AMDGPU: Add comment about clamps

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314952 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AMDGPU/SIFoldOperands.cpp b/lib/Target/AMDGPU/SIFoldOperands.cpp
index a527afb25da032ce533a3970c54ab940af38a65d..a7a12cd1015fcbc51aea8da76680b2f5b921763e 100644 (file)
--- a/lib/Target/AMDGPU/SIFoldOperands.cpp
+++ b/lib/Target/AMDGPU/SIFoldOperands.cpp
@@ -723,6 +723,8 @@ void SIFoldOperands::foldInstOperand(MachineInstr &MI,
   }
 }
 
+// Clamp patterns are canonically selected to v_max_* instructions, so only
+// handle them.
 const MachineOperand *SIFoldOperands::isClamp(const MachineInstr &MI) const {
   unsigned Op = MI.getOpcode();
   switch (Op) {