https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106122
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Roger Sayle <sa...@gcc.gnu.org>: https://gcc.gnu.org/g:55899e33de74082521708a58fdc79510e0c5efad commit r12-8542-g55899e33de74082521708a58fdc79510e0c5efad Author: Roger Sayle <ro...@nextmovesoftware.com> Date: Sun Jul 3 14:01:17 2022 +0100 PR target/106122: Don't update %esp via the stack with -Oz on x86. When optimizing for size with -Oz, setting a register can be minimized by pushing an immediate value to the stack and popping it to the destination. Alas the one general register that shouldn't be updated via the stack is the stack pointer itself, where "pop %esp" can't be represented in GCC's RTL ("use of a register mentioned in pre_inc, pre_dec, post_inc or post_dec is not permitted within the same instruction"). This patch fixes PR target/106122 by explicitly checking for SP_REG in the problematic peephole2. 2022-07-O3 Roger Sayle <ro...@nextmovesoftware.com> gcc/ChangeLog PR target/106122 * config/i386/i386.md (peephole2): Avoid generating pop %esp when optimizing for size. gcc/testsuite/ChangeLog PR target/106122 * gcc.target/i386/pr106122.c: New test case.
