Previously we only used GPR for the destination placeholder in "ldr rD, [pc,
incorrect codegen under the integrated assembler.
This should fix both issues (which probably only affect MachO targets at the
moment).
rdar://problem/15800156
llvm-svn: 199108
The ARM backend has been using most of the MachO related subtarget
checks almost interchangeably, and since the only target it's had to
run on has been IOS (which is all three of MachO, Darwin and IOS) it's
worked out OK so far.
But we'd like to support embedded targets under the "*-*-none-macho"
triple, which means everything starts falling apart and inconsistent
behaviours emerge.
This patch should pick a reasonably sensible set of behaviours for the
new triple (and any others that come along, with luck). Some choices
were debatable (notably FP == r7 or r11), but we can revisit those
later when deficiencies become apparent.
llvm-svn: 198617
The bkpt mnemonic has an implicit immediate constant of 0 unless otherwise
specified. Add an instruction alias for the unvalued breakpoint mnemonic to
treat it as a 0. This improves compatibility with GNU AS.
Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 197913
These are used by MachO only at the moment, and (much like the existing
MOVW/MOVT set) work around the fact that the labels used in the actual
instructions often contain PC-dependent components, which means that repeatedly
materialising the same global can't be CSEed.
With small modifications, it could be adapted to how ELF finds the address of
_GLOBAL_OFFSET_TABLE_, which would give similar benefits in PIC mode there.
llvm-svn: 196090
There is no sane way for an LEApcrel (= single ADR) instruction to generate a
global address on any ARM target I know of. Fortunately, no-one was trying to
any more, but there were vestigial patterns.
llvm-svn: 195644
The hint instructions ("nop", "yield", etc) are mostly Thumb2-only, but have
been ported across to the v6M architecture. Fortunately, v6M seems to sit
nicely between v6 (thumb-1 only) and v6T2, so we can add a feature for it
fairly easily.
rdar://problem/15144406
llvm-svn: 192097
These were pretty straightforward instructions, with some assembly support
required for HLT.
The ARM assembler is keen to split the instruction mnemonic into a
(non-existent) 'H' instruction with the LT condition code. An exception for
HLT is needed.
HLT follows the same rules as BKPT when in IT blocks, so the special BKPT
hadling code has been adapted to handle HLT also.
Regression tests added including diagnostic tests for out of range immediates
and illegal condition codes, as well as negative tests for pre-ARMv8.
llvm-svn: 190053
Back in the mists of time (2008), it seems TableGen couldn't handle the
patterns necessary to match ARM's CMOV node that we convert select operations
to, so we wrote a lot of fairly hairy C++ to do it for us.
TableGen can deal with it now: there were a few minor differences to CodeGen
(see tests), but nothing obviously worse that I could see, so we should
probably address anything that *does* come up in a localised manner.
llvm-svn: 188995
1. The offset range for Thumb1 PC relative loads is [0..1020] and not [-1024..1020]
2. Thumb2 PC relative loads may define the PC, so the restriction placed on target register is removed
3. Removes unneeded alias between "ldr.n" and t1LDRpci. ".n" is actually stripped by both tablegen
and the ASM parser, so this alias rule really does nothing
llvm-svn: 188466
The long encoding for Thumb2 unconditional branches is broken.
Additionally, there is no range checking for target operands; as such
for instructions originating in assembly code, only short Thumb encodings
are generated, regardless of the bitsize needed for the offset.
Adding range checking is non trivial due to the representation of Thumb
branch instructions. There is no true difference between conditional and
unconditional branches in terms of operands and syntax - even unconditional
branches have a predicate which is expected to match that of the IT block
they are in. Yet, the encodings and the permitted size of the offset differ.
Due to this, for any mnemonic there are really 4 encodings to choose for.
The problem cannot be handled in the parser alone or by manipulating td files.
Because the parser builds first a set of match candidates and then checks them
one by one, whatever tablegen-only solution might be found will ultimately be
dependent of the parser's evaluation order. What's worse is that due to the fact
that all branches have the same syntax and the same kinds of operands, that
order is governed by the lexicographical ordering of the names of operand
classes...
To circumvent all this, any necessary disambiguation is added to the instruction
validation pass.
llvm-svn: 188067
instructions. With this patch:
1. ldr.n is recognized as mnemonic for the short encoding
2. ldr.w is recognized as menmonic for the long encoding
3. ldr will map to either short or long encodings depending on the size of the offset
llvm-svn: 186831
1. it should accept only 4-byte aligned addresses
2. the maximum offset should be 1020
3. it should be encoded with the offset scaled by two bits
llvm-svn: 185528
registers. Previously, the register we being marked as implicitly defined, but
not killed. In some cases this would cause the register scavenger to spill a
dead register.
Also, use an empty register mask to simplify the logic and to reduce the memory
footprint.
rdar://12592448
llvm-svn: 167499
When the operand is a plain immediate rather than a label, print it
as [pc, #imm] like we do for the Thumb2 wide encoding variant.
rdar://12154503
llvm-svn: 166991
This wasn't the right way to enforce ordering of atomics.
We are already setting the isVolatile bit on memory operands of atomic
operations which is good enough to enforce the correct ordering.
llvm-svn: 162732
It is not safe to use normal LDR instructions because they may be
reordered by the scheduler. The ATOMIC_LDR pseudos have a mayStore flag
that prevents reordering.
Atomic loads are also prevented from participating in rematerialization
and load folding.
llvm-svn: 162713
Function argument registers are added to the call SDNode, but
InstrEmitter now knows how to make those operands implicit, and the call
instruction doesn't have to be variadic.
Explicit register operands should only be those that are encoded in the
instruction, implicit register operands are for extra dependencies like
call argument and return values.
llvm-svn: 160188
There are patterns to handle immediates when they fit in the immediate field.
e.g. %sub = add i32 %x, -123
=> sub r0, r0, #123
Add patterns to catch immediates that do not fit but should be materialized
with a single movw instruction rather than movw + movt pair.
e.g. %sub = add i32 %x, -65535
=> movw r1, #65535
sub r0, r0, r1
rdar://11726136
llvm-svn: 159057
for the assembler and disassembler. Which were not being set/read correctly
for offsets greater than 22 bits in some cases.
Changes to lib/Target/ARM/ARMAsmBackend.cpp from Gideon Myles!
llvm-svn: 156118
Make sure when parsing the Thumb1 sp+register ADD instruction that
the source and destination operands match. In thumb2, just use the
wide encoding if they don't. In Thumb1, issue a diagnostic.
rdar://11219154
llvm-svn: 155748
After register masks were introdruced to represent the call clobbers, it
is no longer necessary to have duplicate instruction for iOS.
llvm-svn: 154209
We had special instructions for iOS because r9 is call-clobbered, but
that is represented dynamically by the register mask operands now, so
there is no need for the pseudo-instructions.
llvm-svn: 154144
'add r2, #-1024' should just use 'sub r2, #1024' rather than erroring out.
Thumb1 aliases for adding a negative immediate to the stack pointer,
also.
rdar://11192734
llvm-svn: 154123
I'll let the buildbots determine the compile time improvements from this
change, but 464.h264ref has 5% faster codegen at -O2.
This patch does cause some assembly changes. Branch folding can make
different decisions about calls with dead return values.
CriticalAntiDepBreaker may choose different registers because its
liveness tracking is affected. MachineCopyPropagation may sometimes
leave a dead copy behind.
llvm-svn: 151331
The QQ and QQQQ registers are not 'real', they are pseudo-registers used
to model some vld and vst instructions.
This makes the call clobber lists longer, but I intend to get rid of
those soon.
llvm-svn: 148151
My change r146949 added register clobbers to the eh_sjlj_dispatchsetup pseudo
instruction, but on Thumb1 some of those registers cannot be used. This
caused massive failures on the testsuite when compiling for Thumb1. While
fixing that, I noticed that the eh_sjlj_setjmp instruction has a "nofp"
variant, and I realized that dispatchsetup needs the same thing, so I have
added that as well.
llvm-svn: 147204
Use the custom inserter for the ARM setjmp intrinsics. Instead of creating the
SjLj dispatch table in IR, where it frequently violates serveral assumptions --
in particular assumptions made by the landingpad instruction about what can
branch to a landing pad and what cannot. Performing this in the back-end allows
us to violate these assumptions without the IR getting angry at us.
It also allows us to perform a small optimization. We can shove the address of
the dispatch's basic block into the function context and not have to add code
around the setjmp to check for the return value and jump to the dispatch.
Neat, huh?
<rdar://problem/10116753>
llvm-svn: 142294
It really doesn't, but when r141929 removed the hasSideEffects flag from
this instruction, it caused miscompilations. I am guessing that it got
moved across a stack pointer update.
Also clear isRematerializable after checking that this instruction is
in fact never rematerialized in the nightly test suite.
llvm-svn: 142030
TableGen infers unmodeled side effects on instructions without a
pattern. Fix some instruction definitions where that was overlooked.
Also raise an error if a rematerializable instruction has unmodeled side
effects. That doen't make any sense.
llvm-svn: 141929
Tim Northover