Is there a way to limit the number of threads used by the Accelerate framework, for example limiting it to 1. Since I am managing my own parallelism I don't want the frameworks to utilize parallelism in addition.

MacOS 12.3.1 Xcode 13.3.1 When I run my executable under Instruments with the Time Profiler it shows the time per function but when I click on the function name to see the time per line of code it displays the source but with no time information (percentage of time for that line). I've tried a variety of compiler options for my code such as -g and -g3 but that does not seem to matter. I have not used Instruments in a few years but I am pretty sure it displayed the time at the source code level with no special compiler flags in the past. Are special compiler flags needed to see the time per line of C source code? If not, how can I debug this? Thanks