diff options
| author | Jan Beulich <jbeulich@novell.com> | 2018-06-01 08:38:36 +0200 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2018-06-01 08:38:36 +0200 |
| commit | e0c7f900259ee54a6fdbc5d4103f30209dbec1bc (patch) | |
| tree | ada8c61921ab90c4c7a193badf970b2406da78ed /gas | |
| parent | 647957107595c7f8209686577739240b7a222aba (diff) | |
x86: tighten condition for emitting LOCK on control register accesses
The control register is never expressed by REX.B; this bit only affects
the involved GPR. Also only one of the operands can have its "control"
flag set, so only check the correct operand.
Diffstat (limited to 'gas')
| -rw-r--r-- | gas/ChangeLog | 6 | ||||
| -rw-r--r-- | gas/config/tc-i386.c | 7 |
2 files changed, 9 insertions, 4 deletions
diff --git a/gas/ChangeLog b/gas/ChangeLog index 14f03bc810..199a48d830 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,5 +1,11 @@ 2018-06-01 Jan Beulich <jbeulich@suse.com> + * config/tc-i386.c (build_modrm_byte): Drop REX_B from condition + checking for the need of emitting LOCK. Check "control" bit just + once. + +2018-06-01 Jan Beulich <jbeulich@suse.com> + * testsuite/gas/i386/invpcid.s, testsuite/gas/i386/x86-64-invpcid.s: Add test with explicit "oword ptr". diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 36e42eb394..3d04a8361d 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -6894,12 +6894,11 @@ build_modrm_byte (void) if ((i.op[source].regs->reg_flags & RegVRex) != 0) i.vrex |= REX_R; } - if (flag_code != CODE_64BIT && (i.rex & (REX_R | REX_B))) + if (flag_code != CODE_64BIT && (i.rex & REX_R)) { - if (!i.types[0].bitfield.control - && !i.types[1].bitfield.control) + if (!i.types[i.tm.operand_types[0].bitfield.regmem].bitfield.control) abort (); - i.rex &= ~(REX_R | REX_B); + i.rex &= ~REX_R; add_prefix (LOCK_PREFIX_OPCODE); } } |