radeon/llvm: Handle TGSI KIL opcode for SI.

Fixes piglit fp-kil and glBitmap() with radeonsi.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

src/gallium/drivers/radeon/SIISelLowering.cpp

@@ -129,6 +129,9 @@ MachineBasicBlock * SITargetLowering::EmitInstrWithCustomInserter(
   case AMDGPU::SI_INTERP_CONST:
     LowerSI_INTERP_CONST(MI, *BB, I);
     break;
+  case AMDGPU::SI_KIL:
+    LowerSI_KIL(MI, *BB, I, MRI);
+    break;
   case AMDGPU::SI_V_CNDLT:
     LowerSI_V_CNDLT(MI, *BB, I, MRI);
     break;
@@ -193,6 +196,38 @@ void SITargetLowering::LowerSI_INTERP_CONST(MachineInstr *MI,
   MI->eraseFromParent();
 }
 
+void SITargetLowering::LowerSI_KIL(MachineInstr *MI, MachineBasicBlock &BB,
+    MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const
+{
+  // Clear this pixel from the exec mask if the operand is negative
+  BuildMI(BB, I, BB.findDebugLoc(I), TII->get(AMDGPU::V_CMPX_LE_F32_e32),
+          AMDGPU::VCC)
+          .addReg(AMDGPU::SREG_LIT_0)
+          .addOperand(MI->getOperand(0));
+
+  // If the exec mask is non-zero, skip the next two instructions
+  BuildMI(BB, I, BB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECNZ))
+          .addImm(3)
+          .addReg(AMDGPU::EXEC);
+
+  // Exec mask is zero: Export to NULL target...
+  BuildMI(BB, I, BB.findDebugLoc(I), TII->get(AMDGPU::EXP))
+          .addImm(0)
+          .addImm(0x09) // V_008DFC_SQ_EXP_NULL
+          .addImm(0)
+          .addImm(1)
+          .addImm(1)
+          .addReg(AMDGPU::SREG_LIT_0)
+          .addReg(AMDGPU::SREG_LIT_0)
+          .addReg(AMDGPU::SREG_LIT_0)
+          .addReg(AMDGPU::SREG_LIT_0);
+
+  // ... and terminate wavefront
+  BuildMI(BB, I, BB.findDebugLoc(I), TII->get(AMDGPU::S_ENDPGM));
+
+  MI->eraseFromParent();
+}
+
 void SITargetLowering::LowerSI_V_CNDLT(MachineInstr *MI, MachineBasicBlock &BB,
     MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const
 {

src/gallium/drivers/radeon/SIISelLowering.h

@@ -33,6 +33,8 @@ class SITargetLowering : public AMDGPUTargetLowering
               MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const;
   void LowerSI_INTERP_CONST(MachineInstr *MI, MachineBasicBlock &BB,
               MachineBasicBlock::iterator I) const;
+  void LowerSI_KIL(MachineInstr *MI, MachineBasicBlock &BB,
+              MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const;
   void LowerSI_V_CNDLT(MachineInstr *MI, MachineBasicBlock &BB,
               MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const;
 

src/gallium/drivers/radeon/SIInstructions.td

@@ -959,6 +959,13 @@ def SI_INTERP_CONST : InstSI <
                                                  imm:$attr, SReg_32:$params))]
 >;
 
+def SI_KIL : InstSI <
+	(outs),
+	(ins VReg_32:$src),
+	"SI_KIL $src",
+	[(int_AMDGPU_kill VReg_32:$src)]
+>;
+
 } // end usesCustomInserter 
 
 // SI Psuedo branch instructions.  These are used by the CFG structurizer pass