Description
Return a low-width lane from a two-word funnel shift.
Fixed-width arithmetic can wrap, saturate, shift in sign bits or expose discarded bits. Carry, borrow and signed overflow describe different conditions; a local rounding decision or guard/sticky triplet is one part of an arithmetic operation rather than a complete floating-point result.
Return a low-width lane from a two-word funnel shift.
When to use this tool
Use Word Funnel Shift Single Lane when evaluating the stated shift, arithmetic flag or rounding convention.
How to use the tool and how it works
- Enter high, low, shift, width. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read value. Use the output convention below.
Return a low-width lane from a two-word funnel shift. Require width 1..32, bounded high/low words and shift in [0,width]; concatenate high above low, shift right and mask the lowest width bits.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| high | High | Required. Safe integer; minimum 0. |
| low | Low | Required. Safe integer; minimum 0. |
| shift | Shift | Required. Safe integer; minimum 0. |
| width | Width under the stated bit, interval or geometry convention; apply the field-specific units and bounds. | Required. Safe integer; minimum 1; maximum 32. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| value | Value | Required. Safe integer. |
{
"input": {
"high": 10,
"low": 5,
"shift": 4,
"width": 8
},
"output": {
"value": 160
}
}Limitations and assumptions
- Shift zero returns low and full width returns high; lane order is explicit and no machine-specific instruction is executed.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete arithmetic operation with explicit width, signedness, overflow and rounding policy; keep exact integer text when values exceed ordinary numeric precision.
References
Similar or alternative tools
- Bitwise: Word Shift Out Bit Mask
Return bits shifted out of one word.
- Signed Shift Overflow Witness
Return an exact signed left shift and a wrapping witness.