Re: OoO execution

On Mon, 19 May 2025 6:22:42 +0000, Anton Ertl wrote:

You are probably thinking of OoO Execution, where people usually write
as if the Tomasulo algorithm of the 360/91 as implemented the modern
concept of OoO execution.  But the 360/91 only did OoO for FP, did not
support branch prediction, had imprecise exceptions, and the Tomasulo
algorithm was used primarily as a workaround for the dearth of FP
registers in the S/360.

Yes, I was thinking of OoO execution, as opposed to other forms of
pipelining - basic pipelining was used in the 7094 II and even the 6502.
The Pentium II (and Pentium Pro) also only used OoO for floating-point,
while the 68050 only used OoO for integers!
It's true the 360, with only four floating-point registers, had a dearth
of them, but since having lots of registers was a way that RISC tried to
avoid the need for OoO, I would not say that this invalidated the use of
OoO on the 360/195.
John Savard