Allow both signed and unsigned fields in PowerPC cmpli insn

There are legitimate reasons to allow a signed value in a cmpli insn
field, for example to test for a "stw r1,lock@sdarel(r13)" instruction
in user code, a kernel might use
	subis r3,r3,STW_R1_0R13@ha	# subtract off high part
	cmplwi r3,lock@sdarel		# is low part accessing lock?
Since the lock@sdarel may take a range of -32768 to 32767,
the allowed range of cmpli immediate must be at least [-32768,65535].

bfd/
	* elf32-ppc.c (ppc_elf_relocate_section): Treat field of cmpli
	insn as a bitfield; Use complain_overflow_bitfield.
	* elf64-ppc.c (ppc64_elf_relocate_section): Likewise.
opcodes/
	* ppc-opc.c (UISIGNOPT): Define and use with cmpli.
gas/
	* config/tc-ppc.c (ppc_insert_operand): Handle PPC_OPERAND_SIGNOPT
	on unsigned fields.  Comment on PPC_OPERAND_SIGNOPT signed fields
	in 64-bit mode.
gold/
	* powerpc.cc (relocate): Treat field of cmpli insn as a bitfield.

2 files changed, 22 insertions, 3 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index f68f30c..fd331d7 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-07  Alan Modra  <amodra@gmail.com>
+
+	* config/tc-ppc.c (ppc_insert_operand): Handle PPC_OPERAND_SIGNOPT
+	on unsigned fields.  Comment on PPC_OPERAND_SIGNOPT signed fields
+	in 64-bit mode.
+
 2014-06-02  Martin Storsjo  <martin@martin.st>
 
 	* doc/c-aarch64.texi: Fix the documentation on :pg_hi21:.
diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 2c8ce6a..ff4ea64 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -1781,10 +1781,23 @@ ppc_insert_operand (unsigned long insn,
   right = max & -max;
   min = 0;
 
-  if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
+  if ((operand->flags & PPC_OPERAND_SIGNOPT) != 0)
+    {
+      /* Extend the allowed range for addis to [-65536, 65535].
+	 Similarly for some VLE high part insns.  For 64-bit it
+	 would be good to disable this for signed fields since the
+	 value is sign extended into the high 32 bits of the register.
+	 If the value is, say, an address, then we might care about
+	 the high bits.  However, gcc as of 2014-06 uses unsigned
+	 values when loading the high part of 64-bit constants using
+	 lis.
+	 Use the same extended range for cmpli, to allow at least
+	 [-32768, 65535].  */
+      min = ~max & -right;
+    }
+  else if ((operand->flags & PPC_OPERAND_SIGNED) != 0)
     {
-      if ((operand->flags & PPC_OPERAND_SIGNOPT) == 0)
-	max = (max >> 1) & -right;
+      max = (max >> 1) & -right;
       min = ~max & -right;
     }