Commit Graph

166 Commits

Author SHA1 Message Date
Ulrich Weigand
5e220753ff [PowerPC] Add assembler parser
This adds assembler parser support to the PowerPC back end.

The parser will run for any powerpc-*-* and powerpc64-*-* triples,
but was tested only on 64-bit Linux.  The supported syntax is
intended to be compatible with the GNU assembler.

The parser does not yet support all PowerPC instructions, but
it does support anything that is generated by LLVM itself.
There is no support for testing restricted instruction sets yet,
i.e. the parser will always accept any instructions it knows,
no matter what feature flags are given.

Instruction operands will be checked for validity and errors
generated.  (Error handling in general could still be improved.)

The patch adds a number of test cases to verify instruction
and operand encodings.  The tests currently cover all instructions
from the following PowerPC ISA v2.06 Book I facilities:
Branch, Fixed-point, Floating-Point, and Vector. 
Note that a number of these instructions are not yet supported
by the back end; they are marked with FIXME.

A number of follow-on check-ins will add extra features.  When
they are all included, LLVM passes all tests (including bootstrap)
when using clang -cc1as as the system assembler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181050 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-03 19:49:39 +00:00
Ulrich Weigand
a3acc2b6cf PowerPC: Use RegisterOperand instead of RegisterClass operands
In the default PowerPC assembler syntax, registers are specified simply
by number, so they cannot be distinguished from immediate values (without
looking at the opcode).  This means that the default operand matching logic
for the asm parser does not work, and we need to specify custom matchers.
Since those can only be specified with RegisterOperand classes and not
directly on the RegisterClass, all instructions patterns used by the asm
parser need to use a RegisterOperand (instead of a RegisterClass) for
all their register operands.

This patch adds one RegisterOperand for each RegisterClass, using the
same name as the class, just in lower case, and updates all instruction
patterns to use RegisterOperand instead of RegisterClass operands.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180611 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-26 16:53:15 +00:00
Ulrich Weigand
1adc97c901 PowerPC: Fix encoding of rldimi and rldcl instructions
When testing the asm parser, I noticed wrong encodings for the
above instructions (wrong operand name in rldimi, wrong form
and sub-opcode for rldcl).

Tests will be added together with the asm parser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180606 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-26 15:39:12 +00:00
Ulrich Weigand
1fb54cfb0a PowerPC: Mark some more patterns as isCodeGenOnly.
A couple of recently introduced conditional branch patterns
also need to be marked as isCodeGenOnly since they cannot
be handled by the asm parser.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-17 17:19:05 +00:00
Hal Finkel
00e86ad167 Mark all PPC comparison instructions as not having side effects
Now that the CR spilling issues have been resolved, we can remove the
unmodeled-side-effect attributes from the comparison instructions (and also
mark them as isCompare). By allowing these, by default, to have unmodeled side
effects, we were hiding problems with CR spilling; but everything seems much
happier now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179502 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-15 02:37:46 +00:00
Hal Finkel
63496f66c5 Mark all PPC CR registers to be spilled as live-in and tag MFCR appropriately
Leaving MFCR has having unmodeled side effects is not enough to prevent
unwanted instruction reordering post-RA. We could probably apply a stronger
barrier attribute, but there is a better way: Add all (not just the first) CR
to be spilled as live-in to the entry block, and add all CRs to the MFCR
instruction as implicitly killed.

Unfortunately, I don't have a small test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179465 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-13 23:06:15 +00:00
Hal Finkel
598574695b PPC: Remove (broken) nested implicit definition lists
TableGen will not combine nested list 'let' bindings into a single list, and
instead uses only the inner scope. As a result, several instruction definitions
were missing implicit register defs that were in outer scopes. This de-nests
these scopes and makes all instructions have only one let binding which sets
implicit register definitions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179392 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 18:17:57 +00:00
Hal Finkel
171a8adf31 Add PPC instruction record forms and associated query functions
This is prep. work for the implementation of optimizeCompare. Many PPC
instructions have 'record' forms (in almost all cases, this means that the RC
bit is set) that cause the result of the instruction to be compared with zero,
and the result of that comparison saved in a predefined condition register. In
order to add the record forms of the instructions without too much
copy-and-paste, the relevant functions have been refactored into multiclasses
which define both the record and normal forms.

Also, two TableGen-generated mapping functions have been added which allow
querying the instruction code for the record form given the normal form (and
vice versa).

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179356 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 02:18:09 +00:00
Hal Finkel
90dd7fd167 PPC: Prep for if conversion of bctr[l]
This adds in-principle support for if-converting the bctr[l] instructions.
These instructions are used for indirect branching. It seems, however, that the
current if converter will never actually predicate these. To do so, it would
need the ability to hoist a few setup insts. out of the conditionally-executed
block. For example, code like this:
  void foo(int a, int (*bar)()) { if (a != 0) bar(); }
becomes:
        ...
        beq 0, .LBB0_2
        std 2, 40(1)
        mr 12, 4
        ld 3, 0(4)
        ld 11, 16(4)
        ld 2, 8(4)
        mtctr 3
        bctrl
        ld 2, 40(1)
.LBB0_2:
        ...
and it would be safe to do all of this unconditionally with a predicated
beqctrl instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179156 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-10 06:42:34 +00:00
Hal Finkel
7eb0d8148e Allow PPC B and BLR to be if-converted into some predicated forms
This enables us to form predicated branches (which are the same conditional
branches we had before) and also a larger set of predicated returns (including
instructions like bdnzlr which is a conditional return and loop-counter
decrement all in one).

At the moment, if conversion does not capture all possible opportunities. A
simple example is provided in early-ret2.ll, where if conversion forms one
predicated return, and then the PPCEarlyReturn pass picks up the other one. So,
at least for now, we'll keep both mechanisms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179134 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-09 22:58:37 +00:00
Hal Finkel
946a811ef1 PPC rotate instructions don't have unmodeled side effcts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178982 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-07 15:06:53 +00:00
Hal Finkel
f0e3ca012b Most PPC M[TF]CR instructions do not have side effects
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178978 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-07 14:33:13 +00:00
Hal Finkel
3aea7cb7b2 PPC pre-increment load instructions do not have side effects
A few were missed in r178972.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178973 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-07 06:30:47 +00:00
Hal Finkel
fa1d102a05 PPC pre-increment load instructions do not have side effects
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178972 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-07 05:46:58 +00:00
Hal Finkel
012ffd5605 PPC ISEL is a select and never has side effects
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178960 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-06 19:30:28 +00:00
Hal Finkel
4647919784 Add more PPC floating-point conversion instructions
The P7 and A2 have additional floating-point conversion instructions which
allow a direct two-instruction sequence (plus load/store) to convert from all
combinations (signed/unsigned i32/i64) <--> (float/double) (on previous cores,
only some combinations were directly available).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178480 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-01 17:52:07 +00:00
Hal Finkel
1fce88313e Add the PPC popcntw instruction
The popcntw instruction is available whenever the popcntd instruction is
available, and performs a separate popcnt on the lower and upper 32-bits.
Ignoring the high-order count, this can be used for the 32-bit input case
(saving on the explicit zero extension otherwise required to use popcntd).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178470 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-01 15:58:15 +00:00
Hal Finkel
9ad0f4907b Cleanup PPC(64) i32 -> float/double conversion
The existing SINT_TO_FP code for i32 -> float/double conversion was disabled
because it relied on broken EXTSW_32/STD_32 instruction definitions. The
original intent had been to enable these 64-bit instructions to be used on CPUs
that support them even in 32-bit mode.  Unfortunately, this form of lying to
the infrastructure was buggy (as explained in the FIXME comment) and had
therefore been disabled.

This re-enables this functionality, using regular DAG nodes, but only when
compiling in 64-bit mode. The old STD_32/EXTSW_32 definitions (which were dead)
are removed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178438 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-31 01:58:02 +00:00
Hal Finkel
efdd4673d6 Add the PPC64 ldbrx/stdbrx instructions
These are 64-bit load/store with byte-swap, and available on the P7 and the A2.
Like the similar instructions for 16- and 32-bit words, these are matched in the
target DAG-combine phase against load/store-bswap pairs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178276 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-28 19:25:55 +00:00
Hal Finkel
c53ab4d77f Add the PPC64 popcntd instruction
PPC ISA 2.06 (P7, A2, etc.) has a popcntd instruction. Add this instruction and
tell TTI about it so that popcount-loop recognition will know about it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178233 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-28 13:29:47 +00:00
Hal Finkel
d01efc737a Fix typo in PPCInstr64Bit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178219 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-28 03:38:08 +00:00
Hal Finkel
6375e1b87b Use the PPC no-r0 class on the TOC LD pseudos
The register parameter in these instructions becomes the base register in an
r+i ld instruction (and, thus, cannot be r0).

This is not yet testable because we don't yet allocate r0 (and even then any
test would be very fragile).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178121 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-27 06:36:55 +00:00
Hal Finkel
56d926ac14 Apply the no-r0 class to PPC TOC ADDI[S] pseudo instructions
Like the addi/addis instructions themselves, these pseudo instructions also
cannot have r0 as their register parameter (because it will be interpreted as
the value 0).

This is not yet testable because we don't yet allocate r0 (and even when we do,
any regression test would be very fragile because it would depend on the
register allocator heuristics).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178118 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-27 05:57:56 +00:00
Ulrich Weigand
3d386421e0 PowerPC: Mark patterns as isCodeGenOnly.
There remain a number of patterns that cannot (and should not)
be handled by the asm parser, in particular all the Pseudo patterns.

This commit marks those patterns as isCodeGenOnly.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178008 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:57:16 +00:00
Ulrich Weigand
d67768db80 PowerPC: Remove LDrs pattern.
The LDrs pattern is a duplicate of LD, except that it accepts memory
addresses where the displacement is a symbolLo64.  An operand type
"memrs" is defined for just that purpose.

However, this wouldn't be necessary if the default "memrix" operand
type were to simply accept 64-bit symbolic addresses directly.
The only problem with that is that it uses "symbolLo", which is
hardcoded to 32-bit.

To fix this, this commit changes "memri" and "memrix" to use new
operand types for the memory displacement, which allow iPTR
instead of i32.  This will also make address parsing easier to
implment in the asm parser.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178005 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:55:45 +00:00
Ulrich Weigand
2b0850b830 PowerPC: Remove ADDIL patterns.
The ADDI/ADDI8 patterns are currently duplicated into ADDIL/ADDI8L,
which describe the same instruction, except that they accept a
symbolLo[64] operand instead of a s16imm[64] operand.

This duplication confuses the asm parser, and it actually not really
needed, since symbolLo[64] already accepts immediate operands anyway.
So this commit removes the duplicate patterns.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178004 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:55:20 +00:00
Ulrich Weigand
a01c7dbaab PowerPC: Use CCBITRC operand for ISEL patterns.
This commit changes the ISEL patterns to use a CCBITRC operand
instead of a "pred" operand.  This matches the actual instruction
text more directly, and simplifies use of ISEL with the asm parser.
In addition, this change allows some simplification of handling
the "pred" operand, as this is now only used by BCC.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178003 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:54:54 +00:00
Ulrich Weigand
e8680da874 PowerPC: Move some 64-bit branch patterns.
In PPCInstr64Bit.td, some branch patterns appear in a different sequence
than the corresponding 32-bit patterns in PPCInstrInfo.td.

To simplify future changes that affect both files, this commit moves
those patterns to rearrange them into a similar sequence.

No effect on generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178001 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 10:53:03 +00:00
Ulrich Weigand
5b390e4cd8 Use direct types in PowerPC instruction patterns.
This commit updates the PowerPC back-end (PPCInstrInfo.td and
PPCInstr64Bit.td) to use types instead of register classes in
instruction patterns, along the lines of Jakob Stoklund Olesen's
changes in r177835 for Sparc.
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177890 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-25 19:05:30 +00:00
Ulrich Weigand
1492a4e518 Use direct types in PowerPC Pat patterns.
This commit updates the PowerPC back-end (PPCInstrInfo.td and
PPCInstr64Bit.td) to use types instead of register classes in
Pat patterns, along the lines of Jakob Stoklund Olesen's
changes in r177829 for Sparc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177889 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-25 19:04:58 +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
Ulrich Weigand
89ec847ec7 Rename memrr ptrreg and offreg components.
Currently, the sub-operand of a memrr address that corresponds to what
hardware considers the base register is called "offreg", while the
sub-operand that corresponds to the offset is called "ptrreg".

To avoid confusion, this patch simply swaps the named of those two
sub-operands and updates all uses.  No functional change is intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177734 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-22 14:59:13 +00:00
Ulrich Weigand
881a7154b9 Fix swapped BasePtr and Offset in pre-inc memory addresses.
PPCTargetLowering::getPreIndexedAddressParts currently provides
the base part of a memory address in the offset result, and the
offset part in the base result.  That swap is then undone again
when an MI instruction is generated (in PPCDAGToDAGISel::Select
for loads, and using .md Pat patterns for stores).

This patch reverts this double swap, to make common code and
back-end be in sync as to which part of the address is base
and which is offset.

To avoid performance regressions in certain cases, target code
now checks whether the choice of base register would be rejected
for pre-inc accesses by common code, and attempts to swap base
and offset again in such cases.  (Overall, this means that now
pre-ice accesses are generated *more* frequently than before.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177733 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-22 14:58:48 +00:00
Ulrich Weigand
cff0faa16a Remove the xaddroff ComplexPattern.
The xaddroff pattern is currently (mistakenly) used to recognize
the *base* register in pre-inc store patterns.  This patch replaces
those uses by ptr_rc_nor0 (as is elsewhere done to match the base
register of an address), and removes the now unused ComplexPattern.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177731 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-22 14:57:48 +00:00
Hal Finkel
3ea1b064a0 Fix a register-class comparison bug in PPCCTRLoops
Thanks to Jakob for isolating the underlying problem from the
test case in r177423. The original commit had introduced
asymmetric copy operations, but these turned out to be a work-around
to the real problem (the use of == instead of hasSubClassEq in PPCCTRLoops).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177679 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-21 23:23:34 +00:00
Hal Finkel
7ee74a663a Implement builtin_{setjmp/longjmp} on PPC
This implements SJLJ lowering on PPC, making the Clang functions
__builtin_{setjmp/longjmp} functional on PPC platforms. The implementation
strategy is similar to that on X86, with the exception that a branch-and-link
variant is used to get the right jump address. Credit goes to Bill Schmidt for
suggesting the use of the unconditional bcl form (instead of the regular bl
instruction) to limit return-address-cache pollution.

Benchmarking the speed at -O3 of:

static jmp_buf env_sigill;

void foo() {
                __builtin_longjmp(env_sigill,1);
}

main() {
	...

        for (int i = 0; i < c; ++i) {
                if (__builtin_setjmp(env_sigill)) {
                        goto done;
                } else {
                        foo();
                }

done:;
        }

	...
}

vs. the same code using the libc setjmp/longjmp functions on a P7 shows that
this builtin implementation is ~4x faster with Altivec enabled and ~7.25x
faster with Altivec disabled. This comparison is somewhat unfair because the
libc version must also save/restore the VSX registers which we don't yet
support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177666 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-21 21:37:52 +00:00
Ulrich Weigand
dff4d1522a Add missing mayLoad flag to LHAUX8 and LWAUX.
All pre-increment load patterns need to set the mayLoad flag (since
they don't provide a DAG pattern).

This was missing for LHAUX8 and LWAUX, which is added by this patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177431 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 19:53:27 +00:00
Ulrich Weigand
8353d1e0e5 Rewrite LHAU8 pattern to use standard memory operand.
As opposed to to pre-increment store patterns, the pre-increment
load patterns were already using standard memory operands, with
the sole exception of LHAU8.

As there's no real reason why LHAU8 should be different here,
this patch simply rewrites the pattern to also use a memri
operand, just like all the other patterns.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177430 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 19:52:30 +00:00
Ulrich Weigand
5882e3d828 Rewrite pre-increment store patterns to use standard memory operands.
Currently, pre-increment store patterns are written to use two separate
operands to represent address base and displacement:

  stwu $rS, $ptroff($ptrreg)

This causes problems when implementing the assembler parser, so this
commit changes the patterns to use standard (complex) memory operands
like in all other memory access instruction patterns:

  stwu $rS, $dst

To still match those instructions against the appropriate pre_store
SelectionDAG nodes, the patch uses the new feature that allows a Pat
to match multiple DAG operands against a single (complex) instruction
operand.

Approved by Hal Finkel.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177429 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 19:52:04 +00:00
Ulrich Weigand
880d82e3db Fix sub-operand size mismatch in tocentry operands.
The tocentry operand class refers to 64-bit values (it is only used in 64-bit,
where iPTR is a 64-bit type), but its sole suboperand is designated as 32-bit
type.  This causes a mismatch to be detected at compile-time with the TableGen
patch I'll check in shortly.

To fix this, this commit changes the suboperand to a 64-bit type as well.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177427 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 19:50:30 +00:00
Hal Finkel
a548afc98f Prepare to make r0 an allocatable register on PPC
Currently the PPC r0 register is unconditionally reserved. There are two reasons
for this:

 1. r0 is treated specially (as the constant 0) by certain instructions, and so
    cannot be used with those instructions as a regular register.

 2. r0 is used as a temporary register in the CR-register spilling process
    (where, under some circumstances, we require two GPRs).

This change addresses the first reason by introducing a restricted register
class (without r0) for use by those instructions that treat r0 specially. These
register classes have a new pseudo-register, ZERO, which represents the r0-as-0
use. This has the side benefit of making the existing target code simpler (and
easier to understand), and will make it clear to the register allocator that
uses of r0 as 0 don't conflict will real uses of the r0 register.

Once the CR spilling code is improved, we'll be able to allocate r0.

Adding these extra register classes, for some reason unclear to me, causes
requests to the target to copy 32-bit registers to 64-bit registers. The
resulting code seems correct (and causes no test-suite failures), and the new
test case covers this new kind of asymmetric copy.

As r0 is still reserved, no functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177423 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 18:51:05 +00:00
Hal Finkel
ec2e968b7a Cleanup PPC64 unaligned i64 load/store
Remove an accidentally-added instruction definition and add a comment in the
test case. This is in response to a post-commit review by Bill Schmidt.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177404 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19 15:23:39 +00:00
Hal Finkel
08a215c286 Fix PPC unaligned 64-bit loads and stores
PPC64 supports unaligned loads and stores of 64-bit values, but
in order to use the r+i forms, the offset must be a multiple of 4.
Unfortunately, this cannot always be determined by examining the
immediate itself because it might be available only via a TOC entry.

In order to get around this issue, we additionally predicate the
selection of the r+i form on the alignment of the load or store
(forcing it to be at least 4 in order to select the r+i form).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177338 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-18 23:00:58 +00:00
Bill Schmidt
53b0b0e754 Large code model support for PowerPC.
Large code model is identical to medium code model except that the
addis/addi sequence for "local" accesses is never used.  All accesses
use the addis/ld sequence.

The coding changes are straightforward; most of the patch is taken up
with creating variants of the medium model tests for large model.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175767 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-21 17:12:27 +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
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