On 11/17/25 7:59 AM, Richard Braun wrote:
From: Richard Braun <[email protected]>
Instructions have two time-related units associated with them: the
number of delay slots, and the functional unit latency. But some
floating-point multiplication instructions have a functional unit
latency that actually varies depending on the following instructions
scheduled on the same functional unit [1].
For example, the MPYDP instruction is described with a functional unit
latency of 4, but there are additional "cycle-other resource conflicts"
with a following MPYSPDP instruction.
In order to describe that, this patch introduces one pseudo functional
unit per affected instruction, and augments reservations individually
for all implemented instructions that may be affected when following.
[1] 4.3.2 .M-Unit Constraints - SPRUFE8B TMS320C674x DSP CPU and
Instruction Set Reference Guide
gcc/
* gcc/config/c6x/c6x-sched.md.in (mpydp_m_N__CROSS_,
mpyspdp_m_N__CROSS_, mpysp2dp_m_N__CROSS_): Update reservations.
* gcc/config/c6x/c6x.md (m1dp, m1spdp, m2dp, m2spdp): New CPU units.
So the new CPU units aren't used as far as I can tell and trigger a
build error (because they're unused). Was that intentional?
Jeff
