https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82524
--- Comment #22 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Uros Bizjak <u...@gcc.gnu.org>: https://gcc.gnu.org/g:dced5ae64703507a7159972316a1dde48e5f7470 commit r14-5254-gdced5ae64703507a7159972316a1dde48e5f7470 Author: Uros Bizjak <ubiz...@gmail.com> Date: Wed Nov 8 21:46:26 2023 +0100 i386: Apply LRA reload workaround to insns with high registers [PR82524] LRA is not able to reload zero_extracted in-out operand with matched input operand in the same way as strict_low_part in-out operand. The patch applies the strict_low_part workaround, where we allow LRA to generate an instruction with non-matched input operand, which is split post reload to the instruction that inserts non-matched input operand to an in-out operand and the instruction that uses matched operand, also to zero_extracted in-out operand case. The generated code from the pr82524.c testcase improves from: movl %esi, %ecx movl %edi, %eax movsbl %ch, %esi addl %esi, %edx movb %dl, %ah to: movl %edi, %eax movl %esi, %ecx movb %ch, %ah addb %dl, %ah The compiler is now also able to handle non-commutative operations: movl %edi, %eax movl %esi, %ecx movb %ch, %ah subb %dl, %ah and unary operations: movl %edi, %eax movl %esi, %edx movb %dh, %ah negb %ah The patch also robustifies split condition of the splitters to ensure that only alternatives with unmatched operands are split. PR target/82524 gcc/ChangeLog: * config/i386/i386.md (*add<mode>_1_slp): Split insn only for unmatched operand 0. (*sub<mode>_1_slp): Ditto. (*<any_logic:code><mode>_1_slp): Merge pattern from "*and<mode>_1_slp" and "*<any_logic:code><mode>_1_slp" using any_logic code iterator. Split insn only for unmatched operand 0. (*neg<mode>1_slp): Split insn only for unmatched operand 0. (*one_cmpl<mode>_1_slp): Ditto. (*ashl<mode>3_1_slp): Ditto. (*<any_shiftrt:insn><mode>_1_slp): Ditto. (*<any_rotate:insn><mode>_1_slp): Ditto. (*addqi_ext<mode>_1): Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*<plusminus:insn>qi_ext<mode>_2): Merge pattern from "*addqi_ext<mode>_2" and "*subqi_ext<mode>_2" using plusminus code iterator. Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*subqi_ext<mode>_1): Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*<any_logic:code>qi_ext<mode>_0): Merge pattern from "*andqi_ext<mode>_0" and and "*<any_logic:code>qi_ext<mode>_0" using any_logic code iterator. (*<any_logic:code>qi_ext<mode>_1): Merge pattern from "*andqi_ext<mode>_1" and "*<any_logic:code>qi_ext<mode>_1" using any_logic code iterator. Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*<any_logic:code>qi_ext<mode>_1_cc): Merge pattern from "*andqi_ext<mode>_1_cc" and "*xorqi_ext<mode>_1_cc" using any_logic code iterator. Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*<any_logic:code>qi_ext<mode>_2): Merge pattern from "*andqi_ext<mode>_2" and "*<any_or:code>qi_ext<mode>_2" using any_logic code iterator. Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*<any_logic:code>qi_ext<mode>_3): Redefine as define_insn_and_split. Add alternative 1 and split insn after reload for unmatched operand 0. (*negqi_ext<mode>_1): Rename from "*negqi_ext<mode>_2". Add alternative 1 and split insn after reload for unmatched operand 0. (*one_cmplqi_ext<mode>_1): Ditto. (*ashlqi_ext<mode>_1): Ditto. (*<any_shiftrt:insn>qi_ext<mode>_1): Ditto. gcc/testsuite/ChangeLog: * gcc.target/i386/pr78904-1.c (test_sub): New test. * gcc.target/i386/pr78904-1a.c (test_sub): Ditto. * gcc.target/i386/pr78904-1b.c (test_sub): Ditto. * gcc.target/i386/pr78904-2.c (test_sub): Ditto. * gcc.target/i386/pr78904-2a.c (test_sub): Ditto. * gcc.target/i386/pr78904-2b.c (test_sub): Ditto. * gcc.target/i386/pr78952-4.c (test_sub): Ditto. * gcc.target/i386/pr82524.c: New test. * gcc.target/i386/pr82524-1.c: New test. * gcc.target/i386/pr82524-2.c: New test. * gcc.target/i386/pr82524-3.c: New test.