compiler: Extract maximum alignment from target data layout

In particular, i64/double are actually supposed to be aligned
to their size on RISC-V (at least according to the ELF psABI),
though it is unclear to me whether this actually caused any
issues.
This commit is contained in:
David Nadlinger 2022-11-09 21:01:24 +00:00 committed by Sebastien Bourdeauducq
parent a83f330d74
commit 23a4db494f

View File

@ -177,6 +177,15 @@ class LLVMIRGenerator:
self.empty_metadata = self.llmodule.add_metadata([]) self.empty_metadata = self.llmodule.add_metadata([])
self.quote_fail_msg = None self.quote_fail_msg = None
# Maximum alignment required according to the target platform ABI. As this is
# not directly exposed by LLVM, just take the maximum across all the "big"
# elementary types we use. (Vector types, should we ever support them, are
# likely contenders for even larger alignment requirements.)
self.max_target_alignment = max(map(
lambda t: self.abi_layout_info.get_size_align(t)[1],
[lli64, lldouble, llptr]
))
def add_pred(self, pred, block): def add_pred(self, pred, block):
if block not in self.llpred_map: if block not in self.llpred_map:
self.llpred_map[block] = set() self.llpred_map[block] = set()
@ -1529,7 +1538,7 @@ class LLVMIRGenerator:
self.llbuilder.position_at_end(llalloc) self.llbuilder.position_at_end(llalloc)
llalloca = self.llbuilder.alloca(lli8, llsize, name="rpc.alloc") llalloca = self.llbuilder.alloca(lli8, llsize, name="rpc.alloc")
llalloca.align = 4 # maximum alignment required by OR1K ABI llalloca.align = self.max_target_alignment
llphi.add_incoming(llalloca, llalloc) llphi.add_incoming(llalloca, llalloc)
self.llbuilder.branch(llhead) self.llbuilder.branch(llhead)