From cbd36218bf761f971ce22e04c0ee1b49be6ab903 Mon Sep 17 00:00:00 2001 From: Triang3l Date: Wed, 19 Sep 2018 21:25:58 +0300 Subject: [PATCH] [D3D12] DXBC: Use switch instead of if for flow control (experimentally) --- src/xenia/gpu/dxbc_shader_translator.cc | 177 +++++++++++++++++------- 1 file changed, 130 insertions(+), 47 deletions(-) diff --git a/src/xenia/gpu/dxbc_shader_translator.cc b/src/xenia/gpu/dxbc_shader_translator.cc index e2601f84a..2e197fd9a 100644 --- a/src/xenia/gpu/dxbc_shader_translator.cc +++ b/src/xenia/gpu/dxbc_shader_translator.cc @@ -28,6 +28,10 @@ DEFINE_bool(dxbc_indexable_temps, true, "relative addressing of general-purpose registers - shaders rarely " "do that, but when they do, this may improve performance on AMD, " "but may cause unknown issues on Nvidia."); +DEFINE_bool(dxbc_switch, true, + "Use switch rather than if for flow control. Turning this off or " + "on may improve stability, though this heavily depends on the " + "driver."); namespace xe { namespace gpu { @@ -652,16 +656,33 @@ void DxbcShaderTranslator::StartTranslation() { ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); ++stat_.instruction_count; ++stat_.dynamic_flow_control_count; - // First label (pc == 0). - shader_code_.push_back( - ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_IF) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3) | - ENCODE_D3D10_SB_INSTRUCTION_TEST_BOOLEAN(D3D10_SB_INSTRUCTION_TEST_ZERO)); - shader_code_.push_back( - EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 1, 1)); - shader_code_.push_back(system_temp_ps_pc_p0_a0_); - ++stat_.instruction_count; - ++stat_.dynamic_flow_control_count; + // Switch and the first label (pc == 0). + if (FLAGS_dxbc_switch) { + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_SWITCH) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3)); + shader_code_.push_back( + EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 1, 1)); + shader_code_.push_back(system_temp_ps_pc_p0_a0_); + ++stat_.instruction_count; + ++stat_.dynamic_flow_control_count; + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_CASE) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3)); + shader_code_.push_back( + EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); + shader_code_.push_back(0); + ++stat_.instruction_count; + ++stat_.static_flow_control_count; + } else { + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_IF) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3) | + ENCODE_D3D10_SB_INSTRUCTION_TEST_BOOLEAN( + D3D10_SB_INSTRUCTION_TEST_ZERO)); + shader_code_.push_back( + EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 1, 1)); + shader_code_.push_back(system_temp_ps_pc_p0_a0_); + ++stat_.instruction_count; + ++stat_.dynamic_flow_control_count; + } } void DxbcShaderTranslator::CompleteVertexShader() { @@ -1002,10 +1023,20 @@ void DxbcShaderTranslator::CompletePixelShader() { } void DxbcShaderTranslator::CompleteShaderCode() { - // Close the last label. - shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ENDIF) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); - ++stat_.instruction_count; + // Close the last label and the switch. + if (FLAGS_dxbc_switch) { + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_BREAK) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + shader_code_.push_back( + ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ENDSWITCH) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + } else { + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ENDIF) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + } // End the main loop. shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_BREAK) | ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); @@ -2424,37 +2455,69 @@ void DxbcShaderTranslator::ProcessLabel(uint32_t cf_index) { ClosePredicate(); SetExecBoolConstant(kCfExecBoolConstantNone, false); - // Close the previous label. - shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ENDIF) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); - ++stat_.instruction_count; + if (FLAGS_dxbc_switch) { + // Fallthrough to the label from the previous one on the next iteration if + // no `continue` was done. Can't simply fallthrough because in DXBC, a + // non-empty switch case must end with a break. + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_MOV) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(5)); + shader_code_.push_back( + EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0010, 1)); + shader_code_.push_back(system_temp_ps_pc_p0_a0_); + shader_code_.push_back( + EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); + shader_code_.push_back(cf_index); + ++stat_.instruction_count; + ++stat_.mov_instruction_count; + shader_code_.push_back( + ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_CONTINUE) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + // Close the previous label. + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_BREAK) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + // Go to the next label. + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_CASE) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3)); + shader_code_.push_back( + EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); + shader_code_.push_back(cf_index); + ++stat_.instruction_count; + ++stat_.static_flow_control_count; + } else { + // Close the previous label. + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ENDIF) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; - // pc <= cf_index - uint32_t test_register = PushSystemTemp(); - shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_UGE) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(7)); - shader_code_.push_back( - EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0001, 1)); - shader_code_.push_back(test_register); - shader_code_.push_back( - EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); - shader_code_.push_back(cf_index); - shader_code_.push_back( - EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 1, 1)); - shader_code_.push_back(system_temp_ps_pc_p0_a0_); - ++stat_.instruction_count; - ++stat_.uint_instruction_count; - // if (pc <= cf_index) - shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_IF) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3) | - ENCODE_D3D10_SB_INSTRUCTION_TEST_BOOLEAN( - D3D10_SB_INSTRUCTION_TEST_NONZERO)); - shader_code_.push_back( - EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0, 1)); - shader_code_.push_back(test_register); - ++stat_.instruction_count; - ++stat_.dynamic_flow_control_count; - PopSystemTemp(); + // pc <= cf_index + uint32_t test_register = PushSystemTemp(); + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_UGE) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(7)); + shader_code_.push_back( + EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0001, 1)); + shader_code_.push_back(test_register); + shader_code_.push_back( + EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); + shader_code_.push_back(cf_index); + shader_code_.push_back( + EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 1, 1)); + shader_code_.push_back(system_temp_ps_pc_p0_a0_); + ++stat_.instruction_count; + ++stat_.uint_instruction_count; + // if (pc <= cf_index) + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_IF) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(3) | + ENCODE_D3D10_SB_INSTRUCTION_TEST_BOOLEAN( + D3D10_SB_INSTRUCTION_TEST_NONZERO)); + shader_code_.push_back( + EncodeVectorSelectOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0, 1)); + shader_code_.push_back(test_register); + ++stat_.instruction_count; + ++stat_.dynamic_flow_control_count; + PopSystemTemp(); + } } void DxbcShaderTranslator::ProcessExecInstructionBegin( @@ -2491,9 +2554,29 @@ void DxbcShaderTranslator::ProcessExecInstructionEnd( CheckPredicate(cf_exec_predicated_, cf_exec_predicate_condition_); } // Break out of the main loop. - shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_BREAK) | - ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); - ++stat_.instruction_count; + if (FLAGS_dxbc_switch) { + // Write an invalid value to pc. + shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_MOV) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(5)); + shader_code_.push_back( + EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0010, 1)); + shader_code_.push_back(system_temp_ps_pc_p0_a0_); + shader_code_.push_back( + EncodeScalarOperand(D3D10_SB_OPERAND_TYPE_IMMEDIATE32, 0)); + shader_code_.push_back(0xFFFFFFFFu); + ++stat_.instruction_count; + ++stat_.mov_instruction_count; + // Go to the next iteration, where switch cases won't be reached. + shader_code_.push_back( + ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_CONTINUE) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + } else { + shader_code_.push_back( + ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_BREAK) | + ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(1)); + ++stat_.instruction_count; + } } ClosePredicate(); cf_exec_predicated_ = false;