This fixes a bug (found by llvm-stress) in
DAGTypeLegalizer::PromoteIntRes_BUILD_VECTOR where it assumed that the result
type would always be larger than the original operands. This is not always
true, however, with boolean vectors. For example, promoting a node of type v8i1
(where the operands will be of type i32, the type to which i1 is promoted) will
yield a node with a result vector element type of i16 (and operands of type
i32). As a result, we cannot blindly assume that we can ANY_EXTEND the operands
to the result type.

llvm-svn: 185794

[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.

llvm-svn: 185561

[PowerPC] Remove VK_PPC_TLSGD and VK_PPC_TLSLD

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

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

llvm-svn: 185476

There are a couple of (small) related changes here:

1. The printed name of the VRSAVE register has been changed from VRsave to
vrsave in order to match the name accepted by GNU binutils.

2. Support for parsing vrsave has been added to the asm parser (it seems that
there was no test case specifically covering this code, so I've added one).

3. The list of Altivec registers, which was common to all calling conventions,
has been separated out. This allows us to define the base CSR lists, and then
lists for each ABI with Altivec included. This allows SjLj, for example, to
work correctly on non-Altivec targets without using unnatural definitions of
the NoRegs CSR list.

4. VRSAVE is now always reserved on non-Darwin targets and all Altivec
registers are reserved when Altivec is disabled.

With these changes, it is now possible to compile a function containing
__builtin_unwind_init() on Linux/PPC64 with debugging information. This did not
work previously because GNU binutils assumes that all .cfi_offset offsets will
be 8-byte aligned on PPC64 (and errors out if you provide a non-8-byte-aligned
offset). This is not true for the vrsave register, however, because this
register is used only on Darwin, GCC does not bother printing a .cfi_offset
entry for it (even though there is a slot in the stack frame for it as
specified by the ABI). This change allows us to do the same: we will also not
print .cfi_offset directives for vrsave.

llvm-svn: 185409

===================================================================
--- test/CodeGen/PowerPC/reloc-align.ll	(revision 0)
+++ test/CodeGen/PowerPC/reloc-align.ll	(revision 0)
@@ -0,0 +1,34 @@
+; RUN: llc -mcpu=pwr7 -O1 < %s | FileCheck %s
+
+; This test verifies that the peephole optimization of address accesses
+; does not produce a load or store with a relocation that can't be
+; satisfied for a given instruction encoding.  Reduced from a test supplied
+; by Hal Finkel.
+
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+%struct.S1 = type { [8 x i8] }
+
+@main.l_1554 = internal global { i8, i8, i8, i8, i8, i8, i8, i8 } { i8 -1, i8 -6, i8 57, i8 62, i8 -48, i8 0, i8 58, i8 80 }, align 1
+
+; Function Attrs: nounwind readonly
+define signext i32 @main() #0 {
+entry:
+  %call = tail call fastcc signext i32 @func_90(%struct.S1* byval bitcast ({ i8, i8, i8, i8, i8, i8, i8, i8 }* @main.l_1554 to %struct.S1*))
+; CHECK-NOT: ld {{[0-9]+}}, main.l_1554@toc@l
+  ret i32 %call
+}
+
+; Function Attrs: nounwind readonly
+define internal fastcc signext i32 @func_90(%struct.S1* byval nocapture %p_91) #0 {
+entry:
+  %0 = bitcast %struct.S1* %p_91 to i64*
+  %bf.load = load i64* %0, align 1
+  %bf.shl = shl i64 %bf.load, 26
+  %bf.ashr = ashr i64 %bf.shl, 54
+  %bf.cast = trunc i64 %bf.ashr to i32
+  ret i32 %bf.cast
+}
+
+attributes #0 = { nounwind readonly "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
Index: lib/Target/PowerPC/PPCAsmPrinter.cpp
===================================================================
--- lib/Target/PowerPC/PPCAsmPrinter.cpp	(revision 185327)
+++ lib/Target/PowerPC/PPCAsmPrinter.cpp	(working copy)
@@ -679,7 +679,26 @@ void PPCAsmPrinter::EmitInstruction(const MachineI
       OutStreamer.EmitRawText(StringRef("\tmsync"));
       return;
     }
+    break;
+  case PPC::LD:
+  case PPC::STD:
+  case PPC::LWA: {
+    // Verify alignment is legal, so we don't create relocations
+    // that can't be supported.
+    // FIXME:  This test is currently disabled for Darwin.  The test
+    // suite shows a handful of test cases that fail this check for
+    // Darwin.  Those need to be investigated before this sanity test
+    // can be enabled for those subtargets.
+    if (!Subtarget.isDarwin()) {
+      unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
+      const MachineOperand &MO = MI->getOperand(OpNum);
+      if (MO.isGlobal() && MO.getGlobal()->getAlignment() < 4)
+        llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
+    }
+    // Now process the instruction normally.
+    break;
   }
+  }
 
   LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
   OutStreamer.EmitInstruction(TmpInst);
Index: lib/Target/PowerPC/PPCISelDAGToDAG.cpp
===================================================================
--- lib/Target/PowerPC/PPCISelDAGToDAG.cpp	(revision 185327)
+++ lib/Target/PowerPC/PPCISelDAGToDAG.cpp	(working copy)
@@ -1530,6 +1530,14 @@ void PPCDAGToDAGISel::PostprocessISelDAG() {
       if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
         SDLoc dl(GA);
         const GlobalValue *GV = GA->getGlobal();
+        // We can't perform this optimization for data whose alignment
+        // is insufficient for the instruction encoding.
+        if (GV->getAlignment() < 4 &&
+            (StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
+             StorageOpcode == PPC::LWA)) {
+          DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
+          continue;
+        }
         ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, 0, Flags);
       } else if (ConstantPoolSDNode *CP =
                  dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {

llvm-svn: 185380

When phis get lowered, destination copies are inserted using an iterator that is
determined once for all phis in the block, which BuildMI interprets as a request
to insert an instruction directly before the iterator. In the case of a cyclic
phi, source copies may also be inserted directly before this iterator, which can
cause source copies to be inserted before destination copies. The fix is to keep
an iterator to the last phi and then advance it while lowering each phi in order
to insert destination copies directly after the phis.

llvm-svn: 185363

Although you can't generate this from C on PPC64, if you have a loop using a
64-bit counter on PPC32 then you can't form a CTR-based loop for it. This had
been cauing the PPCCTRLoops pass to assert.

Thanks to Joerg Sonnenberger for providing a test case!

llvm-svn: 185361

This fixes PR16418, which reports that a function calling
__builtin_unwind_init() asserts. The cause is that this generates a
spill/restore for VRSAVE, and we support that only on Darwin (because VRSAVE is
only really used on Darwin).

The test case checks only that we don't crash. We can add correctness checks
once someone verifies what behavior the function is supposed to have.

llvm-svn: 185235

On OpenBSD, the stack-smash protection transform uses "__guard_local"
and "__stack_smash_handler" instead of "__stack_chk_guard" and
"__stack_chk_fail".  However, CodeGen/PowerPC/stack-protector.ll
doesn't specify a target OS, so on OpenBSD it fails.

Add -mtriple=ppc32-unknown-linux to make the test host-OS agnostic. While
there, convert to FileCheck.

Patch by Matthew Dempsky.

llvm-svn: 185206

Under certain (evidently rare) circumstances, this code used to convert OR(a,
AND(x, y)) into OR(a, x). This was incorrect.

While there, I've added a comment to the code immediately above.

llvm-svn: 185201

This is a preliminary patch for fast instruction selection on
PowerPC.  Code generation can differ between DAG isel and fast isel.
Existing tests that specify -O0 were written to expect DAG isel.  Make
this explicit by adding -fast-isel=false to the tests.

In some cases specifying -fast-isel=false produces different code even
when there isn't a fast instruction selector specified.  This is
because TM.Options.EnableFastISel = 1 at -O0 whether or not a FastISel
object exists.  Thus disabling fast isel can actually produce less
conservative code.  Because of this, some of the expected code
generation in the -O0 tests needs to be adjusted.

In particular, handling of function arguments is less conservative
with -fast-isel=false (see isOnlyUsedInEntryBlock() in
SelectionDAGBuilder.cpp).  This results in fewer stack accesses and,
in some cases, reduced stack size as uselessly loaded values are no
longer stored back to spill locations in the stack.

No functional change with this patch; test case adjustments only.

llvm-svn: 183939

On PPC32, [su]div,rem on i64 types are transformed into runtime library
function calls. As a result, they are not allowed in counter-based loops (the
counter-loops verification pass caught this error; this change fixes PR16169).

llvm-svn: 183581

For COFF and MachO, sections semantically have relocations that apply to them.
That is not the case on ELF.

In relocatable objects (.o), a section with relocations in ELF has offsets to
another section where the relocations should be applied.

In dynamic objects and executables, relocations don't have an offset, they have
a virtual address. The section sh_info may or may not point to another section,
but that is not actually used for resolving the relocations.

This patch exposes that in the ObjectFile API. It has the following advantages:

* Most (all?) clients can handle this more efficiently. They will normally walk
all relocations, so doing an effort to iterate in a particular order doesn't
save time.

* llvm-readobj now prints relocations in the same way the native readelf does.

* probably most important, relocations that don't point to any section are now
visible. This is the case of relocations in the rela.dyn section. See the
updated relocation-executable.test for example.

llvm-svn: 182908

When expanding unaligned Altivec loads, we use the decremented offset trick to
prevent page faults. Unfortunately, if we have a sequence of consecutive
unaligned loads, this leads to suboptimal code generation because the 'extra'
load from the first unaligned load can be combined with the base load from the
second (but only if the decremented offset trick is not used for the first).
Search up and down the chain, through loads and token factors, looking for
consecutive loads, and if one is found, don't use the offset reduction trick.
These duplicate loads are later combined to yield the desired sequence (in the
future, we might want a more-powerful chain search, but that will require some
changes to allow the combiner routines to access the AA object).

This should complete the initial implementation of the optimized unaligned
Altivec load expansion. There is some refactoring that should be done, but
that will happen when the unaligned store expansion is added.

llvm-svn: 182719

The lvsl permutation control instruction is a function only of the alignment of
the pointer operand (relative to the 16-byte natural alignment of Altivec
vectors). As a result, multiple lvsl intrinsics where the operands differ by a
multiple of 16 can be combined.

llvm-svn: 182708

Altivec only directly supports aligned loads, but the loads have a strange
property: If given an unaligned address, they truncate the address to the next
lower aligned address, and load from there.  This property, along with an extra
load and some special-purpose permutation-control instructions that generate
the appropriate permutations from the original unaligned address, allow
efficient lowering of aligned loads. This code uses the trick explained in the
Apple Velocity Engine optimization overview document to prevent the needed
extra load from possibly causing a page fault if the original address happens
to be aligned.

As noted in the FIXMEs, there are several additional optimizations that can be
performed to reduce the cost of these loads even more. These will be
implemented in future commits.

llvm-svn: 182691

We don't need to reject all inline asm as using the counter register (most does
not). Only those that explicitly clobber the counter register need to prevent
the transformation.

llvm-svn: 182191

We need ppc instead of generic to override native features on ppc machines.

llvm-svn: 182049

Some IR-level instructions (such as FP <-> i64 conversions) are not chained
w.r.t. the mtctr intrinsic and yet may become function calls that clobber the
counter register. At the selection-DAG level, these might be reordered with the
mtctr intrinsic causing miscompiles. To avoid this situation, if an existing
preheader has instructions that might use the counter register, create a new
preheader for the mtctr intrinsic. This extra block will be remerged with the
old preheader at the MI level, but will prevent unwanted reordering at the
selection-DAG level.

llvm-svn: 182045

[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.

llvm-svn: 182032

On PPC32, i64 FP conversions are implemented using runtime calls (which clobber
the counter register). These must be excluded.

llvm-svn: 182023

While testing some experimental code to add vector-scalar registers to
PowerPC, I noticed that a couple of independent instructions were
flipped by the scheduler.  The new CHECK-DAG support is perfect for
avoiding this problem.

llvm-svn: 182020

[PowerPC] Report true displacement value from getPreIndexedAddressParts

DAGCombiner::CombineToPreIndexedLoadStore calls a target routine to
decompose a memory address into a base/offset pair.  It expects the
offset (if constant) to be the true displacement value in order to
perform optional additional optimizations; in particular, to convert
other uses of the original pointer into uses of the new base pointer
after pre-increment.

The PowerPC implementation of getPreIndexedAddressParts, however,
simply calls SelectAddressRegImm, which returns a TargetConstant.
This value is appropriate for encoding into the instruction, but
it is not always usable as true displacement value:

- Its type is always MVT::i32, even on 64-bit, where addresses
  ought to be i64 ... this causes the optimization to simply
  always fail on 64-bit due to this line in DAGCombiner:

      // FIXME: In some cases, we can be smarter about this.
      if (Op1.getValueType() != Offset.getValueType()) {

- Its value is truncated to an unsigned 16-bit value if negative.
  This causes the above opimization to generate wrong code.

This patch fixes both problems by simply returning the true
displacement value (in its original type).  This doesn't
affect any other user of the displacement.

llvm-svn: 182012

I am about to refactor the calls to addFrameMove and some of the ppc
ones were not being tested.

llvm-svn: 182009

Without this change nothing was covering this addFrameMove:

// For 64-bit SVR4 when we have spilled CRs, the spill location
// is SP+8, not a frame-relative slot.
if (Subtarget.isSVR4ABI()
    && Subtarget.isPPC64()
    && (PPC::CR2 <= Reg && Reg <= PPC::CR4)) {
  MachineLocation CSDst(PPC::X1, 8);
  MachineLocation CSSrc(PPC::CR2);
  MMI.addFrameMove(Label, CSDst, CSSrc);
  continue;
}

llvm-svn: 181976

The old PPCCTRLoops pass, like the Hexagon pass version from which it was
derived, could only handle some simple loops in canonical form. We cannot
directly adapt the new Hexagon hardware loops pass, however, because the
Hexagon pass contains a fundamental assumption that non-constant-trip-count
loops will contain a guard, and this is not always true (the result being that
incorrect negative counts can be generated). With this commit, we replace the
pass with a late IR-level pass which makes use of SE to calculate the
backedge-taken counts and safely generate the loop-count expressions (including
any necessary max() parts). This IR level pass inserts custom intrinsics that
are lowered into the desired decrement-and-branch instructions.

The most fragile part of this new implementation is that interfering uses of
the counter register must be detected on the IR level (and, on PPC, this also
includes any indirect branches in addition to function calls). Also, to make
all of this work, we need a variant of the mtctr instruction that is marked
as having side effects. Without this, machine-code level CSE, DCE, etc.
illegally transform the resulting code. Hopefully, this can be improved
in the future.

This new pass is smaller than the original (and much smaller than the new
Hexagon hardware loops pass), and can handle many additional cases correctly.
In addition, the preheader-creation code has been copied from LoopSimplify, and
after we decide on where it belongs, this code will be refactored so that it
can be explicitly shared (making this implementation even smaller).

The new test-case files ctrloop-{le,lt,ne}.ll have been adapted from tests for
the new Hexagon pass. There are a few classes of loops that this pass does not
transform (noted by FIXMEs in the files), but these deficiencies can be
addressed within the SE infrastructure (thus helping many other passes as well).

llvm-svn: 181927

The changes to CR spill handling missed a case for 32-bit PowerPC.
The code in PPCFrameLowering::processFunctionBeforeFrameFinalized()
checks whether CR spill has occurred using a flag in the function
info.  This flag is only set by storeRegToStackSlot and
loadRegFromStackSlot.  spillCalleeSavedRegisters does not call
storeRegToStackSlot, but instead produces MI directly.  Thus we don't
see the CR is spilled when assigning frame offsets, and the CR spill
ends up colliding with some other location (generally the FP slot).

This patch sets the flag in spillCalleeSavedRegisters for PPC32 so
that the CR spill is properly detected and gets its own slot in the
stack frame.

llvm-svn: 181800

This fixes warning messages observed in the oggenc application test in
projects/test-suite.  Special handling is needed for the 64-bit
PowerPC SVR4 ABI when a constant is initialized with a pointer to a
function in a shared library.  Because a function address is
implemented as the address of a function descriptor, the use of copy
relocations can lead to problems with initialization.  GNU ld
therefore replaces copy relocations with dynamic relocations to be
resolved by the dynamic linker.  This means the constant cannot reside
in the read-only data section, but instead belongs in .data.rel.ro,
which is designed for constants containing dynamic relocations.

The implementation creates a class PPC64LinuxTargetObjectFile
inheriting from TargetLoweringObjectFileELF, which behaves like its
parent except to place constants of this sort into .data.rel.ro.

The test case is reduced from the oggenc application.

llvm-svn: 181723

This fixes bug 15821 similarly to the powerpc64-linux fix for bug 14779.

Patch by David Fang.

llvm-svn: 181449

The floating-point record forms on PPC don't set the condition register bits
based on a comparison with zero (like the integer record forms do), but rather
based on the exception status bits.

llvm-svn: 181423

First, taking advantage of the fact that the virtual base registers are allocated in order of the local frame offsets, remove the quadratic register-searching behavior. Because of the ordering, we only need to check the last virtual base register created.

Second, store the frame index in the FrameRef structure, and get the frame index and the local offset from this structure at the top of the loop iteration. This allows us to de-nest the loops in insertFrameReferenceRegisters (and I think makes the code cleaner). I also moved the needsFrameBaseReg check into the first loop over instructions so that we don't bother pushing FrameRefs for instructions that don't want a virtual base register anyway.

Lastly, and this is the only functionality change, avoid the creation of single-use virtual base registers. These are currently not useful because, in general, they end up replacing what would be one r+r instruction with an add and a r+i instruction. Committing this removes the XFAIL in CodeGen/PowerPC/2007-09-07-LoadStoreIdxForms.ll

Jim has okayed this off-list.

llvm-svn: 180799

This will make it easier to turn on struct-path aware TBAA since the metadata
format will change.

llvm-svn: 180796

This fixes pr15763.
Patch by David Fang.

llvm-svn: 180657

When matching a compare with a subtract where the arguments of the compare are
swapped w.r.t. the arguments of the subtract, we need to negate the predicates
(or CR bit indices) of the users. This, however, is not the same as inverting
the predicate (negating LT -> GT, but inverting LT -> GE, for example). The ARM
backend seems to do this correctly, but when I adapted the code for the PPC
backend, I introduced an error in this logic.

Comparison optimization is now enabled again by default.

llvm-svn: 179899

This seems to cause a stage-2 LLVM compile failure (by crashing TableGen); do
I'm disabling this for now.

llvm-svn: 179807

Many PPC instructions have a so-called 'record form' which stores to a specific
condition register the result of comparing the result of the instruction with
zero (always as a signed comparison). For integer operations on PPC64, this is
always a 64-bit comparison.

This implementation is derived from the implementation in the ARM backend;
there are some differences because PPC condition registers are allocatable
virtual registers (although the record forms always use a specific one), and we
look for a matching subtraction instruction after the compare (but before the
first use) in addition to before it.

llvm-svn: 179802

This fixes an ABI bug for non-Darwin PPC64. For the callee-saved condition
registers, the spill location is specified relative to the stack pointer (SP +
8). However, this is not relative to the SP after the new stack frame is
established, but instead relative to the caller's stack pointer (it is stored
into the linkage area of the parent's stack frame).

So, like with the link register, we don't directly spill the CRs with other
callee-saved registers, but just mark them to be spilled during prologue
generation.

In practice, this reverts r179457 for PPC64 (but leaves it in place for PPC32).

llvm-svn: 179500

For functions that need to spill CRs, and have dynamic stack allocations, the
value of the SP during the restore is not what it was during the save, and so
we need to use the FP in these cases (as for all of the other spills and
restores, but the CR restore has a special code path because its reserved slot,
like the link register, is specified directly relative to the adjusted SP).

llvm-svn: 179457

llvm-svn: 179361

llvm-svn: 179276