I'll let the buildbots determine the compile time improvements from this
change, but 464.h264ref has 5% faster codegen at -O2.
This patch does cause some assembly changes. Branch folding can make
different decisions about calls with dead return values.
CriticalAntiDepBreaker may choose different registers because its
liveness tracking is affected. MachineCopyPropagation may sometimes
leave a dead copy behind.
llvm-svn: 151331
The tied source operand of tMUL is the second source operand, not the
first like every other two-address thumb instruction. Special case it
in the size reduction pass to make sure we create the tMUL instruction
properly.
llvm-svn: 151315
rdar://10873652
As part of this I updated the llvm-mc disassembler C API to always call the
SymbolLookUp call back even if there is no getOpInfo call back. If there is a
getOpInfo call back that is tried first and then if that gets no information
then the SymbolLookUp is called. I also made the code more robust by
memset(3)'ing to zero the LLVMOpInfo1 struct before then setting
SymbolicOp.Value before for the call to getOpInfo. And also don't use any
values from the LLVMOpInfo1 struct if getOpInfo returns 0. And also don't
use any of the ReferenceType or ReferenceName values from SymbolLookUp if it
returns NULL. rdar://10873563 and rdar://10873683
For the X86 target also fixed bugs so the annotations get printed.
Also fixed a few places in the ARM target that was not producing symbolic
operands for some instructions. rdar://10878166
llvm-svn: 151267
value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
cmp r9, r4
mov r4, #0
moveq r4, #1
orr lr, lr, r4
should be:
cmp r9, r4
orreq lr, lr, #1
That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).
It's possible to extend this to ADD and SUB but I don't think they are common.
rdar://8659097
llvm-svn: 151224
The c'tor list is stored as a list of 'void ()*'s, so all of the functions are
bitcast to that. However, the dyn_cast doesn't automagically look through
bitcasts. Do that for it.
<rdar://problem/10813350>
llvm-svn: 150572
Now that the clang driver passes the CPU and feature information to
the backend when processing assembly files (150273), this isn't necessary.
llvm-svn: 150274
Moving toward a uniform style of pass definition to allow easier target configuration.
Globally declare Pass ID.
Globally declare pass initializer.
Use INITIALIZE_PASS consistently.
Add a call to the initializer from CodeGen.cpp.
Remove redundant "createPass" functions and "getPassName" methods.
While cleaning up declarations, cleaned up comments (sorry for large diff).
llvm-svn: 150100
This CL delays reading of function bodies from initial parse until
materialization, allowing overlap of compilation with bitcode download.
llvm-svn: 149918
Passes prior to instructon selection are now split into separate configurable stages.
Header dependencies are simplified.
The bulk of this diff is simply removal of the silly DisableVerify flags.
Sorry for the target header churn. Attempting to stabilize them.
llvm-svn: 149754
Allows command line overrides to be centralized in LLVMTargetMachine.cpp.
LLVMTargetMachine can intercept common passes and give precedence to command line overrides.
Allows adding "internal" target configuration options without touching TargetOptions.
Encapsulates the PassManager.
Provides a good point to initialize all CodeGen passes so that Pass ID's can be used in APIs.
Allows modifying the target configuration hooks without rebuilding the world.
llvm-svn: 149672
NEON loads and stores accept single and double spaced pairs, triples,
and quads of D registers. This patch adds new register classes to
accurately model those constraints:
Dn, Dn+1 Dn, Dn+2
----------------------
DPair DPairSpc
DTriple DTripleSpc
DQuad DQuadSpc
Also extend the existing QQ and QQQQ register classes to contains all Q
pairs and quads instead of just the aligned ones.
These new register classes will make it possible to accurately model
constraints on NEON loads and stores, and we can get rid of all the NEON
pseudo-instructions. The late scheduler will be able to accurately
model instruction dependencies from the explicit operands.
This more than doubles the number of ARM registers, but the backend
passes are quite good at handling this. The llc -O0 compile time only
regresses by 1.5%. Future work on register mask operands will recover
this regression.
llvm-svn: 149640
Adjust an example MachObjectWriter diagnostic to use the information
to issue a better message.
Before:
LLVM ERROR: unknown ARM fixup kind!
After:
x.s:6:5: error: unsupported relocation on symbol
beq bar
^
rdar://9800182
llvm-svn: 149093
This enables the linker to match concrete relocation types (absolute or relative) with whatever library or C++ support code is being linked against.
llvm-svn: 149057
"Although a Thumb2 instruction, the IT mnemonic shall be permitted in
ARM mode, and the condition verified to match the condition code(s)
on the following instruction(s)."
PR11853
llvm-svn: 148969
violation -- MC cannot depend on CodeGen.
Specifically, the MCTargetDesc component of each target is actually
a subcomponent of the MC library. As such, it cannot depend on the
target-independent code generator, because MC itself cannot depend on
the target-independent code generator. This change moved a flag from the
ARM MCTargetDesc file ARMMCAsmInfo.cpp to the CodeGen layer in
ARMException.cpp, leaving behind an 'extern' to refer back to it. That
layering order isn't viable givin the constraints outlined above.
Commandline flags are designed to be static specifically to avoid these
types of bugs.
Fixing this is likely going to require some non-trivial refactoring.
llvm-svn: 148759
This change adds an new value to the --arm-enable-ehabi option that
disables emitting unwinding descriptors. This mode gives a working
backtrace() without the (currently broken) exception support.
llvm-svn: 148686
We have patterns for vector sext and zext operations but were missing
anyext. Without those patterns, codegen will fail when the selection DAG
has any_extend nodes.
llvm-svn: 148568
For bit patterns that aren't representable using the 8-bit floating point
representation for vmov.f32, but are representable via vmov.i32, treat
the .f32 syntax as an alias. Most importantly, this covers the case
'vmov.f32 Vd, #0.0'.
rdar://10616677
llvm-svn: 148556
to instruction right after the last instruction in the bundle.
- Add a finalizeBundle() variant that doesn't specify LastMI. Instead, the code
will find the last instruction in the bundle by following the 'InsideBundle'
marker. This is useful in case bundles are formed early (i.e. during MI
scheduling) but finalized later (i.e. after register allocator has finished
rewriting virtual registers with physical registers).
llvm-svn: 148444
Load/store instructions w/ a fixup to be relative a function marked as thumb
don't use the low bit to specify thumb vs. non-thumb like interworking
branches do, so don't set it when dealing with those fixups.
rdar://10348687.
llvm-svn: 148366
When set, this bit indicates that a register is completely defined by
the value of its sub-registers.
Use the CoveredBySubRegs property to infer which super-registers are
call-preserved given a list of callee-saved registers. For example, the
ARM registers D8-D15 are callee-saved. This now automatically implies
that Q4-Q7 are call-preserved.
Conversely, Win64 callees save XMM6-XMM15, but the corresponding
YMM6-YMM15 registers are not call-preserved because they are not fully
defined by their sub-registers.
llvm-svn: 148363
(This time I believe I've checked all the -Wreturn-type warnings from GCC & added the couple of llvm_unreachables necessary to silence them. If I've missed any, I'll happily fix them as soon as I know about them)
llvm-svn: 148262
live across BBs before register allocation. This miscompiled 197.parser
when a cmp + b are optimized to a cbnz instruction even though the CPSR def
is live-in a successor.
cbnz r6, LBB89_12
...
LBB89_12:
ble LBB89_1
The fix consists of two parts. 1) Teach LiveVariables that some unallocatable
registers might be liveouts so don't mark their last use as kill if they are.
2) ARM constantpool island pass shouldn't form cbz / cbnz if the conditional
branch does not kill CPSR.
rdar://10676853
llvm-svn: 148168
The QQ and QQQQ registers are not 'real', they are pseudo-registers used
to model some vld and vst instructions.
This makes the call clobber lists longer, but I intend to get rid of
those soon.
llvm-svn: 148151
Allow LDRD to be formed from pairs with different LDR encodings. This was the original intention of the pass. Somewhere along the way, the LDR opcodes were refined which broke the optimization. We really don't care what the original opcodes are as long as they both map to the same LDRD and the immediate still fits.
Fixes rdar://10435045 ARMLoadStoreOptimization cannot handle mixed LDRi8/LDRi12
llvm-svn: 147922
This function runs after all constant islands have been placed, and may
shrink some instructions to their 2-byte forms. This can actually cause
some constant pool entries to move out of range because of growing
alignment padding.
Treat instructions that may be shrunk the same as inline asm - they
erode the known alignment bits.
Also reinstate an old assertion in verify(). It is correct now that
basic block offsets include alignments.
Add a single large test case that will hopefully exercise many parts of
the constant island pass.
<rdar://problem/10670199>
llvm-svn: 147885
On Thumb, the displacement computation hardware uses the address of the
current instruction rouned down to a multiple of 4. Include this
rounding in the UserOffset we compute for each instruction.
When inline asm is present, the instruction alignment may not be known.
Constrain the maximum displacement instead in that case.
This makes it possible for CreateNewWater() and OffsetIsInRange() to
agree about the valid displacements. When they disagree, infinite
looping happens.
As always, test cases for this stuff are insane.
<rdar://problem/10660175>
llvm-svn: 147825
This eliminates a lot of constant pool entries for -O0 builds of code
with many global variable accesses.
This speeds up -O0 codegen of consumer-typeset by 2x because the
constant island pass no longer has to look at thousands of constant pool
entries.
<rdar://problem/10629774>
llvm-svn: 147712
Now that canRealignStack() understands frozen reserved registers, it is
safe to use it for aligned spill instructions.
It will only return true if the registers reserved at the beginning of
register allocation allow for dynamic stack realignment.
<rdar://problem/10625436>
llvm-svn: 147579
Once register allocation has started the reserved registers are frozen.
Fix the ARM canRealignStack() hook to respect the frozen register state.
Now the hook returns false if register allocation was started with frame
pointer elimination enabled.
It also returns false if register allocation started without a reserved
base pointer, and stack realignment would require a base pointer. This
bug was breaking oggenc on armv6.
No test case, an upcoming patch will use this functionality to realign
the stack for spill slots when possible.
llvm-svn: 147578
This patch caused a miscompilation of oggenc because a frame pointer was
suddenly needed halfway through register allocation.
<rdar://problem/10625436>
llvm-svn: 147487
If anybody has strong feelings about 'default: assert(0 && "blah")' vs
'default: llvm_unreachable("blah")', feel free to regularize the instances of
each in this file.
llvm-svn: 147459
ARM targets with NEON units have access to aligned vector loads and
stores that are potentially faster than unaligned operations.
Add support for spilling the callee-saved NEON registers to an aligned
stack area using 16-byte aligned NEON loads and store.
This feature is off by default, controlled by an -align-neon-spills
command line option.
llvm-svn: 147211
My change r146949 added register clobbers to the eh_sjlj_dispatchsetup pseudo
instruction, but on Thumb1 some of those registers cannot be used. This
caused massive failures on the testsuite when compiling for Thumb1. While
fixing that, I noticed that the eh_sjlj_setjmp instruction has a "nofp"
variant, and I realized that dispatchsetup needs the same thing, so I have
added that as well.
llvm-svn: 147204
The value from the operands isn't right yet, but we weren't encoding it at
all previously. The parser needs to twiddle the values when building the
instruction.
Partial for: rdar://10558523
llvm-svn: 147170
Rather than require the symbol to be explicitly an argument of the directive,
allow it to look ahead and grab the symbol from the next non-whitespace
line.
rdar://10611140
llvm-svn: 147100
Use the spill slot alignment as well as the local variable alignment to
determine when the stack needs to be realigned. This works now that the
ARM target can always realign the stack by using a base pointer.
Still respect the ARMBaseRegisterInfo::canRealignStack() function
vetoing a realigned stack. Don't use aligned spill code in that case.
llvm-svn: 146997
We used to rely on the *eh_sjlj_setjmp instructions to mark that a function
with setjmp/longjmp exception handling clobbers all the registers. But with
the recent reorganization of ARM EH, those eh_sjlj_setjmp instructions are
expanded away earlier, before PEI can see them to determine what registers to
save and restore. Mark the dispatchsetup instruction in the same way, since
that instruction cannot be expanded early. This also more accurately reflects
when the registers are clobbered.
llvm-svn: 146949
"mov r1, r2, lsl #0" should assemble as "mov r1, r2" even though it's
not strictly legal UAL syntax. It's a common extension and the friendly
thing to do.
rdar://10604663
llvm-svn: 146937
Use information computed while inferring new register classes to emit
accurate, table-driven implementations of getMatchingSuperRegClass().
Delete the old manual, error-prone implementations in the targets.
llvm-svn: 146873
This adjustment is already included in the block offsets computed by
BasicBlockInfo, and adjusting again here can cause the pass to loop.
When CreateNewWater splits a basic block, OffsetIsInRange would reject
the new CPE on the next pass because of the too conservative alignment
adjustment. This caused the block to be split again, and so on.
llvm-svn: 146751
The command line option should be removed, but not until the feature has
gotten a lot of testing. The ARMConstantIslandPass tends to have subtle
bugs that only show up after a while.
llvm-svn: 146739
An aligned constant pool entry may require extra alignment padding where
the new water is created. Take that into account when computing offset.
Also consider the alignment of other constant pool entries when
splitting a basic block. Alignment padding may make it necessary to
move the split point higher.
llvm-svn: 146609
r0 = mov #0
r0 = moveq #1
Then the second instruction has an implicit data dependency on the first
instruction. Sadly I have yet to come up with a small test case that
demonstrate the post-ra scheduler taking advantage of this.
llvm-svn: 146583
Work in progress. Parsing for non-writeback, single spaced register lists
works now. The rest have the representations better factored, but still
need more to be able to parse properly.
llvm-svn: 146579
When 'cmp rn #imm' doesn't match due to the immediate not being representable,
but 'cmn rn, #-imm' does match, use the latter in place of the former, as
it's equivalent.
rdar://10552389
llvm-svn: 146567
to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
prevent IT blocks from being broken apart.
llvm-svn: 146542
undefined result. This adds new ISD nodes for the new semantics,
selecting them when the LLVM intrinsic indicates that the undef behavior
is desired. The new nodes expand trivially to the old nodes, so targets
don't actually need to do anything to support these new nodes besides
indicating that they should be expanded. I've done this for all the
operand types that I could figure out for all the targets. Owners of
various targets, please review and let me know if any of these are
incorrect.
Note that the expand behavior is *conservatively correct*, and exactly
matches LLVM's current behavior with these operations. Ideally this
patch will not change behavior in any way. For example the regtest suite
finds the exact same instruction sequences coming out of the code
generator. That's why there are no new tests here -- all of this is
being exercised by the existing test suite.
Thanks to Duncan Sands for reviewing the various bits of this patch and
helping me get the wrinkles ironed out with expanding for each target.
Also thanks to Chris for clarifying through all the discussions that
this is indeed the approach he was looking for. That said, there are
likely still rough spots. Further review much appreciated.
llvm-svn: 146466
Constant pool entries with different alignment may cause more alignment
padding to be inserted. Compute the amount of padding needed, and try to
pick the location that requires the least amount of padding.
Also take the extra padding into account when the water is above the
use.
llvm-svn: 146458
subdirectories to traverse into.
- Originally I wanted to avoid this and just autoscan, but this has one key
flaw in that new subdirectories can not automatically trigger a rerun of the
llvm-build tool. This is particularly a pain when switching back and forth
between trees where one has added a subdirectory, as the dependencies will
tend to be wrong. This will also eliminates FIXME implicitly.
llvm-svn: 146436
These modifiers simply select either the low or high D subregister of a Neon
Q register. I've also removed the unimplemented 'p' modifier, which turns out
to be a bit different than the comment here suggests and as far as I can tell
was only intended for internal use in Apple's version of gcc.
llvm-svn: 146417
Downgrade the alignment of the initial constant island when constant
pool entries are moved elsewhere.
This is all gated by -arm-align-constant-islands.
llvm-svn: 146391
