From cb4634e4cbebb396795ae8d2ceb9f94b408ebe89 Mon Sep 17 00:00:00 2001
From: Aaron Councilman <aaronjc4@illinois.edu>
Date: Fri, 22 Nov 2024 09:47:17 -0600
Subject: [PATCH] Fix bug when read later used in write
- Need to track nodes that are replaced as we perform replacements
---
hercules_opt/src/sroa.rs | 36 ++++++++++++++++++++++++++++++++++++
juno_samples/products.jn | 5 +++--
2 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/hercules_opt/src/sroa.rs b/hercules_opt/src/sroa.rs
index 7430dbca..59ee4a8a 100644
--- a/hercules_opt/src/sroa.rs
+++ b/hercules_opt/src/sroa.rs
@@ -435,8 +435,44 @@ pub fn sroa(editor: &mut FunctionEditor, reverse_postorder: &Vec<NodeID>, types:
});
// Replace uses of old reads
+ // Because a read that is being replaced could also be the node some other read is being
+ // replaced by (if the first read is then written into a product that is then read from again)
+ // we need to track what nodes have already been replaced (and by what) so we can properly
+ // replace uses without leaving users of nodes that should be deleted.
+ // replaced_by tracks what a node has been replaced by while replaced_of tracks everything that
+ // maps to a particular node (which is needed to maintain the data structure efficiently)
+ let mut replaced_by: HashMap<NodeID, NodeID> = HashMap::new();
+ let mut replaced_of: HashMap<NodeID, Vec<NodeID>> = HashMap::new();
for (old, new) in to_replace {
+ let new = match replaced_by.get(&new) {
+ Some(res) => *res,
+ None => new,
+ };
+
editor.edit(|edit| edit.replace_all_uses(old, new));
+ replaced_by.insert(old, new);
+
+ let mut replaced = vec![];
+ match replaced_of.get_mut(&old) {
+ Some(res) => {
+ std::mem::swap(res, &mut replaced);
+ }
+ None => {}
+ }
+
+ let new_of = match replaced_of.get_mut(&new) {
+ Some(res) => res,
+ None => {
+ replaced_of.insert(new, vec![]);
+ replaced_of.get_mut(&new).unwrap()
+ }
+ };
+ new_of.push(old);
+
+ for n in replaced {
+ replaced_by.insert(n, new);
+ new_of.push(n);
+ }
}
// Remove nodes
diff --git a/juno_samples/products.jn b/juno_samples/products.jn
index b97f1088..d39ca246 100644
--- a/juno_samples/products.jn
+++ b/juno_samples/products.jn
@@ -6,6 +6,7 @@ fn test_call(x : i32, y : f32) -> (i32, f32) {
return res;
}
-fn test(x : i32, y : f32) -> (i32, f32) {
- return test_call(x, y);
+fn test(x : i32, y : f32) -> (f32, i32) {
+ let res = test_call(x, y);
+ return (res.1, res.0);
}
--
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