AMDGPU/GlobalISel: Add IMMPopCount xform

Partially fixes BFE pattern import.

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index c0830ac2a0b..095c667e143 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -2128,6 +2128,12 @@ void AMDGPUInstructionSelector::renderBitcastImm(MachineInstrBuilder &MIB,
   }
 }
 
+void AMDGPUInstructionSelector::renderPopcntImm(MachineInstrBuilder &MIB,
+                                                const MachineInstr &MI) const {
+  assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && "Expected G_CONSTANT");
+  MIB.addImm(MI.getOperand(1).getCImm()->getValue().countPopulation());
+}
+
 bool AMDGPUInstructionSelector::isInlineImmediate16(int64_t Imm) const {
   return AMDGPU::isInlinableLiteral16(Imm, STI.hasInv2PiInlineImm());
 }