Intel Lands A Few Noteworthy Improvements Today Into The GCC 14 Compiler

It was a busy day for the GCC 14 (GNU Compiler Collection) development with Intel landing three separate noteworthy contributions just today for this next major open-source compiler release.

First up, this commit now sets the spin count to 1 for x86 hybrid platforms like Intel Core Alder Lake and Raptor Lake processors. With this tweak to the OpenMP spin count value, Intel is seeing a variety of -- mostly small -- improvements to the performance on the likes of SPEC CPU 2017 and OMP2012 test cases. Overall though for this modest change it seems to provide a win overall for the performance and on top of all the other hybrid-related optimizations Intel has made across the Linux software stack over the past 2+ years.

Another change committed today is adding Intel USER_MSR support that is enabled with the new "-musermsr" option. USER_MSR is new with Intel's Clearwater Forest for the URDMSR and UWRMSR instructions. These are new instructions for user read and user write of model-specific registers.

The third notable Intel commit for the day is APX PUSH2POP2 support. This new instruction support is part of the ongoing compiler enablement for Advanced Performance Extensions (APX). The APX PUSH2/POP2 instructions transfer two register values within a single memory operation.

Great as always seeing the countless contributions made by Intel open-source compiler engineers to GCC not only for their future processors / ISA extensions but also general performance optimizations and other tuning. GCC 14.1 will be out in the early months of 2024 as the first stable version of GCC 14.