Syntax
subg $s_reg1, $s_reg2, $d_reg
subg $d_reg/$s_reg1, $s_reg2
Description
Subtract G_floating subtracts the contents of $s_reg2 from the contents of $s_reg1 or $d_reg and places the result into $d_reg. When the difference of the two operands is exactly 0, the difference has a positive sign for all rounding modes except round toward minus infinity (-¥). For that rounding mode, the difference has a negative sign.
Qualifiers
The following table describes the qualifiers for the subg instructions:
| Instruction | Qualifier description |
| no qualifier | VAX Rounding Mode: Normal rounding |
| VAX Trap Mode: Imprecise, underflow disabled | |
| subgc | VAX Rounding Mode: Chopped |
| subgu | VAX Trap Mode: Imprecise, underflow enabled |
| subguc | Combined meanings of subgc and subgu |
| subgs | VAX Trap Mode: Software, underflow disabled |
| subgsc | Combined meanings of subgs and subgc |
| subgsu | VAX Trap Mode: Software, underflow enabled |
| subgsuc | Combined meanings of subgs and subguc |