OpenE2K/binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

i386: Don't add 0x66 prefix to IRET for .code16gcc

Browse Source 
The .code16gcc directive supports 16bit mode with 32-bit address.  Since
IRET (opcode 0xcf) in 16bit mode returns from an interrupt in 16bit mode,
we shouldn't add 0x66 prefix for IRET.

	PR gas/24485
	* config/tc-i386.c (process_suffix): Don't add DATA_PREFIX_OPCODE
	to IRET for .code16gcc.
	* testsuite/gas/i386/jump16.s: Add IRET tests.
	* testsuite/gas/i386/jump16.d: Updated.
This commit is contained in:
H.J. Lu 2019-04-26 10:19:53 -07:00
parent c54f15248e
commit 7cb22ff847
4 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gas/ChangeLog
View File

@ -1,3 +1,11 @@
2019-04-26 H.J. Lu <hongjiu.lu@intel.com>
PR gas/24485
* config/tc-i386.c (process_suffix): Don't add DATA_PREFIX_OPCODE
to IRET for .code16gcc.
* testsuite/gas/i386/jump16.s: Add IRET tests.
* testsuite/gas/i386/jump16.d: Updated.
2019-04-25 Alexandre Oliva <aoliva@redhat.com>
Alan Modra <amodra@gmail.com>

6
gas/config/tc-i386.c
View File

@ -6352,7 +6352,13 @@ process_suffix (void)
if (!add_prefix (ADDR_PREFIX_OPCODE))
return 0;
}
/* stackop_size is set to LONG_MNEM_SUFFIX for the .code16gcc
directive to support 16bit mode with 32-bit address. Since
IRET (opcode 0xcf) in 16bit mode returns from an interrupt
in 16bit mode, we shouldn't add DATA_PREFIX_OPCODE here. */
else if (i.suffix != QWORD_MNEM_SUFFIX
&& (stackop_size != LONG_MNEM_SUFFIX
|| i.tm.base_opcode != 0xcf)
&& !i.tm.opcode_modifier.ignoresize
&& !i.tm.opcode_modifier.floatmf
&& !i.tm.opcode_modifier.vex

2
gas/testsuite/gas/i386/jump16.d
View File

@ -67,4 +67,6 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: ea 10 10 90 90 ljmp \$0x9090,\$0x1010
[ ]*[a-f0-9]+: ea 00 00 90 90 ljmp \$0x9090,\$0x0 ed: (R_386_)?16 xxx
[ ]*[a-f0-9]+: ea 00 00 90 90 ljmp \$0x9090,\$0x0 f2: (R_386_)?16 xxx
[ ]*[a-f0-9]+: cf iret
[ ]*[a-f0-9]+: cf iret
#pass

6
gas/testsuite/gas/i386/jump16.s
View File

@ -71,3 +71,9 @@
jmp 0x9090:0x1010
jmp 0x9090,xxx
jmp 0x9090:xxx
.code16gcc
iret
.code16
iret