A couple of cases where we were accidentally creating constant conditions by
something like "x == a || b" instead of "x == a || x == b". In one case a
conditional & then unreachable was used - I transformed this into a direct
assert instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154324 91177308-0d34-0410-b5e6-96231b3b80d8
x86 addressing modes. This allows PIE-based TLS offsets to fit directly
into an addressing mode immediate offset, which is the last remaining
code quality issue from PR12380. With this patch, that PR is completely
fixed.
To understand why this patch is correct to match these offsets into
addressing mode immediates, break it down by cases:
1) 32-bit is trivially correct, and unmodified here.
2) 64-bit non-small mode is unchanged and never matches.
3) 64-bit small PIC code which is RIP-relative is handled specially in
the match to try to fit RIP into the base register. If it fails, it
now early exits. This behavior is unchanged by the patch.
4) 64-bit small non-PIC code which is not RIP-relative continues to work
as it did before. The reason these immediates are safe is because the
ABI ensures they fit in small mode. This behavior is unchanged.
5) 64-bit small PIC code which is *not* using RIP-relative addressing.
This is the only case changed by the patch, and the primary place you
see it is in TLS, either the win64 section offset TLS or Linux
local-exec TLS model in a PIC compilation. Here the ABI again ensures
that the immediates fit because we are in small mode, and any other
operations required due to the PIC relocation model have been handled
externally to the Wrapper node (extra loads etc are made around the
wrapper node in ISelLowering).
I've tested this as much as I can comparing it with GCC's output, and
everything appears safe. I discussed this with Anton and it made sense
to him at least at face value. That said, if there are issues with PIC
code after this patch, yell and we can revert it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154304 91177308-0d34-0410-b5e6-96231b3b80d8
optimizations which are valid for position independent code being linked
into a single executable, but not for such code being linked into
a shared library.
I discussed the design of this with Eric Christopher, and the decision
was to support an optional bit rather than a completely separate
relocation model. Fundamentally, this is still PIC relocation, its just
that certain optimizations are only valid under a PIC relocation model
when the resulting code won't be in a shared library. The simplest path
to here is to expose a single bit option in the TargetOptions. If folks
have different/better designs, I'm all ears. =]
I've included the first optimization based upon this: changing TLS
models to the *Exec models when PIE is enabled. This is the LLVM
component of PR12380 and is all of the hard work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154294 91177308-0d34-0410-b5e6-96231b3b80d8
in TargetLowering. There was already a FIXME about this location being
odd. The interface is simplified as a consequence. This will also make
it easier to change TLS models when compiling with PIE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154292 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we used three instructions to broadcast an immediate value into a
vector register.
On Sandybridge we continue to load the broadcasted value from the constant pool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154284 91177308-0d34-0410-b5e6-96231b3b80d8
The tLDRr instruction with the last register operand set to the zero register
prints in assembly as if no register was specified, and the assembler encodes
it as a tLDRi instruction with a zero immediate. With the integrated assembler,
that zero register gets emitted as "r0", so we get "ldr rx, [ry, r0]" which
is broken. Emit the instruction as tLDRi with a zero immediate. I don't
know if there's a good way to write a testcase for this. Suggestions welcome.
Opportunities for follow-up work:
1) The asm printer should complain if a non-optional register operand is set
to the zero register, instead of silently dropping it.
2) The integrated assembler should complain in the same situation, instead of
silently emitting the operand as "r0".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154261 91177308-0d34-0410-b5e6-96231b3b80d8
Cygwin-1.7 supports dw2. Some recent mingw distros support one, too.
I have confirmed test-suite/SingleSource/Benchmarks/Shootout-C++/except.cpp can pass on Cygwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154247 91177308-0d34-0410-b5e6-96231b3b80d8
by default.
This is a behaviour configurable in the MCAsmInfo. I've decided to turn
it on by default in (possibly optimistic) hopes that most assemblers are
reasonably sane. If this proves a problem, switching to default seems
reasonable.
I'm not sure if this is the opportune place to test, but it seemed good
to make sure it was tested somewhere.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154235 91177308-0d34-0410-b5e6-96231b3b80d8
After register masks were introdruced to represent the call clobbers, it
is no longer necessary to have duplicate instruction for iOS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154209 91177308-0d34-0410-b5e6-96231b3b80d8
ARM and Thumb2 mode can use cmn instructions to compare against negative
immediates. Thumb1 mode can't.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154183 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154144 91177308-0d34-0410-b5e6-96231b3b80d8
The load/store optimizer splits LDRD/STRD into two instructions when the
register pairing doesn't work out. For negative offsets in Thumb2, it uses
t2STRi8 to do that. That's fine, except for the case when the offset is in
the range [-4,-1]. In that case, we'll also form a second t2STRi8 with
the original offset plus 4, resulting in a t2STRi8 with a non-negative
offset, which ends up as if it were an STRT, which is completely bogus.
Similarly for loads.
No testcase, unfortunately, as any I've been able to construct is both large
and extremely fragile.
rdar://11193937
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154141 91177308-0d34-0410-b5e6-96231b3b80d8
'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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154123 91177308-0d34-0410-b5e6-96231b3b80d8
types for N32 ABI. Test case will be updated after the patch that fixes
TargetLowering::getPICJumpTableRelocBase is checked in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154036 91177308-0d34-0410-b5e6-96231b3b80d8
A MOVCCr instruction can be commuted by inverting the condition. This
can help reduce register pressure and remove unnecessary copies in some
cases.
<rdar://problem/11182914>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154033 91177308-0d34-0410-b5e6-96231b3b80d8
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154011 91177308-0d34-0410-b5e6-96231b3b80d8
This patch allows llvm to recognize that a 64 bit object file is being produced
and that the subsequently generated ELF header has the correct information.
The test case checks for both big and little endian flavors.
Patch by Jack Carter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153889 91177308-0d34-0410-b5e6-96231b3b80d8
