TableGen has a fairly dubious heuristic to decide whether an alias should be
printed: does the alias have lest operands than the real instruction. This is
bad enough (particularly with no way to override it), but it should at least be
calculated consistently for both strings.
This patch implements that logic: first get the *correct* string for the
variant, in the same way as the Matcher, without guessing; then count the
number of whitespace chars.
There are basically 4 changes this brings about after the previous
commits; all of these appear to be good, so I have changed the tests:
+ ARM64: we print "neg X, Y" instead of "sub X, xzr, Y".
+ ARM64: we skip implicit "uxtx" and "uxtw" modifiers.
+ Sparc: we print "mov A, B" instead of "or %g0, A, B".
+ Sparc: we print "fcmpX A, B" instead of "fcmpX %fcc0, A, B"
llvm-svn: 208969
Previously, TableGen assumed that every aliased operand consumed precisely 1
MachineInstr slot (this was reasonable because until a couple of days ago,
nothing more complicated was eligible for printing).
This allows a couple more ARM64 aliases to print so we can remove the special
code.
On the X86 side, I've gone for explicit AT&T size specifiers as the default, so
turned off a few of the aliases that would have just started printing.
llvm-svn: 208880
In terms of assembly, these have too much overlap to be neatly modelled as
disjoint classes: in many cases "lsl" is an acceptable alternative to either
"uxtw" or "uxtx".
llvm-svn: 208563
Previously, LLVM had no knowledge that these instructions actually
modified their address register: fine if they never end up in CodeGen,
but when I'd rather like to write some patterns for them it becomes a
disaster.
The change is mostly straightforward, I think the most significant
design decision was to *always* put the address write-back first. This
allows loads and stores to be accessed more uniformly, for example
permitting the continued sharing of the InstAlias definitions.
I also discovered that the custom Decode logic is no longer needed, so
I removed it.
No tests, because there should be no functionality change.
llvm-svn: 207839
The canonical form of the BFM instruction is always one of the more explicit
extract or insert operations, which makes reading output much easier.
llvm-svn: 207752
AArch64 does not have a CPSR register in the same way that AArch32 does. Most
of its compiler-relevant roles have been taken over by the more specific NZCV
register (representing just the flags set by normal instructions).
Its system control functions still remain, but are now under the
pseudo-register referred to as "PSTATE". They're accessed via various MRS & MSR
instructions described in the reference manual.
llvm-svn: 207645
This is mostly aimed at the NEON logical operations and MOVI/MVNI (since they
accept weird shifts which are more naturally understandable in hex notation).
Also changes BRK/HINT etc, which is probably a neutral change, but easier than
the alternative.
llvm-svn: 207634
Since these instructions only accept a 12-bit immediate, possibly shifted left
by 12, the canonical syntax used by the architecture reference manual is "#N {,
lsl #12 }". We should accept an immediate that has already been shifted, (e.g.
Also, print a comment giving the full addend since it can be helpful.
llvm-svn: 207633
These can have different relocations in ELF. In particular both:
b.eq global
ldr x0, global
are valid, giving different relocations. The only possible way to distinguish
them is via a different fixup, so the operands had to be separated throughout
the backend.
llvm-svn: 207105
no assert at all. ;] Some of these should probably be switched to
llvm_unreachable, but I didn't want to perturb the behavior in this
patch.
Found by -Wstring-conversion, which I'll try to turn on in CMake builds
at least as it is finding useful things.
llvm-svn: 205091
This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.
Everything will be easier with the target in-tree though, hence this
commit.
llvm-svn: 205090
