diff --git a/lib/Target/R600/SIRegisterInfo.cpp b/lib/Target/R600/SIRegisterInfo.cpp index 0131e37f514..cffea129de9 100644 --- a/lib/Target/R600/SIRegisterInfo.cpp +++ b/lib/Target/R600/SIRegisterInfo.cpp @@ -145,6 +145,7 @@ void SIRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI, for (unsigned i = 0, e = NumSubRegs; i < e; ++i) { unsigned SubReg = getPhysRegSubReg(MI->getOperand(0).getReg(), &AMDGPU::SGPR_32RegClass, i); + bool isM0 = SubReg == AMDGPU::M0; struct SIMachineFunctionInfo::SpilledReg Spill = MFI->getSpilledReg(MF, Index, i); @@ -153,10 +154,17 @@ void SIRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI, Ctx.emitError("Ran out of VGPRs for spilling SGPR"); } + if (isM0) { + SubReg = RS->scavengeRegister(&AMDGPU::SGPR_32RegClass, MI, 0); + } + BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_READLANE_B32), SubReg) .addReg(Spill.VGPR) .addImm(Spill.Lane); - + if (isM0) { + BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_MOV_B32), AMDGPU::M0) + .addReg(SubReg); + } } TII->insertNOPs(MI, 3); MI->eraseFromParent(); diff --git a/test/CodeGen/R600/m0-spill.ll b/test/CodeGen/R600/m0-spill.ll new file mode 100644 index 00000000000..a8b0e0d5f10 --- /dev/null +++ b/test/CodeGen/R600/m0-spill.ll @@ -0,0 +1,34 @@ +; RUN: llc < %s -march=r600 -mcpu=SI -verify-machineinstrs | FileCheck %s + +@lds = external addrspace(3) global [64 x float] + +; CHECK-LABEL: {{^}}main: +; CHECK-NOT: v_readlane_b32 m0 +define void @main(<16 x i8> addrspace(2)* inreg, <16 x i8> addrspace(2)* inreg, <32 x i8> addrspace(2)* inreg, i32 inreg) "ShaderType"="0" { +main_body: + %4 = call float @llvm.SI.fs.constant(i32 0, i32 0, i32 %3) + %cmp = fcmp ueq float 0.0, %4 + br i1 %cmp, label %if, label %else + +if: + %lds_ptr = getelementptr [64 x float] addrspace(3)* @lds, i32 0, i32 0 + %lds_data = load float addrspace(3)* %lds_ptr + br label %endif + +else: + %interp = call float @llvm.SI.fs.constant(i32 0, i32 0, i32 %3) + br label %endif + +endif: + %export = phi float [%lds_data, %if], [%interp, %else] + %5 = call i32 @llvm.SI.packf16(float %export, float %export) + %6 = bitcast i32 %5 to float + call void @llvm.SI.export(i32 15, i32 1, i32 1, i32 0, i32 1, float %6, float %6, float %6, float %6) + ret void +} + +declare float @llvm.SI.fs.constant(i32, i32, i32) readnone + +declare i32 @llvm.SI.packf16(float, float) readnone + +declare void @llvm.SI.export(i32, i32, i32, i32, i32, float, float, float, float)