aco: reserve 2 sgprs for each branch

[mesa.git] / src / amd / compiler / aco_insert_NOPs.cpp

diff --git a/src/amd/compiler/aco_insert_NOPs.cpp b/src/amd/compiler/aco_insert_NOPs.cpp
index bb703d7481eb4683e973fdfed711f74bfd7638a5..a609c18d5dc304bdc3e00e6af240d1f58e113791 100644 (file)
--- a/src/amd/compiler/aco_insert_NOPs.cpp
+++ b/src/amd/compiler/aco_insert_NOPs.cpp
@@ -602,20 +602,29 @@ void handle_instruction_gfx10(Program *program, Block *cur_block, NOP_ctx_gfx10
       if (program->wave_size == 64)
          ctx.sgprs_read_by_VMEM.set(exec_hi);
    } else if (instr->isSALU() || instr->format == Format::SMEM) {
+      if (instr->opcode == aco_opcode::s_waitcnt) {
+         /* Hazard is mitigated by "s_waitcnt vmcnt(0)" */
+         uint16_t imm = static_cast<SOPP_instruction*>(instr.get())->imm;
+         unsigned vmcnt = (imm & 0xF) | ((imm & (0x3 << 14)) >> 10);
+         if (vmcnt == 0)
+            ctx.sgprs_read_by_VMEM.reset();
+      } else if (instr->opcode == aco_opcode::s_waitcnt_depctr) {
+         /* Hazard is mitigated by a s_waitcnt_depctr with a magic imm */
+         const SOPP_instruction *sopp = static_cast<const SOPP_instruction *>(instr.get());
+         if (sopp->imm == 0xffe3)
+            ctx.sgprs_read_by_VMEM.reset();
+      }
+
       /* Check if SALU writes an SGPR that was previously read by the VALU */
       if (check_written_regs(instr, ctx.sgprs_read_by_VMEM)) {
          ctx.sgprs_read_by_VMEM.reset();
 
-         /* Insert v_nop to mitigate the problem */
-         aco_ptr<VOP1_instruction> nop{create_instruction<VOP1_instruction>(aco_opcode::v_nop, Format::VOP1, 0, 0)};
-         new_instructions.emplace_back(std::move(nop));
+         /* Insert s_waitcnt_depctr instruction with magic imm to mitigate the problem */
+         aco_ptr<SOPP_instruction> depctr{create_instruction<SOPP_instruction>(aco_opcode::s_waitcnt_depctr, Format::SOPP, 0, 0)};
+         depctr->imm = 0xffe3;
+         depctr->block = -1;
+         new_instructions.emplace_back(std::move(depctr));
       }
-   } else if (instr->opcode == aco_opcode::s_waitcnt) {
-      /* Hazard is mitigated by "s_waitcnt vmcnt(0)" */
-      uint16_t imm = static_cast<SOPP_instruction*>(instr.get())->imm;
-      unsigned vmcnt = (imm & 0xF) | ((imm & (0x3 << 14)) >> 10);
-      if (vmcnt == 0)
-         ctx.sgprs_read_by_VMEM.reset();
    } else if (instr->isVALU()) {
       /* Hazard is mitigated by any VALU instruction */
       ctx.sgprs_read_by_VMEM.reset();
@@ -795,7 +804,9 @@ void mitigate_hazards(Program *program)
 
 void insert_NOPs(Program* program)
 {
-   if (program->chip_class >= GFX10)
+   if (program->chip_class >= GFX10_3)
+      ; /* no hazards/bugs to mitigate */
+   else if (program->chip_class >= GFX10)
       mitigate_hazards<NOP_ctx_gfx10, handle_instruction_gfx10>(program);
    else
       mitigate_hazards<NOP_ctx_gfx6, handle_instruction_gfx6>(program);