MIPS/GAS: Handle resolved R6 PC-relative relocations

Complement commit 7361da2c952e ("Add support for MIPS R6.") and fix
internal errors like:

foo.s: Assembler messages:
foo.s: Internal error!
Assertion failure in md_apply_fix at .../gas/config/tc-mips.c:15028.
Please report this bug.

triggered by resolved R6 PC-relative relocations in sources containing
R6 code fragments wrapped into ISA override blocks embedded within code
otherwise assembled for an older ISA.

	gas/
	* config/tc-mips.c (calculate_reloc) <BFD_RELOC_HI16_S_PCREL>
	<BFD_RELOC_LO16_PCREL>: New switch cases.
	(md_apply_fix) <BFD_RELOC_HI16_S_PCREL, BFD_RELOC_LO16_PCREL>:
	Move switch cases along `BFD_RELOC_MIPS_JMP'.
	<BFD_RELOC_MIPS_21_PCREL_S2, BFD_RELOC_MIPS_26_PCREL_S2>
	<BFD_RELOC_MIPS_18_PCREL_S3, BFD_RELOC_MIPS_19_PCREL_S2>: Handle
	the resolved case.
	* testsuite/gas/mips/pcrel-reloc-4.d: New test.
	* testsuite/gas/mips/pcrel-reloc-4-r6.d: New test.
	* testsuite/gas/mips/pcrel-reloc-5.d: New test.
	* testsuite/gas/mips/pcrel-reloc-5-r6.d: New test.
	* testsuite/gas/mips/pcrel-reloc-6.d: New test.
	* testsuite/gas/mips/pcrel-reloc-6.l: New list test.
	* testsuite/gas/mips/pcrel-reloc-4.s: New test source.
	* testsuite/gas/mips/pcrel-reloc-6.s: New test source.
	* testsuite/gas/mips/mips.exp: Run the new tests.

1 files changed, 54 insertions, 8 deletions

diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index c598806..6891508 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -6972,6 +6972,7 @@ calculate_reloc (bfd_reloc_code_real_type reloc, offsetT operand,
       return TRUE;
 
     case BFD_RELOC_HI16_S:
+    case BFD_RELOC_HI16_S_PCREL:
     case BFD_RELOC_MICROMIPS_HI16_S:
     case BFD_RELOC_MIPS16_HI16_S:
       *result = ((operand + 0x8000) >> 16) & 0xffff;
@@ -6984,6 +6985,7 @@ calculate_reloc (bfd_reloc_code_real_type reloc, offsetT operand,
       return TRUE;
 
     case BFD_RELOC_LO16:
+    case BFD_RELOC_LO16_PCREL:
     case BFD_RELOC_MICROMIPS_LO16:
     case BFD_RELOC_MIPS16_LO16:
       *result = operand & 0xffff;
@@ -14944,6 +14946,8 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
     case BFD_RELOC_MIPS_GOT_LO16:
     case BFD_RELOC_MIPS_CALL_HI16:
     case BFD_RELOC_MIPS_CALL_LO16:
+    case BFD_RELOC_HI16_S_PCREL:
+    case BFD_RELOC_LO16_PCREL:
     case BFD_RELOC_MIPS16_GPREL:
     case BFD_RELOC_MIPS16_GOT16:
     case BFD_RELOC_MIPS16_CALL16:
@@ -15025,12 +15029,39 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
       break;
 
     case BFD_RELOC_MIPS_21_PCREL_S2:
+      if ((*valP & 0x3) != 0)
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("branch to misaligned address (%lx)"), (long) *valP);
+      if (!fixP->fx_done)
+	break;
+
+      if (*valP + 0x400000 <= 0x7fffff)
+	{
+	  insn = read_insn (buf);
+	  insn |= (*valP >> 2) & 0x1fffff;
+	  write_insn (buf, insn);
+	}
+      else
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("branch out of range"));
+      break;
+
     case BFD_RELOC_MIPS_26_PCREL_S2:
       if ((*valP & 0x3) != 0)
 	as_bad_where (fixP->fx_file, fixP->fx_line,
 		      _("branch to misaligned address (%lx)"), (long) *valP);
+      if (!fixP->fx_done)
+	break;
 
-      gas_assert (!fixP->fx_done);
+      if (*valP + 0x8000000 <= 0xfffffff)
+	{
+	  insn = read_insn (buf);
+	  insn |= (*valP >> 2) & 0x3ffffff;
+	  write_insn (buf, insn);
+	}
+      else
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("branch out of range"));
       break;
 
     case BFD_RELOC_MIPS_18_PCREL_S3:
@@ -15042,8 +15073,18 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	as_bad_where (fixP->fx_file, fixP->fx_line,
 		      _("PC-relative access using misaligned offset (%lx)"),
 		      (long) fixP->fx_offset);
+      if (!fixP->fx_done)
+	break;
 
-      gas_assert (!fixP->fx_done);
+      if (*valP + 0x100000 <= 0x1fffff)
+	{
+	  insn = read_insn (buf);
+	  insn |= (*valP >> 3) & 0x3ffff;
+	  write_insn (buf, insn);
+	}
+      else
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("PC-relative access out of range"));
       break;
 
     case BFD_RELOC_MIPS_19_PCREL_S2:
@@ -15051,13 +15092,18 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	as_bad_where (fixP->fx_file, fixP->fx_line,
 		      _("PC-relative access to misaligned address (%lx)"),
 		      (long) *valP);
+      if (!fixP->fx_done)
+	break;
 
-      gas_assert (!fixP->fx_done);
-      break;
-
-    case BFD_RELOC_HI16_S_PCREL:
-    case BFD_RELOC_LO16_PCREL:
-      gas_assert (!fixP->fx_done);
+      if (*valP + 0x100000 <= 0x1fffff)
+	{
+	  insn = read_insn (buf);
+	  insn |= (*valP >> 2) & 0x7ffff;
+	  write_insn (buf, insn);
+	}
+      else
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("PC-relative access out of range"));
       break;
 
     case BFD_RELOC_16_PCREL_S2: