[Mesa-dev] [PATCH] R600/SI: Custom select 64-bit ADD
Matt Arsenault
Matthew.Arsenault at amd.com
Fri Feb 7 10:31:20 PST 2014
I didn't think to try this. Where is the address folding happening?
On 02/07/2014 07:46 AM, Tom Stellard wrote:
> From: Tom Stellard <thomas.stellard at amd.com>
>
> ---
> lib/Target/R600/AMDGPUISelDAGToDAG.cpp | 48 ++++++++++++++++++++++++++++++++++
> lib/Target/R600/SIISelLowering.cpp | 29 --------------------
> lib/Target/R600/SIISelLowering.h | 1 -
> test/CodeGen/R600/add.ll | 10 +++++++
> test/CodeGen/R600/add_i64.ll | 23 +++++++++++-----
> 5 files changed, 75 insertions(+), 36 deletions(-)
>
> diff --git a/lib/Target/R600/AMDGPUISelDAGToDAG.cpp b/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
> index a989135..fea875c 100644
> --- a/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
> +++ b/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
> @@ -200,6 +200,54 @@ SDNode *AMDGPUDAGToDAGISel::Select(SDNode *N) {
> }
> switch (Opc) {
> default: break;
> + // We are selecting i64 ADD here instead of custom lower it during
> + // DAG legalization, so we can fold some i64 ADDs used for address
> + // calculation into the LOAD and STORE instructions.
> + case ISD::ADD: {
> + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>();
> + if (N->getValueType(0) != MVT::i64 ||
> + ST.getGeneration() < AMDGPUSubtarget::SOUTHERN_ISLANDS)
> + break;
> +
> + SDLoc DL(N);
> + SDValue LHS = N->getOperand(0);
> + SDValue RHS = N->getOperand(1);
> +
> + SDValue Sub0 = CurDAG->getTargetConstant(AMDGPU::sub0, MVT::i32);
> + SDValue Sub1 = CurDAG->getTargetConstant(AMDGPU::sub1, MVT::i32);
> +
> + SDNode *Lo0 = CurDAG->getMachineNode(TargetOpcode::EXTRACT_SUBREG,
> + DL, MVT::i32, LHS, Sub0);
> + SDNode *Hi0 = CurDAG->getMachineNode(TargetOpcode::EXTRACT_SUBREG,
> + DL, MVT::i32, LHS, Sub1);
> +
> + SDNode *Lo1 = CurDAG->getMachineNode(TargetOpcode::EXTRACT_SUBREG,
> + DL, MVT::i32, RHS, Sub0);
> + SDNode *Hi1 = CurDAG->getMachineNode(TargetOpcode::EXTRACT_SUBREG,
> + DL, MVT::i32, RHS, Sub1);
> +
> + SDVTList VTList = CurDAG->getVTList(MVT::i32, MVT::Glue);
> +
> + SmallVector<SDValue, 8> AddLoArgs;
> + AddLoArgs.push_back(SDValue(Lo0, 0));
> + AddLoArgs.push_back(SDValue(Lo1, 0));
> +
> + SDNode *AddLo = CurDAG->getMachineNode(AMDGPU::S_ADD_I32, DL,
> + VTList, AddLoArgs);
> + SDValue Carry = SDValue(AddLo, 1);
> + SDNode *AddHi = CurDAG->getMachineNode(AMDGPU::S_ADDC_U32, DL,
> + MVT::i32, SDValue(Hi0, 0),
> + SDValue(Hi1, 0), Carry);
> +
> + SDValue Args[5] = {
> + CurDAG->getTargetConstant(AMDGPU::SReg_64RegClassID, MVT::i32),
> + SDValue(AddLo,0),
> + Sub0,
> + SDValue(AddHi,0),
> + Sub1,
> + };
> + return CurDAG->SelectNodeTo(N, AMDGPU::REG_SEQUENCE, MVT::i64, Args, 5);
> + }
> case ISD::BUILD_VECTOR: {
> unsigned RegClassID;
> const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>();
> diff --git a/lib/Target/R600/SIISelLowering.cpp b/lib/Target/R600/SIISelLowering.cpp
> index 0a22d16..4d2f370 100644
> --- a/lib/Target/R600/SIISelLowering.cpp
> +++ b/lib/Target/R600/SIISelLowering.cpp
> @@ -76,7 +76,6 @@ SITargetLowering::SITargetLowering(TargetMachine &TM) :
> setOperationAction(ISD::VECTOR_SHUFFLE, MVT::v16i32, Expand);
> setOperationAction(ISD::VECTOR_SHUFFLE, MVT::v16f32, Expand);
>
> - setOperationAction(ISD::ADD, MVT::i64, Legal);
> setOperationAction(ISD::ADD, MVT::i32, Legal);
> setOperationAction(ISD::ADDC, MVT::i32, Legal);
> setOperationAction(ISD::ADDE, MVT::i32, Legal);
> @@ -475,7 +474,6 @@ SDValue SITargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
> SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
> switch (Op.getOpcode()) {
> default: return AMDGPUTargetLowering::LowerOperation(Op, DAG);
> - case ISD::ADD: return LowerADD(Op, DAG);
> case ISD::BRCOND: return LowerBRCOND(Op, DAG);
> case ISD::LOAD: {
> LoadSDNode *Load = dyn_cast<LoadSDNode>(Op);
> @@ -613,33 +611,6 @@ SDValue SITargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
> return SDValue();
> }
>
> -SDValue SITargetLowering::LowerADD(SDValue Op,
> - SelectionDAG &DAG) const {
> - if (Op.getValueType() != MVT::i64)
> - return SDValue();
> -
> - SDLoc DL(Op);
> - SDValue LHS = Op.getOperand(0);
> - SDValue RHS = Op.getOperand(1);
> -
> - SDValue Zero = DAG.getConstant(0, MVT::i32);
> - SDValue One = DAG.getConstant(1, MVT::i32);
> -
> - SDValue Lo0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, LHS, Zero);
> - SDValue Hi0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, LHS, One);
> -
> - SDValue Lo1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, RHS, Zero);
> - SDValue Hi1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, RHS, One);
> -
> - SDVTList VTList = DAG.getVTList(MVT::i32, MVT::Glue);
> -
> - SDValue AddLo = DAG.getNode(ISD::ADDC, DL, VTList, Lo0, Lo1);
> - SDValue Carry = AddLo.getValue(1);
> - SDValue AddHi = DAG.getNode(ISD::ADDE, DL, VTList, Hi0, Hi1, Carry);
> -
> - return DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, AddLo, AddHi.getValue(0));
> -}
> -
> /// \brief Helper function for LowerBRCOND
> static SDNode *findUser(SDValue Value, unsigned Opcode) {
>
> diff --git a/lib/Target/R600/SIISelLowering.h b/lib/Target/R600/SIISelLowering.h
> index c9a43e6..ce94a13 100644
> --- a/lib/Target/R600/SIISelLowering.h
> +++ b/lib/Target/R600/SIISelLowering.h
> @@ -31,7 +31,6 @@ class SITargetLowering : public AMDGPUTargetLowering {
> SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG) const;
> SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG) const;
> SDValue LowerZERO_EXTEND(SDValue Op, SelectionDAG &DAG) const;
> - SDValue LowerADD(SDValue Op, SelectionDAG &DAG) const;
> SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
>
> SDValue ResourceDescriptorToi128(SDValue Op, SelectionDAG &DAG) const;
> diff --git a/test/CodeGen/R600/add.ll b/test/CodeGen/R600/add.ll
> index e4e7bc6..8de87f4 100644
> --- a/test/CodeGen/R600/add.ll
> +++ b/test/CodeGen/R600/add.ll
> @@ -75,3 +75,13 @@ entry:
> store <8 x i32> %0, <8 x i32> addrspace(1)* %out
> ret void
> }
> +
> +; FUNC-LABEL: @add64
> +; SI-CHECK: S_ADD_I32
> +; SI-CHECK: S_ADDC_U32
> +define void @add64(i64 addrspace(1)* %out, i64 %a, i64 %b) {
> +entry:
> + %0 = add i64 %a, %b
> + store i64 %0, i64 addrspace(1)* %out
> + ret void
> +}
> diff --git a/test/CodeGen/R600/add_i64.ll b/test/CodeGen/R600/add_i64.ll
> index 303a1cb..82cd8a9 100644
> --- a/test/CodeGen/R600/add_i64.ll
> +++ b/test/CodeGen/R600/add_i64.ll
> @@ -1,14 +1,13 @@
> -; XFAIL: *
> -; This will fail until i64 add is enabled
> -
> ; RUN: llc < %s -march=r600 -mcpu=SI | FileCheck --check-prefix=SI %s
>
>
> -declare i32 @llvm.SI.tid() readnone
> +declare i32 @llvm.r600.read.tidig.x() readnone
>
> ; SI-LABEL: @test_i64_vreg:
> +; SI: V_ADD_I32
> +; SI: V_ADDC_U32
> define void @test_i64_vreg(i64 addrspace(1)* noalias %out, i64 addrspace(1)* noalias %inA, i64 addrspace(1)* noalias %inB) {
> - %tid = call i32 @llvm.SI.tid() readnone
> + %tid = call i32 @llvm.r600.read.tidig.x() readnone
> %a_ptr = getelementptr i64 addrspace(1)* %inA, i32 %tid
> %b_ptr = getelementptr i64 addrspace(1)* %inB, i32 %tid
> %a = load i64 addrspace(1)* %a_ptr
> @@ -20,6 +19,8 @@ define void @test_i64_vreg(i64 addrspace(1)* noalias %out, i64 addrspace(1)* noa
>
> ; Check that the SGPR add operand is correctly moved to a VGPR.
> ; SI-LABEL: @sgpr_operand:
> +; SI: V_ADD_I32
> +; SI: V_ADDC_U32
> define void @sgpr_operand(i64 addrspace(1)* noalias %out, i64 addrspace(1)* noalias %in, i64 addrspace(1)* noalias %in_bar, i64 %a) {
> %foo = load i64 addrspace(1)* %in, align 8
> %result = add i64 %foo, %a
> @@ -31,6 +32,8 @@ define void @sgpr_operand(i64 addrspace(1)* noalias %out, i64 addrspace(1)* noal
> ; SGPR as other operand.
> ;
> ; SI-LABEL: @sgpr_operand_reversed:
> +; SI: V_ADD_I32
> +; SI: V_ADDC_U32
> define void @sgpr_operand_reversed(i64 addrspace(1)* noalias %out, i64 addrspace(1)* noalias %in, i64 %a) {
> %foo = load i64 addrspace(1)* %in, align 8
> %result = add i64 %a, %foo
> @@ -40,6 +43,10 @@ define void @sgpr_operand_reversed(i64 addrspace(1)* noalias %out, i64 addrspace
>
>
> ; SI-LABEL: @test_v2i64_sreg:
> +; SI: S_ADD_I32
> +; SI: S_ADDC_U32
> +; SI: S_ADD_I32
> +; SI: S_ADDC_U32
> define void @test_v2i64_sreg(<2 x i64> addrspace(1)* noalias %out, <2 x i64> %a, <2 x i64> %b) {
> %result = add <2 x i64> %a, %b
> store <2 x i64> %result, <2 x i64> addrspace(1)* %out
> @@ -47,8 +54,12 @@ define void @test_v2i64_sreg(<2 x i64> addrspace(1)* noalias %out, <2 x i64> %a,
> }
>
> ; SI-LABEL: @test_v2i64_vreg:
> +; SI: V_ADD_I32
> +; SI: V_ADDC_U32
> +; SI: V_ADD_I32
> +; SI: V_ADDC_U32
> define void @test_v2i64_vreg(<2 x i64> addrspace(1)* noalias %out, <2 x i64> addrspace(1)* noalias %inA, <2 x i64> addrspace(1)* noalias %inB) {
> - %tid = call i32 @llvm.SI.tid() readnone
> + %tid = call i32 @llvm.r600.read.tidig.x() readnone
> %a_ptr = getelementptr <2 x i64> addrspace(1)* %inA, i32 %tid
> %b_ptr = getelementptr <2 x i64> addrspace(1)* %inB, i32 %tid
> %a = load <2 x i64> addrspace(1)* %a_ptr
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