From 0a6326e6aaaffec59d8490f89b9bc187e79a686d Mon Sep 17 00:00:00 2001
From: Russel Arbore <russel.jma@gmail.com>
Date: Thu, 27 Feb 2025 19:06:34 -0600
Subject: [PATCH] Infer parallelreduce in bfs
---
hercules_ir/src/ir.rs | 17 ++++++--
hercules_opt/src/pred.rs | 63 ++++++++++++++++++++++++++++
hercules_opt/src/schedule.rs | 31 +++++++++++---
juno_samples/rodinia/bfs/src/bfs.jn | 2 +-
juno_samples/rodinia/bfs/src/cpu.sch | 3 +-
5 files changed, 106 insertions(+), 10 deletions(-)
diff --git a/hercules_ir/src/ir.rs b/hercules_ir/src/ir.rs
index 5dfe2915..f6aafa35 100644
--- a/hercules_ir/src/ir.rs
+++ b/hercules_ir/src/ir.rs
@@ -1048,9 +1048,20 @@ impl Constant {
}
}
- /*
- * Useful for GVN.
- */
+ pub fn is_false(&self) -> bool {
+ match self {
+ Constant::Boolean(false) => true,
+ _ => false,
+ }
+ }
+
+ pub fn is_true(&self) -> bool {
+ match self {
+ Constant::Boolean(true) => true,
+ _ => false,
+ }
+ }
+
pub fn is_zero(&self) -> bool {
match self {
Constant::Integer8(0) => true,
diff --git a/hercules_opt/src/pred.rs b/hercules_opt/src/pred.rs
index ed7c3a85..587c4507 100644
--- a/hercules_opt/src/pred.rs
+++ b/hercules_opt/src/pred.rs
@@ -136,6 +136,69 @@ pub fn predication(editor: &mut FunctionEditor, typing: &Vec<TypeID>) {
bad_branches.insert(branch);
}
}
+
+ // Do a quick and dirty rewrite to convert select(a, b, false) to a && b and
+ // select(a, b, true) to a || b.
+ for id in editor.node_ids() {
+ let nodes = &editor.func().nodes;
+ if let Node::Ternary {
+ op: TernaryOperator::Select,
+ first,
+ second,
+ third,
+ } = nodes[id.idx()]
+ {
+ if let Some(cons) = nodes[second.idx()].try_constant()
+ && editor.get_constant(cons).is_false()
+ {
+ editor.edit(|mut edit| {
+ let node = edit.add_node(Node::Binary {
+ op: BinaryOperator::And,
+ left: first,
+ right: third,
+ });
+ edit = edit.replace_all_uses(id, node)?;
+ edit.delete_node(id)
+ });
+ } else if let Some(cons) = nodes[third.idx()].try_constant()
+ && editor.get_constant(cons).is_false()
+ {
+ editor.edit(|mut edit| {
+ let node = edit.add_node(Node::Binary {
+ op: BinaryOperator::And,
+ left: first,
+ right: second,
+ });
+ edit = edit.replace_all_uses(id, node)?;
+ edit.delete_node(id)
+ });
+ } else if let Some(cons) = nodes[second.idx()].try_constant()
+ && editor.get_constant(cons).is_true()
+ {
+ editor.edit(|mut edit| {
+ let node = edit.add_node(Node::Binary {
+ op: BinaryOperator::Or,
+ left: first,
+ right: third,
+ });
+ edit = edit.replace_all_uses(id, node)?;
+ edit.delete_node(id)
+ });
+ } else if let Some(cons) = nodes[third.idx()].try_constant()
+ && editor.get_constant(cons).is_true()
+ {
+ editor.edit(|mut edit| {
+ let node = edit.add_node(Node::Binary {
+ op: BinaryOperator::Or,
+ left: first,
+ right: second,
+ });
+ edit = edit.replace_all_uses(id, node)?;
+ edit.delete_node(id)
+ });
+ }
+ }
+ }
}
/*
diff --git a/hercules_opt/src/schedule.rs b/hercules_opt/src/schedule.rs
index d7ae4048..9bc7823e 100644
--- a/hercules_opt/src/schedule.rs
+++ b/hercules_opt/src/schedule.rs
@@ -69,6 +69,26 @@ pub fn infer_parallel_reduce(
chain_id = reduct;
}
+ // If the use is a phi that uses the reduce and a write, then we might
+ // want to parallelize this still. Set the chain ID to the write.
+ if let Node::Phi {
+ control: _,
+ ref data,
+ } = func.nodes[chain_id.idx()]
+ && data.len()
+ == data
+ .into_iter()
+ .filter(|phi_use| **phi_use == last_reduce)
+ .count()
+ + 1
+ {
+ chain_id = *data
+ .into_iter()
+ .filter(|phi_use| **phi_use != last_reduce)
+ .next()
+ .unwrap();
+ }
+
// Check for a Write-Reduce tight cycle.
if let Node::Write {
collect,
@@ -130,12 +150,13 @@ pub fn infer_monoid_reduce(
reduce_cycles: &HashMap<NodeID, HashSet<NodeID>>,
) {
let is_binop_monoid = |op| {
- matches!(
- op,
- BinaryOperator::Add | BinaryOperator::Mul | BinaryOperator::Or | BinaryOperator::And
- )
+ op == BinaryOperator::Add
+ || op == BinaryOperator::Mul
+ || op == BinaryOperator::Or
+ || op == BinaryOperator::And
};
- let is_intrinsic_monoid = |intrinsic| matches!(intrinsic, Intrinsic::Max | Intrinsic::Min);
+ let is_intrinsic_monoid =
+ |intrinsic| intrinsic == Intrinsic::Max || intrinsic == Intrinsic::Min;
for id in editor.node_ids() {
let func = editor.func();
diff --git a/juno_samples/rodinia/bfs/src/bfs.jn b/juno_samples/rodinia/bfs/src/bfs.jn
index 51dcd945..ca0f7774 100644
--- a/juno_samples/rodinia/bfs/src/bfs.jn
+++ b/juno_samples/rodinia/bfs/src/bfs.jn
@@ -43,10 +43,10 @@ fn bfs<n, m: usize>(graph_nodes: Node[n], source: u32, edges: u32[m]) -> i32[n]
}
@loop2 for i in 0..n {
+ stop = stop && updated[i];
if updated[i] {
mask[i] = true;
visited[i] = true;
- stop = false;
updated[i] = false;
}
}
diff --git a/juno_samples/rodinia/bfs/src/cpu.sch b/juno_samples/rodinia/bfs/src/cpu.sch
index 44cfa8ad..ae67fdd9 100644
--- a/juno_samples/rodinia/bfs/src/cpu.sch
+++ b/juno_samples/rodinia/bfs/src/cpu.sch
@@ -23,7 +23,8 @@ fixpoint {
fork-guard-elim(*);
}
simpl!(*);
+predication(*);
+simpl!(*);
unforkify(*);
-
gcm(*);
--
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