[AMDGPU] Make __GCC_DESTRUCTIVE_SIZE 128 on AMDGPU

[jhuber6]

Summary:
The cache line size on AMDGPU varies between 64 and 128 (The lowest L2
cache also goes to 256 on some architectures.) This macro is intended to
present a size that will not cause destructive interference, so we
choose the larger of those values.

[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-backend-amdgpu

Author: Joseph Huber (jhuber6)

Changes

Summary:
The cache line size on AMDGPU varies between 64 and 128 (The lowest L2
cache also goes to 256 on some architectures.) This macro is intended to
present a size that will not cause destructive interference, so we
choose the larger of those values.

---

Full diff: https://github.com/llvm/llvm-project/pull/115241.diff

1 Files Affected:

• (modified) clang/lib/Basic/Targets/AMDGPU.h (+4)

diff --git a/clang/lib/Basic/Targets/AMDGPU.h b/clang/lib/Basic/Targets/AMDGPU.h
index 6edd3474d4edae..81e96ed65c47bf 100644
--- a/clang/lib/Basic/Targets/AMDGPU.h
+++ b/clang/lib/Basic/Targets/AMDGPU.h
@@ -462,6 +462,10 @@ class LLVM_LIBRARY_VISIBILITY AMDGPUTargetInfo final : public TargetInfo {
   }
 
   bool hasHIPImageSupport() const override { return HasImage; }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(128, 128);
+  }
 };
 
 } // namespace targets

[llvmbot]

@llvm/pr-subscribers-clang

Author: Joseph Huber (jhuber6)

Changes

Summary:
The cache line size on AMDGPU varies between 64 and 128 (The lowest L2
cache also goes to 256 on some architectures.) This macro is intended to
present a size that will not cause destructive interference, so we
choose the larger of those values.

---

Full diff: https://github.com/llvm/llvm-project/pull/115241.diff

1 Files Affected:

• (modified) clang/lib/Basic/Targets/AMDGPU.h (+4)

diff --git a/clang/lib/Basic/Targets/AMDGPU.h b/clang/lib/Basic/Targets/AMDGPU.h
index 6edd3474d4edae..81e96ed65c47bf 100644
--- a/clang/lib/Basic/Targets/AMDGPU.h
+++ b/clang/lib/Basic/Targets/AMDGPU.h
@@ -462,6 +462,10 @@ class LLVM_LIBRARY_VISIBILITY AMDGPUTargetInfo final : public TargetInfo {
   }
 
   bool hasHIPImageSupport() const override { return HasImage; }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(128, 128);
+  }
 };
 
 } // namespace targets

[shiltian]

Test