fromulation of the node, which isn't really the desired behavior from
within the combiner or legalizer, but is necessary within ISel. I've
added a hopefully helpful comment and fixed the only two places where
this took place.
Yet another step toward the combiner and legalizer not needing to use
update listeners with virtual calls to manage the worklists behind
legalization and combining.
llvm-svn: 214574
Now that we can reliably handle forward references to `BlockAddress`
(r214563), change the mechanics to simplify predicting use-list order.
Previously, we created dummy `GlobalVariable`s to represent block
addresses. After every function was materialized, we'd go through any
forward references to its blocks and RAUW them with a proper
`BlockAddress` constant. This causes some (potentially a lot of)
unnecessary use-list churn, since any constant expression that it's a
part of will need to be rematerialized as well.
Instead, pre-construct a `BasicBlock` immediately -- without attaching
it to its (empty) `Function` -- and use that to construct a
`BlockAddress`. This constant will not have to be regenerated. When
the function body is parsed, hook this pre-constructed basic block up
in the right place using `BasicBlock::insertInto()`.
Both before and after this change, the IR is temporarily in an invalid
state that gets resolved when `materializeForwardReferencedFunctions()`
gets called.
This is a prep commit that's part of PR5680, but the only functionality
change is the reduction of churn in the constant pool.
llvm-svn: 214570
Although unlinked `BasicBlock`s can be created, there's currently no way
to insert them into `Function`s after the fact. In particular,
`moveAfter()` and `moveBefore()` require that the basic block is already
linked.
Extract the logic for initially linking a `BasicBlock` out of the
constructor and into a member function that can be used for lazy
insertion.
- Asserts that the basic block is currently unlinked.
- Matches the logic of the constructor.
- Changed the constructor to use it since the logic matches.
This is needed in a follow-up commit for PR5680.
llvm-svn: 214563
so that we can use it to get the old-style JIT out of the subtarget.
This code should be removed when the old-style JIT is removed
(imminently).
llvm-svn: 214560
`BlockAddress`es are interesting in that they can reference basic blocks
from *outside* the block's function. Since basic blocks are not global
values, this presents particular challenges for lazy parsing.
One corner case was found in PR11677 and fixed in r147425. In that
case, a global variable references a block address. It's necessary to
load the relevant function to resolve the forward reference before doing
anything with the module.
By inspection, I found (and have fixed here) two other cases:
- An instruction from one function references a block address from
another function, and only the first function is lazily loaded.
I fixed this the same way as PR11677: by eagerly loading the
referenced function.
- A function whose block address is taken is dematerialized, leaving
invalid references to it.
I fixed this by refusing to dematerialize functions whose block
addresses are taken (if you have to load it, you can't unload it).
llvm-svn: 214559
This is consistent with how we parse them in a standalone .s file, and
inline assembly shouldn't differ.
This fixes errors about requiring more registers than available in
cases like this:
void f();
void __declspec(naked) g() {
__asm pusha
__asm call f
__asm popa
__asm ret
}
There are no registers available to pass the address of 'f' into the asm
blob. The asm should now directly call 'f'.
Tests will land in Clang shortly.
llvm-svn: 214550
This lifts the (very few) places the legalizer would delete dead nodes
into the outer loop around the legalizer. This is significantly simpler
because it doesn't require the legalizer itself to manage the iterator
validity, and it doesn't require the legalizer to be a DAG update
listener in order to remove things from the legalized set. It also makes
the interface much less contrived for the case of the legalizer running
inside the last phase of DAG combining.
I'm working on centralizing the deletion of nodes during both legalizing
and combining as much as possible. My hope is to remove the need for DAG
update listeners from the combiner next, which would remove a costly
virtual dispatch chain on every deletion. This in turn should allow us
to more aggressively delete DAG nodes during combining which will in
turn allow us to combine more aggressively by exposing the actual nodes
which have single users to the combine phases.
llvm-svn: 214546
This patch adds code to emits the StackMap section on ELF systems. This section is required to support llvm.experimental.stackmap and llvm.experimental.patchpoint intrinsics.
Reviewers: ributzka, echristo
Differential Revision: http://reviews.llvm.org/D4574
llvm-svn: 214538
Add branch weights to branch instructions, so that the following passes can
optimize based on it (i.e. basic block ordering).
Fixes <rdar://problem/17887137>.
llvm-svn: 214537
This change adds code to explicitly mark a function which requires runtime stack realignment as not having a fixed frame size in the StackMap section. As it happens, this is not actually a functional change. The size that would be reported without the check is also "-1", but as far as I can tell, that's an accident. The code change makes this explicit.
Note: There's a separate bug in handling of stackmaps and patchpoints in functions which need dynamic frame realignment. The current code assumes that offsets can be calculated from RBP, but realigned frames must use RSP. (There's a variable gap between RBP and the spill slots.) This change set does not address that issue.
Reviewers: atrick, ributzka
Differential Revision: http://reviews.llvm.org/D4572
llvm-svn: 214534
This is a followup patch for r214366, which added the same behavior to the
AArch64 and X86 FastISel code. This fix reproduces the already existing
behavior of SelectionDAG in FastISel.
llvm-svn: 214531
The tbz/tbnz checks the sign bit to convert
op w1, w1, w10
cmp w1, #0
b.lt .LBB0_0
to
op w1, w1, w10
tbnz w1, #31, .LBB0_0
Differential Revision: http://reviews.llvm.org/D4440
llvm-svn: 214518
Found by inspection while looking at PR20280: code would mark slots
in the parameter save area where a byval parameter is passed as
"immutable". This is not correct since code is allowed to modify
byval parameters in place in the parameter save area.
llvm-svn: 214517
Note: The current code in DecodeMSRMask() rejects the unpredictable A/R MSR mask '0000' with Fail. The code in the patch follows this style and rejects unpredictable M-class MSR masks also with Fail (instead of SoftFail). If SoftFail is preferred in this case then additional changes to ARMInstPrinter (to print non-symbolic masks) and ARMAsmParser (to parse non-symbolic masks) will be needed.
Patch by Petr Pavlu!
llvm-svn: 214505
The ARM ARM prohibits LDRB/LDRSB instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
llvm-svn: 214500
The ARM ARM prohibits LDRH/LDRSH instructions with writeback into the source register. With this commit this constraint is now enforced and we stop assembling LDRH/LDRSH instructions with unpredictable behavior.
llvm-svn: 214499
The ARM ARM prohibits LDR instructions with writeback into the destination register. With this commit this constraint is now enforced and we stop assembling LDR instructions with unpredictable behavior.
llvm-svn: 214498
Summary:
Big-endian mode was not correctly adjusting the offset for types smaller
than an ABI slot.
Fixes PR19612
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: sstankovic, llvm-commits
Differential Revision: http://reviews.llvm.org/D4556
llvm-svn: 214493
Altivec vector loads on PowerPC have an interesting property: They always load
from an aligned address (by rounding down the address actually provided if
necessary). In order to generate an actual unaligned load, you can generate two
load instructions, one with the original address, one offset by one vector
length, and use a special permutation to extract the bytes desired.
When this was originally implemented, I generated these two loads using regular
ISD::LOAD nodes, now marked as aligned. Unfortunately, there is a problem with
this:
The alignment of a load does not contribute to its identity, and SDNodes
are uniqued. So, imagine that we have some unaligned load, L1, that is not
aligned. The routine will create two loads, L1(aligned) and (L1+16)(aligned).
Further imagine that there had already existed a load (L1+16)(unaligned) with
the same chain operand as the load L1. When (L1+16)(aligned) is created as part
of the lowering of L1, this load *is* also the (L1+16)(unaligned) node, just
now marked as aligned (because the new alignment overwrites the old). But the
original users of (L1+16)(unaligned) now get the data intended for the
permutation yielding the data for L1, and (L1+16)(unaligned) no longer exists
to get its own permutation-based expansion. This was PR19991.
A second potential problem has to do with the MMOs on these loads, which can be
used by AA during instruction scheduling to break chain-based dependencies. If
the new "aligned" loads get the MMO from the original unaligned load, this does
not represent the fact that it will load data from below the original address.
Normally, this would not matter, but this load might be combined with another
load pair for a previous vector, and then the dependency on the otherwise-
ignored lower bytes can matter.
To fix both problems, instead of generating the necessary loads using regular
ISD::LOAD instructions, ppc_altivec_lvx intrinsics are used instead. These are
provided with MMOs with a conservative address range.
Unfortunately, I no longer have a failing test case (since PR19991 was
reported, other changes in CodeGen have forced this bug back into hiding it
again). Nevertheless, this should fix the underlying problem.
llvm-svn: 214481
ADDS and SUBS cannot encode negative immediates or immediates larger than 12bit.
This fix checks if the immediate version can be used under this constraints and
if we can convert ADDS to SUBS or vice versa to support negative immediates.
Also update the test cases to test the immediate versions.
llvm-svn: 214470
When generating unaligned vector loads, we need to search for other loads or
stores nearby offset by one vector width. If we find one, then we know that we
can safely generate another aligned load at that address. Otherwise, we must
generate the next load using an offset of the vector width minus one byte (so
we don't read off the end of the allocation if the base unaligned address
happened to be aligned at runtime). We had previously done this using only
other vector loads and stores, but did not consider the PowerPC-specific vector
load/store intrinsics. Now we'll also consider vector intrinsics. By itself,
this change is a feature enhancement, but is a necessary step toward fixing the
underlying problem behind PR19991.
llvm-svn: 214469
This improves the diagnostics from the regular assembler, but more
importantly it fixes an assertion when parsing inline assembly. Test
landing in Clang.
llvm-svn: 214468
Abs/neg folding has moved out of foldOperands and into the instruction
selection phase using complex patterns. As a consequence of this
change, we now prefer to select the 64-bit encoding for most
instructions and the modifier operands have been dropped from
integer VOP3 instructions.
llvm-svn: 214467
We were incorrectly assuming that all VOP2 instructions can read SGPRs
in Src0, but this is not true for instructions that read carry-in from
VCC.
The old logic has been replaced with new logic which checks the defined
register classes of the VOP2 instruction to determine whether or not to
legalize the operands.
llvm-svn: 214465
This allows assembling the two new instructions, encls and enclu for the
SKX processor model.
Note the diffs are a bigger than what might think, but to fit the new
MRM_CF and MRM_D7 in things in the right places things had to be
renumbered and shuffled down causing a bit more diffs.
rdar://16228228
llvm-svn: 214460
Chandler Carruth