T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86-64 Windows fastcall ABI support.

Browse Source 
This adds support for the "fastcall" ABI, which is the native C/C++ ABI
on Windows platforms on x86-64. It is similar to but not exactly like
System V; primarily, its argument register assignments are different,
and it requires stack shadow space.

Note that this also adjusts the handling of multi-register values in the
shared ABI implementation, and with this change, adjusts handling of
`i128`s on *both* Fastcall/x64 *and* SysV/x64 platforms. This was done
to align with actual behavior by the "rustc ABI" on both platforms, as
mapped out experimentally (Compiler Explorer link in comments). This
behavior is gated under the `enable_llvm_abi_extensions` flag.

Note also that this does *not* add x64 unwind info on Windows. That will
come in a future PR (but is planned!).
This commit is contained in:
Chris Fallin
2021-02-22 20:28:49 -08:00
parent 98d3e6823f
commit 6c94eb82aa
13 changed files with 997 additions and 475 deletions
Download Patch File Download Diff File Expand all files Collapse all files

101
cranelift/codegen/src/isa/aarch64/abi.rs
View File

@@ -78,41 +78,41 @@ fn try_fill_baldrdash_reg(call_conv: isa::CallConv, param: &ir::AbiParam) -> Opt
match &param.purpose {
&ir::ArgumentPurpose::VMContext => {
// This is SpiderMonkey's `WasmTlsReg`.
Some(ABIArg::Reg {
regs: ValueRegs::one(xreg(BALDRDASH_TLS_REG).to_real_reg()),
ty: ir::types::I64,
extension: param.extension,
purpose: param.purpose,
})
Some(ABIArg::reg(
xreg(BALDRDASH_TLS_REG).to_real_reg(),
ir::types::I64,
param.extension,
param.purpose,
))
}
&ir::ArgumentPurpose::SignatureId => {
// This is SpiderMonkey's `WasmTableCallSigReg`.
Some(ABIArg::Reg {
regs: ValueRegs::one(xreg(BALDRDASH_SIG_REG).to_real_reg()),
ty: ir::types::I64,
extension: param.extension,
purpose: param.purpose,
})
Some(ABIArg::reg(
xreg(BALDRDASH_SIG_REG).to_real_reg(),
ir::types::I64,
param.extension,
param.purpose,
))
}
&ir::ArgumentPurpose::CalleeTLS => {
// This is SpiderMonkey's callee TLS slot in the extended frame of Wasm's ABI-2020.
assert!(call_conv == isa::CallConv::Baldrdash2020);
Some(ABIArg::Stack {
offset: BALDRDASH_CALLEE_TLS_OFFSET,
ty: ir::types::I64,
extension: ir::ArgumentExtension::None,
purpose: param.purpose,
})
Some(ABIArg::stack(
BALDRDASH_CALLEE_TLS_OFFSET,
ir::types::I64,
ir::ArgumentExtension::None,
param.purpose,
))
}
&ir::ArgumentPurpose::CallerTLS => {
// This is SpiderMonkey's caller TLS slot in the extended frame of Wasm's ABI-2020.
assert!(call_conv == isa::CallConv::Baldrdash2020);
Some(ABIArg::Stack {
offset: BALDRDASH_CALLER_TLS_OFFSET,
ty: ir::types::I64,
extension: ir::ArgumentExtension::None,
purpose: param.purpose,
})
Some(ABIArg::stack(
BALDRDASH_CALLER_TLS_OFFSET,
ir::types::I64,
ir::ArgumentExtension::None,
param.purpose,
))
}
_ => None,
}
@@ -161,6 +161,7 @@ impl ABIMachineSpec for AArch64MachineDeps {
fn compute_arg_locs(
call_conv: isa::CallConv,
_flags: &settings::Flags,
params: &[ir::AbiParam],
args_or_rets: ArgsOrRets,
add_ret_area_ptr: bool,
@@ -253,12 +254,12 @@ impl ABIMachineSpec for AArch64MachineDeps {
RegClass::V128 => vreg(*next_reg),
_ => unreachable!(),
};
ret.push(ABIArg::Reg {
regs: ValueRegs::one(reg.to_real_reg()),
ty: param.value_type,
extension: param.extension,
purpose: param.purpose,
});
ret.push(ABIArg::reg(
reg.to_real_reg(),
param.value_type,
param.extension,
param.purpose,
));
*next_reg += 1;
remaining_reg_vals -= 1;
} else {
@@ -268,13 +269,13 @@ impl ABIMachineSpec for AArch64MachineDeps {
let size = std::cmp::max(size, 8);
// Align.
debug_assert!(size.is_power_of_two());
next_stack = (next_stack + size - 1) & !(size - 1);
ret.push(ABIArg::Stack {
offset: next_stack as i64,
ty: param.value_type,
extension: param.extension,
purpose: param.purpose,
});
next_stack = align_to(next_stack, size);
ret.push(ABIArg::stack(
next_stack as i64,
param.value_type,
param.extension,
param.purpose,
));
next_stack += size;
}
}
@@ -286,19 +287,19 @@ impl ABIMachineSpec for AArch64MachineDeps {
let extra_arg = if add_ret_area_ptr {
debug_assert!(args_or_rets == ArgsOrRets::Args);
if next_xreg < max_per_class_reg_vals && remaining_reg_vals > 0 {
ret.push(ABIArg::Reg {
regs: ValueRegs::one(xreg(next_xreg).to_real_reg()),
ty: I64,
extension: ir::ArgumentExtension::None,
purpose: ir::ArgumentPurpose::Normal,
});
ret.push(ABIArg::reg(
xreg(next_xreg).to_real_reg(),
I64,
ir::ArgumentExtension::None,
ir::ArgumentPurpose::Normal,
));
} else {
ret.push(ABIArg::Stack {
offset: next_stack as i64,
ty: I64,
extension: ir::ArgumentExtension::None,
purpose: ir::ArgumentPurpose::Normal,
});
ret.push(ABIArg::stack(
next_stack as i64,
I64,
ir::ArgumentExtension::None,
ir::ArgumentPurpose::Normal,
));
next_stack += 8;
}
Some(ret.len() - 1)
@@ -306,7 +307,7 @@ impl ABIMachineSpec for AArch64MachineDeps {
None
};
next_stack = (next_stack + 15) & !15;
next_stack = align_to(next_stack, 16);
// To avoid overflow issues, limit the arg/return size to something
// reasonable -- here, 128 MB.