[llvm] [RISCV] Convert -mtune=generic to generic-rv32/rv64 in RISCVSubtarget::initializeSubtargetDependencies. (PR #168612)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

The "generic" entry in tablegen is really a dummy entry. We shouldn't use it for anything. Remap "generic" to either generic-rv32 or generic-rv64 based on the triple.

---
Full diff: https://github.com/llvm/llvm-project/pull/168612.diff


1 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVSubtarget.cpp (+2) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.cpp b/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
index 926cc9ea547a6..f86265a21d17e 100644
--- a/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
+++ b/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
@@ -88,6 +88,8 @@ RISCVSubtarget::initializeSubtargetDependencies(const Triple &TT, StringRef CPU,
 
   if (TuneCPU.empty())
     TuneCPU = CPU;
+  if (TuneCPU == "generic")
+    TuneCPU = Is64Bit ? "generic-rv64" : "generic-rv32";
 
   TuneInfo = RISCVTuneInfoTable::getRISCVTuneInfo(TuneCPU);
   // If there is no TuneInfo for this CPU, we fail back to generic.

``````````

</details>


https://github.com/llvm/llvm-project/pull/168612