Commit Graph

3262 Commits

Author SHA1 Message Date
Chad Rosier
108fb3202a [PEI] Pass the frame index operand number to the eliminateFrameIndex function.
Each target implementation was needlessly recomputing the index.
Part of rdar://13076458

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174083 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 20:02:54 +00:00
Hal Finkel
9a79b320cb PPC QPX requires a 32-byte aligned stack
On systems which support the QPX vector instructions, the stack must be
32-byte aligned.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173993 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-30 23:43:27 +00:00
Hal Finkel
f9cd7738a3 Initialize hasQPX in PPCSubtarget
This should have gone in with r173973.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173984 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-30 22:43:44 +00:00
Hal Finkel
5bb16fdbb3 Add definitions for the PPC a2q core marked as having QPX available
This is the first commit of a large series which will add support for the
QPX vector instruction set to the PowerPC backend. This instruction set is
used on the IBM Blue Gene/Q supercomputers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173973 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-30 21:17:42 +00:00
Evan Cheng
8688a58c53 Teach SDISel to combine fsin / fcos into a fsincos node if the following
conditions are met:
1. They share the same operand and are in the same BB.
2. Both outputs are used.
3. The target has a native instruction that maps to ISD::FSINCOS node or
   the target provides a sincos library call.

Implemented the generic optimization in sdisel and enabled it for
Mac OSX. Also added an additional optimization for x86_64 Mac OSX by
using an alternative entry point __sincos_stret which returns the two
results in xmm0 / xmm1.

rdar://13087969
PR13204


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173755 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-29 02:32:37 +00:00
Hal Finkel
d3427d3f40 Add isBGQ method to PPCSubtarget
This function will be used in future commits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173729 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-29 00:22:47 +00:00
Dmitri Gribenko
395210d15b Remove unused variables, silences -Wunused-variable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173526 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 23:17:21 +00:00
Hal Finkel
a8b289b70d Initial implementation of PPCTargetTransformInfo
This provides a place to add customized operation cost information and
control some other target-specific IR-level transformations.

The only non-trivial logic in this checkin assigns a higher cost to
unaligned loads and stores (covered by the included test case).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173520 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 23:05:59 +00:00
Hal Finkel
5928deaf20 More cleanup of PPC register definitions.
Uses the new !add TableGen operator to do more cleanup of the
PPC register definitions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173446 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 14:49:10 +00:00
Hal Finkel
78e1057371 Start cleanup of PPC register definitions using foreach loops.
No functionality change intended.

This captures the first two cases GPR32/64. For the others, we need
an addition operator (if we have one, I've not yet found it).

Based on a suggestion made by Tom Stellard in the AArch64 review!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-24 20:43:18 +00:00
Eli Bendersky
e807d1ea1e Fix powerpc test failure - forgot to initialize stack slot size for PPCLinuxMCAsmInfo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173275 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23 17:12:15 +00:00
Eli Bendersky
e752feee52 Clean up assignment of CalleeSaveStackSlotSize: get rid of the default and explicitly set this in every target that needs to change it from the default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173270 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23 16:22:04 +00:00
Chandler Carruth
90230c8466 Sort all of the includes. Several files got checked in with mis-sorted
includes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172891 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-19 08:03:47 +00:00
Bill Schmidt
8f4ee4b2a2 This patch fixes PR13626 by providing i128 support in the return
calling convention.  128-bit integers are now properly returned
in GPR3 and GPR4 on PowerPC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172745 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-17 19:34:57 +00:00
Bill Schmidt
792b123338 This patch fixes the PPC calling convention to handle returns of
_Complex float and _Complex long double, by simply increasing the
number of floating point registers available for return values.

The test case verifies that the correct registers are loaded.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172733 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-17 17:45:19 +00:00
Adhemerval Zanella
a1db5de9e7 PowerPC: EH adjustments
This patch adjust the r171506 to make all DWARF enconding pc-relative
for PPC64. It also adds the R_PPC64_REL32 relocation handling in MCJIT
(since the eh_frame will not generate PIC-relative relocation) and also
adds the emission of stubs created by the TTypeEncoding.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171979 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 17:08:15 +00:00
Eric Christopher
68ca56285f These functions have default arguments of 0 for the last arg. Use
them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171933 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 01:57:54 +00:00
Eli Bendersky
251040bc18 Renamed MCInstFragment to MCRelaxableFragment and added some comments.
No change in functionality.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171822 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-08 00:22:56 +00:00
Bill Schmidt
5b7f9216c3 This patch addresses bug 14678 by fixing two problems in medium code model
code generation.  Variables addressed through a GlobalAlias were not being
handled, and variables with available_externally linkage were treated
incorrectly.  The patch contains two new tests to verify the correct code
generation for these cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171778 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 19:29:18 +00:00
Chandler Carruth
aeef83c6af Switch TargetTransformInfo from an immutable analysis pass that requires
a TargetMachine to construct (and thus isn't always available), to an
analysis group that supports layered implementations much like
AliasAnalysis does. This is a pretty massive change, with a few parts
that I was unable to easily separate (sorry), so I'll walk through it.

The first step of this conversion was to make TargetTransformInfo an
analysis group, and to sink the nonce implementations in
ScalarTargetTransformInfo and VectorTargetTranformInfo into
a NoTargetTransformInfo pass. This allows other passes to add a hard
requirement on TTI, and assume they will always get at least on
implementation.

The TargetTransformInfo analysis group leverages the delegation chaining
trick that AliasAnalysis uses, where the base class for the analysis
group delegates to the previous analysis *pass*, allowing all but tho
NoFoo analysis passes to only implement the parts of the interfaces they
support. It also introduces a new trick where each pass in the group
retains a pointer to the top-most pass that has been initialized. This
allows passes to implement one API in terms of another API and benefit
when some other pass above them in the stack has more precise results
for the second API.

The second step of this conversion is to create a pass that implements
the TargetTransformInfo analysis using the target-independent
abstractions in the code generator. This replaces the
ScalarTargetTransformImpl and VectorTargetTransformImpl classes in
lib/Target with a single pass in lib/CodeGen called
BasicTargetTransformInfo. This class actually provides most of the TTI
functionality, basing it upon the TargetLowering abstraction and other
information in the target independent code generator.

The third step of the conversion adds support to all TargetMachines to
register custom analysis passes. This allows building those passes with
access to TargetLowering or other target-specific classes, and it also
allows each target to customize the set of analysis passes desired in
the pass manager. The baseline LLVMTargetMachine implements this
interface to add the BasicTTI pass to the pass manager, and all of the
tools that want to support target-aware TTI passes call this routine on
whatever target machine they end up with to add the appropriate passes.

The fourth step of the conversion created target-specific TTI analysis
passes for the X86 and ARM backends. These passes contain the custom
logic that was previously in their extensions of the
ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces.
I separated them into their own file, as now all of the interface bits
are private and they just expose a function to create the pass itself.
Then I extended these target machines to set up a custom set of analysis
passes, first adding BasicTTI as a fallback, and then adding their
customized TTI implementations.

The fourth step required logic that was shared between the target
independent layer and the specific targets to move to a different
interface, as they no longer derive from each other. As a consequence,
a helper functions were added to TargetLowering representing the common
logic needed both in the target implementation and the codegen
implementation of the TTI pass. While technically this is the only
change that could have been committed separately, it would have been
a nightmare to extract.

The final step of the conversion was just to delete all the old
boilerplate. This got rid of the ScalarTargetTransformInfo and
VectorTargetTransformInfo classes, all of the support in all of the
targets for producing instances of them, and all of the support in the
tools for manually constructing a pass based around them.

Now that TTI is a relatively normal analysis group, two things become
straightforward. First, we can sink it into lib/Analysis which is a more
natural layer for it to live. Second, clients of this interface can
depend on it *always* being available which will simplify their code and
behavior. These (and other) simplifications will follow in subsequent
commits, this one is clearly big enough.

Finally, I'm very aware that much of the comments and documentation
needs to be updated. As soon as I had this working, and plausibly well
commented, I wanted to get it committed and in front of the build bots.
I'll be doing a few passes over documentation later if it sticks.

Commits to update DragonEgg and Clang will be made presently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 01:37:14 +00:00
Adhemerval Zanella
7b449889e7 PowerPC: Fix eh_frame relocation for PIC
This patch fixes the PPC eh_frame definitions for the personality and 
frame unwinding for PIC objects. It makes PIC build correctly creates
relative relocations in the '.rela.eh_frame' segments and thus avoiding
a text relocation that generates a DT_TEXTREL segments in link phase.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171506 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-04 19:08:13 +00:00
Chandler Carruth
0b8c9a80f2 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00
Bill Wendling
831737d329 Remove the Function::getFnAttributes method in favor of using the AttributeSet
directly.

This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171253 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-30 10:32:01 +00:00
Hal Finkel
cd9ea51986 Expand PPC64 atomic load and store
Use of store or load with the atomic specifier on 64-bit types would
cause instruction-selection failures. As with the 32-bit case, these
can use the default expansion in terms of cmp-and-swap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171072 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-25 17:22:53 +00:00
Rafael Espindola
399532b25a Undefine PPC harder.
This was causing a build failure while trying to build on ppc ubuntu 12.10 with
cmake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170668 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 05:13:09 +00:00
Benjamin Kramer
91223a41ef PowerPC: Expand VSELECT nodes.
There's probably a better expansion for those nodes than the default for
altivec, but this is better than crashing. VSELECTs occur in loop vectorizer
output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170551 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-19 15:49:14 +00:00
Bill Wendling
034b94b170 Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170502 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-19 07:18:57 +00:00
Bill Schmidt
d3eb4f46f0 This patch removes some nondeterminism from direct object file output
for TLS dynamic models on 64-bit PowerPC ELF.  The default sort routine
for relocations only sorts on the r_offset field; but with TLS, there
can be two relocations with the same r_offset.  For PowerPC, this patch
sorts secondarily on descending r_type, which matches the behavior
expected by the linker.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170237 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-14 20:28:38 +00:00
Bill Schmidt
b453e16855 This patch improves the 64-bit PowerPC InitialExec TLS support by providing
for a wider range of GOT entries that can hold thread-relative offsets.
This matches the behavior of GCC, which was not documented in the PPC64 TLS
ABI.  The ABI will be updated with the new code sequence.

Former sequence:

  ld 9,x@got@tprel(2)
  add 9,9,x@tls

New sequence:

  addis 9,2,x@got@tprel@ha
  ld 9,x@got@tprel@l(9)
  add 9,9,x@tls

Note that a linker optimization exists to transform the new sequence into
the shorter sequence when appropriate, by replacing the addis with a nop
and modifying the base register and relocation type of the ld.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170209 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-14 17:02:38 +00:00
Bill Schmidt
1e18b86192 This is another cleanup patch for 64-bit PowerPC TLS processing. I had
some hackery in place that hid my poor use of TblGen, which I've now sorted
out and cleaned up.  No change in observable behavior, so no new test cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170149 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-13 20:57:10 +00:00
Bill Schmidt
dfebc4cc4c This is just a clean-up patch that simplifies the initial-exec TLS logic by
avoiding use of machine operand flags.  No change in observable behavior, so
no new test cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170141 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-13 18:45:54 +00:00
Bill Schmidt
349c2787cf This patch implements local-dynamic TLS model support for the 64-bit
PowerPC target.  This is the last of the four models, so we now have 
full TLS support.

This is mostly a straightforward extension of the general dynamic model.
I had to use an additional Chain operand to tie ADDIS_DTPREL_HA to the
register copy following ADDI_TLSLD_L; otherwise everything above the
ADDIS_DTPREL_HA appeared dead and was removed.

As before, there are new test cases to test the assembly generation, and
the relocations output during integrated assembly.  The expected code
gen sequence can be read in test/CodeGen/PowerPC/tls-ld.ll.

There are a couple of things I think can be done more efficiently in the
overall TLS code, so there will likely be a clean-up patch forthcoming;
but for now I want to be sure the functionality is in place.

Bill


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170003 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 19:29:35 +00:00
Evan Cheng
946a3a9f22 Sorry about the churn. One more change to getOptimalMemOpType() hook. Did I
mention the inline memcpy / memset expansion code is a mess?

This patch split the ZeroOrLdSrc argument into two: IsMemset and ZeroMemset.
The first indicates whether it is expanding a memset or a memcpy / memmove.
The later is whether the memset is a memset of zero. It's totally possible
(likely even) that targets may want to do different things for memcpy and
memset of zero.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169959 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 02:34:41 +00:00
Evan Cheng
7d34267df6 - Rename isLegalMemOpType to isSafeMemOpType. "Legal" is a very overloade term.
Also added more comments to explain why it is generally ok to return true.
- Rename getOptimalMemOpType argument IsZeroVal to ZeroOrLdSrc. It's meant to
be true for loaded source (memcpy) or zero constants (memset). The poor name
choice is probably some kind of legacy issue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169954 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 01:32:07 +00:00
Bill Schmidt
57ac1f458a This patch implements the general dynamic TLS model for 64-bit PowerPC.
Given a thread-local symbol x with global-dynamic access, the generated
code to obtain x's address is:

     Instruction                            Relocation            Symbol
  addis ra,r2,x@got@tlsgd@ha           R_PPC64_GOT_TLSGD16_HA       x
  addi  r3,ra,x@got@tlsgd@l            R_PPC64_GOT_TLSGD16_L        x
  bl __tls_get_addr(x@tlsgd)           R_PPC64_TLSGD                x
                                       R_PPC64_REL24           __tls_get_addr
  nop
  <use address in r3>

The implementation borrows from the medium code model work for introducing
special forms of ADDIS and ADDI into the DAG representation.  This is made
slightly more complicated by having to introduce a call to the external
function __tls_get_addr.  Using the full call machinery is overkill and,
more importantly, makes it difficult to add a special relocation.  So I've
introduced another opcode GET_TLS_ADDR to represent the function call, and
surrounded it with register copies to set up the parameter and return value.

Most of the code is pretty straightforward.  I ran into one peculiarity
when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like
BL8_NOP_ELF except that it takes another parameter to represent the symbol
("x" above) that requires a relocation on the call.  Something in the 
TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated
identically during the emit phase, so this second operand was never
visited to generate relocations.  This is the reason for the slightly
messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding().

Two new tests are included to demonstrate correct external assembly and
correct generation of relocations using the integrated assembler.

Comments welcome!

Thanks,
Bill


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169910 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-11 20:30:11 +00:00
Bill Schmidt
d7802bf0dd This patch introduces initial-exec model support for thread-local storage
on 64-bit PowerPC ELF.

The patch includes code to handle external assembly and MC output with the
integrated assembler.  It intentionally does not support the "old" JIT.

For the initial-exec TLS model, the ABI requires the following to calculate
the address of external thread-local variable x:

 Code sequence            Relocation                  Symbol
  ld 9,x@got@tprel(2)      R_PPC64_GOT_TPREL16_DS      x
  add 9,9,x@tls            R_PPC64_TLS                 x

The register 9 is arbitrary here.  The linker will replace x@got@tprel
with the offset relative to the thread pointer to the generated GOT
entry for symbol x.  It will replace x@tls with the thread-pointer
register (13).

The two test cases verify correct assembly output and relocation output
as just described.

PowerPC-specific selection node variants are added for the two
instructions above:  LD_GOT_TPREL and ADD_TLS.  These are inserted
when an initial-exec global variable is encountered by
PPCTargetLowering::LowerGlobalTLSAddress(), and later lowered to
machine instructions LDgotTPREL and ADD8TLS.  LDgotTPREL is a pseudo
that uses the same LDrs support added for medium code model's LDtocL,
with a different relocation type.

The rest of the processing is straightforward.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169281 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-04 16:18:08 +00:00
Chandler Carruth
a1514e24cc Sort includes for all of the .h files under the 'lib' tree. These were
missed in the first pass because the script didn't yet handle include
guards.

Note that the script is now able to handle all of these headers without
manual edits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169224 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-04 07:12:27 +00:00
Chandler Carruth
d04a8d4b33 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00
Adhemerval Zanella
375cbe4143 This patch fixes the Altivec addend construction for the fused multiply-add
instruction (vmaddfp) to conform with IEEE to ensure the sign of a zero
result when resulting product is -0.0.

The -0.0 vector addend to vmaddfp is generated by a creating a vector
with full bits sets and then shifting each elements by 31-bits to the
left, resulting in a vector of 0x80000000 (or -0.0 as float).

The 'buildvec_canonicalize.ll' was adjusted to reflect this change and
the 'vec_mul.ll' was complemented with the float vector multiplication
test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168998 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30 13:05:44 +00:00
Ulrich Weigand
781dfbd482 Fix initial frame state on powerpc64.
The createPPCMCAsmInfo routine used PPC::R1 as the initial frame
pointer register, but on PPC64 the 32-bit R1 register does not
have a corresponding DWARF number, causing invalid CIE initial
frame state to be emitted.  Fix by using PPC::X1 instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168799 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-28 18:21:03 +00:00
Jakob Stoklund Olesen
a9fa4fd973 Remove all references to TargetInstrInfoImpl.
This class has been merged into its super-class TargetInstrInfo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168760 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-28 02:35:17 +00:00
Bill Schmidt
daa65f5e08 This patch makes medium code model the default for 64-bit PowerPC ELF.
When the CodeGenInfo is to be created for the PPC64 target machine,
a default code-model selection is converted to CodeModel::Medium
provided we are not targeting the Darwin OS.  Defaults for Darwin
are unaffected.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168747 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-27 23:36:26 +00:00
Bill Schmidt
34a9d4b3b9 This patch implements medium code model support for 64-bit PowerPC.
The default for 64-bit PowerPC is small code model, in which TOC entries
must be addressable using a 16-bit offset from the TOC pointer.  Additionally,
only TOC entries are addressed via the TOC pointer.

With medium code model, TOC entries and data sections can all be addressed
via the TOC pointer using a 32-bit offset.  Cooperation with the linker
allows 16-bit offsets to be used when these are sufficient, reducing the
number of extra instructions that need to be executed.  Medium code model
also does not generate explicit TOC entries in ".section toc" for variables
that are wholly internal to the compilation unit.

Consider a load of an external 4-byte integer.  With small code model, the
compiler generates:

	ld 3, .LC1@toc(2)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc ei[TC],ei

With medium model, it instead generates:

	addis 3, 2, .LC1@toc@ha
	ld 3, .LC1@toc@l(3)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc ei[TC],ei

Here .LC1@toc@ha is a relocation requesting the upper 16 bits of the
32-bit offset of ei's TOC entry from the TOC base pointer.  Similarly,
.LC1@toc@l is a relocation requesting the lower 16 bits.  Note that if
the linker determines that ei's TOC entry is within a 16-bit offset of
the TOC base pointer, it will replace the "addis" with a "nop", and
replace the "ld" with the identical "ld" instruction from the small
code model example.

Consider next a load of a function-scope static integer.  For small code
model, the compiler generates:

	ld 3, .LC1@toc(2)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc test_fn_static.si[TC],test_fn_static.si
	.type	test_fn_static.si,@object
	.local	test_fn_static.si
	.comm	test_fn_static.si,4,4

For medium code model, the compiler generates:

	addis 3, 2, test_fn_static.si@toc@ha
	addi 3, 3, test_fn_static.si@toc@l
	lwz 4, 0(3)

	.type	test_fn_static.si,@object
	.local	test_fn_static.si
	.comm	test_fn_static.si,4,4

Again, the linker may replace the "addis" with a "nop", calculating only
a 16-bit offset when this is sufficient.

Note that it would be more efficient for the compiler to generate:

	addis 3, 2, test_fn_static.si@toc@ha
        lwz 4, test_fn_static.si@toc@l(3)

The current patch does not perform this optimization yet.  This will be
addressed as a peephole optimization in a later patch.

For the moment, the default code model for 64-bit PowerPC will remain the
small code model.  We plan to eventually change the default to medium code
model, which matches current upstream GCC behavior.  Note that the different
code models are ABI-compatible, so code compiled with different models will
be linked and execute correctly.

I've tested the regression suite and the application/benchmark test suite in
two ways:  Once with the patch as submitted here, and once with additional
logic to force medium code model as the default.  The tests all compile
cleanly, with one exception.  The mandel-2 application test fails due to an
unrelated ABI compatibility with passing complex numbers.  It just so happens
that small code model was incredibly lucky, in that temporary values in 
floating-point registers held the expected values needed by the external
library routine that was called incorrectly.  My current thought is to correct
the ABI problems with _Complex before making medium code model the default,
to avoid introducing this "regression."

Here are a few comments on how the patch works, since the selection code
can be difficult to follow:

The existing logic for small code model defines three pseudo-instructions:
LDtoc for most uses, LDtocJTI for jump table addresses, and LDtocCPT for
constant pool addresses.  These are expanded by SelectCodeCommon().  The
pseudo-instruction approach doesn't work for medium code model, because
we need to generate two instructions when we match the same pattern.
Instead, new logic in PPCDAGToDAGISel::Select() intercepts the TOC_ENTRY
node for medium code model, and generates an ADDIStocHA followed by either
a LDtocL or an ADDItocL.  These new node types correspond naturally to
the sequences described above.

The addis/ld sequence is generated for the following cases:
 * Jump table addresses
 * Function addresses
 * External global variables
 * Tentative definitions of global variables (common linkage)

The addis/addi sequence is generated for the following cases:
 * Constant pool entries
 * File-scope static global variables
 * Function-scope static variables

Expanding to the two-instruction sequences at select time exposes the
instructions to subsequent optimization, particularly scheduling.

The rest of the processing occurs at assembly time, in
PPCAsmPrinter::EmitInstruction.  Each of the instructions is converted to
a "real" PowerPC instruction.  When a TOC entry needs to be created, this
is done here in the same manner as for the existing LDtoc, LDtocJTI, and
LDtocCPT pseudo-instructions (I factored out a new routine to handle this).

I had originally thought that if a TOC entry was needed for LDtocL or
ADDItocL, it would already have been generated for the previous ADDIStocHA.
However, at higher optimization levels, the ADDIStocHA may appear in a 
different block, which may be assembled textually following the block
containing the LDtocL or ADDItocL.  So it is necessary to include the
possibility of creating a new TOC entry for those two instructions.

Note that for LDtocL, we generate a new form of LD called LDrs.  This
allows specifying the @toc@l relocation for the offset field of the LD
instruction (i.e., the offset is replaced by a SymbolLo relocation).
When the peephole optimization described above is added, we will need
to do similar things for all immediate-form load and store operations.

The seven "mcm-n.ll" test cases are kept separate because otherwise the
intermingling of various TOC entries and so forth makes the tests fragile
and hard to understand.

The above assumes use of an external assembler.  For use of the
integrated assembler, new relocations are added and used by
PPCELFObjectWriter.  Testing is done with "mcm-obj.ll", which tests for
proper generation of the various relocations for the same sequences
tested with the external assembler.






git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168708 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-27 17:35:46 +00:00
Benjamin Kramer
ed9e442cf0 Decouple MCInstBuilder from the streamer per Eli's request.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168597 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26 18:05:52 +00:00
Benjamin Kramer
391271f3bb Add MCInstBuilder, a utility class to simplify MCInst creation similar to MachineInstrBuilder.
Simplify some repetitive code with it. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168587 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26 13:34:22 +00:00
Benjamin Kramer
d3022b8946 PPC: Reinstate the fatal error when trying to emit a macho file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168543 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-24 15:23:49 +00:00
Benjamin Kramer
915558e775 PPC: MCize most of the darwin PIC emission.
The last remaining bit is "bcl 20, 31, AnonSymbol", which I couldn't find the
instruction definition for. Only whitespace changes in assembly output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168541 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-24 13:18:25 +00:00
Benjamin Kramer
e8ca482c97 PPC: Share applyFixup between ELF and Darwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168540 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-24 13:18:17 +00:00
Benjamin Kramer
8f2dce0cda PPC: Simplify code with Twines.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168539 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-24 13:18:11 +00:00
Joe Abbey
48f63be368 Using const cast to alleviate a warning.
A PR is being filed to address some code issues here.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168185 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-16 19:38:42 +00:00