[llvm] [AMDGPU][Disassembler] Use target feature for `.amdhsa_reserve_xnack_mask` instead of hard code zero (PR #161771)

[Shilei Tian via llvm-commits]

https://github.com/shiltian updated https://github.com/llvm/llvm-project/pull/161771

>From 0bae295459e5f33047eafc00ad651a8604b40d63 Mon Sep 17 00:00:00 2001
From: Shilei Tian <i at tianshilei.me>
Date: Thu, 2 Oct 2025 23:36:46 -0400
Subject: [PATCH 1/2] [AMDGPU][Disassembler] Use target feature for
 `.amdhsa_reserve_xnack_mask` instead of hard code zero

There is no test change at this moment because we don't have a target that has this feature by default yet.
---
 llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
index 2d5ae29c1037c..3d86e41e9e1b7 100644
--- a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
+++ b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
@@ -2303,7 +2303,12 @@ Expected<bool> AMDGPUDisassembler::decodeCOMPUTE_PGM_RSRC1(
   KdStream << Indent << ".amdhsa_reserve_vcc " << 0 << '\n';
   if (!hasArchitectedFlatScratch())
     KdStream << Indent << ".amdhsa_reserve_flat_scratch " << 0 << '\n';
-  KdStream << Indent << ".amdhsa_reserve_xnack_mask " << 0 << '\n';
+  bool ReservedXnackMask = STI.hasFeature(AMDGPU::FeatureXNACK);
+#ifndef NDEBUG
+  assert(!ReservedXnackMask || STI.hasFeature(AMDGPU::FeatureSupportsXNACK));
+#endif
+  KdStream << Indent << ".amdhsa_reserve_xnack_mask " << ReservedXnackMask
+           << '\n';
   KdStream << Indent << ".amdhsa_next_free_sgpr " << NextFreeSGPR << "\n";
 
   CHECK_RESERVED_BITS(COMPUTE_PGM_RSRC1_PRIORITY);

>From a4dad07978450ee60b3944c2b00083879108efd4 Mon Sep 17 00:00:00 2001
From: Shilei Tian <i at tianshilei.me>
Date: Fri, 3 Oct 2025 01:09:44 -0400
Subject: [PATCH 2/2] fix comment

---
 llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
index 3d86e41e9e1b7..2120bf8f3afb2 100644
--- a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
+++ b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
@@ -2304,9 +2304,7 @@ Expected<bool> AMDGPUDisassembler::decodeCOMPUTE_PGM_RSRC1(
   if (!hasArchitectedFlatScratch())
     KdStream << Indent << ".amdhsa_reserve_flat_scratch " << 0 << '\n';
   bool ReservedXnackMask = STI.hasFeature(AMDGPU::FeatureXNACK);
-#ifndef NDEBUG
   assert(!ReservedXnackMask || STI.hasFeature(AMDGPU::FeatureSupportsXNACK));
-#endif
   KdStream << Indent << ".amdhsa_reserve_xnack_mask " << ReservedXnackMask
            << '\n';
   KdStream << Indent << ".amdhsa_next_free_sgpr " << NextFreeSGPR << "\n";