[llvm] r375265 - AMDGPU: Fix SMEM WAR hazard for gfx10 readlane

[Austin Kerbow via llvm-commits]

Author: kerbowa
Date: Fri Oct 18 11:20:30 2019
New Revision: 375265

URL: http://llvm.org/viewvc/llvm-project?rev=375265&view=rev
Log:
AMDGPU: Fix SMEM WAR hazard for gfx10 readlane

Summary: Hazard recognizer fails to see hazard with V_READLANE_B32_gfx10.

Reviewers: rampitec

Reviewed By: rampitec

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69172

Modified:
    llvm/trunk/lib/Target/AMDGPU/GCNHazardRecognizer.cpp
    llvm/trunk/test/CodeGen/AMDGPU/smem-war-hazard.mir

Modified: llvm/trunk/lib/Target/AMDGPU/GCNHazardRecognizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/GCNHazardRecognizer.cpp?rev=375265&r1=375264&r2=375265&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/GCNHazardRecognizer.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/GCNHazardRecognizer.cpp Fri Oct 18 11:20:30 2019
@@ -952,6 +952,7 @@ bool GCNHazardRecognizer::fixSMEMtoVecto
   unsigned SDSTName;
   switch (MI->getOpcode()) {
   case AMDGPU::V_READLANE_B32:
+  case AMDGPU::V_READLANE_B32_gfx10:
   case AMDGPU::V_READFIRSTLANE_B32:
     SDSTName = AMDGPU::OpName::vdst;
     break;

Modified: llvm/trunk/test/CodeGen/AMDGPU/smem-war-hazard.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/smem-war-hazard.mir?rev=375265&r1=375264&r2=375265&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/smem-war-hazard.mir (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/smem-war-hazard.mir Fri Oct 18 11:20:30 2019
@@ -304,6 +304,21 @@ body: |
     S_ENDPGM 0
 ...
 
+# Workaround since spilling/restoring SGPRs use real opcodes.
+# GCN-LABEL: name: hazard_smem_war_readlane_gfx10
+# GCN:      S_LOAD_DWORD_IMM
+# GCN:      $sgpr_null = S_MOV_B32 0
+# GCN-NEXT: V_READLANE_B32_gfx10
+---
+name: hazard_smem_war_readlane_gfx10
+body: |
+  bb.0:
+    liveins: $sgpr0, $sgpr1, $sgpr3, $vgpr0
+    $sgpr2 = S_LOAD_DWORD_IMM $sgpr0_sgpr1, 0, 0, 0
+    $sgpr0 = V_READLANE_B32_gfx10 $vgpr0, $sgpr3
+    S_ENDPGM 0
+...
+
 # GCN-LABEL: name: hazard_smem_war_readfirstlane
 # GCN:      S_LOAD_DWORD_IMM
 # GCN:      $sgpr_null = S_MOV_B32 0