From 21e8e8b230af38b6bd8c953fa5f31e4a5a128e1c Mon Sep 17 00:00:00 2001 From: Fredrik Noring Date: Sun, 21 Oct 2018 17:38:21 +0200 Subject: [PATCH] target/mips: Support R5900 three-operand MULT and MULTU instructions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The three-operand MULT and MULTU are the only R5900-specific instructions emitted by GCC 7.3. The R5900 also implements the three- operand MADD and MADDU instructions, but they are omitted in QEMU for now since they are absent in programs compiled by current GCC versions. Likewise, the R5900-specific pipeline 1 instruction variants MULT1, MULTU1, DIV1, DIVU1, MADD1, MADDU1, MFHI1, MFLO1, MTHI1 and MTLO1 are omitted here as well. Reviewed-by: Aleksandar Markovic Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Fredrik Noring Signed-off-by: Aleksandar Markovic --- target/mips/translate.c | 74 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/target/mips/translate.c b/target/mips/translate.c index 1c0400c4ae..3dc6d80ce1 100644 --- a/target/mips/translate.c +++ b/target/mips/translate.c @@ -4766,6 +4766,78 @@ static void gen_muldiv(DisasContext *ctx, uint32_t opc, tcg_temp_free(t1); } +/* + * These MULT and MULTU instructions implemented in for example the + * Toshiba/Sony R5900 and the Toshiba TX19, TX39 and TX79 core + * architectures are special three-operand variants with the syntax + * + * MULT[U] rd, rs, rt + * + * such that + * + * (rd, LO, HI) <- rs * rt + * + * where the low-order 32-bits of the result is placed into both the + * GPR rd and the special register LO. The high-order 32-bits of the + * result is placed into the special register HI. + * + * If the GPR rd is omitted in assembly language, it is taken to be 0, + * which is the zero register that always reads as 0. + */ +static void gen_mul_txx9(DisasContext *ctx, uint32_t opc, + int rd, int rs, int rt) +{ + TCGv t0 = tcg_temp_new(); + TCGv t1 = tcg_temp_new(); + int acc = 0; + + gen_load_gpr(t0, rs); + gen_load_gpr(t1, rt); + + switch (opc) { + case OPC_MULT: + { + TCGv_i32 t2 = tcg_temp_new_i32(); + TCGv_i32 t3 = tcg_temp_new_i32(); + tcg_gen_trunc_tl_i32(t2, t0); + tcg_gen_trunc_tl_i32(t3, t1); + tcg_gen_muls2_i32(t2, t3, t2, t3); + if (rd) { + tcg_gen_ext_i32_tl(cpu_gpr[rd], t2); + } + tcg_gen_ext_i32_tl(cpu_LO[acc], t2); + tcg_gen_ext_i32_tl(cpu_HI[acc], t3); + tcg_temp_free_i32(t2); + tcg_temp_free_i32(t3); + } + break; + case OPC_MULTU: + { + TCGv_i32 t2 = tcg_temp_new_i32(); + TCGv_i32 t3 = tcg_temp_new_i32(); + tcg_gen_trunc_tl_i32(t2, t0); + tcg_gen_trunc_tl_i32(t3, t1); + tcg_gen_mulu2_i32(t2, t3, t2, t3); + if (rd) { + tcg_gen_ext_i32_tl(cpu_gpr[rd], t2); + } + tcg_gen_ext_i32_tl(cpu_LO[acc], t2); + tcg_gen_ext_i32_tl(cpu_HI[acc], t3); + tcg_temp_free_i32(t2); + tcg_temp_free_i32(t3); + } + break; + default: + MIPS_INVAL("mul TXx9"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + + out: + tcg_temp_free(t0); + tcg_temp_free(t1); +} + static void gen_mul_vr54xx (DisasContext *ctx, uint32_t opc, int rd, int rs, int rt) { @@ -23490,6 +23562,8 @@ static void decode_opc_special_legacy(CPUMIPSState *env, DisasContext *ctx) check_insn(ctx, INSN_VR54XX); op1 = MASK_MUL_VR54XX(ctx->opcode); gen_mul_vr54xx(ctx, op1, rd, rs, rt); + } else if (ctx->insn_flags & INSN_R5900) { + gen_mul_txx9(ctx, op1, rd, rs, rt); } else { gen_muldiv(ctx, op1, rd & 3, rs, rt); }