JIT: reduce importer spilling for some stfld #51158
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
If we know which local is going to be updated, just spill that local.
ghost
added
the
area-CodeGen-coreclr
Member
Author
|
Inspired by this example using System;
using System.Runtime.CompilerServices;
public struct StructField<T>
{
public T Value;
}
class X
{
static volatile int value;
[MethodImpl(MethodImplOptions.NoInlining)]
public void StructOfStructOfField1()
{
var x = new StructField<StructField<int>> { Value = new StructField<int> { Value = 123 } };
value = x.Value.Value;
}
}Old codegen was: G_M12726_IG01:
push rax
xor eax, eax
mov qword ptr [rsp], rax
;; bbWeight=1 PerfScore 2.25
G_M12726_IG02:
lea rax, bword ptr [rsp]
mov dword ptr [rax], 123
mov eax, dword ptr [rsp]
mov dword ptr [reloc classVar[0xd1ffab1e]], eax
;; bbWeight=1 PerfScore 3.50
G_M12726_IG03:
add rsp, 8
ret
New codegen is G_M12726_IG01:
;; bbWeight=1 PerfScore 0.00
G_M12726_IG02:
mov dword ptr [reloc classVar[0xd1ffab1e]], 123
;; bbWeight=1 PerfScore 1.00
G_M12726_IG03:
ret
@sandreeko PTAL Detail diffsDetail diffsDetail diffsDetail diffsDetail diffs |
Member
Author
|
fyi @stephentoub, still apparently simple. |
sandreenko
approved these changes
Apr 14, 2021
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
4 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
If we know which local is going to be updated, just spill that local.