Code in CGCall.cpp that loads up function arguments that need to be
coerced to a different type may in some cases ignore the fact that
the source of the argument is not naturally aligned. This may cause
incorrect code to be generated. In some places in CreateCoercedLoad,
we already have setAlignment calls to address this, but I ran into one
where it was missing, causing wrong code generation on SystemZ.
However, in that location, we do not actually know what alignment of
the source location we can rely on; the callers do not pass anything
to this routine. This is already an issue in other places in
CreateCoercedLoad; and the same problem exists for CreateCoercedStore.
To avoid pessimising code, and to fix the FIXMEs already in place,
this patch also adds an alignment argument to the CreateCoerced*
routines and uses it instead of forcing an alignment of 1. The
callers are changed to pass in the best information they have.
This actually requires changes in a number of existing test cases
since we now get better alignment in many places.
Differential Revision: http://reviews.llvm.org/D11033
llvm-svn: 241898
Something like { void*, void * } would be passed to a function as a [2 x i64], but returned as an i128. This patch unifies the 2 behaviours so that we also return it as a [2 x i64].
This is better for the quality of the IR, and the size of the final LLVM binary as we tend to want to insert/extract values from these types and do so with the insert/extract instructions is less IR than shifting, truncating, and or'ing values.
Reviewed by Tim Northover.
llvm-svn: 235231
Now that LLVM can count the registers needed to implement AAPCS rules, we don't
need to duplicate that logic here. This means we can drop the explicit padding
and also use more natural types in many cases (e.g. "struct { float arr[3]; }"
used to end up as "[2 x double]" to avoid holes on the stack.
The one wrinkle is that AAPCS va_arg was also using the register counting
machinery. But the local replacement isn't too bad.
llvm-svn: 222904
Unlike the standard AAPCS64 ABI, variadic arguments are always passed on the
stack with the Darwin ABI, and this was not being considered when deciding
whether to expand HFA/HVA arguments in a call. An HFA argument with a "float"
base type was being expanded into separate "float" arguments, each of which
was then extended to a double, resulting in a serious mismatch from what is
expected by the va_arg implementation. <rdar://problem/15777067>
llvm-svn: 206729
This adds Clang support for the ARM64 backend. There are definitely
still some rough edges, so please bring up any issues you see with
this patch.
As with the LLVM commit though, we think it'll be more useful for
merging with AArch64 from within the tree.
llvm-svn: 205100
Ulrich Weigand