Skip to content

[DirectX] Remove intrinsic definitions with no use #133459

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

Merged
merged 2 commits into from
Mar 29, 2025
Merged

[DirectX] Remove intrinsic definitions with no use #133459

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c80789d
[DirectX] Remove intrinsic definitions with no use
farzonl Mar 28, 2025
82cac25
revert changes to LegalizerPass, instead do cleanup in DXILFinalizeLi…
farzonl Mar 28, 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
12 changes: 10 additions & 2 deletions llvm/lib/Target/DirectX/DXILFinalizeLinkage.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,15 +18,15 @@
using namespace llvm;

static bool finalizeLinkage(Module &M) {
SmallPtrSet<Function *, 8> Funcs;
SmallVector<Function *> Funcs;
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

just a cleanup since I'm touching this file.


// Collect non-entry and non-exported functions to set to internal linkage.
for (Function &EF : M.functions()) {
if (EF.isIntrinsic())
continue;
if (EF.hasFnAttribute("hlsl.shader") || EF.hasFnAttribute("hlsl.export"))
continue;
Funcs.insert(&EF);
Funcs.push_back(&EF);
}

for (Function *F : Funcs) {
Expand All @@ -36,6 +36,14 @@ static bool finalizeLinkage(Module &M) {
M.getFunctionList().erase(F);
}

// Do a pass over intrinsics that are no longer used and remove them.
Funcs.clear();
for (Function &F : M.functions())
if (F.isIntrinsic() && F.use_empty())
Funcs.push_back(&F);
for (Function *F : Funcs)
F->eraseFromParent();

return false;
}

Expand Down
22 changes: 22 additions & 0 deletions llvm/test/CodeGen/DirectX/remove-dead-intriniscs.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@

; RUN: llc %s -mtriple=dxil-pc-shadermodel6.3-library --filetype=asm -o - | FileCheck %s

declare void @llvm.lifetime.start.p0(i64, ptr) #1
declare void @llvm.lifetime.end.p0(i64, ptr) #1
declare i32 @llvm.dx.udot.v4i32(<4 x i32>, <4 x i32>) #2
declare void @llvm.memset.p0.i32(ptr, i8, i32, i1) #3

; CHECK-NOT: declare void @llvm.lifetime.start.p0(i64, ptr)
; CHECK-NOT: declare void @llvm.lifetime.end.p0(i64, ptr)
; CHECK-NOT: declare i32 @llvm.dx.udot.v4i32(<4 x i32>, <4 x i32>)
; CHECK-NOT: declare void @llvm.memset.p0.i32(ptr, i8, i32, i1)

; CHECK-LABEL: empty_fn
define void @empty_fn () local_unnamed_addr #0 {
ret void
}

attributes #0 = { convergent norecurse nounwind "hlsl.export"}
attributes #1 = { nounwind memory(argmem: readwrite) }
attributes #2 = { nounwind memory(none) }
attributes #3 = { nounwind memory(argmem: write) }
Loading