[ARM, gas] Don't warn on REG_SP when used in CRC32 instructions

[Jiong Wang]

Hi,

   According to ARMv8-A architecture manual, REG_SP is allowed in CRC32 instructions
in Thumb mode.  It is REG_PC that will cause unpredictable behaviours on both ARM
and Thumb.

   This patch removes the incorrect warning on Thumb mode.

   Meanwhile the disassembler is updated to use format "<bitfield>R" instead of
"<bitfield>S".  "<bitfield>S" is not used elsewhere. so I have deleted related
code from the disassembler.

   cross and native gas check OK.

   OK for master and backport to 2.28 and 2.29?

   Thanks.

2017-08-09  Jiong Wang  <jiong.wang@arm.com>

opcodes/
	* arm-dis.c (thumb32_opcodes): Use format 'R' instead of 'S' for
	register operands in CRC instructions.
	(print_insn_thumb32): Remove "<bitfield>S" support.  Updated the
	comments.

gas/
	* config/tc-arm.c (do_crc32_1): Remove warning on REG_SP for thumb_mode.
	* testsuite/gas/arm/crc32-armv8-a-bad.d: Update exepcted result.
	* testsuite/gas/arm/crc32-armv8-r-bad.d: Likewise
	* testsuite/gas/arm/crc32-armv8-a.d: Likewise
	* testsuite/gas/arm/crc32-armv8-r.d: Likewise
	* testsuite/gas/arm/crc32-armv8-ar-bad.s: Update test case.
	* testsuite/gas/arm/crc32-armv8-ar.s: Likewise
	* testsuite/gas/arm/crc32-bad.l: Update expected error message.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: fix.patch
Type: text/x-patch
Size: 8987 bytes
Desc: not available
URL: <https://sourceware.org/pipermail/binutils/attachments/20170809/a9832955/attachment.bin>