[PowerPC] Revert r185476 and fix up TLS variant kinds

In the commit message to r185476 I wrote:

>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modi

[PowerPC] Revert r185476 and fix up TLS variant kinds

In the commit message to r185476 I wrote:

>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
>This causes some confusion with the asm parser, since VK_PPC_TLSGD
>is output as @tlsgd, which is then read back in as VK_TLSGD.
>
>To avoid this confusion, this patch removes the PowerPC-specific
>modifiers and uses the generic modifiers throughout. (The only
>drawback is that the generic modifiers are printed in upper case
>while the usual convention on PowerPC is to use lower-case modifiers.
>But this is just a cosmetic issue.)

This was unfortunately incorrect, there is is fact another,
serious drawback to using the default VK_TLSLD/VK_TLSGD
variant kinds: using these causes ELFObjectWriter::RelocNeedsGOT
to return true, which in turn causes the ELFObjectWriter to emit
an undefined reference to _GLOBAL_OFFSET_TABLE_.

This is a problem on powerpc64, because it uses the TOC instead
of the GOT, and the linker does not provide _GLOBAL_OFFSET_TABLE_,
so the symbol remains undefined. This means shared libraries
using TLS built with the integrated assembler are currently
broken.

While the whole RelocNeedsGOT / _GLOBAL_OFFSET_TABLE_ situation
probably ought to be properly fixed at some point, for now I'm
simply reverting the r185476 commit. Now this in turn exposes
the breakage of handling @tlsgd/@tlsld in the asm parser that
this check-in was originally intended to fix.

To avoid this regression, I'm also adding a different fix for
this problem: while common code now parses @tlsgd as VK_TLSGD,
a special hack in the asm parser translates this code to the
platform-specific VK_PPC_TLSGD that the back-end now expects.
While this is not really pretty, it's self-contained and
shouldn't hurt anything else for now. One the underlying
problem is fixed, this hack can be reverted again.

llvm-svn: 185945

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[PowerPC] Add some special @got@tprel fixup cases

When a target@got@tprel or target@got@tprel@l symbol variant is used in
a fixup_ppc_half16 (*not* fixup_ppc_half16ds) context, we currently fail,
si

[PowerPC] Add some special @got@tprel fixup cases

When a target@got@tprel or target@got@tprel@l symbol variant is used in
a fixup_ppc_half16 (*not* fixup_ppc_half16ds) context, we currently fail,
since the corresponding R_PPC64_GOT_TPREL16 / R_PPC64_GOT_TPREL16_LO
relocation types do not exist.

However, since such symbol variants resolve to GOT offsets which are
always 4-aligned, we can simply instead use the _DS variants of the
relocation types, which *do* exist.

The same applies for the @got@dtprel variants.

llvm-svn: 185700

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[PowerPC] Support @tls in the asm parser

This adds support for the last missing construct to parse TLS-related
assembler code:
add 3, 4, symbol@tls

The ADD8TLS currently hard-codes the @tls into

[PowerPC] Support @tls in the asm parser

This adds support for the last missing construct to parse TLS-related
assembler code:
add 3, 4, symbol@tls

The ADD8TLS currently hard-codes the @tls into the assembler string.
This cannot be handled by the asm parser, since @tls is parsed as
a symbol variant. This patch changes ADD8TLS to have the @tls suffix
printed as symbol variant on output too, which allows us to remove
the isCodeGenOnly marker from ADD8TLS. This in turn means that we
can add a AsmOperand to accept @tls marked symbols on input.

As a side effect, this means that the fixup_ppc_tlsreg fixup type
is no longer necessary and can be merged into fixup_ppc_nofixup.

llvm-svn: 185692

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[PowerPC] Remove VK_PPC_TLSGD and VK_PPC_TLSLD

The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
This causes some confus

[PowerPC] Remove VK_PPC_TLSGD and VK_PPC_TLSLD

The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
This causes some confusion with the asm parser, since VK_PPC_TLSGD
is output as @tlsgd, which is then read back in as VK_TLSGD.

To avoid this confusion, this patch removes the PowerPC-specific
modifiers and uses the generic modifiers throughout. (The only
drawback is that the generic modifiers are printed in upper case
while the usual convention on PowerPC is to use lower-case modifiers.
But this is just a cosmetic issue.)

llvm-svn: 185476

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[PowerPC] Add support for TLS data relocations

This adds support for TLS data relocations and modifiers:
.quad target@dtpmod
.quad target@tprel
.quad target@dtprel
Currently exp

[PowerPC] Add support for TLS data relocations

This adds support for TLS data relocations and modifiers:
.quad target@dtpmod
.quad target@tprel
.quad target@dtprel
Currently exploited by the asm parser only.

llvm-svn: 185394

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[PowerPC] Fix @got references to local symbols

A @got reference must always result in a relocation, so that
the linker has a chance to set up the GOT entry, even if the
symbol happens to be local.

[PowerPC] Fix @got references to local symbols

A @got reference must always result in a relocation, so that
the linker has a chance to set up the GOT entry, even if the
symbol happens to be local.

Add a PPCELFObjectWriter::ExplicitRelSym routine that enforces
a relocation to be emitted for GOT references.

llvm-svn: 185353

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[PowerPC] Support @got modifier

Add VK_... values and relocation types necessary to support
the @got family of modifiers. Used by the asm parser only.

llvm-svn: 184860

[PowerPC] Support absolute branches

There is currently only limited support for the "absolute" variants
of branch instructions. This patch adds support for the absolute
variants of all branches tha

[PowerPC] Support absolute branches

There is currently only limited support for the "absolute" variants
of branch instructions. This patch adds support for the absolute
variants of all branches that are currently otherwise supported.

This requires adding new fixup types so that the correct variant
of relocation type can be selected by the object writer.

While the compiler will continue to usually choose the relative
branch variants, this will allow the asm parser to fully support
the absolute branches, with either immediate (numerical) or
symbolic target addresses.

No change in code generation intended.

llvm-svn: 184721

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[PowerPC] Support R_PPC_REL16 family of relocations

The GNU assembler supports (as extension to the ABI) use of PC-relative
relocations in half16 fields, which allows writing code like:

li 1, bas

[PowerPC] Support R_PPC_REL16 family of relocations

The GNU assembler supports (as extension to the ABI) use of PC-relative
relocations in half16 fields, which allows writing code like:

li 1, base-.

This patch adds support for those relocation types in the assembler.

llvm-svn: 184552

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[PowerPC] Support various tls-related modifiers

The current code base only supports the minimum set of tls-related
relocations and @modifiers that are necessary to support compiler-
generated code.

[PowerPC] Support various tls-related modifiers

The current code base only supports the minimum set of tls-related
relocations and @modifiers that are necessary to support compiler-
generated code. This patch extends this to the full set defined
in the ABI (and supported by the GNU assembler) for the benefit
of the assembler parser.

llvm-svn: 184551

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[PowerPC] Support @higher et.al. modifiers

This adds support for the @higher, @highera, @highest, and @highesta
modifers, including some missing relocation types.

llvm-svn: 184550

[PowerPC] Support @toc@h modifier

This adds the relocation type and other necessary infrastructure
to use the @toc@h modifier in the assembler.

llvm-svn: 184549

[PowerPC] Support @h modifier

This adds necessary infrastructure to support the @h modifier.
Note that all required relocation types were already present
(and unused).

This patch provides support f

[PowerPC] Support @h modifier

This adds necessary infrastructure to support the @h modifier.
Note that all required relocation types were already present
(and unused).

This patch provides support for using @h in the assembler;
it would also be possible to now use this feature in code
generated by the compiler, but this is not done yet.

llvm-svn: 184548

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[PowerPC] Rename some more VK_PPC_ enums

This renames more VK_PPC_ enums, to make them more closely reflect
the @modifier string they represent. This also prepares for adding
a bunch of new VK_PPC_

[PowerPC] Rename some more VK_PPC_ enums

This renames more VK_PPC_ enums, to make them more closely reflect
the @modifier string they represent. This also prepares for adding
a bunch of new VK_PPC_ enums in upcoming patches.

For consistency, some MO_ flags related to VK_PPC_ enums are
likewise renamed.

No change in behaviour.

llvm-svn: 184547

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[PowerPC] Clean up VK_PPC_TOC... names

This is another minor cleanup; to bring enum names in line
with the corresponding @modifier names, this renames:

VK_PPC_TOC -> VK_PPC_TOCBASE
VK_PPC_TOC_E

[PowerPC] Clean up VK_PPC_TOC... names

This is another minor cleanup; to bring enum names in line
with the corresponding @modifier names, this renames:

VK_PPC_TOC -> VK_PPC_TOCBASE
VK_PPC_TOC_ENTRY -> VK_PPC_TOC16

No code change intended.

llvm-svn: 184491

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[PowerPC] Minor cleanup in PPCELFObjectWriter::getRelocTypeInner

This just re-sorts the big switch statement in
PPCELFObjectWriter::getRelocTypeInner to follow
the (numerical) order of the reloc typ

[PowerPC] Minor cleanup in PPCELFObjectWriter::getRelocTypeInner

This just re-sorts the big switch statement in
PPCELFObjectWriter::getRelocTypeInner to follow
the (numerical) order of the reloc types, and
fixes a couple of whitespace issues.

llvm-svn: 184485

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[PowerPC] Clean up generation of ha16() / lo16() markers

When targeting the Darwin assembler, we need to generate markers ha16() and
lo16() to designate the high and low parts of a (symbolic) immedi

[PowerPC] Clean up generation of ha16() / lo16() markers

When targeting the Darwin assembler, we need to generate markers ha16() and
lo16() to designate the high and low parts of a (symbolic) immediate. This
is necessary not just for plain symbols, but also for certain symbolic
expression, typically along the lines of ha16(A - B). The latter doesn't
work when simply using VariantKind flags on the symbol reference.
This is why the current back-end uses hacks (explicitly called out as such
via multiple FIXMEs) in the symbolLo/symbolHi print methods.

This patch uses target-defined MCExpr codes to represent the Darwin
ha16/lo16 constructs, following along the lines of the equivalent solution
used by the ARM back end to handle their :upper16: / :lower16: markers.
This allows us to get rid of special handling both in the symbolLo/symbolHi
print method and in the common code MCExpr::print routine. Instead, the
ha16 / lo16 markers are printed simply in a custom print routine for the
target MCExpr types. (As a result, the symbolLo/symbolHi print methods
can now replaced by a single printS16ImmOperand routine that also handles
symbolic operands.)

The patch also provides a EvaluateAsRelocatableImpl routine to handle
ha16/lo16 constructs. This is not actually used at the moment by any
in-tree code, but is provided as it makes merging into David Fang's
out-of-tree Mach-O object writer simpler.

Since there is no longer any need to treat VK_PPC_GAS_HA16 and
VK_PPC_DARWIN_HA16 differently, they are merged into a single
VK_PPC_ADDR16_HA (and likewise for the _LO16 types).

llvm-svn: 182616

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[PowerPC] Merge/rename PPC fixup types

Now that fixup_ppc_ha16 and fixup_ppc_lo16 are being treated exactly
the same everywhere, it no longer makes sense to have two fixup types.

This patch merges

[PowerPC] Merge/rename PPC fixup types

Now that fixup_ppc_ha16 and fixup_ppc_lo16 are being treated exactly
the same everywhere, it no longer makes sense to have two fixup types.

This patch merges them both into a single type fixup_ppc_half16,
and renames fixup_ppc_lo16_ds to fixup_ppc_half16ds for consistency.
(The half16 and half16ds names are taken from the description of
relocation types in the PowerPC ABI.)

No change in code generation expected.

llvm-svn: 182092

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[PowerPC] Fix processing of ha16/lo16 fixups

The current PowerPC MC back end distinguishes between fixup_ppc_ha16
and fixup_ppc_lo16, which are determined by the instruction the fixup
applies to, an

[PowerPC] Fix processing of ha16/lo16 fixups

The current PowerPC MC back end distinguishes between fixup_ppc_ha16
and fixup_ppc_lo16, which are determined by the instruction the fixup
applies to, and uses this distinction to decide whether a fixup ought
to resolve to the high or the low part of a symbol address.

This isn't quite correct, however. It is valid -if unusual- assembler
to use, e.g.
li 1, symbol@ha
or
lis 1, symbol@l
Whether the high or the low part of the address is used depends solely
on the @ suffix, not on the instruction.

In addition, both
li 1, symbol
and
lis 1, symbol
are valid, assuming the symbol address fits into 16 bits; again, both
will then refer to the actual symbol value (so li will load the value
itself, while lis will load the value shifted by 16).


To fix this, two places need to be adapted. If the fixup cannot be
resolved at assembler time, a relocation needs to be emitted via
PPCELFObjectWriter::getRelocType. This routine already looks at
the VK_ type to determine the relocation. The only problem is that
will reject any _LO modifier in a ha16 fixup and vice versa. This
is simply incorrect; any of those modifiers ought to be accepted
for either fixup type.

If the fixup *can* be resolved at assembler time, adjustFixupValue
currently selects the high bits of the symbol value if the fixup
type is ha16. Again, this is incorrect; see the above example
lis 1, symbol

Now, in theory we'd have to respect a VK_ modifier here. However,
in fact common code never even attempts to resolve symbol references
using any nontrivial VK_ modifier at assembler time; it will always
fall back to emitting a reloc and letting the linker handle it.

If this ever changes, presumably there'd have to be a target callback
to resolve VK_ modifiers. We'd then have to handle @ha etc. there.

llvm-svn: 182091

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Cleanup relocation sorting for ELF.

We want the order to be deterministic on all platforms. NAKAMURA Takumi
fixed that in r181864. This patch is just two small cleanups:

* Move the function to the

Cleanup relocation sorting for ELF.

We want the order to be deterministic on all platforms. NAKAMURA Takumi
fixed that in r181864. This patch is just two small cleanups:

* Move the function to the cpp file. It is only passed to array_pod_sort.
* Remove the ppc implementation which is now redundant

llvm-svn: 181910

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[PowerPC] Remove need for adjustFixupOffst hack

Now that applyFixup understands differently-sized fixups, we can define
fixup_ppc_lo16/fixup_ppc_lo16_ds/fixup_ppc_ha16 to properly be 2-byte
fixups,

[PowerPC] Remove need for adjustFixupOffst hack

Now that applyFixup understands differently-sized fixups, we can define
fixup_ppc_lo16/fixup_ppc_lo16_ds/fixup_ppc_ha16 to properly be 2-byte
fixups, applied at an offset of 2 relative to the start of the
instruction text.

This has the benefit that if we actually need to generate a real
relocation record, its address will come out correctly automatically,
without having to fiddle with the offset in adjustFixupOffset.

Tested on both 64-bit and 32-bit PowerPC, using external and
integrated assembler.

llvm-svn: 181894

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[PowerPC] Fix regression in generating @ha/@l relocs

The patch I committed as revision 167864 introduced a regression that
causes LLVM to no longer generate appropriate relocs for @ha/@l symbol
refe

[PowerPC] Fix regression in generating @ha/@l relocs

The patch I committed as revision 167864 introduced a regression that
causes LLVM to no longer generate appropriate relocs for @ha/@l symbol
references (but fail an assertion instead).

This is fixed here by re-enabling support for the VK_PPC_GAS_HA16/
VK_PPC_GAS_LO16 variant kinds (and their Darwin variants) in
PPCELFObjectWriter.cpp.

Tested by running projects/test-suite in -m32 mode with the integrated
assembler forced on. A standalone test case will be committed shortly
as well.

llvm-svn: 181450

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PowerPC: Support PC-relative fixup_ppc_brcond14.

When testing the asm parser, I ran into an error when using a conditional
branch to an external symbol (this doesn't occur in compiler-generated
code

PowerPC: Support PC-relative fixup_ppc_brcond14.

When testing the asm parser, I ran into an error when using a conditional
branch to an external symbol (this doesn't occur in compiler-generated
code) due to missing support in PPCELFObjectWriter::getRelocTypeInner.

llvm-svn: 180605

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PowerPC: Simplify handling of fixups.

MCTargetDesc/PPCMCCodeEmitter.cpp current has code like:

if (isSVR4ABI() && is64BitMode())
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),

PowerPC: Simplify handling of fixups.

MCTargetDesc/PPCMCCodeEmitter.cpp current has code like:

if (isSVR4ABI() && is64BitMode())
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_toc16));
else
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_lo16));

This is a problem for the asm parser, since it requires knowledge of
the ABI / 64-bit mode to be set up. However, more fundamentally,
at this point we shouldn't make such distinctions anyway; in an assembler
file, it always ought to be possible to e.g. generate TOC relocations even
when the main ABI is one that doesn't use TOC.

Fortunately, this is actually completely unnecessary; that code was added
to decide whether to generate TOC relocations, but that information is in
fact already encoded in the VariantKind of the underlying symbol.

This commit therefore merges those fixup types into one, and then decides
which relocation to use based on the VariantKind.

No changes in generated code.

llvm-svn: 178007

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Fix missing relocation for TLS addressing peephole optimization.

Report and fix due to Kai Nacke. Testcase update by me.

llvm-svn: 176029