From 7cb22ff84745da0856bf74578b9bd7dff4379ed5 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 26 Apr 2019 10:19:53 -0700 Subject: 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. --- gas/config/tc-i386.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'gas/config/tc-i386.c') 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 -- cgit v1.1