This actually totally breaks and causes the machine verifier to cry in several cases, one of which being:
%RAX<def> = COPY %RCX<kill>
%ECX<def> = COPY %EAX<kill>, %RAX<imp-use,kill>
These subregister copies are together identified as noops, so are both removed. However, the second one as it has an imp-use gets converted into a kill:
%ECX<def> = KILL %EAX<kill>, %RAX<imp-use,kill>
As the original COPY has been removed, the verifier goes into tears at the use of undefined EAX and RAX.
There are several hacky solutions to this hacky problem (which is all to do with imp-use/def weirdnesses), but the least hacky I've come up with is to *always* remove COPYs by converting to KILLs. KILLs are no-ops to the code generator so the generated code doesn't change (which is why they were partially used in the first place), but using them also keeps the def/use and imp-def/imp-use chains alive:
%RAX<def> = KILL %RCX<kill>
%ECX<def> = KILL %EAX<kill>, %RAX<imp-use,kill>
The patch passes all test cases including the ones that check the removal of MOVs in this circumstance, along with an extra test I added to check subregister behaviour (which made the machine verifier fall over before my patch).
The patch also adds some DEBUG() statements because the file hadn't got any.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199797 91177308-0d34-0410-b5e6-96231b3b80d8
inconsistent results for different orderings of alloca slices. The
fundamental issue is that it is just always a mistake to return early
from this function. There is no effective early exit to leverage. This
patch stops trynig to do so and simplifies the code a bit as
a consequence.
Original diagnosis and patch by James Molloy with some name tweaks by me
in part reflecting feedback from Duncan Smith on the mailing list.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199771 91177308-0d34-0410-b5e6-96231b3b80d8
The constructors of classes deriving from Binary normally take an error_code
as an argument to the constructor. My original intent was to change them
to have a trivial constructor and move the initial parsing logic to a static
method returning an ErrorOr. I changed my mind because:
* A constructor with an error_code out parameter is extremely convenient from
the implementation side. We can incrementally construct the object and give
up when we find an error.
* It is very efficient when constructing on the stack or when there is no
error. The only inefficient case is where heap allocating and an error is
found (we have to free the memory).
The result is that this is a much smaller patch. It just standardizes the
create* helpers to return an ErrorOr.
Almost no functionality change: The only difference is that this found that
we were trying to read past the end of COFF import library but ignoring the
error.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199770 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a crash in SjLjEHPrepare::lowerIncomingArguments caused by treating
VectorType like an aggregate. It's first-class!
<rdar://problem/15854596>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199768 91177308-0d34-0410-b5e6-96231b3b80d8
Generalized the heuristic that looks at the (very rough) size of the
register file before enabling regpressure tracking.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199766 91177308-0d34-0410-b5e6-96231b3b80d8
For PPC64 SVR (and Darwin), the stores that take byval aggregate parameters
from registers into the stack frame had MachinePointerInfo objects with
incorrect offsets. These offsets are relative to the object itself, not to the
stack frame base.
This fixes self hosting on PPC64 when compiling with -enable-aa-sched-mi.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199763 91177308-0d34-0410-b5e6-96231b3b80d8
This is apparently a bit of a white lie (they can affect DSPControl for
overflow etc) but similar to how we currently handle floating-point operations.
When it becomes relevant the whole lot can be reviewed properly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199718 91177308-0d34-0410-b5e6-96231b3b80d8
