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[binutils-gdb] i386: Don't add 0x66 prefix to IRET for .code16gcc
- From: H.J.Lu <hjl at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 26 Apr 2019 17:22:23 -0000
- Subject: [binutils-gdb] i386: Don't add 0x66 prefix to IRET for .code16gcc
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7cb22ff84745da0856bf74578b9bd7dff4379ed5
commit 7cb22ff84745da0856bf74578b9bd7dff4379ed5
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Apr 26 10:19:53 2019 -0700
i386: Don't add 0x66 prefix to IRET for .code16gcc
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.
Diff:
---
gas/ChangeLog | 8 ++++++++
gas/config/tc-i386.c | 6 ++++++
gas/testsuite/gas/i386/jump16.d | 2 ++
gas/testsuite/gas/i386/jump16.s | 6 ++++++
4 files changed, 22 insertions(+)
diff --git a/gas/ChangeLog b/gas/ChangeLog
index 8558ecd..c94ffdd 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -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>
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 5eb6c4c..032b1d3 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -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
diff --git a/gas/testsuite/gas/i386/jump16.d b/gas/testsuite/gas/i386/jump16.d
index a83bad6..7a1dc76 100644
--- a/gas/testsuite/gas/i386/jump16.d
+++ b/gas/testsuite/gas/i386/jump16.d
@@ -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
diff --git a/gas/testsuite/gas/i386/jump16.s b/gas/testsuite/gas/i386/jump16.s
index f8bc0ea..aff5665 100644
--- a/gas/testsuite/gas/i386/jump16.s
+++ b/gas/testsuite/gas/i386/jump16.s
@@ -71,3 +71,9 @@
jmp 0x9090:0x1010
jmp 0x9090,xxx
jmp 0x9090:xxx
+
+.code16gcc
+ iret
+
+.code16
+ iret