[llvm] Suppress template parameter information in the skeleton CU. (PR #173342)

[Liu Ke via llvm-commits]

https://github.com/Sockke created https://github.com/llvm/llvm-project/pull/173342

Suppress template parameter information to optimize gmlt-like inline scope information in the skeleton CU.

Such information may not need to be copied to the skeleton CU?

A project within ByteDance enabled flags such as `-fsplit-dwarf-inlining` and `-O3`, resulting in a **5%** reduction in overall size, with the debug_info section reduced by over **30%**:
<img width="3448" height="1634" alt="image" src="https://github.com/user-attachments/assets/5b5041e7-e106-4711-a56d-a41e9c5b6b74" />


>From 1f99e2438772a499583688bc5abdf304f59bf4f6 Mon Sep 17 00:00:00 2001
From: "liuke.gehry" <liuke.gehry at bytedance.com>
Date: Tue, 23 Dec 2025 14:38:03 +0800
Subject: [PATCH] Suppress template parameter information to optimize gmlt-like
 inline scope information in the skeleton CU.

---
 llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp   | 3 ++-
 llvm/test/DebugInfo/X86/fission-template.ll | 4 +---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 330fe333a58cc..b7e603c58792b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1420,7 +1420,8 @@ bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP,
   }
 
   // Add function template parameters.
-  addTemplateParams(SPDie, SP->getTemplateParams());
+  if (!Minimal)
+    addTemplateParams(SPDie, SP->getTemplateParams());
 
   // Add the linkage name if we have one and it isn't in the Decl.
   StringRef LinkageName = SP->getLinkageName();
diff --git a/llvm/test/DebugInfo/X86/fission-template.ll b/llvm/test/DebugInfo/X86/fission-template.ll
index b45b650846d00..7faf7cc2fa973 100644
--- a/llvm/test/DebugInfo/X86/fission-template.ll
+++ b/llvm/test/DebugInfo/X86/fission-template.ll
@@ -20,9 +20,7 @@
 ; CHECK:          DW_TAG_subprogram
 ; CHECK-NEXT:     DW_AT_linkage_name	("_Z2f2IiEvv")
 ; CHECK-NEXT:     DW_AT_name	("f2<int>")
-; CHECK:          DW_TAG_template_type_parameter
-; CHECK-NEXT:       DW_AT_type	(0x{{.*}} "int")
-; CHECK-NEXT:       DW_AT_name	("T")
+; CHECK-NOT:      DW_TAG_template_type_parameter
 ; CHECK:      .debug_info.dwo contents:
 ; CHECK:        DW_TAG_compile_unit
 ; CHECK:          DW_TAG_subprogram