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tcg/riscv: Add branch and jump instructions

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Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <c356657e627168d89cb5b012b7e21e4efbbe83f3.1545246859.git.alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Alistair Francis 2018-12-19 19:19:00 +00:00 committed by Richard Henderson
parent 28ca738e9d
commit 15840069e1
1 changed files with 145 additions and 0 deletions
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145
tcg/riscv/tcg-target.inc.c
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@ -750,3 +750,148 @@ static void tcg_out_addsub2(TCGContext *s,
tcg_out_opc_reg(s, opc_add, rh, th, TCG_REG_TMP0);
}
}
static const struct {
RISCVInsn op;
bool swap;
} tcg_brcond_to_riscv[] = {
[TCG_COND_EQ] = { OPC_BEQ, false },
[TCG_COND_NE] = { OPC_BNE, false },
[TCG_COND_LT] = { OPC_BLT, false },
[TCG_COND_GE] = { OPC_BGE, false },
[TCG_COND_LE] = { OPC_BGE, true },
[TCG_COND_GT] = { OPC_BLT, true },
[TCG_COND_LTU] = { OPC_BLTU, false },
[TCG_COND_GEU] = { OPC_BGEU, false },
[TCG_COND_LEU] = { OPC_BGEU, true },
[TCG_COND_GTU] = { OPC_BLTU, true }
};
static void tcg_out_brcond(TCGContext *s, TCGCond cond, TCGReg arg1,
TCGReg arg2, TCGLabel *l)
{
RISCVInsn op = tcg_brcond_to_riscv[cond].op;
tcg_debug_assert(op != 0);
if (tcg_brcond_to_riscv[cond].swap) {
TCGReg t = arg1;
arg1 = arg2;
arg2 = t;
}
if (l->has_value) {
intptr_t diff = tcg_pcrel_diff(s, l->u.value_ptr);
if (diff == sextreg(diff, 0, 12)) {
tcg_out_opc_branch(s, op, arg1, arg2, diff);
} else {
/* Invert the conditional branch. */
tcg_out_opc_branch(s, op ^ (1 << 12), arg1, arg2, 8);
tcg_out_opc_jump(s, OPC_JAL, TCG_REG_ZERO, diff - 4);
}
} else {
tcg_out_reloc(s, s->code_ptr, R_RISCV_BRANCH, l, 0);
tcg_out_opc_branch(s, op, arg1, arg2, 0);
/* NOP to allow patching later */
tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_ZERO, TCG_REG_ZERO, 0);
}
}
static void tcg_out_setcond(TCGContext *s, TCGCond cond, TCGReg ret,
TCGReg arg1, TCGReg arg2)
{
switch (cond) {
case TCG_COND_EQ:
tcg_out_opc_reg(s, OPC_SUB, ret, arg1, arg2);
tcg_out_opc_imm(s, OPC_SLTIU, ret, ret, 1);
break;
case TCG_COND_NE:
tcg_out_opc_reg(s, OPC_SUB, ret, arg1, arg2);
tcg_out_opc_reg(s, OPC_SLTU, ret, TCG_REG_ZERO, ret);
break;
case TCG_COND_LT:
tcg_out_opc_reg(s, OPC_SLT, ret, arg1, arg2);
break;
case TCG_COND_GE:
tcg_out_opc_reg(s, OPC_SLT, ret, arg1, arg2);
tcg_out_opc_imm(s, OPC_XORI, ret, ret, 1);
break;
case TCG_COND_LE:
tcg_out_opc_reg(s, OPC_SLT, ret, arg2, arg1);
tcg_out_opc_imm(s, OPC_XORI, ret, ret, 1);
break;
case TCG_COND_GT:
tcg_out_opc_reg(s, OPC_SLT, ret, arg2, arg1);
break;
case TCG_COND_LTU:
tcg_out_opc_reg(s, OPC_SLTU, ret, arg1, arg2);
break;
case TCG_COND_GEU:
tcg_out_opc_reg(s, OPC_SLTU, ret, arg1, arg2);
tcg_out_opc_imm(s, OPC_XORI, ret, ret, 1);
break;
case TCG_COND_LEU:
tcg_out_opc_reg(s, OPC_SLTU, ret, arg2, arg1);
tcg_out_opc_imm(s, OPC_XORI, ret, ret, 1);
break;
case TCG_COND_GTU:
tcg_out_opc_reg(s, OPC_SLTU, ret, arg2, arg1);
break;
default:
g_assert_not_reached();
break;
}
}
static void tcg_out_brcond2(TCGContext *s, TCGCond cond, TCGReg al, TCGReg ah,
TCGReg bl, TCGReg bh, TCGLabel *l)
{
/* todo */
g_assert_not_reached();
}
static void tcg_out_setcond2(TCGContext *s, TCGCond cond, TCGReg ret,
TCGReg al, TCGReg ah, TCGReg bl, TCGReg bh)
{
/* todo */
g_assert_not_reached();
}
static inline void tcg_out_goto(TCGContext *s, tcg_insn_unit *target)
{
ptrdiff_t offset = tcg_pcrel_diff(s, target);
tcg_debug_assert(offset == sextreg(offset, 1, 20) << 1);
tcg_out_opc_jump(s, OPC_JAL, TCG_REG_ZERO, offset);
}
static void tcg_out_call_int(TCGContext *s, tcg_insn_unit *arg, bool tail)
{
TCGReg link = tail ? TCG_REG_ZERO : TCG_REG_RA;
ptrdiff_t offset = tcg_pcrel_diff(s, arg);
int ret;
if (offset == sextreg(offset, 1, 20) << 1) {
/* short jump: -2097150 to 2097152 */
tcg_out_opc_jump(s, OPC_JAL, link, offset);
} else if (TCG_TARGET_REG_BITS == 32 ||
offset == sextreg(offset, 1, 31) << 1) {
/* long jump: -2147483646 to 2147483648 */
tcg_out_opc_upper(s, OPC_AUIPC, TCG_REG_TMP0, 0);
tcg_out_opc_imm(s, OPC_JALR, link, TCG_REG_TMP0, 0);
ret = reloc_call(s->code_ptr - 2, arg);\
tcg_debug_assert(ret == true);
} else if (TCG_TARGET_REG_BITS == 64) {
/* far jump: 64-bit */
tcg_target_long imm = sextreg((tcg_target_long)arg, 0, 12);
tcg_target_long base = (tcg_target_long)arg - imm;
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_TMP0, base);
tcg_out_opc_imm(s, OPC_JALR, link, TCG_REG_TMP0, imm);
} else {
g_assert_not_reached();
}
}
static void tcg_out_call(TCGContext *s, tcg_insn_unit *arg)
{
tcg_out_call_int(s, arg, false);
}