llvm-project

385f59f9 - [llvm-mca] Teach MCA constant registers do not create dependencies (#89387)

[llvm-mca] Teach MCA constant registers do not create dependencies (#89387) Constant registers like the zero registers XZR and WZR are treated as any other register by LLVM-MCA. This can create non existent dependency chains. Currently there is no method in MCA to query if a register is constant. This patch fixes the issue by adding a bool Constant variable to MCRegisterDesc that is true for constant registers. Since constant registers do not create dependencies, it makes sense to add this check to MCA.