From f3645945cfd49e1e1a33cc4273e4951cf6020202 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@airs.com>
Date: Tue, 5 Apr 1994 19:57:32 +0000
Subject: [PATCH] 	* config/tc-mips.c (mips_ip): For case 'o', when
 generating 	embedded PIC code, accept the difference between two local
 symbols 	as being constant. 	(mips_force_relocation): Only force a
 reloc to be generated for a 	PC relative fixup. 	(md_apply_fix): For
 BFD_RELOC_32 and BFD_RELOC_LO16, put the fixup 	value into the file if
 the fixup will not generate a reloc.

---
 gas/ChangeLog        | 10 ++++++++
 gas/config/tc-mips.c | 55 +++++++++++++++++++++++++++++++++++---------
 2 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c8c80a41a23..0c46784bff0 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,13 @@
+Tue Apr  5 15:48:03 1994  Ian Lance Taylor  (ian@tweedledumb.cygnus.com)
+
+	* config/tc-mips.c (mips_ip): For case 'o', when generating
+	embedded PIC code, accept the difference between two local symbols
+	as being constant.
+	(mips_force_relocation): Only force a reloc to be generated for a
+	PC relative fixup.
+	(md_apply_fix): For BFD_RELOC_32 and BFD_RELOC_LO16, put the fixup
+	value into the file if the fixup will not generate a reloc.
+
 Tue Apr  5 11:14:14 1994  Ken Raeburn  (raeburn@rtl.cygnus.com)
 
 	* config/tc-sparc.c (s_reserve): If section passed isn't bss,
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 08c5bb600a1..b11831651dc 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -4534,14 +4534,25 @@ mips_ip (str, ip)
 
 	    case 'o':		/* 16 bit offset */
 	      c = my_getSmallExpression (&offset_expr, s);
-	      /*
-	       * If this value won't fit into a 16 bit offset, then
-	       * go find a macro that will generate the 32 bit offset
-	       * code pattern.
-	       */
-	      if (offset_expr.X_op != O_constant
-		  || offset_expr.X_add_number >= 0x8000
-		  || offset_expr.X_add_number < -0x8000)
+
+	      /* If this value won't fit into a 16 bit offset, then go
+		 find a macro that will generate the 32 bit offset
+		 code pattern.  As a special hack, we accept the
+		 difference of two local symbols as a constant.  This
+		 is required to suppose embedded PIC switches, which
+		 use an instruction which looks like
+		     lw $4,$L12-$LS12($4)
+		 The problem with handling this in a more general
+		 fashion is that the macro function doesn't expect to
+		 see anything which can be handled in a single
+		 constant instruction.  */
+	      if ((offset_expr.X_op != O_constant
+		   || offset_expr.X_add_number >= 0x8000
+		   || offset_expr.X_add_number < -0x8000)
+		  && (mips_pic != EMBEDDED_PIC
+		      || offset_expr.X_op != O_subtract
+		      || ! S_IS_LOCAL (offset_expr.X_add_symbol)
+		      || ! S_IS_LOCAL (offset_expr.X_op_symbol)))
 		break;
 
 	      offset_reloc = BFD_RELOC_LO16;
@@ -5060,7 +5071,7 @@ int
 mips_force_relocation (fixp)
      fixS *fixp;
 {
-  return mips_pic == EMBEDDED_PIC;
+  return fixp->fx_pcrel && mips_pic == EMBEDDED_PIC;
 }
 
 /* Apply a fixup to the object file.  */
@@ -5083,11 +5094,9 @@ md_apply_fix (fixP, valueP)
 
   switch (fixP->fx_r_type)
     {
-    case BFD_RELOC_32:
     case BFD_RELOC_MIPS_JMP:
     case BFD_RELOC_HI16:
     case BFD_RELOC_HI16_S:
-    case BFD_RELOC_LO16:
     case BFD_RELOC_MIPS_GPREL:
     case BFD_RELOC_MIPS_LITERAL:
     case BFD_RELOC_MIPS_CALL16:
@@ -5096,6 +5105,30 @@ md_apply_fix (fixP, valueP)
       /* Nothing needed to do. The value comes from the reloc entry */
       break;
 
+    case BFD_RELOC_32:
+      /* If we are deleting this reloc entry, we must fill in the
+	 value now.  This can happen if we have a .word which is not
+	 resolved when it appears but is later defined.  */
+      if (fixP->fx_done)
+	md_number_to_chars (fixP->fx_frag->fr_literal + fixP->fx_where,
+			    value, 4);
+      break;
+
+    case BFD_RELOC_LO16:
+      /* When handling an embedded PIC switch statement, we can wind
+	 up deleting a LO16 reloc.  See the 'o' case in mips_ip.  */
+      if (fixP->fx_done)
+	{
+	  if (value < -0x8000 || value > 0x7fff)
+	    as_bad_where (fixP->fx_file, fixP->fx_line,
+			  "relocation overflow");
+	  buf = fixP->fx_frag->fr_literal + fixP->fx_where;
+	  if (byte_order == BIG_ENDIAN)
+	    buf += 2;
+	  md_number_to_chars (buf, value, 2);
+	}
+      break;
+
     case BFD_RELOC_16_PCREL_S2:
       /*
        * We need to save the bits in the instruction since fixup_segment()
-- 
2.30.2