From 7cb22ff84745da0856bf74578b9bd7dff4379ed5 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 26 Apr 2019 10:19:53 -0700 Subject: [PATCH] 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/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 8558ecd7b48..c94ffdda0b3 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,11 @@ +2019-04-26 H.J. Lu + + 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 Alan Modra diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 5eb6c4c2692..032b1d30811 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 a83bad61570..7a1dc7661ee 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 f8bc0ea5b47..aff56657201 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 -- 2.30.2