https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101723
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Earnshaw <rearn...@gcc.gnu.org>: https://gcc.gnu.org/g:c1cdabe3aab817d95a8db00a8b5e9f6bcdea936f commit r12-2762-gc1cdabe3aab817d95a8db00a8b5e9f6bcdea936f Author: Richard Earnshaw <rearn...@arm.com> Date: Thu Jul 29 11:00:31 2021 +0100 arm: reorder assembler architecture directives [PR101723] A change to the way gas interprets the .fpu directive in binutils-2.34 means that issuing .fpu will clear any features set by .arch_extension that apply to the floating point or simd units. This unfortunately causes problems for more recent versions of the architecture because we currently emit .arch, .arch_extension and .fpu directives at different times and try to suppress redundant changes. This change addresses this by firstly unifying all the places where we emit these directives to a single block of code and secondly (re)emitting all the directives if any changes have been made to the target options. Whilst this is slightly more than the strict minimum it should be enough to catch all cases where a change could have happened. The new code also emits the directives in the order: .arch, .fpu, .arch_extension. This ensures that the additional architectural extensions are not removed by a later .fpu directive. Whilst writing this patch I also noticed that in the corner case where the last function to be compiled had a non-standard set of architecture flags, the assembler would add an incorrect set of derived attributes for the file as a whole. Instead of reflecting the command-line options it would reflect the flags from the last file in the function. To address this I've also added a call to re-emit the flags from the asm_file_end callback so the assembler will be in the correct state when it finishes processing the intput. There's some slight churn to the testsuite as a consequence of this, because previously we had a hack to suppress emitting a .fpu directive for one specific case, but with the new order this is no-longer necessary. gcc/ChangeLog: PR target/101723 * config/arm/arm-cpus.in (generic-armv7-a): Add quirk to suppress writing .cpu directive in asm output. * config/arm/arm.c (arm_identify_fpu_from_isa): New variable. (arm_last_printed_arch_string): Delete. (arm_last-printed_fpu_string): Delete. (arm_configure_build_target): If use of floating-point/SIMD is disabled, remove all fp/simd related features from the target ISA. (last_arm_targ_options): New variable. (arm_print_asm_arch_directives): Add new parameters. Change order of emitted directives and handle all cases here. (arm_file_start): Always call arm_print_asm_arch_directives, move all generation of .arch/.arch_extension here. (arm_file_end): Call arm_print_asm_arch. (arm_declare_function_name): Call arm_print_asm_arch_directives instead of printing .arch/.fpu directives directly. gcc/testsuite/ChangeLog: PR target/101723 * gcc.target/arm/cortex-m55-nofp-flag-hard.c: Update expected output. * gcc.target/arm/cortex-m55-nofp-flag-softfp.c: Likewise. * gcc.target/arm/cortex-m55-nofp-nomve-flag-softfp.c: Likewise. * gcc.target/arm/mve/intrinsics/mve_fpu1.c: Convert to dg-do assemble. Add a non-no-op function body. * gcc.target/arm/mve/intrinsics/mve_fpu2.c: Likewise. * gcc.target/arm/pr98636.c (dg-options): Add -mfloat-abi=softfp. * gcc.target/arm/attr-neon.c: Tighten scan-assembler tests. * gcc.target/arm/attr-neon2.c: Use -Ofast, convert test to use check-function-bodies. * gcc.target/arm/attr-neon3.c: Likewise. * gcc.target/arm/pr69245.c: Tighten scan-assembler match, but allow multiple instances. * gcc.target/arm/pragma_fpu_attribute.c: Likewise. * gcc.target/arm/pragma_fpu_attribute_2.c: Likewise.