This finishes the job started in r198756, and creates separate opcodes for
64-bit vs. 32-bit versions of the rest of the RET instructions too.
LRETL/LRETQ are interesting... I can't see any justification for their
existence in the SDM. There should be no 'LRETL' in 64-bit mode, and no
need for a REX.W prefix for LRETQ. But this is what GAS does, and my
Sandybridge CPU and an Opteron 6376 concur when tested as follows:
asm __volatile__("pushq $0x1234\nmovq $0x33,%rax\nsalq $32,%rax\norq $1f,%rax\npushq %rax\nlretl $8\n1:");
asm __volatile__("pushq $1234\npushq $0x33\npushq $1f\nlretq $8\n1:");
asm __volatile__("pushq $0x33\npushq $1f\nlretq\n1:");
asm __volatile__("pushq $0x1234\npushq $0x33\npushq $1f\nlretq $8\n1:");
cf. PR8592 and commit r118903, which added LRETQ. I only added LRETIQ to
match it.
I don't quite understand how the Intel syntax parsing for ret
instructions is working, despite r154468 allegedly fixing it. Aren't the
explicitly sized 'retw', 'retd' and 'retq' supposed to work? I have at
least made the 'lretq' work with (and indeed *require*) the 'q'.
llvm-svn: 199106
The target specific parser should return `false' if the target AsmParser handles
the directive, and `true' if the generic parser should handle the directive.
Many of the target specific directive handlers would `return Error' which does
not follow these semantics. This change simply changes the target specific
routines to conform to the semantis of the ParseDirective correctly.
Conformance to the semantics improves diagnostics emitted for the invalid
directives. X86 is taken as a sample to ensure that multiple diagnostics are
not presented for a single error.
llvm-svn: 199068
We can't do a perfect job here. We *have* to allow (%dx) even in 64-bit
mode, for example, because it might be used for an unofficial form of
the in/out instructions. We actually want to do a better job of validation
*later*. Perhaps *instead* of doing it where we are at the moment.
But for now, doing what validation we *can* do in the place that the code
already has its validation, is an improvement.
llvm-svn: 198760
It seems there is no separate instruction class for having AdSize *and*
OpSize bits set, which is required in order to disambiguate between all
these instructions. So add that to the disassembler.
Hm, perhaps we do need an AdSize16 bit after all?
llvm-svn: 198759
Where "where possible" means that it's an immediate value and it's below
0x10000. In fact GAS will either truncate or error with larger values,
and will insist on using the addr32 prefix to get 32-bit addressing. So
perhaps we should do that, in a later patch.
llvm-svn: 198758
JCXZ should have the 0x67 prefix only if we're in 32-bit mode, so make that
appropriately conditional. And JECXZ needs the prefix instead.
llvm-svn: 198757
I couldn't see how to do this sanely without splitting RETQ from RETL.
Eric says: "sad about the inability to roundtrip them now, but...".
I have no idea what that means, but perhaps it wants preserving in the
commit comment.
llvm-svn: 198756
This fixes the bulk of 16-bit output, and the corresponding test case
x86-16.s now looks mostly like the x86-32.s test case that it was
originally based on. A few irrelevant instructions have been dropped,
and there are still some corner cases to be fixed in subsequent patches.
llvm-svn: 198752
The 0x66 prefix toggles between 16-bit and 32-bit addressing mode.
So in 32-bit mode it is used to switch to 16-bit addressing mode for the
following instruction, while in 16-bit mode it's the other way round — it's
used to switch to 32-bit mode instead.
Thus, emit the 0x66 prefix byte for OpSize only in 32-bit (and 64-bit) mode,
and introduce a new OpSize16 bit which is used in 16-bit mode instead.
This is just the basic infrastructure for that change; a subsequent patch
will add the new OpSize16 bit to the 32-bit instructions that need it.
Patch from David Woodhouse.
llvm-svn: 198586
This is not really expected to work right yet. Mostly because we will
still emit the OpSize (0x66) prefix in all the wrong places, along with
a number of other corner cases. Those will all be fixed in the subsequent
commits.
Patch from David Woodhouse.
llvm-svn: 198584
Add some tests to validate correct register selection, including a fix
to an existing test which was requiring the *wrong* output.
Patch from David Woodhouse.
llvm-svn: 198566
this commit as the only one on the Blamelist so I quickly reverted this.
However it was actually Nick's change who has since fixed that issue.
Original commit message:
Changed the X86 assembler for intel syntax to work with directional labels.
The X86 assembler as a separate code to parser the intel assembly syntax
in X86AsmParser::ParseIntelOperand(). This did not parse directional labels.
And if something like 1f was used as a branch target it would get an
"Unexpected token" error.
The fix starts in X86AsmParser::ParseIntelExpression() in the case for
AsmToken::Integer, it needs to grab the IntVal from the current token
then look for a 'b' or 'f' following an Integer. Then it basically needs to
do what is done in AsmParser::parsePrimaryExpr() for directional
labels. It saves the MCExpr it creates in the IntelExprStateMachine
in the Sym field.
When it returns to X86AsmParser::ParseIntelOperand() it looks
for a non-zero Sym field in the IntelExprStateMachine and if
set it creates a memory operand not an immediate operand
it would normally do for the Integer.
rdar://14961158
llvm-svn: 197744
The X86 assembler has a separate code to parser the intel assembly syntax
in X86AsmParser::ParseIntelOperand(). This did not parse directional labels.
And if something like 1f was used as a branch target it would get an
"Unexpected token" error.
The fix starts in X86AsmParser::ParseIntelExpression() in the case for
AsmToken::Integer, it needs to grab the IntVal from the current token
then look for a 'b' or 'f' following the Integer. Then it basically needs to
do what is done in AsmParser::parsePrimaryExpr() for directional
labels. It saves the MCExpr it creates in the IntelExprStateMachine
in the Sym field.
When it returns to X86AsmParser::ParseIntelOperand() it looks
for a non-zero Sym field in the IntelExprStateMachine and if
set it creates a memory operand not an immediate operand
it would normally do for the Integer.
rdar://14961158
llvm-svn: 197728
Patch by Mikulas Patocka. I added the test. I checked that for cpu names that
gas knows about, it also doesn't generate nopl.
The modified cpus:
i686 - there are i686-class CPUs that don't have nopl: Via c3, Transmeta
Crusoe, Microsoft VirtualBox - see
https://bbs.archlinux.org/viewtopic.php?pid=775414
k6, k6-2, k6-3, winchip-c6, winchip2 - these are 586-class CPUs
via c3 c3-2 - see https://bugs.archlinux.org/task/19733 as a proof that
Via c3 and c3-Nehemiah don't have nopl
llvm-svn: 195679
On darwin, when trying to create compact unwind info, a .cfi_cfa_def
directive would case an llvm_unreachable() to be hit. Back off when we
see this directive and generate the regular DWARF style eh_frame.
rdar://15406518
llvm-svn: 194285
This allows the instruction to be encoded using the 2-byte VEX form instead of the 3-byte VEX form. The GNU assembler has similar behavior and instruction selection already does this.
llvm-svn: 192088
Add basic assembly/disassembly support for the first Intel SHA
instruction 'sha1rnds4'. Also includes feature flag, and test cases.
Support for the remaining instructions will follow in a separate patch.
llvm-svn: 190611
David Woodhouse