Three new instructions:
umonitor - Sets up a linear address range to be
monitored by hardware and activates the monitor.
The address range should be a writeback memory
caching type.
umwait - A hint that allows the processor to
stop instruction execution and enter an
implementation-dependent optimized state
until occurrence of a class of events.
tpause - Directs the processor to enter an
implementation-dependent optimized state
until the TSC reaches the value in EDX:EAX.
Also modifying the description of the mfence
instruction, as the rep prefix (0xF3) was allowed
before, which would conflict with umonitor during
disassembly.
Before:
$ echo 0xf3,0x0f,0xae,0xf0 | llvm-mc -disassemble
.text
mfence
After:
$ echo 0xf3,0x0f,0xae,0xf0 | llvm-mc -disassemble
.text
umonitor %rax
Reviewers: craig.topper, zvi
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D45253
llvm-svn: 330462
Similar to the wbinvd instruction, except this
one does not invalidate caches. Ring 0 only.
The encoding matches a wbinvd instruction with
an F3 prefix.
Reviewers: craig.topper, zvi, ashlykov
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D43816
llvm-svn: 329847
The bound instruction does not have reversed operands in gas.
Fixes PR27653.
Patch by Maya Madhavan.
Differential Revision: https://reviews.llvm.org/D43243
llvm-svn: 325178
Summary:
Intel documentation shows the memory operand as the first operand. But we currently treat it as the second operand. Conceptually the order doesn't matter since it doesn't write memory. We have aliases to parse with the operands in either order and the isel matching is commutable.
For the register®ister form order does matter for the assembly parser. PR22995 was previously filed and fixed by changing the register®ister form from MRMSrcReg to MRMDestReg to match gas. Ideally the memory form should match by using MRMDestMem.
I believe this supercedes D38025 which was trying to switch the register®ister form back to pre-PR22995.
Reviewers: aymanmus, RKSimon, zvi
Reviewed By: aymanmus
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38120
llvm-svn: 314639
The disassembler has a special case for 'L' vs. 'W' in its heuristic for
checking for 32-bit and 16-bit equivalents. We could expand the heuristic,
but better just to be consistent in using the 'L' suffix.
llvm-svn: 199652
When disassembling in 16-bit mode the meaning of the OpSize bit is
inverted. Instructions found in the IC_OPSIZE context will actually
*not* have the 0x66 prefix, and instructions in the IC context will
have the 0x66 prefix. Make use of the existing special-case handling
for the 0x66 prefix being in the wrong place, to cope with this.
llvm-svn: 199650
Gabor Buella