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

Shrink the size of SigData in Cranelift (#5261)

Browse Source 
* Shrink the size of SigData in Cranelift

* Update cranelift/codegen/src/machinst/abi.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

* Change ret arg length to u16

* Add test

Co-authored-by: Jamey Sharp <jamey@minilop.net>
This commit is contained in:
Timothy Chen
2022-11-16 16:15:19 -08:00
committed by GitHub
parent 54a290cd53
commit de6e4a4e20
1 changed files with 56 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
cranelift/codegen/src/machinst/abi.rs
View File

@@ -119,7 +119,6 @@ use std::collections::HashMap;
use std::convert::TryFrom;
use std::marker::PhantomData;
use std::mem;
use std::ops::Range;
/// A small vector of instructions (with some reasonable size); appropriate for
/// a small fixed sequence implementing one operation.
@@ -612,17 +611,23 @@ cranelift_entity::entity_impl!(Sig);
/// ABI information shared between body (callee) and caller.
#[derive(Clone, Debug)]
pub struct SigData {
/// Argument locations (regs or stack slots). Stack offsets are relative to
/// Argument location starting offset (regs or stack slots). Stack offsets are relative to
/// SP on entry to function.
///
/// These are indices into the `SigSet::abi_args`.
arg_indices: Range<u32>,
/// This is a index into the `SigSet::abi_args`.
args_start: u32,
/// Return-value locations. Stack offsets are relative to the return-area
/// Amount of arguments in the stack.
args_length: u16,
/// Return-value location starting offset. Stack offsets are relative to the return-area
/// pointer.
///
/// These are indices into the `SigSet::abi_args`.
ret_indices: Range<u32>,
/// This is a index into the `SigSet::abi_args`.
rets_start: u32,
/// Amount of Return value locations in the stack.
rets_length: u16,
/// Space on stack used to store arguments.
sized_stack_arg_space: i64,
@@ -631,7 +636,7 @@ pub struct SigData {
sized_stack_ret_space: i64,
/// Index in `args` of the stack-return-value-area argument.
stack_ret_arg: Option<usize>,
stack_ret_arg: Option<u16>,
/// Calling convention used.
call_conv: isa::CallConv,
@@ -671,22 +676,28 @@ impl SigData {
)?;
let args_end = u32::try_from(sigs.abi_args.len()).unwrap();
let arg_indices = args_start..args_end;
let ret_indices = rets_start..rets_end;
let args_length = u16::try_from(args_end - args_start).unwrap();
let rets_length = u16::try_from(rets_end - rets_start).unwrap();
trace!(
"ABISig: sig {:?} => args = {:?} rets = {:?} arg stack = {} ret stack = {} stack_ret_arg = {:?}",
"ABISig: sig {:?} => args start = {} args len = {} rets start = {} rets len = {}
arg stack = {} ret stack = {} stack_ret_arg = {:?}",
sig,
arg_indices,
ret_indices,
args_start,
args_length,
rets_start,
rets_length,
sized_stack_arg_space,
sized_stack_ret_space,
stack_ret_arg,
);
let stack_ret_arg = stack_ret_arg.map(|s| u16::try_from(s).unwrap());
Ok(SigData {
arg_indices,
ret_indices,
args_start,
args_length,
rets_start,
rets_length,
sized_stack_arg_space,
sized_stack_ret_space,
stack_ret_arg,
@@ -696,15 +707,15 @@ impl SigData {
/// Get this signature's ABI arguments.
pub fn args<'a>(&self, sigs: &'a SigSet) -> &'a [ABIArg] {
let start = usize::try_from(self.arg_indices.start).unwrap();
let end = usize::try_from(self.arg_indices.end).unwrap();
let start = usize::try_from(self.args_start).unwrap();
let end = usize::try_from(self.args_start + u32::from(self.args_length)).unwrap();
&sigs.abi_args[start..end]
}
/// Get this signature's ABI returns.
pub fn rets<'a>(&self, sigs: &'a SigSet) -> &'a [ABIArg] {
let start = usize::try_from(self.ret_indices.start).unwrap();
let end = usize::try_from(self.ret_indices.end).unwrap();
let start = usize::try_from(self.rets_start).unwrap();
let end = usize::try_from(self.rets_start + u32::from(self.rets_length)).unwrap();
&sigs.abi_args[start..end]
}
@@ -742,13 +753,13 @@ impl SigData {
/// Get the number of arguments expected.
pub fn num_args(&self) -> usize {
let len = self.arg_indices.end - self.arg_indices.start;
let len = usize::try_from(len).unwrap();
if self.stack_ret_arg.is_some() {
len - 1
let num = if self.stack_ret_arg.is_some() {
self.args_length - 1
} else {
len
}
self.args_length
};
usize::from(num)
}
/// Get information specifying how to pass one argument.
@@ -763,8 +774,7 @@ impl SigData {
/// Get the number of return values expected.
pub fn num_rets(&self) -> usize {
let len = self.ret_indices.end - self.ret_indices.start;
usize::try_from(len).unwrap()
usize::from(self.rets_length)
}
/// Get information specifying how to pass one return value.
@@ -780,7 +790,7 @@ impl SigData {
/// Get information specifying how to pass the implicit pointer
/// to the return-value area on the stack, if required.
pub fn get_ret_arg(&self, sigs: &SigSet) -> Option<ABIArg> {
let ret_arg = self.stack_ret_arg?;
let ret_arg = usize::from(self.stack_ret_arg?);
Some(self.args(sigs)[ret_arg].clone())
}
@@ -1598,8 +1608,11 @@ impl<M: ABIMachineSpec> Callee<M> {
/// pointer to that memory.
pub fn gen_retval_area_setup(&mut self, sigs: &SigSet) -> Option<M::I> {
if let Some(i) = sigs[self.sig].stack_ret_arg {
let insts =
self.gen_copy_arg_to_regs(sigs, i, ValueRegs::one(self.ret_area_ptr.unwrap()));
let insts = self.gen_copy_arg_to_regs(
sigs,
i.into(),
ValueRegs::one(self.ret_area_ptr.unwrap()),
);
insts.into_iter().next().map(|inst| {
trace!(
"gen_retval_area_setup: inst {:?}; ptr reg is {:?}",
@@ -2338,7 +2351,7 @@ impl<M: ABIMachineSpec> Caller<M> {
rd,
I8,
));
for inst in self.gen_arg(ctx, i, ValueRegs::one(rd.to_reg())) {
for inst in self.gen_arg(ctx, i.into(), ValueRegs::one(rd.to_reg())) {
ctx.emit(inst);
}
}
@@ -2365,3 +2378,15 @@ impl<M: ABIMachineSpec> Caller<M> {
}
}
}
#[cfg(test)]
mod tests {
use super::SigData;
#[test]
fn sig_data_size() {
// The size of `SigData` is performance sensitive, so make sure
// we don't regress it unintentionally.
assert_eq!(std::mem::size_of::<SigData>(), 40);
}
}