Commit Graph

126 Commits

Author SHA1 Message Date
Ulrich Weigand
7a34599db0 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185945 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 16:41:09 +00:00
Ulrich Weigand
a68f58ab2b [PowerPC] Always use "assembler dialect" 1
A setting in MCAsmInfo defines the "assembler dialect" to use.  This is used
by common code to choose between alternatives in a multi-alternative GNU
inline asm statement like the following:

  __asm__ ("{sfe|subfe} %0,%1,%2" : "=r" (out) : "r" (in1), "r" (in2));

The meaning of these dialects is platform specific, and GCC defines those
for PowerPC to use dialect 0 for old-style (POWER) mnemonics and 1 for
new-style (PowerPC) mnemonics, like in the example above.

To be compatible with inline asm used with GCC, LLVM ought to do the same.
Specifically, this means we should always use assembler dialect 1 since
old-style mnemonics really aren't supported on any current platform.

However, the current LLVM back-end uses:
  AssemblerDialect = 1;           // New-Style mnemonics.
in PPCMCAsmInfoDarwin, and
  AssemblerDialect = 0;           // Old-Style mnemonics.
in PPCLinuxMCAsmInfo.

The Linux setting really isn't correct, we should be using new-style
mnemonics everywhere.  This is changed by this commit.

Unfortunately, the setting of this variable is overloaded in the back-end
to decide whether or not we are on a Darwin target.  This is done in
PPCInstPrinter (the "SyntaxVariant" is initialized from the MCAsmInfo
AssemblerDialect setting), and also in PPCMCExpr.  Setting AssemblerDialect
to 1 for both Darwin and Linux no longer allows us to make this distinction.

Instead, this patch uses the MCSubtargetInfo passed to createPPCMCInstPrinter
to distinguish Darwin targets, and ignores the SyntaxVariant parameter.
As to PPCMCExpr, this patch adds an explicit isDarwin argument that needs
to be passed in by the caller when creating a target MCExpr.  (To do so
this patch implicitly also reverts commit 184441.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185858 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-08 20:20:51 +00:00
Ulrich Weigand
457571ed69 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185700 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 13:49:46 +00:00
Ulrich Weigand
23a72c8f7e [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185692 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 12:22:36 +00:00
Ulrich Weigand
972befb3f2 [PowerPC] Implement writeNopData
This implements a proper PPCAsmBackend::writeNopData routine
that actually writes PowerPC nop instructions.

This fixes the last remaining difference in object file output
(text section) between the integrated assembler and GNU as
that I've seen anywhere.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185662 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-04 18:28:46 +00:00
Ulrich Weigand
33efedc048 [PowerPC] Use mtocrf when available
Just as with mfocrf, it is also preferable to use mtocrf instead of
mtcrf when only a single CR register is to be written.

Current code however always emits mtcrf.  This probably does not matter
when using an external assembler, since the GNU assembler will in fact
automatically replace mtcrf with mtocrf when possible.  It does create
inefficient code with the integrated assembler, however.

To fix this, this patch adds MTOCRF/MTOCRF8 instruction patterns and
uses those instead of MTCRF/MTCRF8 everything.  Just as done in the
MFOCRF patch committed as 185556, these patterns will be converted
back to MTCRF if MTOCRF is not available on the machine.

As a side effect, this allows to modify the MTCRF pattern to accept
the full range of mask operands for the benefit of the asm parser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185561 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 17:59:07 +00:00
Ulrich Weigand
965b20e39c [PowerPC] Always use mfocrf if available
When accessing just a single CR register, it is always preferable to
use mfocrf instead of mfcr, if the former is available on the CPU.

Current code makes that distinction in many, but not all places
where a single CR register value is retrieved.  One missing
location is PPCRegisterInfo::lowerCRSpilling.

To fix this and make this simpler in the future, this patch changes
the bulk of the back-end to always assume mfocrf is available and
simply generate it when needed.

On machines that actually do not support mfocrf, the instruction
is replaced by mfcr at the very end, in EmitInstruction.

This has the additional benefit that we no longer need the
MFCRpseud hack, since before EmitInstruction we always have
a MFOCRF instruction pattern, which already models data flow
as required.

The patch also adds the MFOCRF8 version of the instruction,
which was missing so far.

Except for the PPCRegisterInfo::lowerCRSpilling case, no change
in generated code intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185556 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 17:05:42 +00:00
Ulrich Weigand
a17a7e1868 [PowerPC] Rework TLS call operand processing
As part of the global-dynamic and local-dynamic TLS sequences, we need
to use a special form of the call instruction:

 bl __tls_get_addr(sym@tlsld)
 bl __tls_get_addr(sym@tlsgd)

which generates two fixups.  The current implementation of this causes
problems with recognizing this form in the asm parser.  To fix this,
this patch reworks operand processing for this special form by using
a single operand to hold both __tls_get_addr and sym@tlsld and defining
a print method to output the above form, and an encoding method to
generate the two fixups.

As a side simplification, the patch replaces the two instruction
patterns BL8_NOP_TLSGD and BL8_NOP_TLSLD by a single BL8_NOP_TLS,
since the patterns already operate in an identical fashion (whether
we have a local-dynamic or global-dynamic symbol is already encoded
in the symbol modifier).

No change in code generation intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185477 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 21:31:04 +00:00
Ulrich Weigand
58fc1f52ce [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.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185476 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 21:29:06 +00:00
Ulrich Weigand
228e0afcfd [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185394 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-01 23:33:29 +00:00
Ulrich Weigand
222e781d92 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185353 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-01 18:19:56 +00:00
Ulrich Weigand
0b8594268f [PowerPC] Support symbolic u16imm operands
Currently, all instructions taking s16imm operands support symbolic
operands.  However, for u16imm operands, we only support actual
immediate integers.  This causes the assembler to reject code like

  ori %r5, %r5, symbol@l

This patch changes the u16imm operand definition to likewise
accept symbolic operands.  In fact, s16imm and u16imm can
share the same encoding routine, now renamed to getImm16Encoding.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184944 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-26 13:49:15 +00:00
Ulrich Weigand
5de735a962 [PowerPC] Support @got modifier
Add VK_... values and relocation types necessary to support
the @got family of modifiers.  Used by the asm parser only.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184860 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-25 16:49:50 +00:00
Ulrich Weigand
2e8bd89503 [PowerPC] Add predicted forms of branches
This adds support for the predicted forms of branches (+/-).
There are three cases to consider:
- Branches using a PPC::Predicate code
  For these, I've added new PPC::Predicate codes corresponding
  to the BO values for predicted branch forms, and updated insn
  printing to print them correctly.  I've also added new aliases
  for the asm parser matching the new forms.
- bt/bf
  I've added new aliases matching to gBC etc.
- bd(n)z variants
  I've added new instruction patterns for the predicted forms.

In all cases, the new patterns are used for the asm parser only.
(The new infrastructure ought to be sufficient to allow use by
the compiler too at some point.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184754 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 16:52:04 +00:00
Ulrich Weigand
9679c47a07 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184721 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 11:03:33 +00:00
Ulrich Weigand
84569698f0 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184552 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:44:37 +00:00
Ulrich Weigand
cab0a19338 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184551 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:44:15 +00:00
Ulrich Weigand
f7c1ee79fe [PowerPC] Support @higher et.al. modifiers
This adds support for the @higher, @highera, @highest, and @highesta
modifers, including some missing relocation types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184550 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:43:42 +00:00
Ulrich Weigand
f8f87dcfce [PowerPC] Support @toc@h modifier
This adds the relocation type and other necessary infrastructure
to use the @toc@h modifier in the assembler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184549 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:43:10 +00:00
Ulrich Weigand
d284957246 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184548 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:42:49 +00:00
Ulrich Weigand
92cfa61c50 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184547 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:42:20 +00:00
Ulrich Weigand
846565924a [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184491 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 22:39:42 +00:00
Ulrich Weigand
769accfb4d [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184485 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 22:04:40 +00:00
Ulrich Weigand
027e94479c [PowerPC] Optimize @ha/@l constructs
This patch adds support for having the assembler optimize fixups
to constructs like "symbol@ha" or "symbol@l" if "symbol" can be
resolved at assembler time.

This optimization is already present in the PPCMCExpr.cpp code
for handling PPC_HA16/PPC_LO16 target expressions.  However,
those target expression were used only on Darwin targets.

This patch changes target expression code so that they are
usable also with the GNU assembler (using the @ha / @l syntax
instead of the ha16() / lo16() syntax), and changes the
MCInst lowering code to generate those target expressions
where appropriate.

It also changes the asm parser to generate HA16/LO16 target
expressions when parsing assembler source that uses the
@ha / @l modifiers.  The effect is that now the above-
mentioned optimization automatically becomes available
for those situations too.
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184436 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 16:23:52 +00:00
Bill Wendling
99cb622041 Use pointers to the MCAsmInfo and MCRegInfo.
Someone may want to do something crazy, like replace these objects if they
change or something.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 07:20:20 +00:00
David Blaikie
7e17024400 Revert r183854 (PPC: Fix switch warnings from r183841)
Now that the PRED_BAD has been removed, this is failing the Clang
-Werror build due to -Wcovered-switch-default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183863 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-12 20:57:32 +00:00
Bill Schmidt
6289533853 [PowerPC] Remove PRED_BAD from PPC::Predicate enumeration.
I'm taking David Blaikie's suggestion to use an
Optional<PPC::Predicate> return value instead.  That's the right
solution for this problem.  Thanks for pointing out that possibility!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183858 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-12 20:22:24 +00:00
Bill Schmidt
dab366bf25 [PowerPC] Fix switch warnings from r183841.
Introducing PRED_BAD caused some unexpected warnings that are now
suppressed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183854 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-12 19:20:32 +00:00
Bill Schmidt
f69ead4651 Add artificial PRED_BAD to PPC::Predicate enumeration.
Allows returning a PPC::Predicate from a function with a no-predicate
value possible.  Preparatory patch for fast-isel on PPC64 ELF.  No
behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183841 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-12 15:14:42 +00:00
Ulrich Weigand
c1f4a4b264 [MC/DWARF] Support .debug_frame / .debug_line code alignment factors
I've been comparing the object file output of LLVM's integrated
assembler against the external assembler on PowerPC, and one
area where differences still remain are in DWARF sections.

In particular, the GNU assembler generates .debug_frame and
.debug_line sections using a code alignment factor of 4, since
all PowerPC instructions have size 4 and must be aligned to a
multiple of 4.  However, current MC code hard-codes a code
alignment factor of 1.

This patch changes this by adding a "minimum instruction alignment"
data element to MCAsmInfo and using this as code alignment factor.

This requires passing a MCContext into MCDwarfLineAddr::Encode
and MCDwarfLineAddr::EncodeAdvanceLoc.  Note that one caller,
MCDwarfLineAddr::Write, didn't actually have that information
available.  However, it turns out that this routine is in fact
never used in the whole code base, so the patch simply removes
it.  If it turns out to be needed again at a later time, it
could be re-added with an updated interface.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183834 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-12 14:46:54 +00:00
Ulrich Weigand
edaa58ee66 [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).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182616 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-23 22:26:41 +00:00
Ulrich Weigand
4456a8ec76 [PowerPC] Fix hi/lo encoding in old-style code emitter
This patch implements the equivalent change to r182091/r182092
in the old-style code emitter.  Instead of having two separate
16-bit immediate encoding routines depending on the instruction,
this patch introduces a single encoder that checks the machine
operand flags to decide whether the low or high half of a
symbol address is required.

Since now both encoders make no further distinction between
"symbolLo" and "symbolHi", the .td operand can now use a
single getS16ImmEncoding method.

Tested by running the old-style JIT tests on 32-bit Linux.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182097 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-17 14:14:12 +00:00
Ulrich Weigand
e152eac63e [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182092 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-17 12:37:21 +00:00
Ulrich Weigand
c299ad32c8 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182091 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-17 12:36:29 +00:00
Ulrich Weigand
347a5079e1 [PowerPC] Use true offset value in "memrix" machine operands
This is the second part of the change to always return "true"
offset values from getPreIndexedAddressParts, tackling the
case of "memrix" type operands.

This is about instructions like LD/STD that only have a 14-bit
field to encode immediate offsets, which are implicitly extended
by two zero bits by the machine, so that in effect we can access
16-bit offsets as long as they are a multiple of 4.

The PowerPC back end currently handles such instructions by
carrying the 14-bit value (as it will get encoded into the
actual machine instructions) in the machine operand fields
for such instructions.  This means that those values are
in fact not the true offset, but rather the offset divided
by 4 (and then truncated to an unsigned 14-bit value).

Like in the case fixed in r182012, this makes common code
operations on such offset values not work as expected.
Furthermore, there doesn't really appear to be any strong
reason why we should encode machine operands this way.

This patch therefore changes the encoding of "memrix" type
machine operands to simply contain the "true" offset value
as a signed immediate value, while enforcing the rules that
it must fit in a 16-bit signed value and must also be a
multiple of 4.

This change must be made simultaneously in all places that
access machine operands of this type.  However, just about
all those changes make the code simpler; in many cases we
can now just share the same code for memri and memrix
operands.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182032 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-16 17:58:02 +00:00
Rafael Espindola
4ef61f2ad4 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181910 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 18:22:01 +00:00
Ulrich Weigand
9122396a4d [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181894 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 15:07:06 +00:00
Ulrich Weigand
b1cf8de85a [PowerPC] Correctly handle fixups of other than 4 byte size
The PPCAsmBackend::applyFixup routine handles the case where a
fixup can be resolved within the same object file.  However,
this routine is currently hard-coded to assume the size of
any fixup is always exactly 4 bytes.

This is sort-of correct for fixups on instruction text; even
though it only works because several of what really would be
2-byte fixups are presented as 4-byte fixups instead (requiring
another hack in PPCELFObjectWriter::adjustFixupOffset to clean
it up).

However, this assumption breaks down completely for fixups
on data, which legitimately can be of any size (1, 2, 4, or 8).

This patch makes applyFixup aware of fixups of varying sizes,
introducing a new helper routine getFixupKindNumBytes (along
the lines of what the ARM back end does).  Note that in order
to handle fixups of size 8, we also need to fix the return type
of adjustFixupValue to uint64_t to avoid truncation.

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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181891 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 15:01:46 +00:00
Rafael Espindola
4a971705bc Remove the MachineMove class.
It was just a less powerful and more confusing version of
MCCFIInstruction. A side effect is that, since MCCFIInstruction uses
dwarf register numbers, calls to getDwarfRegNum are pushed out, which
should allow further simplifications.

I left the MachineModuleInfo::addFrameMove interface unchanged since
this patch was already fairly big.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181680 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-13 01:16:13 +00:00
Rafael Espindola
6e53180db1 Remove unused argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181618 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-10 18:16:59 +00:00
Ulrich Weigand
a3967b6844 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181450 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-08 17:50:07 +00:00
Ulrich Weigand
8ade909308 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180605 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-26 15:38:30 +00:00
Hal Finkel
abe64dc6f7 Move PPC getSwappedPredicate for reuse
The getSwappedPredicate function can be used in other places (such as in
improvements to the PPCCTRLoops pass). Instead of trapping it as a static
function in PPCInstrInfo, move it into PPCPredicates with other
predicate-related things.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179926 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-20 05:16:26 +00:00
Hal Finkel
aa6047d23d PPC: Use HWEncoding and TRI->getEncodingValue
As pointed out by Jakob, we don't need to maintain a separate
register-numbering table. Instead we should let TableGen generate the table for
us from the information (already present) in PPCRegisterInfo.td.
TRI->getEncodingValue is now used to access register-encoding values.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178067 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 20:08:20 +00:00
Benjamin Kramer
d6f5a581ab Remove default case from fully covered switch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178025 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 14:17:42 +00:00
Ulrich Weigand
65e90c0364 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178007 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:56:47 +00:00
Ulrich Weigand
3b25529336 PowerPC: Simplify BLR pattern.
The BLR pattern cannot be recognized by the asm parser in its current form.
This complexity is due to an apparent attempt to enable conditional BLR
variants.  However, none of those can ever be generated by current code;
the pattern is only ever created using the default "pred" operand.

To simplify the pattern and allow it to be recognized by the parser,
this commit removes those attempts at conditional BLR support.

When we later come back to actually add real conditional BLR, this
should probably be done via a fully generic conditional branch pattern.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178002 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:53:27 +00:00
Hal Finkel
526d6c451b PPC ZERO register needs a register number of 0.
In order for the new ZERO register to be used with MC, etc. we need to specify
its register number (0).

Thanks to Kai for reporting the problem!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177833 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-23 22:06:07 +00:00
Ulrich Weigand
86765fbe17 Remove ABI-duplicated call instruction patterns.
We currently have a duplicated set of call instruction patterns depending
on the ABI to be followed (Darwin vs. Linux).  This is a bit odd; while the
different ABIs will result in different instruction sequences, the actual
instructions themselves ought to be independent of the ABI.  And in fact it
turns out that the only nontrivial difference between the two sets of
patterns is that in the PPC64 Linux ABI, the instruction used for indirect
calls is marked to take X11 as extra input register (which is indeed used
only with that ABI to hold an incoming environment pointer for nested
functions).  However, this does not need to be hard-coded at the .td
pattern level; instead, the C++ code expanding calls can simply add that
use, just like it adds uses for argument registers anyway.

No change in generated code expected.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177735 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-22 15:24:13 +00:00
Sylvestre Ledru
53856be683 To avoid symbol clash, undefine PPC here. PPC may be predefined on some hosts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177234 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-17 12:40:42 +00:00