Bit scan forward instruction
WebFeb 5, 2024 · The next instructions are for bit-scanning. BSF r, r/m ; d = index of first set bit in s BSR r, r/m ; d = index of last set bit in s The BSF (bit scan forward) instruction searches for the least significant set bit in the source value and sets the destination register to the index of that bit.
Bit scan forward instruction
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WebMay 22, 2016 · Bit Scan Instructions: 80386 instruction set has two bit scan mnemonics, such as BSF (bit scan forward) and BSR (bit scan reverse). Both of these instructions scan the operand for a '1' bit, without actually rotating it. The BSF instruction scans the operand from right to left. If a '1' is encountered during the scan, zero flag is set and the ... WebBit-Scan Instructions The 80386 processor has two bit-scan instructions such as BSF (Bit-Scan Forward) and BSR (Bit-Scan Reverse). The BSF and BSR instructions can …
WebInstruction Meaning; POPCNT: Compute number of bits set to 1: TEST: Logical compare: BT: Bit test: BTS: Bit test and set: BTR: Bit test and reset: BTC: Bit test and complement: BSF: Bit scan forward: BSR: Bit scan reverse: SETE: Set byte if equal: SETA: Set byte if above: SETAE: Set byte if above or equal: SETB: Set byte if below: SETBE: Set ... WebInstruction Meaning Notes BSF: Bit scan forward: BSF and BSR produce undefined results if the source argument is all-0s. BSR: Bit scan reverse BT: Bit test: BTC: Bit test and complement: Instructions atomic only if LOCK prefix present. BTR: Bit test and reset BTS: Bit test and set: CDQ: Convert double-word to quad-word
WebIn computer software and hardware, find first set (ffs) or find first one is a bit operation that, given an unsigned machine word, designates the index or position of the least significant … WebBit scan operations search for the least-significant bit or most-significant bit set in a data set. The Intel® IA-32 architecture provides hardware assist for such operations via the BSF (bit scan forward) and BSR (bit scan reverse) instructions. On the IA-32 architecture these instructions operate on 8-bit, 16-bit or 32-bit values.
WebOct 18, 2013 · Bit scanning equivalencies. A lot of bit manipulation operations exist basically everywhere: AND, OR, XOR/EOR, shifts, and so forth. Some exist only on some architectures but have obvious implementations everywhere else – NAND, NOR, equivalence/XNOR and so forth. Some exist as built-in instructions on some …
WebJan 31, 2012 · As far as I'm aware, there is no MSIL instruction for this "find first set" operation. The simplest thing to do is write your own C++ native DLL that exports a … lady a and chris tomlin songWebBit Scan Forward (bsf) Bit Scan Reverse (bsr) Bit Test (bt) Bit Test And Complement (btc) Bit Test And Reset (btr) Bit Test And Set (bts) Exchange Instructions. Compare and Exchange (cmpxchg)[486] Floating-Point Transcendental Instructions. Floating-Point Sine (fsin) Floating-Point Cosine (fcos) Floating-Point Sine and Cosine (fsincos) Floating ... property for rent chiantiWebBSF - Bit Scan Forward (386+) Usage: BSF dest,src Modifies flags: ZF Scans source operand for first bit set. Sets ZF if a bit is found set and loads the destination with an … property for rent chobhamWebTZCNT is almost identical to the Bit Scan Forward (BSF) instruction, but sets the ZF (if the result is zero) and CF (if the source is zero) flags rather than setting the ZF (if the … property for rent chicagoWebBSR scans the bits in the second word or doubleword operand from the most significant bit to the least significant bit. The ZF flag is cleared if the bits are all 0; otherwise, ZF is set and the destination register is loaded with the bit index of the first set bit found when scanning in the reverse direction. Flags Affected ZF as described above property for rent centervilleWebBSF - Bit Scan Forward; BSR - Bit Scan Reverse; BSWAP - Byte Swap; BT - Bit Test; BTC - Bit Test and Compliment; BTR - Bit Test and Reset; BTS - Bit Test and Set; C. CALL - Call Procedure; CBW - Convert Byte to Word; CDQ - Convert Double to Quad; CLC - Clear Carry Flag; CLD - Clear Direction Flag; CLI - Clear Interrupt Flag; CLTS - Clear Task ... lady a and chris tomlinWebJan 2, 2024 · it will include all SSE/AVX headers which are enabled according to compiler switches like -march=haswell or just -march=native. Additionally some x86 specific instructions like bswap or ror become available as intrinsics. The MSVC equivalent of this header . If you just want portable SIMD, use #include . lady a baby it\u0027s cold outside