Currently canCheckPtrAtRT returns two flags NeedRTCheck and CanDoRT.
NeedRTCheck says whether we need checks and CanDoRT whether we can
generate the checks. The idea is to encode three states with these:
Need/Can:
(1) false/dont-care: no checks are needed
(2) true/false: we need checks but can't generate them
(3) true/true: we need checks and we can generate them
This is pretty unnecessary since the caller (analyzeLoop) is only
interested in whether we can generate the checks if we actually need
them (i.e. 1 or 3).
So this change cleans up to return just that (CanDoRTIfNeeded) and pulls
all the underlying logic into canCheckPtrAtRT.
By doing all this, we simplify analyzeLoop which is the complex function
in LAA.
There is further room for improvement here by using RtCheck.Need
directly rather than a new local variable NeedRTCheck but that's for a
later patch.
llvm-svn: 241866
The runtime does not restore CSRs when transferring control back to the
function handling the exception. According to the experts on IRC, LLVM's
register allocator has no way to model register clobbers that only
happen on one edge of the CFG. For now, don't worry about trying to use
the meager three CSRs available on 32-bit X86 and just say that such
invokes preserve nothing.
llvm-svn: 241865
This commit adds a new error which is reported when the MIR Parser encounters
a machine function without any machine basic blocks. The machine verifier
expects that the machine functions have at least one MBB, and this error will
prevent machine functions without MBBs from reaching the machine verifier and
crashing with an assertion.
llvm-svn: 241862
Summary:
Before this change ImplicitNullChecks would only pick loads of the form:
```
test Reg, Reg
jz elsewhere
fallthrough:
movl 32(Reg), Reg2
```
but not (say)
```
test Reg, Reg
jz elsewhere
fallthrough:
inc Reg3
movl 32(Reg), Reg2
```
This change teaches ImplicitNullChecks to look through "unrelated"
instructions like `inc Reg3` when searching for a load instruction
to convert to a trapping load.
Reviewers: atrick, JosephTremoulet, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11044
llvm-svn: 241850
They should probably be created on anything that is not windows or linux, but I will
test on freebsd before changing that.
With this it is possible to bootstrap with llvm-ar instead of ar+ranlib on OS X.
llvm-svn: 241849
This commit serializes the 13 scalar boolean and integer attributes from the
MachineFrameInfo class: IsFrameAddressTaken, IsReturnAddressTaken, HasStackMap,
HasPatchPoint, StackSize, OffsetAdjustment, MaxAlignment, AdjustsStack,
HasCalls, MaxCallFrameSize, HasOpaqueSPAdjustment, HasVAStart, and
HasMustTailInVarArgFunc. These attributes are serialized as part
of the frameInfo YAML mapping, which itself is a part of the machine function's
YAML mapping.
llvm-svn: 241844
It looks like ld64 requires it. With this we seem to be able to bootstrap using
llvm-ar+/usr/bin/true instead of ar+ranlib (currently on stage2).
llvm-svn: 241842
Summary:
In RewriteLoopExitValues, before expanding out an SCEV expression using
SCEVExpander, try to see if an existing LLVM IR expression already
computes the value we're interested in. If so use that existing
expression.
Apart from reducing IndVars' reliance on the rest of the compilation
pipeline, this also prevents IndVars from concluding some expressions as
"high cost" when they're not. For instance,
`InductiveRangeCheckElimination` often emits code of the following form:
```
len = umin(len_A, len_B)
loop:
...
if (i++ < len)
goto loop
outside_loop:
use(i)
```
`SCEVExpander` refuses to rewrite the use of `i` in `outside_loop`,
since it thinks the value of `i` on loop exit, `len`, is a high cost
expansion since it contains an `umax` in it. With this change,
`IndVars` can see that it can re-use `len` instead of creating a new
expression to compute `umin(len_A, len_B)`.
I considered putting this cleverness in `SCEVExpander`, but I was
worried that it may then have a deterimental effect on other passes
that use it. So I decided it was better to just do this in the one
place where it seems like an obviously good idea, with the intent of
generalizing later if needed.
Reviewers: atrick, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10782
llvm-svn: 241838
Don't let the disassembler pick call <.text> if a function happens to
live at the start of the section by only using function symbols.
llvm-svn: 241830
This patch allows the read_register and write_register intrinsics to
read/write the RBP/EBP registers on X86 iff the targeted register is
the frame pointer for the containing function.
Differential Revision: http://reviews.llvm.org/D10977
llvm-svn: 241827
This patch fixes bugs that were exposed by the addition of fast-math-flags in the DAG:
r237046 ( http://reviews.llvm.org/rL237046 ):
1. When replacing a division node, it's not enough to RAUW.
We should call CombineTo() to delete dead nodes and combine again.
2. Because we are changing the DAG, we can't return an empty SDValue
after the transform. As the code comments say:
Visitation implementation - Implement dag node combining for different node types.
The semantics are as follows: Return Value:
SDValue.getNode() == 0 - No change was made
SDValue.getNode() == N - N was replaced, is dead and has been handled.
otherwise - N should be replaced by the returned Operand.
The new test case shows no difference with or without this patch, but it will crash if
we re-apply r237046 or enable FMF via the current -enable-fmf-dag cl::opt.
Differential Revision: http://reviews.llvm.org/D9893
llvm-svn: 241826
Summary:
We were missing a corner case where DepCands was not available,
but we were using DepCands to compute the checking pointer
groups.
This adds a test for that regression.
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11068
llvm-svn: 241818
Summary:
The checking pointer group construction algorithm relied on the iteration on DepCands.
We would need the same leaders across runs and the same iteration order over the underlying std::set for determinism.
This changes the algorithm to process the pointers in the order in which they were added to the runtime check, which is deterministic.
We need to update the tests, since the order in which pointers appear has changed.
No new tests were added, since it is impossible to test for non-determinism.
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11064
llvm-svn: 241809
The gnu ar format uses BE numbers. The BSD one uses LE. Add a helper for one or the
other. NFC for now, just removes some noise from the following patch.
llvm-svn: 241808
Summary: If shift amount is a constant value > 64 bit it is handled incorrectly during type legalization and X86 lowering. This patch the type of shift amount argument in function DAGTypeLegalizer::ExpandShiftByConstant from unsigned to APInt.
Reviewers: nadav, majnemer, sanjoy, RKSimon
Subscribers: RKSimon, llvm-commits
Differential Revision: http://reviews.llvm.org/D10767
llvm-svn: 241806
The nest attribute is currently supported on the x86 (32-bit) and x86-64
backends, but not on ARM (32-bit) or AArch64. This patch adds support for
nest to the AArch64 backend.
Register x18 is used by GCC for this purpose and hence is used here.
As discussed on the GCC mailing list the register choice is an ABI issue
and so choosing the same register as GCC means __builtin_call_with_static_chain
is compatible.
Patch by Stephen Cross.
llvm-svn: 241794
The newly added function returns the size of the specified floating
point semantics in bits.
Differential revision: http://reviews.llvm.org/D8413
llvm-svn: 241793
Summary: If shift amount is a constant value > 64 bit it is handled incorrectly during type legalization and X86 lowering. This patch the type of shift amount argument in function DAGTypeLegalizer::ExpandShiftByConstant from unsigned to APInt.
Reviewers: nadav, majnemer, sanjoy, RKSimon
Subscribers: RKSimon, llvm-commits
Differential Revision: http://reviews.llvm.org/D10767
llvm-svn: 241790
