[MC] [IAS] Add support for the \@ .macro pseudo-variable.
Summary:
When used, it is substituted with the number of .macro instantiations we've done up to that point in time.
So if this is the 1st time we've instantiated a .macro (any .macro, regardless of name), \@ will instantiate to 0, if it's the 2nd .macro instantiation, it will instantiate to 1 etc.
It can only be used inside a .macro definition, an .irp definition or an .irpc definition (those last 2 uses are undocumented).
Constfold insertelement to undef when index is out-of-bounds
Summary:
This patch adds constant folding of insertelement instruction to undef value when index operand is constant and is not less than vector size or is undef.
InstCombine does not support this case, but I'm happy to add it there also if this change is accepted.
Test Plan: Unittests and regression tests for ConstProp pass.
Philip Reames [Sun, 26 Apr 2015 22:15:18 +0000 (22:15 +0000)]
Add two new items to PerformanceTips
1) Turns out we're not great at recognizing redundant checks when one is a != and the other is an ==. This is a bug, but it's one that matters to frontend authors.
2) Frontends shouldn't use intrinsics unless strictly neccessary. This has been pretty widely proven by this point and is good to document.
Philip Reames [Sun, 26 Apr 2015 22:00:34 +0000 (22:00 +0000)]
Make the message associated with a fatal error slightly more helpful
Looking into 23095, my best guess is that the CodeGen library itself isn't getting linked and initialized properly. To make this slightly more obvious to consumers of LLVM, emit a different error message if we can tell that the registry is empty vs you've simply happened to name a collector which hasn't been registered.
Philip Reames [Sun, 26 Apr 2015 19:48:03 +0000 (19:48 +0000)]
[RewriteStatepointsForGC] Exclude constant values from being considered live at a safepoint
There can be various constant pointers in the IR which do not get relocated at a safepoint. One example is the address of a global variable. Another example is a pointer created via inttoptr. Note that the optimizer itself likes to create such inttoptrs when locally propagating constants through dynamically dead code.
To deal with this, we need to exclude uses of constants from contributing to the liveness of a safepoint which might reach that use. At some later date, it might be worth exploring what could be done to support the relocation of various special types of "constants", but that's future work.
Philip Reames [Sun, 26 Apr 2015 19:41:23 +0000 (19:41 +0000)]
Don't Place Entry Safepoints Before the llvm.frameescape() Intrinsic
llvm.frameescape() intrinsic is not a real call. The intrinsic can only exist in the entry block. Inserting a gc.statepoint() before llvm.frameescape() may split the entry block, and push the intrinsic out of the entry block.
[x86] instcombine more cases of insertps into a shufflevector
This is a follow-on to D8833 (insertps optimization when the zero mask is not used).
In this patch, we check for the case where the zmask is used, but both input vectors
to the insertps intrinsic are the same operand or the zmask overrides the destination
lane. This lets us replace the 2nd shuffle input operand with the zero vector.
IR: Add assembly/bitcode support for function metadata attachments
Add serialization support for function metadata attachments (added in
r235783). The syntax is:
define @foo() !attach !0 {
Metadata attachments are only allowed on functions with bodies. Since
they come before the `{`, they're not really part of the body; since
they require a body, they're not really part of the header. In
`LLParser` I gave them a separate function called from `ParseDefine()`,
`ParseOptionalFunctionMetadata()`.
In bitcode, I'm using the same `METADATA_ATTACHMENT` record used by
instructions. Instruction metadata attachments are included in a
special "attachment" block at the end of a `Function`. The attachment
records are laid out like this:
InstID (KindID MetadataID)+
Note that these records always have an odd number of fields. The new
code takes advantage of this to recognize function attachments (which
don't need an instruction ID):
(KindID MetadataID)+
This means we can use the same attachment block already used for
instructions.
Verifier: Function metadata attachments require a body
Add a verifier check that only functions with bodies have metadata
attachments. This should help catch bugs in frontends and
transformation passes. Part of PR23340.
Add IR support for `Metadata` attachments. Assembly and bitcode support
will follow shortly, but for now we just have unit tests. This is part
of PR23340.
[DAGCombiner] Fix the type used in canFoldInAddressingMode to account for the
right scaling.
In the function canFoldInAddressingMode, VT is computed as the type of the
destination/source of a LOAD/STORE operations, instead of the memory type of the
operation.
On targets with a scaling factor on the offset of the LOAD/STORE operations, the
function may return false for actually valid cases. This may then prevent the
selection of profitable pre or post indexed load/store operations, and instead
select pre or post indexed load/store for unprofitable cases.
Patch by Francois de Ferriere <francois.de-ferriere@st.com>!
AsmWriter: Parameterize the syntactic separator for attachments
Parameterize the separator for attachments, since `Function` metadata
attachments (PR23340) aren't going to use a `,` (comma). No real
functionality change.
AsmWriter: Only collect attachment names once per module
Collect metadata names once per `AssemblyWriter` instead of every time
we need to print some attachments. Just a drive-by; this caught my eye
while I was refactoring the code in r235772.
Hans Wennborg [Fri, 24 Apr 2015 20:57:56 +0000 (20:57 +0000)]
SimplifyCFG: Correctly handle switch lookup tables which fully cover the input type and use bit tests to check for holes
When using bit tests for hole checks, we call AddPredecessorToBlock to give the
phi node a value from the bit test block. This would break if we've
previously called removePredecessor on the default destination because the
switch is fully covered.
IR: Use a bitmask to access GlobalObject subclass data
Make room for more than just `Function::isMaterializable()` in the
`GlobalObject` subclass data bitfield. Since we're treating it like a
bitfield, change `Function::Function()` to zero-out the whole thing.
IR: Extract set logic from Instruction attachments, NFC
Extract the set logic for metadata attachments from `Instruction` so it
can be reused for `Function` (PR23340).
This data structure makes a `SmallVector<>` look (a little) like a map,
just doing the bare minimum to support the `Instruction` (and soon,
`Function`) metadata API.
[SEH] Implement GetExceptionCode in __except blocks
This introduces an intrinsic called llvm.eh.exceptioncode. It is lowered
by copying the EAX value live into whatever basic block it is called
from. Obviously, this only works if you insert it late during codegen,
because otherwise mid-level passes might reschedule it.
IR: Use remove_if for Instruction::dropUnknownMetadata()
Technically the operations are different -- the old logic moved items
from the back into the opened-up slots, instead of the usual
`remove_if()` logic of a slow and a fast iterator -- but unless a
profile tells us otherwise I prefer the simpler logic here. Regardless,
there shouldn't be an observable function change.
David Blaikie [Fri, 24 Apr 2015 19:32:54 +0000 (19:32 +0000)]
[opaque pointer type] Add textual IR support for explicit type parameter to the invoke instruction
Same as r235145 for the call instruction - the justification, tradeoffs,
etc are all the same. The conversion script worked the same without any
false negatives (after replacing 'call' with 'invoke').
Chris Bieneman [Fri, 24 Apr 2015 17:09:20 +0000 (17:09 +0000)]
[CMake] Fix for PR 23328: LLVM_OPTIMIZED_TABLEGEN broken
In CMake dependencies can be filenames or targets, and targets can't be filenames. The Ninja generator handles filename dependencies because it generates targets for every output file from a command. For example:
With the Ninja generator this generates a target foo.txt, but with the Makefile generator it doesn't. This is probably because Ninja explicitly requires these hard dependency ties, and Make just behaves oddly in general.
To fix this we need to make the tablegen actions depend on a target rather than a filename.
Linker: Update -override testcase to check callers
Check that `@main` is calling `@foo2` (the renamed internal function),
not the `@foo` with external linkage that's been pulled in from the
override file.
[mips][FastISel] Specify which types we handle for integer extension.
Summary:
Perform integer extension only when the destination type is one of
i8, i16 & i32 and when the source type is i1, i8 or i16. For other
combinations we fall back to SelectionDAG.
This fixes the test MultiSource/Benchmarks/7zip that was failing in our
out-of-tree MIPS buildbots.
Summary: Constant folding of extractelement with out-of-bound index produces undef also for indexes bigger than 64bit (instead of crash assert failure as before)
Summary: This patch fixes step D4 of Knuth's division algorithm implementation. Negative sign of the step result was not always detected due to incorrect "borrow" handling.
Test Plan: Unit test that reveals the bug included.
This should make it clear under which narrow circumstances implicit
physreg uses are okay when rematerializing and prevent people from
accidentally allowing too much when overriding
isReallyTriviallyReMaterializable() even with the weaker assert in the
RegisterCoalescer.
Matt Arsenault [Thu, 23 Apr 2015 23:34:05 +0000 (23:34 +0000)]
MC: Allow targets to stop symbol name quoting
Currently symbol names are printed in quotes if it contains something
outside of the arbitrary set of characters that isAcceptableChar tests
for. On somem targets, it is never OK to print a symbol name in quotes
so allow targets to opt out of this behavior.
RegisterCoalescer: Avoid unnecessary register class widening for some rematerializations
I couldn't provide a testcase as none of the public targets has wide
register classes with alot of subregisters and at the same time an
instruction which "ReMaterializable" and "AsCheapAsAMove" (could
probably be added for R600).
Hal Finkel [Thu, 23 Apr 2015 22:47:57 +0000 (22:47 +0000)]
[PowerPC] Add asm/disasm support for dcbt with hint
Add assembler/disassembler support for dcbt/dcbtst (and aliases) with the hint
field specified (non-zero). Unforunately, the syntax for this instruction is
special in that it differs for server vs. embedded cores:
dcbt ra, rb, th [server]
dcbt th, ra, rb [embedded]
where th can be omitted when it is 0. dcbtst is the same. Thus we need to play
games in the parser and the printer to flip the operands around on the embedded
cores. We'll use the server syntax as the default (binutils currently uses the
embedded form by default, but IBM is changing that).
We also stop marking dcbtst as having unmodeled side effects (this is not
necessary, it is just a hint like dcbt -- noticed by inspection, so no separate
test case).
David Blaikie [Thu, 23 Apr 2015 21:36:23 +0000 (21:36 +0000)]
Recommit r235458: [opaque pointer type] Avoid using PointerType::getElementType for a few cases of CallInst
(reverted in r235533)
Original commit message:
"Calls to llvm::Value::mutateType are becoming extra-sensitive now that
instructions have extra type information that will not be derived from
operands or result type (alloca, gep, load, call/invoke, etc... ). The
special-handling for mutateType will get more complicated as this work
continues - it might be worth making mutateType virtual & pushing the
complexity down into the classes that need special handling. But with
only two significant uses of mutateType (vectorization and linking) this
seems OK for now.
Totally open to ideas/suggestions/improvements, of course.
With this, and a bunch of exceptions, we can roundtrip an indirect call
site through bitcode and IR. (a direct call site is actually trickier...
I haven't figured out how to deal with the IR deserializer's lazy
construction of Function/GlobalVariable decl's based on the type of the
entity which means looking through the "pointer to T" type referring to
the global)"
The remapping done in ValueMapper for LTO was insufficient as the types
weren't correctly mapped (though I was using the post-mapped operands,
some of those operands might not have been mapped yet so the type
wouldn't be post-mapped yet). Instead use the pre-mapped type and
explicitly map all the types.
We were asserting on code like this:
extern "C" unsigned long _exception_code();
void might_crash(unsigned long);
void foo() {
__try {
might_crash(0);
} __except(1) {
might_crash(_exception_code());
}
}
Gtest and many other libraries get the exception code from the __except
block. What's supposed to happen here is that EAX is live into the
__except block, and it contains the exception code. Eventually we'll
represent that as a use of the landingpad ehptr value, but for now we
can replace it with undef.
[MachineCopyPropagation] Handle undef flags conservatively so that we do not
remove copies that are useful after breaking some hardware dependencies.
In other words, handle this kind of situations conservatively by assuming reg2
is redefined by the undef flag.
reg1 = copy reg2
= inst reg2<undef>
reg2 = copy reg1
Copy propagation used to remove the last copy.
This is incorrect because the undef flag on reg2 in inst, allows next
passes to put whatever trashed value in reg2 that may help.
In practice we end up with this code:
reg1 = copy reg2
reg2 = 0
= inst reg2<undef>
reg2 = copy reg1
Tom Stellard [Thu, 23 Apr 2015 20:32:01 +0000 (20:32 +0000)]
R600/SI: Fix indirect addressing with a negative constant offset
When the base register index of the vector plus the constant offset
was less than zero, we were passing the wrong base register to the indirect
addressing instruction.
In this case, we need to set the base register to v0 and then add
the computed (negative) index to m0.
Thumb2: When applying branch optimizations, visit branches in reverse order.
The order in which branches appear in ImmBranches is approximately their
order within the function body. By visiting later branches first, we reduce
the distance between earlier forward branches and their targets, making it
more likely that the cbn?z optimization, which can only apply to forward
branches, will succeed for those earlier branches.
ARM: When re-creating a branch via InsertBranch, preserve CPSR flags.
In particular, this preserves the kill flag, which allows the Thumb2 cbn?z
optimization to be applied in cases where a branch has been re-created after
the live variables analysis pass, e.g. by the machine block placement pass.
This appears to be low risk; a number of other targets seem to already be
doing something similar, e.g. AArch64, PowerPC.
ARM: Only enforce 4-byte alignment on Thumb-2 functions with constant pools.
This appears to have been introduced back in r76698 as part of an unrelated
change. I can find no official ARM documentation stating that Thumb-2 functions
require 4-byte alignment; in fact, ARM documentation appears to contradict
this (see, e.g., ARM Architecture Reference Manual Thumb-2 Supplement,
section 2.6.1: "Thumb-2 enforces 16-bit alignment on all instructions.").
Also remove code that sets alignment for ARM functions, which is redundant
with code in the MachineFunction constructor, and remove the hidden
-arm-align-constant-islands flag, which has been enabled by default since
r146739 (Dec 2011) and has probably received sufficient testing by now.
Since A[i] and A[i-1] are likely to be independent pointers,
getUnderlyingObjects should not assume that Curr and Prev share the same
underlying object in the inner loop.
If it did we would try to dependence-analyze Curr and Prev and the
analysis of the corresponding SCEVs would fail with non-constant
distance.
To fix this, the getUnderlyingObjects API is extended with an optional
LoopInfo parameter. This is effectively what controls whether we want
the above behavior or the original. Currently, I only changed to use
this approach for LoopAccessAnalysis.
The other testcase is to guard the opposite case where we do want to
look through the loop PHI. If we step through an array by incrementing
a pointer, the underlying object is the incoming value of the phi as the
loop is entered.
projects / llvm / log