Filter
Top Products
Instruction Descriptions 4–99
4.9 Branch Format Floating-Point Instructions
Alpha provides six floating conditional branch instructions. These branch-format instructions
test the value of a floating-point register and conditionally change the PC.
They do not interpret the bits tested in any way; specifically, they do not trap on non-finite
values.
The test is based on the sign bit and whether the rest of the register is all zero bits. All 64 bits
of the register are tested. The test is independent of the format of the operand in the register.
Both plus and minus zero are equal to zero. A non-zero value with a sign of zero is greater than
zero. A non-zero value with a sign of one is less than zero. No reserved operand or non-finite
checking is done.
The floating-point branch operations are summarized in Table 4–15:
Table 4–15: Floating-Point Branch Instructions Summary
Mnemonic Operation Subset
FBEQ Floating Branch Equal Both
FBGE Floating Branch Greater Than or Equal Both
FBGT Floating Branch Greater Than Both
FBLE Floating Branch Less Than or Equal Both
FBLT Floating Branch Less Than Both
FBNE Floating Branch Not Equal Both