[clang] [llvm] [AMDGPU] Emit a waitcnt instruction after each memory instruction (PR #79236)

[Jun Wang via cfe-commits]

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@@ -355,6 +356,18 @@ class SICacheControl {
                                    MachineBasicBlock::iterator &MI) const {
     return false;
   }
+
+public:
+  // The following is for supporting precise memory mode. When the option
+  // amdgpu-precise-memory is enabled, an s_waitcnt instruction is inserted
+  // after each memory instruction.
+
+  virtual bool
+  handleNonAtomicForPreciseMemory(MachineBasicBlock::iterator &MI) = 0;
+  /// Handles atomic instruction \p MI with \p IsAtomicWithRet indicating
+  /// whether \p MI returns a result.
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jwanggit86 wrote:

Adding the comments is mainly to be consistent with the existing code. Here the comment points out that the 2nd parameter is a property of the first parameter (MI), which is not absolutely clear by just looking at the code.

https://github.com/llvm/llvm-project/pull/79236