag (right.X_add_symbol)
 		   == symbol_get_frag (resultP->X_add_symbol))
-	       && SEG_NORMAL (S_GET_SEGMENT (right.X_add_symbol)))
-
+	       && SEG_NORMAL (rightseg))
 	{
 	  resultP->X_add_number -= right.X_add_number;
 	  resultP->X_add_number += (S_GET_VALUE (resultP->X_add_symbol)
@@ -1865,7 +1849,14 @@ expr (rankarg, resultP)
 	  if (op_left == O_add)
 	    resultP->X_add_number += right.X_add_number;
 	  else if (op_left == O_subtract)
-	    resultP->X_add_number -= right.X_add_number;
+	    {
+	      resultP->X_add_number -= right.X_add_number;
+	      if (retval == rightseg && SEG_NORMAL (retval))
+		{
+		  retval = absolute_section;
+		  rightseg = absolute_section;
+		}
+	    }
 	}
       else
 	{
@@ -1877,6 +1868,21 @@ expr (rankarg, resultP)
 	  resultP->X_unsigned = 1;
 	}
 
+      if (retval != rightseg)
+	{
+	  if (! SEG_NORMAL (retval))
+	    {
+	      if (retval != undefined_section || SEG_NORMAL (rightseg))
+		retval = rightseg;
+	    }
+	  else if (SEG_NORMAL (rightseg)
+#ifdef DIFF_EXPR_OK
+		   && op_left != O_subtract
+#endif
+		   )
+	    as_bad (_("operation combines symbols in different segments"));
+	}
+
       op_left = op_right;
     }				/* While next operator is >= this rank.  */
 
diff --git a/gas/symbols.c b/gas/symbols.c
index 1f4e988..201b03e 100644
--- a/gas/symbols.c
+++ b/gas/symbols.c
@@ -914,13 +914,16 @@ resolve_symbol_value (symp)
 	case O_symbol:
 	case O_symbol_rva:
 	  left = resolve_symbol_value (add_symbol);
-	do_symbol:
+	  seg_left = S_GET_SEGMENT (add_symbol);
+	  if (finalize_syms)
+	    symp->sy_value.X_op_symbol = NULL;
 
+	do_symbol:
 	  if (symp->sy_mri_common)
 	    {
 	      /* This is a symbol inside an MRI common section.  The
-                 relocation routines are going to handle it specially.
-                 Don't change the value.  */
+		 relocation routines are going to handle it specially.
+		 Don't change the value.  */
 	      resolved = symbol_resolved_p (add_symbol);
 	      break;
 	    }
@@ -933,31 +936,51 @@ resolve_symbol_value (symp)
 	      copy_symbol_attributes (symp, add_symbol);
 	    }
 
-	  /* If we have equated this symbol to an undefined symbol, we
-             keep X_op set to O_symbol, and we don't change
-             X_add_number.  This permits the routine which writes out
-             relocation to detect this case, and convert the
-             relocation to be against the symbol to which this symbol
-             is equated.  */
+	  /* If we have equated this symbol to an undefined or common
+	     symbol, keep X_op set to O_symbol, and don't change
+	     X_add_number.  This permits the routine which writes out
+	     relocation to detect this case, and convert the
+	     relocation to be against the symbol to which this symbol
+	     is equated.  */
 	  if (! S_IS_DEFINED (add_symbol) || S_IS_COMMON (add_symbol))
 	    {
 	      if (finalize_syms)
 		{
-		  final_seg = S_GET_SEGMENT (add_symbol);
 		  symp->sy_value.X_op = O_symbol;
 		  symp->sy_value.X_add_symbol = add_symbol;
 		  symp->sy_value.X_add_number = final_val;
+		  /* Use X_op_symbol as a flag.  */
+		  symp->sy_value.X_op_symbol = add_symbol;
+		  final_seg = seg_left;
 		}
 	      final_val = 0;
 	      resolved = symbol_resolved_p (add_symbol);
 	      symp->sy_resolving = 0;
 	      goto exit_dont_set_value;
 	    }
+	  else if (finalize_syms && final_seg == expr_section
+		   && seg_left != expr_section)
+	    {
+	      /* If the symbol is an expression symbol, do similarly
+		 as for undefined and common syms above.  Handles
+		 "sym +/- expr" where "expr" cannot be evaluated
+		 immediately, and we want relocations to be against
+		 "sym", eg. because it is weak.  */
+	      symp->sy_value.X_op = O_symbol;
+	      symp->sy_value.X_add_symbol = add_symbol;
+	      symp->sy_value.X_add_number = final_val;
+	      symp->sy_value.X_op_symbol = add_symbol;
+	      final_seg = seg_left;
+	      final_val += symp->sy_frag->fr_address + left;
+	      resolved = symbol_resolved_p (add_symbol);
+	      symp->sy_resolving = 0;
+	      goto exit_dont_set_value;
+	    }
 	  else
 	    {
 	      final_val += symp->sy_frag->fr_address + left;
 	      if (final_seg == expr_section || final_seg == undefined_section)
-		final_seg = S_GET_SEGMENT (add_symbol);
+		final_seg = seg_left;
 	    }
 
 	  resolved = symbol_resolved_p (add_symbol);
@@ -1008,42 +1031,49 @@ resolve_symbol_value (symp)
 
 	  /* Simplify addition or subtraction of a constant by folding the
 	     constant into X_add_number.  */
-	  if (op == O_add || op == O_subtract)
+	  if (op == O_add)
 	    {
 	      if (seg_right == absolute_section)
 		{
-		  if (op == O_add)
-		    final_val += right;
-		  else
-		    final_val -= right;
-		  op = O_symbol;
-		  op_symbol = NULL;
+		  final_val += right;
 		  goto do_symbol;
 		}
-	      else if (seg_left == absolute_section && op == O_add)
+	      else if (seg_left == absolute_section)
 		{
-		  op = O_symbol;
 		  final_val += left;
 		  add_symbol = op_symbol;
 		  left = right;
-		  op_symbol = NULL;
+		  seg_left = seg_right;
+		  goto do_symbol;
+		}
+	    }
+	  else if (op == O_subtract)
+	    {
+	      if (seg_right == absolute_section)
+		{
+		  final_val -= right;
 		  goto do_symbol;
 		}
 	    }
 
-	  /* Subtraction is permitted if both operands are in the same
-	     section.  Otherwise, both operands must be absolute.  We
-	     already handled the case of addition or subtraction of a
-	     constant above.  This will probably need to be changed
-	     for an object file format which supports arbitrary
-	     expressions, such as IEEE-695.  */
-	  /* Don't emit messages unless we're finalizing the symbol value,
+	  /* Equality and non-equality tests are permitted on anything.
+	     Subtraction, and other comparison operators are permitted if
+	     both operands are in the same section.  Otherwise, both
+	     operands must be absolute.  We already handled the case of
+	     addition or subtraction of a constant above.  This will
+	     probably need to be changed for an object file format which
+	     supports arbitrary expressions, such as IEEE-695.
+
+	     Don't emit messages unless we're finalizing the symbol value,
 	     otherwise we may get the same message multiple times.  */
-	  if ((seg_left != absolute_section
-	       || seg_right != absolute_section)
-	      && (op != O_subtract
+	  if (op != O_eq && op != O_ne
+	      && (seg_left != absolute_section
+		  || seg_right != absolute_section)
+	      && ((op != O_subtract
+		   && op != O_lt && op != O_le && op != O_ge && op != O_gt)
 		  || seg_left != seg_right
-		  || seg_left == undefined_section)
+		  || (seg_left == undefined_section
+		      && add_symbol != op_symbol))
 	      && finalize_syms)
 	    {
 	      char *file;
@@ -1085,7 +1115,7 @@ resolve_symbol_value (symp)
 	  if ((op == O_divide || op == O_modulus) && right == 0)
 	    {
 	      /* If seg_right is not absolute_section, then we've
-                 already issued a warning about using a bad symbol.  */
+		 already issued a warning about using a bad symbol.  */
 	      if (seg_right == absolute_section && finalize_syms)
 		{
 		  char *file;
@@ -1114,8 +1144,15 @@ resolve_symbol_value (symp)
 	    case O_bit_and:		left &= right; break;
 	    case O_add:			left += right; break;
 	    case O_subtract:		left -= right; break;
-	    case O_eq:	left = left == right ? ~ (offsetT) 0 : 0; break;
-	    case O_ne:	left = left != right ? ~ (offsetT) 0 : 0; break;
+	    case O_eq:
+	    case O_ne:
+	      left = (left == right && seg_left == seg_right
+		      && (seg_left != undefined_section
+			  || add_symbol == op_symbol)
+		      ? ~ (offsetT) 0 : 0);
+	      if (symp->sy_value.X_op == O_ne)
+		left = ~left;
+	      break;
 	    case O_lt:	left = left <  right ? ~ (offsetT) 0 : 0; break;
 	    case O_le:	left = left <= right ? ~ (offsetT) 0 : 0; break;
 	    case O_ge:	left = left >= right ? ~ (offsetT) 0 : 0; break;
@@ -2146,6 +2183,24 @@ symbol_equated_p (s)
   return s->sy_value.X_op == O_symbol;
 }
 
+/* Return whether a symbol is equated to another symbol, and should be
+   treated specially when writing out relocs.  */
+
+int
+symbol_equated_reloc_p (s)
+     symbolS *s;
+{
+  if (LOCAL_SYMBOL_CHECK (s))
+    return 0;
+  /* X_op_symbol, normally not used for O_symbol, is set by
+     resolve_symbol_value to flag expression syms that have been
+     equated.  */
+  return (s->sy_value.X_op == O_symbol
+	  && ((s->sy_resolved && s->sy_value.X_op_symbol != NULL)
+	      || ! S_IS_DEFINED (s)
+	      || S_IS_COMMON (s)));
+}
+
 /* Return whether a symbol has a constant value.  */
 
 int
diff --git a/gas/symbols.h b/gas/symbols.h
index e798905..a80ca8c 100644
--- a/gas/symbols.h
+++ b/gas/symbols.h
@@ -185,6 +185,7 @@ extern void symbol_mark_resolved PARAMS ((symbolS *));
 extern int symbol_resolved_p PARAMS ((symbolS *));
 extern int symbol_section_p PARAMS ((symbolS *));
 extern int symbol_equated_p PARAMS ((symbolS *));
+extern int symbol_equated_reloc_p PARAMS ((symbolS *));
 extern int symbol_constant_p PARAMS ((symbolS *));
 
 #ifdef BFD_ASSEMBLER
diff --git a/gas/write.c b/gas/write.c
index c096eb5..14fbf04 100644
--- a/gas/write.c
+++ b/gas/write.c
@@ -769,8 +769,7 @@ adjust_reloc_syms (abfd, sec, xxx)
 
 	/* If this symbol is equated to an undefined symbol, convert
            the fixup to being against that symbol.  */
-	if (sym != NULL && symbol_equated_p (sym)
-	    && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
+	if (sym != NULL && symbol_equated_reloc_p (sym))
 	  {
 	    fixp->fx_offset += symbol_get_value_expression (sym)->X_add_number;
 	    sym = symbol_get_value_expression (sym)->X_add_symbol;
@@ -983,11 +982,10 @@ write_relocs (abfd, sec, xxx)
 	}
 
       /* If this is an undefined symbol which was equated to another
-         symbol, then use generate the reloc against the latter symbol
+         symbol, then generate the reloc against the latter symbol
          rather than the former.  */
       sym = fixp->fx_addsy;
-      while (symbol_equated_p (sym)
-	     && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
+      while (symbol_equated_reloc_p (sym))
 	{
 	  symbolS *n;
 
@@ -1059,8 +1057,7 @@ write_relocs (abfd, sec, xxx)
          symbol, then generate the reloc against the latter symbol
          rather than the former.  */
       sym = fixp->fx_addsy;
-      while (symbol_equated_p (sym)
-	     && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
+      while (symbol_equated_reloc_p (sym))
 	sym = symbol_get_value_expression (sym)->X_add_symbol;
       fixp->fx_addsy = sym;
 
@@ -1960,8 +1957,7 @@ write_object_file ()
 
 	  /* Skip symbols which were equated to undefined or common
              symbols.  */
-	  if (symbol_equated_p (symp)
-	      && (! S_IS_DEFINED (symp) || S_IS_COMMON (symp)))
+	  if (symbol_equated_reloc_p (symp))
 	    {
 	      symbol_remove (symp, &symbol_rootP, &symbol_lastP);
 	      continue;
@@ -2264,6 +2260,12 @@ relax_segment (segment_frag_root, segment)
 	  break;
 
 	case rs_machine_dependent:
+	  /* If fr_symbol is an expression, this call to
+	     resolve_symbol_value sets up the correct segment, which will
+	     likely be needed in md_estimate_size_before_relax.  */
+	  if (fragP->fr_symbol)
+	    resolve_symbol_value (fragP->fr_symbol);
+
 	  address += md_estimate_size_before_relax (fragP, segment);
 	  break;