[PATCH] D101966: [AMDGPU] Fix WQM failure with single block inactive demote

[Carl Ritson via Phabricator via llvm-commits]

critson created this revision.
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Instruction test for inactive kill/demote needs to be based on
actual opcode not whether instruction would be lowered to demote.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D101966

Files:
  llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
  llvm/test/CodeGen/AMDGPU/llvm.amdgcn.wqm.demote.ll


Index: llvm/test/CodeGen/AMDGPU/llvm.amdgcn.wqm.demote.ll
===================================================================
--- llvm/test/CodeGen/AMDGPU/llvm.amdgcn.wqm.demote.ll
+++ llvm/test/CodeGen/AMDGPU/llvm.amdgcn.wqm.demote.ll
@@ -1184,6 +1184,44 @@
   ret void
 }
 
+define amdgpu_ps void @static_exact_nop(float %arg0, float %arg1) {
+; SI-LABEL: static_exact_nop:
+; SI:       ; %bb.0: ; %.entry
+; SI-NEXT:    v_cmp_gt_f32_e32 vcc, 0, v0
+; SI-NEXT:    v_cndmask_b32_e64 v0, 0, 1.0, vcc
+; SI-NEXT:    exp mrt1 v0, v0, v0, v0 done vm
+; SI-NEXT:    s_endpgm
+;
+; GFX9-LABEL: static_exact_nop:
+; GFX9:       ; %bb.0: ; %.entry
+; GFX9-NEXT:    v_cmp_gt_f32_e32 vcc, 0, v0
+; GFX9-NEXT:    v_cndmask_b32_e64 v0, 0, 1.0, vcc
+; GFX9-NEXT:    exp mrt1 v0, v0, v0, v0 done vm
+; GFX9-NEXT:    s_endpgm
+;
+; GFX10-32-LABEL: static_exact_nop:
+; GFX10-32:       ; %bb.0: ; %.entry
+; GFX10-32-NEXT:    v_cmp_gt_f32_e32 vcc_lo, 0, v0
+; GFX10-32-NEXT:    v_cndmask_b32_e64 v0, 0, 1.0, vcc_lo
+; GFX10-32-NEXT:    exp mrt1 v0, v0, v0, v0 done vm
+; GFX10-32-NEXT:    s_endpgm
+;
+; GFX10-64-LABEL: static_exact_nop:
+; GFX10-64:       ; %bb.0: ; %.entry
+; GFX10-64-NEXT:    v_cmp_gt_f32_e32 vcc, 0, v0
+; GFX10-64-NEXT:    v_cndmask_b32_e64 v0, 0, 1.0, vcc
+; GFX10-64-NEXT:    exp mrt1 v0, v0, v0, v0 done vm
+; GFX10-64-NEXT:    s_endpgm
+.entry:
+  %c0 = fcmp olt float %arg0, 0.000000e+00
+  %c1 = fcmp oge float %arg1, 0.0
+  call void @llvm.amdgcn.wqm.demote(i1 true)
+  %tmp1 = select i1 %c0, float 1.000000e+00, float 0.000000e+00
+  call void @llvm.amdgcn.exp.f32(i32 1, i32 15, float %tmp1, float %tmp1, float %tmp1, float %tmp1, i1 true, i1 true) #0
+  ret void
+}
+
+
 declare void @llvm.amdgcn.wqm.demote(i1) #0
 declare i1 @llvm.amdgcn.live.mask() #0
 declare void @llvm.amdgcn.exp.f32(i32, i32, float, float, float, float, i1, i1) #0
Index: llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
+++ llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
@@ -923,7 +923,7 @@
     } else {
       // Static: kill does nothing
       MachineInstr *NewTerm = nullptr;
-      if (IsDemote) {
+      if (MI.getOpcode() == AMDGPU::SI_DEMOTE_I1) {
         LIS->RemoveMachineInstrFromMaps(MI);
       } else {
         assert(MBB.succ_size() == 1);


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