https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120427
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <h...@gcc.gnu.org>: https://gcc.gnu.org/g:4c80062d7b8c272e2e193b8074a8440dbb4fe588 commit r16-1575-g4c80062d7b8c272e2e193b8074a8440dbb4fe588 Author: H.J. Lu <hjl.to...@gmail.com> Date: Sun May 25 07:40:29 2025 +0800 x86: Enable *mov<mode>_(and|or) only for -Oz commit ef26c151c14a87177d46fd3d725e7f82e040e89f Author: Roger Sayle <ro...@nextmovesoftware.com> Date: Thu Dec 23 12:33:07 2021 +0000 x86: PR target/103773: Fix wrong-code with -Oz from pop to memory. added "*mov<mode>_and" and extended "*mov<mode>_or" to transform "mov $0,mem" to the shorter "and $0,mem" and "mov $-1,mem" to the shorter "or $-1,mem" for -Oz. But the new pattern: (define_insn "*mov<mode>_and" [(set (match_operand:SWI248 0 "memory_operand" "=m") (match_operand:SWI248 1 "const0_operand")) (clobber (reg:CC FLAGS_REG))] "reload_completed" "and{<imodesuffix>}\t{%1, %0|%0, %1}" [(set_attr "type" "alu1") (set_attr "mode" "<MODE>") (set_attr "length_immediate" "1")]) and the extended pattern: (define_insn "*mov<mode>_or" [(set (match_operand:SWI248 0 "nonimmediate_operand" "=rm") (match_operand:SWI248 1 "constm1_operand")) (clobber (reg:CC FLAGS_REG))] "reload_completed" "or{<imodesuffix>}\t{%1, %0|%0, %1}" [(set_attr "type" "alu1") (set_attr "mode" "<MODE>") (set_attr "length_immediate" "1")]) aren't guarded for -Oz. As a result, "and $0,mem" and "or $-1,mem" are generated without -Oz. 1. Change *mov<mode>_and" to define_insn_and_split and split it to "mov $0,mem" if not -Oz. 2. Change "*mov<mode>_or" to define_insn_and_split and split it to "mov $-1,mem" if not -Oz. 3. Don't transform "mov $-1,reg" to "push $-1; pop reg" for -Oz since it should be transformed to "or $-1,reg". gcc/ PR target/120427 * config/i386/i386.md (*mov<mode>_and): Changed to define_insn_and_split. Split it to "mov $0,mem" if not -Oz. (*mov<mode>_or): Changed to define_insn_and_split. Split it to "mov $-1,mem" if not -Oz. (peephole2): Don't transform "mov $-1,reg" to "push $-1; pop reg" for -Oz since it will be transformed to "or $-1,reg". gcc/testsuite/ PR target/120427 * gcc.target/i386/cold-attribute-4.c: Compile with -Oz. * gcc.target/i386/pr120427-1.c: New test. * gcc.target/i386/pr120427-2.c: Likewise. * gcc.target/i386/pr120427-3.c: Likewise. * gcc.target/i386/pr120427-4.c: Likewise. Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
