diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 84497dc308a993c765e8e0e7fa61623d1b93260d..bb36a66955b81fb8b247d56c96f9f0f4b4f618d1 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -3479,7 +3479,37 @@ static void disas_fp_3src(DisasContext *s, uint32_t insn) */ static void disas_fp_imm(DisasContext *s, uint32_t insn) { - unsupported_encoding(s, insn); + int rd = extract32(insn, 0, 5); + int imm8 = extract32(insn, 13, 8); + int is_double = extract32(insn, 22, 2); + uint64_t imm; + TCGv_i64 tcg_res; + + if (is_double > 1) { + unallocated_encoding(s); + return; + } + + /* The imm8 encodes the sign bit, enough bits to represent + * an exponent in the range 01....1xx to 10....0xx, + * and the most significant 4 bits of the mantissa; see + * VFPExpandImm() in the v8 ARM ARM. + */ + if (is_double) { + imm = (extract32(imm8, 7, 1) ? 0x8000 : 0) | + (extract32(imm8, 6, 1) ? 0x3fc0 : 0x4000) | + extract32(imm8, 0, 6); + imm <<= 48; + } else { + imm = (extract32(imm8, 7, 1) ? 0x8000 : 0) | + (extract32(imm8, 6, 1) ? 0x3e00 : 0x4000) | + (extract32(imm8, 0, 6) << 3); + imm <<= 16; + } + + tcg_res = tcg_const_i64(imm); + write_fp_dreg(s, rd, tcg_res); + tcg_temp_free_i64(tcg_res); } /* C3.6.29 Floating point <-> fixed point conversions