diff options
Diffstat (limited to 'riscv/insns/pssha_dhs.h')
| -rw-r--r-- | riscv/insns/pssha_dhs.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/riscv/insns/pssha_dhs.h b/riscv/insns/pssha_dhs.h new file mode 100644 index 00000000..a85d2a5a --- /dev/null +++ b/riscv/insns/pssha_dhs.h @@ -0,0 +1,45 @@ +require_rv32; +P_RD_RS1_DW_LOOP(16, 16, { + uint64_t bits_SMIN = (uint64_t{1} << (16 - 1)); + uint64_t bits_SMAX = ((uint64_t{1} << (16 - 1)) - 1); + bool ov = false; + int8_t m = P_FIELD(RS2, 0, 8); + int8_t rev = static_cast<int8_t>(m); + rev = (m < 0) ? static_cast<uint8_t>(~m + 1u) : m; + uint64_t mask = ((uint64_t{1} << 16) - 1); + p_rs1 &= mask; + if(m < 0){ + unsigned sh = ((unsigned)(uint8_t)rev > 255u) ? 255u : (unsigned)(uint8_t)rev; + uint64_t sign = (p_rs1 >> (16 - 1)) & 1u; + + if(sh >= 16) p_rd = (uint16_t)(sign ? mask : 0u); + else{ + uint64_t shifted = (p_rs1 >> sh); + uint64_t fill = (~uint64_t{0}) << (16 - sh); + shifted |= fill; + p_rd = (uint16_t)(shifted & mask); + } + } + else{ + if(rev==0) p_rd = (uint16_t)p_rs1; + else if(rev >= 16){ + if(p_rs1==0) p_rd = 0; + else{ + ov = true; + uint64_t sign = (p_rs1 >> (16 - 1)) & 1u; + p_rd = (uint16_t)(sign ? bits_SMIN : bits_SMAX); + } + } + else{ + uint64_t sign = (p_rs1 >> (16 - 1)) & 1u; + uint64_t top = (p_rs1 >> (16 - rev)); + uint64_t need = sign ? ((uint64_t{1} << rev) - 1) : 0u; + ov = (top != need); + if(ov) + p_rd = (uint16_t)(sign ? bits_SMIN : bits_SMAX); + else + p_rd = (uint16_t)((p_rs1 << rev) & mask); + } + } + if (ov) P.VU.vxsat->write(1); +})
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