From c6c8a05c509b30600d2ccb4be635f05cd71c68a4 Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Thu, 17 May 2012 13:36:12 -0400
Subject: [PATCH] radeon/llvm: Lower lrp intrinsic during ISel

---
 .../drivers/radeon/AMDGPUISelLowering.cpp      | 18 ++++++++++++++++++
 .../drivers/radeon/AMDGPUISelLowering.h        |  1 +
 src/gallium/drivers/radeon/R600Instructions.td |  7 -------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/gallium/drivers/radeon/AMDGPUISelLowering.cpp b/src/gallium/drivers/radeon/AMDGPUISelLowering.cpp
index 53f04c57de1..0417273d971 100644
--- a/src/gallium/drivers/radeon/AMDGPUISelLowering.cpp
+++ b/src/gallium/drivers/radeon/AMDGPUISelLowering.cpp
@@ -45,6 +45,8 @@ SDValue AMDGPUTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
     default: return Op;
     case AMDGPUIntrinsic::AMDIL_abs:
       return LowerIntrinsicIABS(Op, DAG);
+    case AMDGPUIntrinsic::AMDGPU_lrp:
+      return LowerIntrinsicLRP(Op, DAG);
     case AMDGPUIntrinsic::AMDIL_mad:
       return DAG.getNode(AMDILISD::MAD, DL, VT, Op.getOperand(1),
                               Op.getOperand(2), Op.getOperand(3));
@@ -73,6 +75,22 @@ SDValue AMDGPUTargetLowering::LowerIntrinsicIABS(SDValue Op,
   return DAG.getNode(AMDGPUISD::SMAX, DL, VT, Neg, Op.getOperand(1));
 }
 
+/// Linear Interpolation
+/// LRP(a, b, c) = muladd(a,  b, (1 - a) * c)
+SDValue AMDGPUTargetLowering::LowerIntrinsicLRP(SDValue Op,
+    SelectionDAG &DAG) const
+{
+  DebugLoc DL = Op.getDebugLoc();
+  EVT VT = Op.getValueType();
+  SDValue OneSubA = DAG.getNode(ISD::FSUB, DL, VT, DAG.getConstant(1, VT),
+                                                   Op.getOperand(1));
+  SDValue OneSubAC = DAG.getNode(ISD::FMUL, DL, VT, OneSubA,
+                                                    Op.getOperand(3));
+  return DAG.getNode(AMDILISD::MAD, DL, VT, Op.getOperand(1),
+                                               Op.getOperand(2),
+                                               OneSubAC);
+}
+
 void AMDGPUTargetLowering::addLiveIn(MachineInstr * MI,
     MachineFunction * MF, MachineRegisterInfo & MRI,
     const TargetInstrInfo * TII, unsigned reg) const
diff --git a/src/gallium/drivers/radeon/AMDGPUISelLowering.h b/src/gallium/drivers/radeon/AMDGPUISelLowering.h
index e4c778787a2..3e5e81bfef5 100644
--- a/src/gallium/drivers/radeon/AMDGPUISelLowering.h
+++ b/src/gallium/drivers/radeon/AMDGPUISelLowering.h
@@ -41,6 +41,7 @@ public:
 
   virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerIntrinsicIABS(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerIntrinsicLRP(SDValue Op, SelectionDAG &DAG) const;
   virtual const char* getTargetNodeName(unsigned Opcode) const;
 
 };
diff --git a/src/gallium/drivers/radeon/R600Instructions.td b/src/gallium/drivers/radeon/R600Instructions.td
index df2d56bbde0..459010c7833 100644
--- a/src/gallium/drivers/radeon/R600Instructions.td
+++ b/src/gallium/drivers/radeon/R600Instructions.td
@@ -672,11 +672,6 @@ class DIV_Common <InstR600 recip_ieee> : Pat<
   (MUL R600_Reg32:$src0, (recip_ieee R600_Reg32:$src1))
 >;
 
-class LRP_Common <InstR600 muladd> : Pat <
-  (int_AMDGPU_lrp R600_Reg32:$src0, R600_Reg32:$src1, R600_Reg32:$src2),
-  (muladd R600_Reg32:$src0, R600_Reg32:$src1, (MUL (SUB_f32 ONE, R600_Reg32:$src0), R600_Reg32:$src2))
->;
-
 class SSG_Common <InstR600 cndgt, InstR600 cndge> : Pat <
   (int_AMDGPU_ssg R600_Reg32:$src),
   (cndgt R600_Reg32:$src, (f32 ONE), (cndge R600_Reg32:$src, (f32 ZERO), (f32 NEG_ONE)))
@@ -725,7 +720,6 @@ let Gen = AMDGPUGen.R600 in {
 } // End AMDGPUGen.R600
 
   def DIV_r600 : DIV_Common<RECIP_IEEE_r600>;
-  def LRP_r600 : LRP_Common<MULADD_r600>;
   def POW_r600 : POW_Common<LOG_IEEE_r600, EXP_IEEE_r600, MUL, GPRF32>;
   def SSG_r600 : SSG_Common<CNDGT_r600, CNDGE_r600>;
   def TGSI_LIT_Z_r600 : TGSI_LIT_Z_Common<MUL_LIT_r600, LOG_CLAMPED_r600, EXP_IEEE_r600>;
@@ -904,7 +898,6 @@ let Gen = AMDGPUGen.EG_CAYMAN in {
 } // End AMDGPUGen.EG_CAYMAN
 
   def DIV_eg : DIV_Common<RECIP_IEEE_eg>;
-  def LRP_eg : LRP_Common<MULADD_eg>;
   def POW_eg : POW_Common<LOG_IEEE_eg, EXP_IEEE_eg, MUL, GPRF32>;
   def SSG_eg : SSG_Common<CNDGT_eg, CNDGE_eg>;
   def TGSI_LIT_Z_eg : TGSI_LIT_Z_Common<MUL_LIT_eg, LOG_CLAMPED_eg, EXP_IEEE_eg>;
-- 
2.30.2