Teach the generic instruction selection helper functions to constrain
the register classes of their input operands. For non-physical register
references, the generic code needs to be careful not to mess that up
when replacing references to result registers. As the comment indicates
for MachineRegisterInfo::replaceRegWith(), it's important to call
constrainRegClass() first.
rdar://12594152
llvm-svn: 188593
Lots of machine verifier errors result from using a plain GPR regclass
for incoming argument copies. A more restrictive rGPR class is more
appropriate since it more accurately represents what's happening, plus
it lines up better with isel later on so the verifier is happier.
Reduces the number of ARM fast-isel tests not running with the verifier
enabled by over half.
rdar://12594152
llvm-svn: 188592
This regards how mips16 is viewed. It's not really a target type but
there has always been a target for it in the td files. It's more properly
-mcpu=mips32 -mattr=+mips16 . This is how clang treats it but we have
always had the -mcpu=mips16 which I probably should delete now but it will
require updating all the .ll test cases for mips16. In this case it changed
how we decide if we have a count bits instruction and whether instruction
lowering should then expand ctlz. Now that we have dual mode compilation,
-mattr=+mips16 really just indicates the inital processor mode that
we are compiling for. (It is also possible to have -mcpu=64 -mattr=+mips16
but as far as I know, nobody has even built such a processor, though there
is an architecture manual for this).
llvm-svn: 188586
safe on PPC32 SVR4 ABI
[Patch and following text by Mark Minich; committing on his behalf.]
There are FIXME's in PowerPC/PPCFrameLowering.cpp, method
PPCFrameLowering::emitPrologue() related to "negative offsets of R1"
on PPC32 SVR4. They're true, but the real issue is that on PPC32 SVR4
(and any ABI without a Red Zone), no spills may be made until after
the stackframe is claimed, which also includes the LR spill which is
at a positive offset. The same problem exists in emitEpilogue(),
though there's no FIXME for it. I intend to fix this issue, making
LLVM-compiled code finally safe for use on SVR4/EABI/e500 32-bit
platforms (including in particular, OS-free embedded systems & kernel
code, where interrupts may share the same stack as user code).
In preparation for making these changes, to make the diffs for the
functional changes less cluttered, I am providing the non-functional
refactorings in two stages:
Stage 1 does some minor fluffy refactorings to pull multiple method
calls up into a single bool, creating named bools for repeated uses of
obscure logic, moving some code up earlier because either stage 2 or
my final version will require it earlier, and rewording/adding some
comments. My stage 1 changes can be characterized as primarily fluffy
cleanup, the purpose of which may be unclear until the stage 2 or
final changes are made.
My stage 2 refactorings combine the separate PPC32 & PPC64 logic,
which is currently performed by largely duplicate code, into a single
flow, with the differences handled by a group of constants initialized
early in the methods.
This submission is for my stage 1 changes. There should be no
functional changes whatsoever; this is a pure refactoring.
llvm-svn: 188573
If an ELF relocation is pointed at an absolute address, it will have a symbol ID of zero.
RuntimeDyldELF::processRelocationRef was not previously handling this case, and was instead trying to handle it as a section-relative fixup.
I think this is the right fix here, but my elf-fu is poor on some of the more exotic platforms, so I'd appreciate it if anyone with greater knowledge could verify this.
llvm-svn: 188572
The logic in SIInsertWaits::getHwCounts() only really made sense for SMRD
instructions, and trying to shoehorn it into handling DS_WRITE_B32 caused
it to corrupt the encoding of that by clobbering the first operand with
the second one.
Undo that damage and only apply the SMRD logic to that.
Fixes some derivates related piglit regressions with radeonsi.
Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
llvm-svn: 188558
This unbreaks PIC with fast isel on ELF targets (PR16717). The output matches
what GCC and SDag do for PIC but may not cover all of the many flavors of PIC
that exist.
llvm-svn: 188551
Thumb2 literal loads use an offset encoding which allows for
negative zero. This fixes parsing and encoding so that #-0
is correctly processed. The parser represents #-0 as INT32_MIN.
llvm-svn: 188549
There are many Thumb instructions which take 12-bit immediates encoded in a special
8-byte value + 4-byte rotator form. Not all numbers are represented, and it's legal
to transform an assembly instruction to be able to encode the immediate.
For example: AND and BIC are complementary instructions; one can switch the AND
to a BIC as long as the immediate is complemented.
The intent is to switch one instruction into its complementary one when the immediate
cannot be encoded in the form requested in the original assembly and when the
complementary immediate is encodable.
The patch addresses two issues:
1. definition of t2SOImmNot immediate - it has to check that the orignal value is
not encoded naturally
2. t2AND and t2BIC instruction aliases which should use the Thumb2 SOImm operand
rather than the ARM one.
llvm-svn: 188548
Generalize r188163 to cope with return types other than MVT::i32, just
as the existing visitMemCmpCall code did. I've split this out into a
subroutine so that it can be used for other upcoming patches.
I also noticed that I'd used the wrong API to record the out chain.
It's a load that uses DAG.getRoot() rather than getRoot(), so the out
chain should go on PendingLoads. I don't have a testcase for that because
we don't do any interesting scheduling on z yet.
llvm-svn: 188540
r188163 used CLC to implement memcmp. Code that compares the result
directly against zero can test the CC value produced by CLC, but code
that needs an integer result must use IPM. The sequence I'd used was:
ipm <reg>
sll <reg>, 2
sra <reg>, 30
but I'd forgotten that this inverts the order, so that CC==1 ("less")
becomes an integer greater than zero, and CC==2 ("greater") becomes
an integer less than zero. This sequence should only be used if the
CLC arguments are reversed to compensate. The problem then is that
the branch condition must also be reversed when testing the CLC
result directly.
Rather than do that, I went for a different sequence that works with
the natural CLC order:
ipm <reg>
srl <reg>, 28
rll <reg>, <reg>, 31
One advantage of this is that it doesn't clobber CC. A disadvantage
is that any sign extension to 64 bits must be done separately,
rather than being folded into the shifts.
llvm-svn: 188538
- Benjamin fixed the emission of this file in r179937, but it still lives on a
few buildbots. We should probably clean up the build dirs once in a while,
eh?
llvm-svn: 188527
The SIInsertWaits pass was overwriting the first operand (gds bit) of
DS_WRITE_B32 with the second operand (value to write). This meant that
any time the value to write was stored in an odd number VGPR, the gds
bit would be set causing the instruction to write to GDS instead of LDS.
llvm-svn: 188522
