COP1: Difference between revisions

Jump to navigation Jump to search
Content added Content deleted
VisualWikitext
(→‎Comparisons: subnormals do not trigger invalid operation)
Line 200: Line 200:
If multiple bits are set, the conditions are ORed together: For example, UEQ is considered true if the two operands are equal or unordered.
If multiple bits are set, the conditions are ORed together: For example, UEQ is considered true if the two operands are equal or unordered.


Not that inputs qNAN as well as subnormals always signal Invalid Operation. Using all bit combinations, this gives the following instructions:
Note that inputs of qNAN always signal Invalid Operation. Using all bit combinations, this gives the following instructions:


{| class="wikitable"
{| class="wikitable"
Line 207: Line 207:
! SignalOnSNAN (Bit 3) !! Smaller (Bit 2) || Equal (Bit 1) || Unordered (Bit 0) || Name || Result formula || Invalid Operation Condition
! SignalOnSNAN (Bit 3) !! Smaller (Bit 2) || Equal (Bit 1) || Unordered (Bit 0) || Name || Result formula || Invalid Operation Condition
|-
|-
| 0 || 0 || 0 || 0 || F || Result = false || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 0 || 0 || 0 || F || Result = false || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 0 || 0 || 1 || UN || Result = unordered(arg1, arg2) || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 0 || 0 || 1 || UN || Result = unordered(arg1, arg2) || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 0 || 1 || 0 || EQ || Result = arg1 == arg2 || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 0 || 1 || 0 || EQ || Result = arg1 == arg2 || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 0 || 1 || 1 || UEQ || Result = unordered(arg1, arg2) OR (arg1 == arg2) || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 0 || 1 || 1 || UEQ || Result = unordered(arg1, arg2) OR (arg1 == arg2) || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 1 || 0 || 0 || OLT || Result = arg1 < arg2 || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 1 || 0 || 0 || OLT || Result = arg1 < arg2 || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 1 || 0 || 1 || ULT || Result = unordered(arg1, arg2) OR (arg1 < arg2) || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 1 || 0 || 1 || ULT || Result = unordered(arg1, arg2) OR (arg1 < arg2) || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 1 || 1 || 0 || OLE || Result = arg1 <= arg2 || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 1 || 1 || 0 || OLE || Result = arg1 <= arg2 || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 0 || 1 || 1 || 1 || ULE || Result = unordered(arg1, arg2) OR (arg1 <= arg2) || IsQNAN(arg1) OR isQNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 0 || 1 || 1 || 1 || ULE || Result = unordered(arg1, arg2) OR (arg1 <= arg2) || IsQNAN(arg1) OR isQNAN(arg2)
|-
|-
| 1 || 0 || 0 || 0 || SF || Result = false || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 0 || 0 || 0 || SF || Result = false || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 0 || 0 || 1 || NGLE || Result = unordered(arg1, arg2) || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 0 || 0 || 1 || NGLE || Result = unordered(arg1, arg2) || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 0 || 1 || 0 || SEQ || Result = arg1 == arg2 || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 0 || 1 || 0 || SEQ || Result = arg1 == arg2 || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 0 || 1 || 1 || NGL || Result = unordered(arg1, arg2) OR (arg1 == arg2) || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 0 || 1 || 1 || NGL || Result = unordered(arg1, arg2) OR (arg1 == arg2) || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 1 || 0 || 0 || LT || Result = arg1 < arg2 || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 1 || 0 || 0 || LT || Result = arg1 < arg2 || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 1 || 0 || 1 || NGE || Result = unordered(arg1, arg2) OR (arg1 < arg2) || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 1 || 0 || 1 || NGE || Result = unordered(arg1, arg2) OR (arg1 < arg2) || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 1 || 1 || 0 || LE || Result = arg1 <= arg2 || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 1 || 1 || 0 || LE || Result = arg1 <= arg2 || IsNAN(arg1) OR isNAN(arg2)
|-
|-
| 1 || 1 || 1 || 1 || NGT || Result = unordered(arg1, arg2) OR (arg1 <= arg2) || IsNAN(arg1) OR isNAN(arg2) OR isSubnormal(arg1) OR isSubnormal(arg2)
| 1 || 1 || 1 || 1 || NGT || Result = unordered(arg1, arg2) OR (arg1 <= arg2) || IsNAN(arg1) OR isNAN(arg2)
|}
|}


Retrieved from "https://n64brew.dev/wiki/COP1"