Hi, As Kee’s requested in this PR: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101891
===== Currently -fzero-call-used-regs will use a pattern of: XOR regA,regA MOV regA,regB MOV regA,regC ... RET However, this introduces both a register ordering dependency (e.g. the CPU cannot clear regB without clearing regA first), and while greatly reduces available ROP gadgets, it does technically leave a set of "MOV" ROP gadgets at the end of functions (e.g. "MOV regA,regC; RET"). Please switch to always using XOR: XOR regA,regA XOR regB,regB XOR regC,regC ... RET ======= This patch switch all MOV to XOR on i386. Bootstrapped and regresstion tested on x86_64-linux-gnu. Okay for gcc13? Thanks. Qing ==========================================
0001-change-mov-to-xor-fix-all-testing-cases.patch
Description: 0001-change-mov-to-xor-fix-all-testing-cases.patch
