Summary:
This patch also fixes an issue with the way the Mips assembler enables/disables architecture
features. Before this patch, the assembler never disabled feature bits. For example,
.set mips64
.set mips32r2
would result in the 'OR' of mips64 with mips32r2 feature bits which isn't right.
Unfortunately this isn't trivial to fix because there's not an easy way to clear
feature bits as the algorithm in MCSubtargetInfo (ToggleFeature) only clears the bits
that imply the feature being cleared and not the implied bits by the feature (there's a
better explanation to the code I added).
Patch by Matheus Almeida and updated by Toma Tabacu
Reviewers: vmedic, matheusalmeida, dsanders
Reviewed By: dsanders
Subscribers: tomatabacu, llvm-commits
Differential Revision: http://reviews.llvm.org/D4123
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when let can do the same thing. Keep the 64bit variants as codegen-only.
While they have a different register class, the encoding is the same for
32bit and 64bit mode. Having both present would otherwise confuse the
disassembler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214636 91177308-0d34-0410-b5e6-96231b3b80d8
Note: The current code in DecodeMSRMask() rejects the unpredictable A/R MSR mask '0000' with Fail. The code in the patch follows this style and rejects unpredictable M-class MSR masks also with Fail (instead of SoftFail). If SoftFail is preferred in this case then additional changes to ARMInstPrinter (to print non-symbolic masks) and ARMAsmParser (to parse non-symbolic masks) will be needed.
Patch by Petr Pavlu!
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The ARM ARM prohibits LDRB/LDRSB instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214500 91177308-0d34-0410-b5e6-96231b3b80d8
The ARM ARM prohibits LDRH/LDRSH instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
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The ARM ARM prohibits LDR instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDR instructions with unpredictable behavior.
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This allows assembling the two new instructions, encls and enclu for the
SKX processor model.
Note the diffs are a bigger than what might think, but to fit the new
MRM_CF and MRM_D7 in things in the right places things had to be
renumbered and shuffled down causing a bit more diffs.
rdar://16228228
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The subtarget information is the ultimate source of truth for the feature set
that is enabled at this point. We would previously not propagate the feature
information to the subtarget. While this worked for the most part (features
would be enabled/disabled as requested), if another operation that changed the
feature bits was encountered (such as a mode switch via a .arm or .thumb
directive), we would end up resetting the behaviour of the architectural
extensions.
Handling this properly requires a slightly more complicated handling. We need
to check if the feature is now being toggled. If so, only then do we toggle the
features. In return, we no longer have to calculate the feature bits ourselves.
The test changes are mostly to the diagnosis, which is now more uniform (a nice
side effect!). Add an additional test to ensure that we handle this case
properly.
Thanks to Nico Weber for alerting me to this issue!
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This patch minimizes the number of nops that must be emitted on X86 to satisfy
stackmap shadow constraints.
To minimize the number of nops inserted, the X86AsmPrinter now records the
size of the most recent stackmap's shadow in the StackMapShadowTracker class,
and tracks the number of instruction bytes emitted since the that stackmap
instruction was encountered. Padding is emitted (if it is required at all)
immediately before the next stackmap/patchpoint instruction, or at the end of
the basic block.
This optimization should reduce code-size and improve performance for people
using the llvm stackmap intrinsic on X86.
<rdar://problem/14959522>
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This target is identical to the Windows MSVC (and follows Microsoft ABI for C).
Correct the library call setup for this target. The same set of library calls
are missing on this environment.
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The ARM ARM prohibits STRH instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STRH instructions with unpredictable behavior.
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The ARM ARM prohibits STRB instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STRB instructions with unpredictable behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213750 91177308-0d34-0410-b5e6-96231b3b80d8
There really is no arm64_be: it was a useful fiction to test big-endian support
while both backends existed in parallel, but now the only platform that uses
the name (iOS) doesn't have a big-endian variant, let alone one called
"arm64_be".
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The ARM ARM prohibits STR instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling STR instructions with unpredictable behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213745 91177308-0d34-0410-b5e6-96231b3b80d8
Without this, we produce non-extern relocations when targeting older OS X
versions that ld64 can't cope with in the particular context of __eh_frame
sections (who'd want generic relocation-processing anyway?).
This means that an updated linker (ld64 from Xcode 3.2.6 or later) may be
needed when targeting such platforms with a modern version of LLVM, but this is
probably the case anyway and a reasonable requirement.
PR20212, rdar://problem/17544795
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This abstraction allows us to support the various records that can be placed in
the .MIPS.options section in the future. We currently use it to record register
usage information (the ODK_REGINFO record in our ELF64 spec).
Each .MIPS.options record should subclass MipsOptionRecord and provide an
implementation of EmitMipsOptionRecord.
Patch by Matheus Almeida and Toma Tabacu
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213522 91177308-0d34-0410-b5e6-96231b3b80d8
As discussed in a previous checking to support the .localentry
directive on PowerPC, we need to inspect the actual target symbol
in needsRelocateWithSymbol to make the appropriate decision based
on that symbol's st_other bits.
Currently, needsRelocateWithSymbol does not get the target symbol.
However, it is directly available to its sole caller. This patch
therefore simply extends the needsRelocateWithSymbol by a new
parameter "const MCSymbolData &SD", passes in the target symbol,
and updates all derived implementations.
In particular, in the PowerPC implementation, this patch removes
the FIXME added by the previous checkin.
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A second binutils feature needed to support ELFv2 is the .localentry
directive. In the ELFv2 ABI, functions may have two entry points:
one for calling the routine locally via "bl", and one for calling the
function via function pointer (either at the source level, or implicitly
via a PLT stub for global calls). The two entry points share a single
ELF symbol, where the ELF symbol address identifies the global entry
point address, while the local entry point is found by adding a delta
offset to the symbol address. That offset is encoded into three
platform-specific bits of the ELF symbol st_other field.
The .localentry directive instructs the assembler to set those fields
to encode a particular offset. This is typically used by a function
prologue sequence like this:
func:
addis r2, r12, (.TOC.-func)@ha
addi r2, r2, (.TOC.-func)@l
.localentry func, .-func
Note that according to the ABI, when calling the global entry point,
r12 must be set to point the global entry point address itself; while
when calling the local entry point, r2 must be set to point to the TOC
base. The two instructions between the global and local entry point in
the above example translate the first requirement into the second.
This patch implements support in the PowerPC MC streamers to emit the
.localentry directive (both into assembler and ELF object output), as
well as support in the assembler parser to parse that directive.
In addition, there is another change required in MC fixup/relocation
handling to properly deal with relocations targeting function symbols
with two entry points: When the target function is known local, the MC
layer would immediately handle the fixup by inserting the target
address -- this is wrong, since the call may need to go to the local
entry point instead. The GNU assembler handles this case by *not*
directly resolving fixups targeting functions with two entry points,
but always emits the relocation and relies on the linker to handle
this case correctly. This patch changes LLVM MC to do the same (this
is done via the processFixupValue routine).
Similarly, there are cases where the assembler would normally emit a
relocation, but "simplify" it to a relocation targeting a *section*
instead of the actual symbol. For the same reason as above, this
may be wrong when the target symbol has two entry points. The GNU
assembler again handles this case by not performing this simplification
in that case, but leaving the relocation targeting the full symbol,
which is then resolved by the linker. This patch changes LLVM MC
to do the same (via the needsRelocateWithSymbol routine).
NOTE: The method used in this patch is overly pessimistic, since the
needsRelocateWithSymbol routine currently does not have access to the
actual target symbol, and thus must always assume that it might have
two entry points. This will be improved upon by a follow-on patch
that modifies common code to pass the target symbol when calling
needsRelocateWithSymbol.
Reviewed by Hal Finkel.
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ELFv2 binaries are marked by a bit in the ELF header e_flags field.
A new assembler directive .abiversion can be used to set that flag.
This patch implements support in the PowerPC MC streamers to emit the
.abiversion directive (both into assembler and ELF binary output),
as well as support in the assembler parser to parse the .abiversion
directive.
Reviewed by Hal Finkel.
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This adds initial support for PPC32 ELF PIC (Position Independent Code; the
-fPIC variety), thus rectifying a long-standing deficiency in the PowerPC
backend.
Patch by Justin Hibbits!
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