AMDGPU: Remove special case of SGPR_LO class in imm folding

[arsenm]

Previous change accidentally broke this which shows it's not
doing anything.

[arsenm]

• AMDGPU: Remove special case of SGPR_LO class in imm folding #155518 👈 (View in Graphite)
• AMDGPU: Fold mov imm to copy to av_32 class #155428
• main

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[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

Changes

Previous change accidentally broke this which shows it's not
doing anything.

---

Full diff: https://github.com/llvm/llvm-project/pull/155518.diff

1 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/SIFoldOperands.cpp (-8)

diff --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
index e1bc6d0239111..3979e1e0c44aa 100644
--- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
@@ -1260,14 +1260,6 @@ void SIFoldOperandsImpl::foldOperand(
       return;
 
     const TargetRegisterClass *DestRC = TRI->getRegClassForReg(*MRI, DestReg);
-    // Allow immediates COPYd into sgpr_lo16 to be further folded while
-    // still being legal if not further folded
-    if (DestRC == &AMDGPU::SGPR_LO16RegClass) {
-      assert(ST->useRealTrue16Insts());
-      MRI->setRegClass(DestReg, &AMDGPU::SGPR_32RegClass);
-      DestRC = &AMDGPU::SGPR_32RegClass;
-    }
-
     // In order to fold immediates into copies, we need to change the copy to a
     // MOV. Find a compatible mov instruction with the value.
     for (unsigned MovOp :

[rampitec]

LGTM since there are no test changes. Unless it fails testing.