diff options
Diffstat (limited to 'target/arm/translate-a64.c')
| -rw-r--r-- | target/arm/translate-a64.c | 81 |
1 files changed, 29 insertions, 52 deletions
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index f673d939e1..a59c90c9ad 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -3216,67 +3216,44 @@ static void disas_bitfield(DisasContext *s, uint32_t insn) low 32-bits anyway. */ tcg_tmp = read_cpu_reg(s, rn, 1); - /* Recognize the common aliases. */ - if (opc == 0) { /* SBFM */ - if (ri == 0) { - if (si == 7) { /* SXTB */ - tcg_gen_ext8s_i64(tcg_rd, tcg_tmp); - goto done; - } else if (si == 15) { /* SXTH */ - tcg_gen_ext16s_i64(tcg_rd, tcg_tmp); - goto done; - } else if (si == 31) { /* SXTW */ - tcg_gen_ext32s_i64(tcg_rd, tcg_tmp); - goto done; - } - } - if (si == 63 || (si == 31 && ri <= si)) { /* ASR */ - if (si == 31) { - tcg_gen_ext32s_i64(tcg_tmp, tcg_tmp); - } - tcg_gen_sari_i64(tcg_rd, tcg_tmp, ri); + /* Recognize simple(r) extractions. */ + if (si <= ri) { + /* Wd<s-r:0> = Wn<s:r> */ + len = (si - ri) + 1; + if (opc == 0) { /* SBFM: ASR, SBFX, SXTB, SXTH, SXTW */ + tcg_gen_sextract_i64(tcg_rd, tcg_tmp, ri, len); goto done; - } - } else if (opc == 2) { /* UBFM */ - if (ri == 0) { /* UXTB, UXTH, plus non-canonical AND */ - tcg_gen_andi_i64(tcg_rd, tcg_tmp, bitmask64(si + 1)); + } else if (opc == 2) { /* UBFM: UBFX, LSR, UXTB, UXTH */ + tcg_gen_extract_i64(tcg_rd, tcg_tmp, ri, len); return; } - if (si == 63 || (si == 31 && ri <= si)) { /* LSR */ - if (si == 31) { - tcg_gen_ext32u_i64(tcg_tmp, tcg_tmp); - } - tcg_gen_shri_i64(tcg_rd, tcg_tmp, ri); - return; - } - if (si + 1 == ri && si != bitsize - 1) { /* LSL */ - int shift = bitsize - 1 - si; - tcg_gen_shli_i64(tcg_rd, tcg_tmp, shift); - goto done; - } - } - - if (opc != 1) { /* SBFM or UBFM */ - tcg_gen_movi_i64(tcg_rd, 0); - } - - /* do the bit move operation */ - if (si >= ri) { - /* Wd<s-r:0> = Wn<s:r> */ - tcg_gen_shri_i64(tcg_tmp, tcg_tmp, ri); + /* opc == 1, BXFIL fall through to deposit */ + tcg_gen_extract_i64(tcg_tmp, tcg_tmp, ri, len); pos = 0; - len = (si - ri) + 1; } else { - /* Wd<32+s-r,32-r> = Wn<s:0> */ - pos = bitsize - ri; + /* Handle the ri > si case with a deposit + * Wd<32+s-r,32-r> = Wn<s:0> + */ len = si + 1; + pos = (bitsize - ri) & (bitsize - 1); } - tcg_gen_deposit_i64(tcg_rd, tcg_rd, tcg_tmp, pos, len); + if (opc == 0 && len < ri) { + /* SBFM: sign extend the destination field from len to fill + the balance of the word. Let the deposit below insert all + of those sign bits. */ + tcg_gen_sextract_i64(tcg_tmp, tcg_tmp, 0, len); + len = ri; + } - if (opc == 0) { /* SBFM - sign extend the destination field */ - tcg_gen_shli_i64(tcg_rd, tcg_rd, 64 - (pos + len)); - tcg_gen_sari_i64(tcg_rd, tcg_rd, 64 - (pos + len)); + if (opc == 1) { /* BFM, BXFIL */ + tcg_gen_deposit_i64(tcg_rd, tcg_rd, tcg_tmp, pos, len); + } else { + /* SBFM or UBFM: We start with zero, and we haven't modified + any bits outside bitsize, therefore the zero-extension + below is unneeded. */ + tcg_gen_deposit_z_i64(tcg_rd, tcg_tmp, pos, len); + return; } done: |