From cbf902727862881735953df83463788583c1a615 Mon Sep 17 00:00:00 2001 From: Lioncash Date: Fri, 12 Mar 2021 13:16:52 -0500 Subject: [PATCH] thumb32: Implement STRB immediate variants --- src/frontend/A32/decoder/thumb32.inc | 8 +- .../impl/thumb32_store_single_data_item.cpp | 74 +++++++++++++++++++ .../A32/translate/impl/translate_thumb.h | 4 + 3 files changed, 82 insertions(+), 4 deletions(-) diff --git a/src/frontend/A32/decoder/thumb32.inc b/src/frontend/A32/decoder/thumb32.inc index bf2bc56a..c41766a6 100644 --- a/src/frontend/A32/decoder/thumb32.inc +++ b/src/frontend/A32/decoder/thumb32.inc @@ -124,10 +124,10 @@ INST(thumb32_UDF, "Invalid decoding", "11110-111-------10-0-- INST(thumb32_B_cond, "B (cond)", "11110Sccccvvvvvv10i0ivvvvvvvvvvv") // Store Single Data Item -//INST(thumb32_STRB_imm_1, "STRB (imm)", "111110000000--------1--1--------") -//INST(thumb32_STRB_imm_2, "STRB (imm)", "111110000000--------1100--------") -//INST(thumb32_STRB_imm_3, "STRB (imm)", "111110001000--------------------") -//INST(thumb32_STRBT, "STRBT", "111110000000--------1110--------") +INST(thumb32_STRB_imm_1, "STRB (imm)", "111110000000nnnntttt1PU1iiiiiiii") +INST(thumb32_STRB_imm_2, "STRB (imm)", "111110000000nnnntttt1100iiiiiiii") +INST(thumb32_STRB_imm_3, "STRB (imm)", "111110001000nnnnttttiiiiiiiiiiii") +INST(thumb32_STRBT, "STRBT", "111110000000nnnntttt1110iiiiiiii") INST(thumb32_STRB, "STRB (reg)", "111110000000nnnntttt000000iimmmm") //INST(thumb32_STRH_imm_1, "STRH (imm)", "111110000010--------1--1--------") //INST(thumb32_STRH_imm_2, "STRH (imm)", "111110000010--------1100--------") diff --git a/src/frontend/A32/translate/impl/thumb32_store_single_data_item.cpp b/src/frontend/A32/translate/impl/thumb32_store_single_data_item.cpp index 0b776e75..3b5617f6 100644 --- a/src/frontend/A32/translate/impl/thumb32_store_single_data_item.cpp +++ b/src/frontend/A32/translate/impl/thumb32_store_single_data_item.cpp @@ -29,6 +29,80 @@ static bool StoreRegister(ThumbTranslatorVisitor& v, Reg n, Reg t, Imm<2> imm2, return true; } +static bool StoreByteImmediate(ThumbTranslatorVisitor& v, Reg n, Reg t, bool P, bool U, bool W, Imm<8> imm8) { + const auto imm32 = imm8.ZeroExtend(); + const auto reg_n = v.ir.GetRegister(n); + const auto reg_t = v.ir.GetRegister(t); + + const IR::U32 offset_address = U ? v.ir.Add(reg_n, v.ir.Imm32(imm32)) + : v.ir.Sub(reg_n, v.ir.Imm32(imm32)); + const IR::U32 address = P ? offset_address + : reg_n; + const IR::U8 data = v.ir.LeastSignificantByte(reg_t); + + v.ir.WriteMemory8(address, data); + if (W) { + v.ir.SetRegister(n, offset_address); + } + + return true; +} + +bool ThumbTranslatorVisitor::thumb32_STRB_imm_1(Reg n, Reg t, bool P, bool U, Imm<8> imm8) { + if (n == Reg::PC) { + return UndefinedInstruction(); + } + if (t == Reg::PC || n == t) { + return UnpredictableInstruction(); + } + return StoreByteImmediate(*this, n, t, P, U, true, imm8); +} + +bool ThumbTranslatorVisitor::thumb32_STRB_imm_2(Reg n, Reg t, Imm<8> imm8) { + if (n == Reg::PC) { + return UndefinedInstruction(); + } + if (t == Reg::PC) { + return UnpredictableInstruction(); + } + return StoreByteImmediate(*this, n, t, true, false, false, imm8); +} + +bool ThumbTranslatorVisitor::thumb32_STRB_imm_3(Reg n, Reg t, Imm<12> imm12) { + if (n == Reg::PC) { + return UndefinedInstruction(); + } + if (t == Reg::PC) { + return UnpredictableInstruction(); + } + + const auto imm32 = imm12.ZeroExtend(); + const auto reg_n = ir.GetRegister(n); + const auto reg_t = ir.GetRegister(t); + const auto address = ir.Add(reg_n, ir.Imm32(imm32)); + const auto data = ir.LeastSignificantByte(reg_t); + + ir.WriteMemory8(address, data); + return true; +} + +bool ThumbTranslatorVisitor::thumb32_STRBT(Reg n, Reg t, Imm<8> imm8) { + // TODO: Add an unpredictable instruction path if this + // is executed in hypervisor mode if we ever support + // privileged execution levels. + + if (n == Reg::PC) { + return UndefinedInstruction(); + } + if (t == Reg::PC) { + return UnpredictableInstruction(); + } + + // Treat this as a normal STRB, given we don't support + // execution levels other than EL0 currently. + return StoreByteImmediate(*this, n, t, true, true, false, imm8); +} + bool ThumbTranslatorVisitor::thumb32_STRB(Reg n, Reg t, Imm<2> imm2, Reg m) { return StoreRegister(*this, n, t, imm2, m, [this](const IR::U32& offset_address, const IR::U32& data) { ir.WriteMemory8(offset_address, ir.LeastSignificantByte(data)); diff --git a/src/frontend/A32/translate/impl/translate_thumb.h b/src/frontend/A32/translate/impl/translate_thumb.h index d85942fd..6541842e 100644 --- a/src/frontend/A32/translate/impl/translate_thumb.h +++ b/src/frontend/A32/translate/impl/translate_thumb.h @@ -243,6 +243,10 @@ struct ThumbTranslatorVisitor final { bool thumb32_B_cond(Imm<1> S, Cond cond, Imm<6> hi, Imm<1> j1, Imm<1> j2, Imm<11> lo); // thumb32 store single data item instructions + bool thumb32_STRB_imm_1(Reg n, Reg t, bool P, bool U, Imm<8> imm8); + bool thumb32_STRB_imm_2(Reg n, Reg t, Imm<8> imm8); + bool thumb32_STRB_imm_3(Reg n, Reg t, Imm<12> imm12); + bool thumb32_STRBT(Reg n, Reg t, Imm<8> imm8); bool thumb32_STRB(Reg n, Reg t, Imm<2> imm2, Reg m); bool thumb32_STRH(Reg n, Reg t, Imm<2> imm2, Reg m); bool thumb32_STR_reg(Reg n, Reg t, Imm<2> imm2, Reg m);