/* * Tiny Code Generator for QEMU * * Copyright (c) 2018 SiFive, Inc * Copyright (c) 2008-2009 Arnaud Patard * Copyright (c) 2009 Aurelien Jarno * Copyright (c) 2008 Fabrice Bellard * * Based on i386/tcg-target.c and mips/tcg-target.c * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "tcg-pool.inc.c" #ifdef CONFIG_DEBUG_TCG static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { "zero", "ra", "sp", "gp", "tp", "t0", "t1", "t2", "s0", "s1", "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "s2", "s3", "s4", "s5", "s6", "s7", "s8", "s9", "s10", "s11", "t3", "t4", "t5", "t6" }; #endif static const int tcg_target_reg_alloc_order[] = { /* Call saved registers */ /* TCG_REG_S0 reservered for TCG_AREG0 */ TCG_REG_S1, TCG_REG_S2, TCG_REG_S3, TCG_REG_S4, TCG_REG_S5, TCG_REG_S6, TCG_REG_S7, TCG_REG_S8, TCG_REG_S9, TCG_REG_S10, TCG_REG_S11, /* Call clobbered registers */ TCG_REG_T0, TCG_REG_T1, TCG_REG_T2, TCG_REG_T3, TCG_REG_T4, TCG_REG_T5, TCG_REG_T6, /* Argument registers */ TCG_REG_A0, TCG_REG_A1, TCG_REG_A2, TCG_REG_A3, TCG_REG_A4, TCG_REG_A5, TCG_REG_A6, TCG_REG_A7, }; static const int tcg_target_call_iarg_regs[] = { TCG_REG_A0, TCG_REG_A1, TCG_REG_A2, TCG_REG_A3, TCG_REG_A4, TCG_REG_A5, TCG_REG_A6, TCG_REG_A7, }; static const int tcg_target_call_oarg_regs[] = { TCG_REG_A0, TCG_REG_A1, }; #define TCG_CT_CONST_ZERO 0x100 #define TCG_CT_CONST_S12 0x200 #define TCG_CT_CONST_N12 0x400 #define TCG_CT_CONST_M12 0x800 static inline tcg_target_long sextreg(tcg_target_long val, int pos, int len) { if (TCG_TARGET_REG_BITS == 32) { return sextract32(val, pos, len); } else { return sextract64(val, pos, len); } } /* parse target specific constraints */ static const char *target_parse_constraint(TCGArgConstraint *ct, const char *ct_str, TCGType type) { switch (*ct_str++) { case 'r': ct->ct |= TCG_CT_REG; ct->u.regs = 0xffffffff; break; case 'L': /* qemu_ld/qemu_st constraint */ ct->ct |= TCG_CT_REG; ct->u.regs = 0xffffffff; /* qemu_ld/qemu_st uses TCG_REG_TMP0 */ #if defined(CONFIG_SOFTMMU) tcg_regset_reset_reg(ct->u.regs, tcg_target_call_iarg_regs[0]); tcg_regset_reset_reg(ct->u.regs, tcg_target_call_iarg_regs[1]); tcg_regset_reset_reg(ct->u.regs, tcg_target_call_iarg_regs[2]); tcg_regset_reset_reg(ct->u.regs, tcg_target_call_iarg_regs[3]); tcg_regset_reset_reg(ct->u.regs, tcg_target_call_iarg_regs[4]); #endif break; case 'I': ct->ct |= TCG_CT_CONST_S12; break; case 'N': ct->ct |= TCG_CT_CONST_N12; break; case 'M': ct->ct |= TCG_CT_CONST_M12; break; case 'Z': /* we can use a zero immediate as a zero register argument. */ ct->ct |= TCG_CT_CONST_ZERO; break; default: return NULL; } return ct_str; } /* test if a constant matches the constraint */ static int tcg_target_const_match(tcg_target_long val, TCGType type, const TCGArgConstraint *arg_ct) { int ct = arg_ct->ct; if (ct & TCG_CT_CONST) { return 1; } if ((ct & TCG_CT_CONST_ZERO) && val == 0) { return 1; } if ((ct & TCG_CT_CONST_S12) && val == sextreg(val, 0, 12)) { return 1; } if ((ct & TCG_CT_CONST_N12) && -val == sextreg(-val, 0, 12)) { return 1; } if ((ct & TCG_CT_CONST_M12) && val >= -0xfff && val <= 0xfff) { return 1; } return 0; } /* * RISC-V Base ISA opcodes (IM) */ typedef enum { OPC_ADD = 0x33, OPC_ADDI = 0x13, OPC_AND = 0x7033, OPC_ANDI = 0x7013, OPC_AUIPC = 0x17, OPC_BEQ = 0x63, OPC_BGE = 0x5063, OPC_BGEU = 0x7063, OPC_BLT = 0x4063, OPC_BLTU = 0x6063, OPC_BNE = 0x1063, OPC_DIV = 0x2004033, OPC_DIVU = 0x2005033, OPC_JAL = 0x6f, OPC_JALR = 0x67, OPC_LB = 0x3, OPC_LBU = 0x4003, OPC_LD = 0x3003, OPC_LH = 0x1003, OPC_LHU = 0x5003, OPC_LUI = 0x37, OPC_LW = 0x2003, OPC_LWU = 0x6003, OPC_MUL = 0x2000033, OPC_MULH = 0x2001033, OPC_MULHSU = 0x2002033, OPC_MULHU = 0x2003033, OPC_OR = 0x6033, OPC_ORI = 0x6013, OPC_REM = 0x2006033, OPC_REMU = 0x2007033, OPC_SB = 0x23, OPC_SD = 0x3023, OPC_SH = 0x1023, OPC_SLL = 0x1033, OPC_SLLI = 0x1013, OPC_SLT = 0x2033, OPC_SLTI = 0x2013, OPC_SLTIU = 0x3013, OPC_SLTU = 0x3033, OPC_SRA = 0x40005033, OPC_SRAI = 0x40005013, OPC_SRL = 0x5033, OPC_SRLI = 0x5013, OPC_SUB = 0x40000033, OPC_SW = 0x2023, OPC_XOR = 0x4033, OPC_XORI = 0x4013, #if TCG_TARGET_REG_BITS == 64 OPC_ADDIW = 0x1b, OPC_ADDW = 0x3b, OPC_DIVUW = 0x200503b, OPC_DIVW = 0x200403b, OPC_MULW = 0x200003b, OPC_REMUW = 0x200703b, OPC_REMW = 0x200603b, OPC_SLLIW = 0x101b, OPC_SLLW = 0x103b, OPC_SRAIW = 0x4000501b, OPC_SRAW = 0x4000503b, OPC_SRLIW = 0x501b, OPC_SRLW = 0x503b, OPC_SUBW = 0x4000003b, #else /* Simplify code throughout by defining aliases for RV32. */ OPC_ADDIW = OPC_ADDI, OPC_ADDW = OPC_ADD, OPC_DIVUW = OPC_DIVU, OPC_DIVW = OPC_DIV, OPC_MULW = OPC_MUL, OPC_REMUW = OPC_REMU, OPC_REMW = OPC_REM, OPC_SLLIW = OPC_SLLI, OPC_SLLW = OPC_SLL, OPC_SRAIW = OPC_SRAI, OPC_SRAW = OPC_SRA, OPC_SRLIW = OPC_SRLI, OPC_SRLW = OPC_SRL, OPC_SUBW = OPC_SUB, #endif OPC_FENCE = 0x0000000f, } RISCVInsn; /* * RISC-V immediate and instruction encoders (excludes 16-bit RVC) */ /* Type-R */ static int32_t encode_r(RISCVInsn opc, TCGReg rd, TCGReg rs1, TCGReg rs2) { return opc | (rd & 0x1f) << 7 | (rs1 & 0x1f) << 15 | (rs2 & 0x1f) << 20; } /* Type-I */ static int32_t encode_imm12(uint32_t imm) { return (imm & 0xfff) << 20; } static int32_t encode_i(RISCVInsn opc, TCGReg rd, TCGReg rs1, uint32_t imm) { return opc | (rd & 0x1f) << 7 | (rs1 & 0x1f) << 15 | encode_imm12(imm); } /* Type-S */ static int32_t encode_simm12(uint32_t imm) { int32_t ret = 0; ret |= (imm & 0xFE0) << 20; ret |= (imm & 0x1F) << 7; return ret; } static int32_t encode_s(RISCVInsn opc, TCGReg rs1, TCGReg rs2, uint32_t imm) { return opc | (rs1 & 0x1f) << 15 | (rs2 & 0x1f) << 20 | encode_simm12(imm); } /* Type-SB */ static int32_t encode_sbimm12(uint32_t imm) { int32_t ret = 0; ret |= (imm & 0x1000) << 19; ret |= (imm & 0x7e0) << 20; ret |= (imm & 0x1e) << 7; ret |= (imm & 0x800) >> 4; return ret; } static int32_t encode_sb(RISCVInsn opc, TCGReg rs1, TCGReg rs2, uint32_t imm) { return opc | (rs1 & 0x1f) << 15 | (rs2 & 0x1f) << 20 | encode_sbimm12(imm); } /* Type-U */ static int32_t encode_uimm20(uint32_t imm) { return imm & 0xfffff000; } static int32_t encode_u(RISCVInsn opc, TCGReg rd, uint32_t imm) { return opc | (rd & 0x1f) << 7 | encode_uimm20(imm); } /* Type-UJ */ static int32_t encode_ujimm20(uint32_t imm) { int32_t ret = 0; ret |= (imm & 0x0007fe) << (21 - 1); ret |= (imm & 0x000800) << (20 - 11); ret |= (imm & 0x0ff000) << (12 - 12); ret |= (imm & 0x100000) << (31 - 20); return ret; } static int32_t encode_uj(RISCVInsn opc, TCGReg rd, uint32_t imm) { return opc | (rd & 0x1f) << 7 | encode_ujimm20(imm); } /* * RISC-V instruction emitters */ static void tcg_out_opc_reg(TCGContext *s, RISCVInsn opc, TCGReg rd, TCGReg rs1, TCGReg rs2) { tcg_out32(s, encode_r(opc, rd, rs1, rs2)); } static void tcg_out_opc_imm(TCGContext *s, RISCVInsn opc, TCGReg rd, TCGReg rs1, TCGArg imm) { tcg_out32(s, encode_i(opc, rd, rs1, imm)); } static void tcg_out_opc_store(TCGContext *s, RISCVInsn opc, TCGReg rs1, TCGReg rs2, uint32_t imm) { tcg_out32(s, encode_s(opc, rs1, rs2, imm)); } static void tcg_out_opc_branch(TCGContext *s, RISCVInsn opc, TCGReg rs1, TCGReg rs2, uint32_t imm) { tcg_out32(s, encode_sb(opc, rs1, rs2, imm)); } static void tcg_out_opc_upper(TCGContext *s, RISCVInsn opc, TCGReg rd, uint32_t imm) { tcg_out32(s, encode_u(opc, rd, imm)); } static void tcg_out_opc_jump(TCGContext *s, RISCVInsn opc, TCGReg rd, uint32_t imm) { tcg_out32(s, encode_uj(opc, rd, imm)); } static void tcg_out_nop_fill(tcg_insn_unit *p, int count) { int i; for (i = 0; i < count; ++i) { p[i] = encode_i(OPC_ADDI, TCG_REG_ZERO, TCG_REG_ZERO, 0); } } /* * Relocations */ static bool reloc_sbimm12(tcg_insn_unit *code_ptr, tcg_insn_unit *target) { intptr_t offset = (intptr_t)target - (intptr_t)code_ptr; if (offset == sextreg(offset, 1, 12) << 1) { code_ptr[0] |= encode_sbimm12(offset); return true; } return false; } static bool reloc_jimm20(tcg_insn_unit *code_ptr, tcg_insn_unit *target) { intptr_t offset = (intptr_t)target - (intptr_t)code_ptr; if (offset == sextreg(offset, 1, 20) << 1) { code_ptr[0] |= encode_ujimm20(offset); return true; } return false; } static bool reloc_call(tcg_insn_unit *code_ptr, tcg_insn_unit *target) { intptr_t offset = (intptr_t)target - (intptr_t)code_ptr; int32_t lo = sextreg(offset, 0, 12); int32_t hi = offset - lo; if (offset == hi + lo) { code_ptr[0] |= encode_uimm20(hi); code_ptr[1] |= encode_imm12(lo); return true; } return false; } static bool patch_reloc(tcg_insn_unit *code_ptr, int type, intptr_t value, intptr_t addend) { uint32_t insn = *code_ptr; intptr_t diff; bool short_jmp; tcg_debug_assert(addend == 0); switch (type) { case R_RISCV_BRANCH: diff = value - (uintptr_t)code_ptr; short_jmp = diff == sextreg(diff, 0, 12); if (short_jmp) { return reloc_sbimm12(code_ptr, (tcg_insn_unit *)value); } else { /* Invert the condition */ insn = insn ^ (1 << 12); /* Clear the offset */ insn &= 0x01fff07f; /* Set the offset to the PC + 8 */ insn |= encode_sbimm12(8); /* Move forward */ code_ptr[0] = insn; /* Overwrite the NOP with jal x0,value */ diff = value - (uintptr_t)(code_ptr + 1); insn = encode_uj(OPC_JAL, TCG_REG_ZERO, diff); code_ptr[1] = insn; return true; } break; case R_RISCV_JAL: return reloc_jimm20(code_ptr, (tcg_insn_unit *)value); break; case R_RISCV_CALL: return reloc_call(code_ptr, (tcg_insn_unit *)value); break; default: tcg_abort(); } } /* * TCG intrinsics */ static void tcg_out_mov(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg) { if (ret == arg) { return; } switch (type) { case TCG_TYPE_I32: case TCG_TYPE_I64: tcg_out_opc_imm(s, OPC_ADDI, ret, arg, 0); break; default: g_assert_not_reached(); } } static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd, tcg_target_long val) { tcg_target_long lo, hi, tmp; int shift, ret; if (TCG_TARGET_REG_BITS == 64 && type == TCG_TYPE_I32) { val = (int32_t)val; } lo = sextreg(val, 0, 12); if (val == lo) { tcg_out_opc_imm(s, OPC_ADDI, rd, TCG_REG_ZERO, lo); return; } hi = val - lo; if (TCG_TARGET_REG_BITS == 32 || val == (int32_t)val) { tcg_out_opc_upper(s, OPC_LUI, rd, hi); if (lo != 0) { tcg_out_opc_imm(s, OPC_ADDIW, rd, rd, lo); } return; } /* We can only be here if TCG_TARGET_REG_BITS != 32 */ tmp = tcg_pcrel_diff(s, (void *)val); if (tmp == (int32_t)tmp) { tcg_out_opc_upper(s, OPC_AUIPC, rd, 0); tcg_out_opc_imm(s, OPC_ADDI, rd, rd, 0); ret = reloc_call(s->code_ptr - 2, (tcg_insn_unit *)val); tcg_debug_assert(ret == true); return; } /* Look for a single 20-bit section. */ shift = ctz64(val); tmp = val >> shift; if (tmp == sextreg(tmp, 0, 20)) { tcg_out_opc_upper(s, OPC_LUI, rd, tmp << 12); if (shift > 12) { tcg_out_opc_imm(s, OPC_SLLI, rd, rd, shift - 12); } else { tcg_out_opc_imm(s, OPC_SRAI, rd, rd, 12 - shift); } return; } /* Look for a few high zero bits, with lots of bits set in the middle. */ shift = clz64(val); tmp = val << shift; if (tmp == sextreg(tmp, 12, 20) << 12) { tcg_out_opc_upper(s, OPC_LUI, rd, tmp); tcg_out_opc_imm(s, OPC_SRLI, rd, rd, shift); return; } else if (tmp == sextreg(tmp, 0, 12)) { tcg_out_opc_imm(s, OPC_ADDI, rd, TCG_REG_ZERO, tmp); tcg_out_opc_imm(s, OPC_SRLI, rd, rd, shift); return; } /* Drop into the constant pool. */ new_pool_label(s, val, R_RISCV_CALL, s->code_ptr, 0); tcg_out_opc_upper(s, OPC_AUIPC, rd, 0); tcg_out_opc_imm(s, OPC_LD, rd, rd, 0); } static void tcg_out_ext8u(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_ANDI, ret, arg, 0xff); } static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16); tcg_out_opc_imm(s, OPC_SRLIW, ret, ret, 16); } static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_SLLI, ret, arg, 32); tcg_out_opc_imm(s, OPC_SRLI, ret, ret, 32); } static void tcg_out_ext8s(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 24); tcg_out_opc_imm(s, OPC_SRAIW, ret, ret, 24); } static void tcg_out_ext16s(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16); tcg_out_opc_imm(s, OPC_SRAIW, ret, ret, 16); } static void tcg_out_ext32s(TCGContext *s, TCGReg ret, TCGReg arg) { tcg_out_opc_imm(s, OPC_ADDIW, ret, arg, 0); } static void tcg_out_ldst(TCGContext *s, RISCVInsn opc, TCGReg data, TCGReg addr, intptr_t offset) { intptr_t imm12 = sextreg(offset, 0, 12); if (offset != imm12) { intptr_t diff = offset - (uintptr_t)s->code_ptr; if (addr == TCG_REG_ZERO && diff == (int32_t)diff) { imm12 = sextreg(diff, 0, 12); tcg_out_opc_upper(s, OPC_AUIPC, TCG_REG_TMP2, diff - imm12); } else { tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_TMP2, offset - imm12); if (addr != TCG_REG_ZERO) { tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP2, TCG_REG_TMP2, addr); } } addr = TCG_REG_TMP2; } switch (opc) { case OPC_SB: case OPC_SH: case OPC_SW: case OPC_SD: tcg_out_opc_store(s, opc, addr, data, imm12); break; case OPC_LB: case OPC_LBU: case OPC_LH: case OPC_LHU: case OPC_LW: case OPC_LWU: case OPC_LD: tcg_out_opc_imm(s, opc, data, addr, imm12); break; default: g_assert_not_reached(); } } static void tcg_out_ld(TCGContext *s, TCGType type, TCGReg arg, TCGReg arg1, intptr_t arg2) { bool is32bit = (TCG_TARGET_REG_BITS == 32 || type == TCG_TYPE_I32); tcg_out_ldst(s, is32bit ? OPC_LW : OPC_LD, arg, arg1, arg2); } static void tcg_out_st(TCGContext *s, TCGType type, TCGReg arg, TCGReg arg1, intptr_t arg2) { bool is32bit = (TCG_TARGET_REG_BITS == 32 || type == TCG_TYPE_I32); tcg_out_ldst(s, is32bit ? OPC_SW : OPC_SD, arg, arg1, arg2); } static bool tcg_out_sti(TCGContext *s, TCGType type, TCGArg val, TCGReg base, intptr_t ofs) { if (val == 0) { tcg_out_st(s, type, TCG_REG_ZERO, base, ofs); return true; } return false; }