rl78: relaxation fixes

Various fixes to linker relaxation.  In general, we need to support
relaxing every branch, even if we don't relax it in the assembler,
so we can optionally defer relaxation to the linker.

* elf32-rl78.c (rl78_offset_for_reloc): Add more relocs.
(rl78_elf_relax_section): Add bc/bz/bnc/bnz/bh/bnh.  Fix reloc
choices.

* config/rl78-parse.y: Make all branches relaxable via
rl78_linkrelax_branch().
* config/tc-rl78.c (rl78_linkrelax_branch): Mark all relaxable
branches with relocs.
(options): Add OPTION_NORELAX.
(md_longopts): Add -mnorelax.
(md_parse_option): Support OPTION_NORELAX.
(op_type_T): Add bh, sk, call, and br.
(rl78_opcode_type): Likewise.
(rl78_relax_frag): Fix not-relaxing logic.  Add sk.
(md_convert_frag): Fix relocation handling.
(tc_gen_reloc): Strip relax relocs when not linker relaxing.
(md_apply_fix): Defer overflow handling for anything that needs a
PLT, to the linker.
* config/tc-rl78.h (TC_FORCE_RELOCATION): Force all relocations to
the linker when linker relaxing.
* doc/c-rl78.texi (norelax): Add.

5 files changed, 106 insertions, 26 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 8a50708..6fb81a1 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,23 @@
+2015-12-08  DJ Delorie  <dj@redhat.com>
+
+	* config/rl78-parse.y: Make all branches relaxable via
+	rl78_linkrelax_branch().
+	* config/tc-rl78.c (rl78_linkrelax_branch): Mark all relaxable
+	branches with relocs.
+	(options): Add OPTION_NORELAX.
+	(md_longopts): Add -mnorelax.
+	(md_parse_option): Support OPTION_NORELAX.
+	(op_type_T): Add bh, sk, call, and br.
+	(rl78_opcode_type): Likewise.
+	(rl78_relax_frag): Fix not-relaxing logic.  Add sk.
+	(md_convert_frag): Fix relocation handling.
+	(tc_gen_reloc): Strip relax relocs when not linker relaxing.
+	(md_apply_fix): Defer overflow handling for anything that needs a
+	PLT, to the linker.
+	* config/tc-rl78.h (TC_FORCE_RELOCATION): Force all relocations to
+	the linker when linker relaxing.
+	* doc/c-rl78.texi (norelax): Add.
+
 2015-12-07  Alan Modra  <amodra@gmail.com>
 
 	* config/tc-ppc.c (md_apply_fix): Localize variables.  Reduce casts.
diff --git a/gas/config/rl78-parse.y b/gas/config/rl78-parse.y
index b879581..ff017cf 100644
--- a/gas/config/rl78-parse.y
+++ b/gas/config/rl78-parse.y
@@ -294,22 +294,22 @@ statement :
 /* ---------------------------------------------------------------------- */
 
 	| BC '$' EXPR
-	  { B1 (0xdc); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B1 (0xdc); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BNC '$' EXPR
-	  { B1 (0xde); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B1 (0xde); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BZ '$' EXPR
-	  { B1 (0xdd); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B1 (0xdd); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BNZ '$' EXPR
-	  { B1 (0xdf); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B1 (0xdf); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BH '$' EXPR
-	  { B2 (0x61, 0xc3); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B2 (0x61, 0xc3); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BNH '$' EXPR
-	  { B2 (0x61, 0xd3); PC1 ($3); rl78_relax (RL78_RELAX_BRANCH, 0); }
+	  { B2 (0x61, 0xd3); PC1 ($3); rl78_linkrelax_branch (); }
 
 /* ---------------------------------------------------------------------- */
 
@@ -337,7 +337,7 @@ statement :
 	  { B2 (0x61, 0xcb); }
 
 	| BR '$' EXPR
-	  { B1 (0xef); PC1 ($3); }
+	  { B1 (0xef); PC1 ($3); rl78_linkrelax_branch (); }
 
 	| BR '$' '!' EXPR
 	  { B1 (0xee); PC2 ($4); rl78_linkrelax_branch (); }
@@ -1022,22 +1022,22 @@ statement :
 /* ---------------------------------------------------------------------- */
 
 	| SKC
-	  { B2 (0x61, 0xc8); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xc8); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 	| SKH
-	  { B2 (0x61, 0xe3); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xe3); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 	| SKNC
-	  { B2 (0x61, 0xd8); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xd8); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 	| SKNH
-	  { B2 (0x61, 0xf3); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xf3); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 	| SKNZ
-	  { B2 (0x61, 0xf8); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xf8); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 	| SKZ
-	  { B2 (0x61, 0xe8); rl78_linkrelax_branch (); }
+	  { B2 (0x61, 0xe8); rl78_relax (RL78_RELAX_BRANCH, 0); }
 
 /* ---------------------------------------------------------------------- */
 
@@ -1161,8 +1161,8 @@ andor1	: AND1 { $$ = 0x05; rl78_bit_insn = 1; }
 	| XOR1 { $$ = 0x07; rl78_bit_insn = 1; }
 	;
 
-bt_bf	: BT { $$ = 0x02;    rl78_bit_insn = 1; rl78_relax (RL78_RELAX_BRANCH, 0); }
-	| BF { $$ = 0x04;    rl78_bit_insn = 1; rl78_relax (RL78_RELAX_BRANCH, 0); }
+bt_bf	: BT { $$ = 0x02;    rl78_bit_insn = 1; rl78_linkrelax_branch (); }
+	| BF { $$ = 0x04;    rl78_bit_insn = 1; rl78_linkrelax_branch (); }
 	| BTCLR { $$ = 0x00; rl78_bit_insn = 1; }
 	;
 
diff --git a/gas/config/tc-rl78.c b/gas/config/tc-rl78.c
index 9fbaa42..ad04795 100644
--- a/gas/config/tc-rl78.c
+++ b/gas/config/tc-rl78.c
@@ -102,6 +102,7 @@ rl78_linkrelax_addr16 (void)
 void
 rl78_linkrelax_branch (void)
 {
+  rl78_relax (RL78_RELAX_BRANCH, 0);
   rl78_bytes.link_relax |= RL78_RELAXA_BRA;
 }
 
@@ -280,6 +281,7 @@ rl78_field (int val, int pos, int sz)
 enum options
 {
   OPTION_RELAX = OPTION_MD_BASE,
+  OPTION_NORELAX,
   OPTION_G10,
   OPTION_G13,
   OPTION_G14,
@@ -294,6 +296,7 @@ const char * md_shortopts = RL78_SHORTOPTS;
 struct option md_longopts[] =
 {
   {"relax", no_argument, NULL, OPTION_RELAX},
+  {"norelax", no_argument, NULL, OPTION_NORELAX},
   {"mg10", no_argument, NULL, OPTION_G10},
   {"mg13", no_argument, NULL, OPTION_G13},
   {"mg14", no_argument, NULL, OPTION_G14},
@@ -312,6 +315,9 @@ md_parse_option (int c, char * arg ATTRIBUTE_UNUSED)
     case OPTION_RELAX:
       linkrelax = 1;
       return 1;
+    case OPTION_NORELAX:
+      linkrelax = 0;
+      return 1;
 
     case OPTION_G10:
       elf_flags &= ~ E_FLAG_RL78_CPU_MASK;
@@ -757,7 +763,10 @@ typedef enum
   OT_bt_sfr,
   OT_bt_es,
   OT_bc,
-  OT_bh
+  OT_bh,
+  OT_sk,
+  OT_call,
+  OT_br,
 } op_type_T;
 
 /* We're looking for these types of relaxations:
@@ -780,8 +789,10 @@ typedef enum
    a different size later.  */
 
 static op_type_T
-rl78_opcode_type (char * op)
+rl78_opcode_type (char * ops)
 {
+  unsigned char *op = (unsigned char *)ops;
+
   if (op[0] == 0x31
       && ((op[1] & 0x0f) == 0x05
 	  || (op[1] & 0x0f) == 0x03))
@@ -805,6 +816,20 @@ rl78_opcode_type (char * op)
       && (op[1] & 0xef) == 0xc3)
     return OT_bh;
 
+  if (op[0] == 0x61
+      && (op[1] & 0xcf) == 0xc8)
+    return OT_sk;
+
+  if (op[0] == 0x61
+      && (op[1] & 0xef) == 0xe3)
+    return OT_sk;
+
+  if (op[0] == 0xfc)
+    return OT_call;
+
+  if ((op[0] & 0xec) == 0xec)
+    return OT_br;
+
   return OT_other;
 }
 
@@ -901,6 +926,11 @@ rl78_relax_frag (segT segment ATTRIBUTE_UNUSED, fragS * fragP, long stretch)
 			   fragP->tc_frag_data->relax[ri].type != RL78_RELAX_BRANCH,
 			   & sym_addr))
     {
+      /* If we don't expect the linker to do relaxing, don't emit
+	 expanded opcodes that only the linker will relax.  */
+      if (!linkrelax)
+	return newsize - oldsize;
+
       /* If we don't, we must use the maximum size for the linker.  */
       switch (fragP->tc_frag_data->relax[ri].type)
 	{
@@ -920,7 +950,10 @@ rl78_relax_frag (segT segment ATTRIBUTE_UNUSED, fragS * fragP, long stretch)
 	    case OT_bh:
 	      newsize = 6;
 	      break;
-	    case OT_other:
+	    case OT_sk:
+	      newsize = 2;
+	      break;
+	    default:
 	      newsize = oldsize;
 	      break;
 	    }
@@ -967,7 +1000,10 @@ rl78_relax_frag (segT segment ATTRIBUTE_UNUSED, fragS * fragP, long stretch)
 	  else
 	    newsize = 6;
 	  break;
-	case OT_other:
+	case OT_sk:
+	  newsize = 2;
+	  break;
+	default:
 	  newsize = oldsize;
 	  break;
 	}
@@ -1062,6 +1098,7 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	case OPCODE (OT_bt, 3): /* BT A,$ - no change.  */
 	  disp -= 3;
 	  op[2] = disp;
+	  reloc_type = keep_reloc ? BFD_RELOC_8_PCREL : BFD_RELOC_NONE;
 	  break;
 
 	case OPCODE (OT_bt, 6): /* BT A,$ - long version.  */
@@ -1079,6 +1116,7 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	case OPCODE (OT_bt_sfr, 4): /* BT PSW,$ - no change.  */
 	  disp -= 4;
 	  op[3] = disp;
+	  reloc_type = keep_reloc ? BFD_RELOC_8_PCREL : BFD_RELOC_NONE;
 	  break;
 
 	case OPCODE (OT_bt_sfr, 7): /* BT PSW,$ - long version.  */
@@ -1096,6 +1134,7 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	case OPCODE (OT_bt_es, 4): /* BT ES:[HL],$ - no change.  */
 	  disp -= 4;
 	  op[3] = disp;
+	  reloc_type = keep_reloc ? BFD_RELOC_8_PCREL : BFD_RELOC_NONE;
 	  break;
 
 	case OPCODE (OT_bt_es, 7): /* BT PSW,$ - long version.  */
@@ -1113,6 +1152,7 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	case OPCODE (OT_bc, 2): /* BC $ - no change.  */
 	  disp -= 2;
 	  op[1] = disp;
+	  reloc_type = keep_reloc ? BFD_RELOC_8_PCREL : BFD_RELOC_NONE;
 	  break;
 
 	case OPCODE (OT_bc, 5): /* BC $ - long version.  */
@@ -1130,6 +1170,7 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	case OPCODE (OT_bh, 3): /* BH $ - no change.  */
 	  disp -= 3;
 	  op[2] = disp;
+	  reloc_type = keep_reloc ? BFD_RELOC_8_PCREL : BFD_RELOC_NONE;
 	  break;
 
 	case OPCODE (OT_bh, 6): /* BC $ - long version.  */
@@ -1144,11 +1185,13 @@ md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 	  reloc_adjust = 2;
 	  break;
 
-	default:
-	  fprintf(stderr, "Missed case %d %d at 0x%lx\n",
-		  rl78_opcode_type (fragP->fr_opcode), fragP->fr_subtype, mypc);
-	  abort ();
+	case OPCODE (OT_sk, 2): /* SK<cond> - no change */
+	  reloc_type = keep_reloc ? BFD_RELOC_16_PCREL : BFD_RELOC_NONE;
+	  break;
 
+	default:
+	  reloc_type = fix ? fix->fx_r_type : BFD_RELOC_NONE;
+	  break;
 	}
       break;
 
@@ -1215,6 +1258,12 @@ tc_gen_reloc (asection * seg ATTRIBUTE_UNUSED, fixS * fixp)
       return reloc;
     }
 
+  if (fixp->fx_r_type == BFD_RELOC_RL78_RELAX && !linkrelax)
+    {
+      reloc[0] = NULL;
+      return reloc;
+    }
+
   if (fixp->fx_subsy
       && S_GET_SEGMENT (fixp->fx_subsy) == absolute_section)
     {
@@ -1376,6 +1425,11 @@ md_apply_fix (struct fix * f ATTRIBUTE_UNUSED,
   char * op;
   unsigned long val;
 
+  /* We always defer overflow checks for these to the linker, as it
+     needs to do PLT stuff.  */
+  if (f->fx_r_type == BFD_RELOC_RL78_CODE)
+    f->fx_no_overflow = 1;
+
   if (f->fx_addsy && S_FORCE_RELOC (f->fx_addsy, 1))
     return;
   if (f->fx_subsy && S_FORCE_RELOC (f->fx_subsy, 1))
@@ -1384,13 +1438,16 @@ md_apply_fix (struct fix * f ATTRIBUTE_UNUSED,
   op = f->fx_frag->fr_literal + f->fx_where;
   val = (unsigned long) * t;
 
+  if (f->fx_addsy == NULL)
+    f->fx_done = 1;
+
   switch (f->fx_r_type)
     {
     case BFD_RELOC_NONE:
       break;
 
     case BFD_RELOC_RL78_RELAX:
-      f->fx_done = 1;
+      f->fx_done = 0;
       break;
 
     case BFD_RELOC_8_PCREL:
@@ -1461,8 +1518,6 @@ md_apply_fix (struct fix * f ATTRIBUTE_UNUSED,
       break;
     }
 
-  if (f->fx_addsy == NULL)
-    f->fx_done = 1;
 }
 
 valueT
diff --git a/gas/config/tc-rl78.h b/gas/config/tc-rl78.h
index b9ede61..82f798e 100644
--- a/gas/config/tc-rl78.h
+++ b/gas/config/tc-rl78.h
@@ -99,3 +99,5 @@ extern void rl78_elf_final_processing (void);
    || TC_FORCE_RELOCATION (FIX))
 
 #define DWARF2_USE_FIXED_ADVANCE_PC 1
+
+#define TC_FORCE_RELOCATION(FIX) (linkrelax)
diff --git a/gas/doc/c-rl78.texi b/gas/doc/c-rl78.texi
index 5cb568f..49e4ee4 100644
--- a/gas/doc/c-rl78.texi
+++ b/gas/doc/c-rl78.texi
@@ -28,6 +28,9 @@
 @item relax
 Enable support for link-time relaxation.
 
+@item norelax
+Disable support for link-time relaxation (default).
+
 @item mg10
 Mark the generated binary as targeting the G10 variant of the RL78
 architecture.