Commit c8f0d27e authored by Jay Foad's avatar Jay Foad
Browse files

[AMDGPU] Fix the gfx10 scheduling model for f32 conversions 

Summary:
As far as I can tell on gfx10 conversions to/from f32 (that are not
converting f32 to/from f64) are full rate instructions, but they were
marked as quarter rate instructions.

I have fixed this for gfx10 only. I assume the scheduling model was
correct for older architectures, though I don't have any documentation
handy to confirm that.

Reviewers: rampitec, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75392
parent 47ec8702

llvm/lib/Target/AMDGPU/SISchedule.td

+3 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ def MIMFMARead : SchedRead; 


// Vector ALU instructions

def Write32Bit         : SchedWrite;

def WriteFloatCvt      : SchedWrite;

def WriteQuarterRate32 : SchedWrite;



def WriteFloatFMA   : SchedWrite;
@@ -126,6 +127,7 @@ multiclass SICommonWriteRes { 


  def : HWVALUWriteRes<Write32Bit,         1>;

  def : HWVALUWriteRes<Write64Bit,         2>;

  def : HWVALUWriteRes<WriteFloatCvt,      4>;

  def : HWVALUWriteRes<WriteQuarterRate32, 4>;

  def : HWVALUWriteRes<Write2PassMAI,      2>;

  def : HWVALUWriteRes<Write8PassMAI,      8>;
@@ -185,6 +187,7 @@ let SchedModel = GFX10SpeedModel in { 
// The latency values are 1 / (operations / cycle).

// Add 1 stall cycle for VGPR read.

def : HWWriteRes<Write32Bit,         [HWVALU, HWRC],   5>;

def : HWWriteRes<WriteFloatCvt,      [HWVALU, HWRC],   5>;

def : HWWriteRes<Write64Bit,         [HWVALU, HWRC],   9>;

def : HWWriteRes<WriteQuarterRate32, [HWVALU, HWRC],   17>;

def : HWWriteRes<WriteFloatFMA,      [HWVALU, HWRC],   5>;

llvm/lib/Target/AMDGPU/VOP1Instructions.td

+2 −2
Original line number Diff line number Diff line
@@ -190,7 +190,7 @@ defm V_CVT_U32_F64 : VOP1Inst <"v_cvt_u32_f64", VOP_I32_F64, fp_to_uint>; 
defm V_CVT_F64_U32 : VOP1Inst <"v_cvt_f64_u32", VOP1_F64_I32, uint_to_fp>;

} // End SchedRW = [WriteDoubleCvt]



let SchedRW = [WriteQuarterRate32] in {

let SchedRW = [WriteFloatCvt] in {

defm V_CVT_F32_I32 : VOP1Inst <"v_cvt_f32_i32", VOP1_F32_I32, sint_to_fp>;

defm V_CVT_F32_U32 : VOP1Inst <"v_cvt_f32_u32", VOP1_F32_I32, uint_to_fp>;

defm V_CVT_U32_F32 : VOP1Inst <"v_cvt_u32_f32", VOP_I32_F32, fp_to_uint>;
@@ -202,7 +202,7 @@ defm V_CVT_F32_F16 : VOP1Inst <"v_cvt_f32_f16", VOP_F32_F16, fpextend>; 
defm V_CVT_RPI_I32_F32 : VOP1Inst <"v_cvt_rpi_i32_f32", VOP_I32_F32, cvt_rpi_i32_f32>;

defm V_CVT_FLR_I32_F32 : VOP1Inst <"v_cvt_flr_i32_f32", VOP_I32_F32, cvt_flr_i32_f32>;

defm V_CVT_OFF_F32_I4 : VOP1Inst  <"v_cvt_off_f32_i4", VOP1_F32_I32>;

} // End SchedRW = [WriteQuarterRate32]

} // End SchedRW = [WriteFloatCvt]



defm V_CVT_F32_UBYTE0 : VOP1Inst <"v_cvt_f32_ubyte0", VOP1_F32_I32, AMDGPUcvt_f32_ubyte0>;

defm V_CVT_F32_UBYTE1 : VOP1Inst <"v_cvt_f32_ubyte1", VOP1_F32_I32, AMDGPUcvt_f32_ubyte1>;