Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

More trace optimisations #1552

Merged
merged 9 commits into from
Jan 20, 2025
+576 −230
Merged

More trace optimisations #1552

Changes from 6 commits
Commits
Show all changes
9 commits
Select commit Hold shift + click to select a range
b59fffc
The canonicalisation case can't possibly happen.
ltratt Jan 15, 2025
301c652
Constant fold `BinOp::Shl`.
ltratt Jan 15, 2025
eb6dbc1
Optimise `0 << x` and `0 >> x` to `0`.
ltratt Jan 15, 2025
eec0fda
Bork when we find obvious constant folding we haven't yet implemented.
ltratt Jan 15, 2025
cdcd6fd
If we see non-ints with bit ops (shift left etc.) we have malformed IR.
ltratt Jan 15, 2025
1d39af2
Optimise `BinOp::Xor`.
ltratt Jan 15, 2025
e890a7b
Add canonicalisation tests.
ltratt Jan 15, 2025
713e240
Deal with poison in `Shl` properly.
ltratt Jan 15, 2025
4cee455
Optimise `Select` instructions.
ltratt Jan 15, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
234 changes: 211 additions & 23 deletions ykrt/src/compile/jitc_yk/opt/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -249,7 +249,7 @@ impl Opt {
)?;
self.m.replace(iidx, Inst::Const(cidx));
}
_ => todo!(),
_ => panic!(),
}
}
(Operand::Var(_), Operand::Var(_)) => (),
Expand All @@ -259,26 +259,18 @@ impl Opt {
self.an.op_map(&self.m, x.rhs(&self.m)),
) {
(Operand::Var(op_iidx), Operand::Const(op_cidx)) => {
match self.m.const_(op_cidx) {
Const::Int(_, 0) => {
// Replace `x >> 0` with `x`.
self.m.replace(iidx, Inst::Copy(op_iidx));
}
_ => {
// Canonicalise to (Var, Const).
self.m.replace(
iidx,
BinOpInst::new(
Operand::Var(op_iidx),
BinOp::LShr,
Operand::Const(op_cidx),
)
.into(),
);
}
if let Const::Int(_, 0) = self.m.const_(op_cidx) {
// Replace `x >> 0` with `x`.
self.m.replace(iidx, Inst::Copy(op_iidx));
}
}
(Operand::Const(op_cidx), Operand::Var(_)) => {
if let Const::Int(tyidx, 0) = self.m.const_(op_cidx) {
// Replace `0 >> x` with `0`.
let new_cidx = self.m.insert_const_int(*tyidx, 0)?;
self.m.replace(iidx, Inst::Const(new_cidx));
}
}
(Operand::Const(_), Operand::Var(_)) => (),
(Operand::Const(lhs_cidx), Operand::Const(rhs_cidx)) => {
match (self.m.const_(lhs_cidx), self.m.const_(rhs_cidx)) {
(Const::Int(lhs_tyidx, lhs_v), Const::Int(rhs_tyidx, rhs_v)) => {
Expand All @@ -292,7 +284,7 @@ impl Opt {
)?;
self.m.replace(iidx, Inst::Const(cidx));
}
_ => todo!(),
_ => panic!(),
}
}
(Operand::Var(_), Operand::Var(_)) => (),
Expand Down Expand Up @@ -392,7 +384,42 @@ impl Opt {
)?;
self.m.replace(iidx, Inst::Const(cidx));
}
_ => todo!(),
_ => panic!(),
}
}
(Operand::Var(_), Operand::Var(_)) => (),
},
BinOp::Shl => match (
self.an.op_map(&self.m, x.lhs(&self.m)),
self.an.op_map(&self.m, x.rhs(&self.m)),
) {
(Operand::Var(op_iidx), Operand::Const(op_cidx)) => {
if let Const::Int(_, 0) = self.m.const_(op_cidx) {
// Replace `x << 0` with `x`.
self.m.replace(iidx, Inst::Copy(op_iidx));
}
}
(Operand::Const(op_cidx), Operand::Var(_)) => {
if let Const::Int(tyidx, 0) = self.m.const_(op_cidx) {
// Replace `0 << x` with `0`.
let new_cidx = self.m.insert_const_int(*tyidx, 0)?;
self.m.replace(iidx, Inst::Const(new_cidx));
}
}
(Operand::Const(lhs_cidx), Operand::Const(rhs_cidx)) => {
match (self.m.const_(lhs_cidx), self.m.const_(rhs_cidx)) {
(Const::Int(lhs_tyidx, lhs_v), Const::Int(rhs_tyidx, rhs_v)) => {
debug_assert_eq!(lhs_tyidx, rhs_tyidx);
let Ty::Integer(bits) = self.m.type_(*lhs_tyidx) else {
panic!()
};
let cidx = self.m.insert_const_int(
*lhs_tyidx,
(lhs_v << rhs_v).truncate(*bits),
)?;
self.m.replace(iidx, Inst::Const(cidx));
}
_ => panic!(),
}
}
(Operand::Var(_), Operand::Var(_)) => (),
Expand Down Expand Up @@ -425,7 +452,57 @@ impl Opt {
}
(Operand::Const(_), Operand::Var(_)) | (Operand::Var(_), Operand::Var(_)) => (),
},
_ => (),
BinOp::Xor => match (
self.an.op_map(&self.m, x.lhs(&self.m)),
self.an.op_map(&self.m, x.rhs(&self.m)),
) {
(Operand::Const(op_cidx), Operand::Var(op_iidx))
| (Operand::Var(op_iidx), Operand::Const(op_cidx)) => {
match self.m.const_(op_cidx) {
Const::Int(_, 0) => {
// Replace `x ^ 0` with `x`.
self.m.replace(iidx, Inst::Copy(op_iidx));
}
_ => {
// Canonicalise to (Var, Const).
self.m.replace(
iidx,
BinOpInst::new(
Operand::Var(op_iidx),
BinOp::Xor,
Operand::Const(op_cidx),
)
.into(),
);
}
}
}
(Operand::Const(lhs_cidx), Operand::Const(rhs_cidx)) => {
match (self.m.const_(lhs_cidx), self.m.const_(rhs_cidx)) {
(Const::Int(lhs_tyidx, lhs_v), Const::Int(rhs_tyidx, rhs_v)) => {
debug_assert_eq!(lhs_tyidx, rhs_tyidx);
let Ty::Integer(bits) = self.m.type_(*lhs_tyidx) else {
panic!()
};
let cidx = self.m.insert_const_int(
*lhs_tyidx,
(lhs_v ^ rhs_v).truncate(*bits),
)?;
self.m.replace(iidx, Inst::Const(cidx));
}
_ => panic!(),
}
}
(Operand::Var(_), Operand::Var(_)) => (),
},
_ => {
if let (Operand::Const(_), Operand::Const(_)) = (
self.an.op_map(&self.m, x.lhs(&self.m)),
self.an.op_map(&self.m, x.rhs(&self.m)),
) {
todo!("{:?}", x.binop());
}
}
},
Inst::DynPtrAdd(x) => {
if let Operand::Const(cidx) = self.an.op_map(&self.m, x.num_elems(&self.m)) {
Expand Down Expand Up @@ -963,6 +1040,22 @@ mod test {
black_box %0
",
);

Module::assert_ir_transform_eq(
"
entry:
%0: i8 = param 0
%1: i8 = lshr 0i8, %0
black_box %1
",
|m| opt(m).unwrap(),
"
...
entry:
%0: i8 = param ...
black_box 0i8
",
);
}

#[test]
Expand All @@ -984,6 +1077,60 @@ mod test {
);
}

#[test]
fn opt_shl_zero() {
Module::assert_ir_transform_eq(
"
entry:
%0: i8 = param 0
%1: i8 = shl %0, 0i8
black_box %1
",
|m| opt(m).unwrap(),
"
...
entry:
%0: i8 = param ...
black_box %0
",
);

Module::assert_ir_transform_eq(
"
entry:
%0: i8 = param 0
%1: i8 = shl 0i8, %0
black_box %1
",
|m| opt(m).unwrap(),
"
...
entry:
%0: i8 = param ...
black_box 0i8
",
);
}

#[test]
fn opt_shl_const() {
Module::assert_ir_transform_eq(
"
entry:
%0: i8 = 2i8
%1: i8 = 1i8
%2: i8 = shl %0, %1
black_box %2
",
|m| opt(m).unwrap(),
"
...
entry:
black_box 4i8
",
);
}

#[test]
fn opt_or_zero() {
Module::assert_ir_transform_eq(
Expand Down Expand Up @@ -1012,7 +1159,7 @@ mod test {
"
entry:
%0: i8 = 2i8
%1: i8 = 1i8
%1: i8 = 3i8
ptersilie marked this conversation as resolved.
Show resolved Hide resolved
%2: i8 = or %0, %1
black_box %2
",
Expand Down Expand Up @@ -1137,6 +1284,47 @@ mod test {
);
}

#[test]
fn opt_xor_zero() {
Module::assert_ir_transform_eq(
"
entry:
%0: i8 = param 0
%1: i8 = xor %0, 0i8
%2: i8 = xor 0i8, %0
black_box %1
black_box %2
",
|m| opt(m).unwrap(),
"
...
entry:
%0: i8 = param ...
black_box %0
black_box %0
",
);
}

#[test]
fn opt_xor_const() {
Module::assert_ir_transform_eq(
"
entry:
%0: i8 = 2i8
%1: i8 = 3i8
%2: i8 = xor %0, %1
black_box %2
",
|m| opt(m).unwrap(),
"
...
entry:
black_box 1i8
",
);
}

#[test]
fn opt_icmp_const() {
Module::assert_ir_transform_eq(
Expand Down