[llvm] c8f0d27 - [AMDGPU] Fix the gfx10 scheduling model for f32 conversions

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2020-03-10T19:31:24Z
New Revision: c8f0d27ef37cf9f6a808b5830c9bdc5686cc5bc4

URL: https://github.com/llvm/llvm-project/commit/c8f0d27ef37cf9f6a808b5830c9bdc5686cc5bc4
DIFF: https://github.com/llvm/llvm-project/commit/c8f0d27ef37cf9f6a808b5830c9bdc5686cc5bc4.diff

LOG: [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

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/SISchedule.td
    llvm/lib/Target/AMDGPU/VOP1Instructions.td

Removed: 
    


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diff  --git a/llvm/lib/Target/AMDGPU/SISchedule.td b/llvm/lib/Target/AMDGPU/SISchedule.td
index 5236e6c86c33..fdd1ad43a7b5 100644
--- a/llvm/lib/Target/AMDGPU/SISchedule.td
+++ b/llvm/lib/Target/AMDGPU/SISchedule.td
@@ -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>;

diff  --git a/llvm/lib/Target/AMDGPU/VOP1Instructions.td b/llvm/lib/Target/AMDGPU/VOP1Instructions.td
index 554612427efd..d39e698d9809 100644
--- a/llvm/lib/Target/AMDGPU/VOP1Instructions.td
+++ b/llvm/lib/Target/AMDGPU/VOP1Instructions.td
@@ -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>;