Re: [PATCH v3 15/16] [gdb/testsuite] sme: Add SVE/SME testcases

[Thiago Jung Bauermann <thiago.bauermann@linaro.org>]

Luis Machado via Gdb-patches <gdb-patches@sourceware.org> writes:

> diff --git a/gdb/testsuite/gdb.arch/aarch64-sme-core-0.exp b/gdb/testsuite/gdb.arch/aarch64-sme-core-0.exp
> new file mode 100644
> index 00000000000..c4755346bc8
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/aarch64-sme-core-0.exp
> @@ -0,0 +1,18 @@
> +# Copyright 2023 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +set id_start 0
> +set id_end 24

It would be useful to have a comment mentioning that the range above
tests the fpsimd state.

Same comment for the other aarch64-sme-*.exp tests.

> +source $srcdir/$subdir/aarch64-sme-core.exp.tcl

<snip>

> +require is_aarch64_target
> +
> +if {![allow_aarch64_sve_tests]} {
> +    verbose "Skipping ${gdb_test_file_name}."
> +    return
> +}
> +
> +if {![allow_aarch64_sme_tests]} {
> +    verbose "Skipping ${gdb_test_file_name}."
> +    return
> +}

Can these "allow" tests also be invoked using "require"?
This question applies for all aarch64-sme-*.exp.tcl files.

> +
> +test_sme_core_file $id_start $id_end

<snip>

> +#
> +# Return the state string based on STATE
> +#
> +proc state_id_to_state_string { state } {
> +  if {$state == 0} {
> +    return "fpsimd"
> +  } elseif {$state == 1} {
> +    return "sve"
> +  } elseif {$state == 2} {
> +    return "ssve"
> +  } elseif {$state == 3} {
> +    return "za"
> +  } elseif {$state == 4} {
> +    return "za_ssve"
> +  }
> +}
> +
> +#
> +# Given a test ID, return the string representing the register state.
> +# The state is one of fpsimd, sve, ssve, za and za_ssve.
> +#
> +proc test_id_to_state { id } {
> +  set state [expr $id / 25]
> +
> +  return [state_id_to_state_string $state]
> +}
> +
> +#
> +# Given a test ID, return the associated vector length.
> +#
> +proc test_id_to_vl { id } {
> +  return [expr 16 << (($id / 5) % 5)]
> +}
> +
> +#
> +# Given a test ID, return the associated streaming vector length.
> +#
> +proc test_id_to_svl { id } {
> +  return [expr 16 << ($id % 5)]
> +}

I suggest adding an sme_ prefix to the procedures above, since "id" here
is specific to SME testcases.

> +#
> +# With register STATE, vector length VL and streaming vector length SVL,
> +# run some register state checks to make sure the values are the expected
> +# ones
> +#
> +proc check_state { state vl svl } {
> +    # The FPSIMD registers are initialized with a value of 0x55 (85)
> +    # for each byte.
> +    #
> +    # The SVE registers are initialized with a value of 0xff (255) for each
> +    # byte, including the predicate registers and FFR.
> +    #
> +    # The SME (ZA) register is initialized with a value of 0xaa (170) for
> +    # each byte.
> +
> +    # Check VG to make sure it is correct
> +    set expected_vg [expr $vl / 8]
> +    # If streaming mode is enabled, then vg is actually svg.
> +    if {$state == "ssve" || $state == "za_ssve"} {
> +	set expected_vg [expr $svl / 8]
> +    }
> +    gdb_test "print \$vg" " = ${expected_vg}"
> +
> +    # Check SVG to make sure it is correct
> +    set expected_svg [expr $svl / 8]
> +    gdb_test "print \$svg" " = ${expected_svg}"
> +
> +    # Check the value of SVCR.
> +    gdb_test "print \$svcr" [get_svcr_value $state]
> +
> +    # When we have any SVE or SSVE state, the FPSIMD registers will have
> +    # the same values as the SVE/SSVE Z registers.
> +    set fpsimd_byte 85
> +    if {$state == "sve" || $state == "ssve" || $state == "za_ssve"} {
> +	set fpsimd_byte 255
> +    }
> +
> +    set sve_byte 255
> +    if {$state == "fpsimd" || $state == "za"} {
> +	set sve_byte 85
> +    }
> +
> +    # Check FPSIMD registers
> +    check_fpsimd_regs $fpsimd_byte $state $vl $svl
> +    # Check SVE registers
> +    check_sve_regs $sve_byte $state $vl $svl
> +    # Check SME registers
> +    check_sme_regs 170 $state $svl
> +}

Also here, perhaps call this function "check_sme_state"?

> +# Run a test on the target to see if it supports Aarch64 SME extensions.
> +# Return 0 if so, 1 if it does not.  Note this causes a restart of GDB.
> +
> +gdb_caching_proc allow_aarch64_sme_tests {} {
> +    global srcdir subdir gdb_prompt inferior_exited_re
> +
> +    set me "allow_aarch64_sme_tests"
> +
> +    if { ![is_aarch64_target]} {
> +	return 0
> +    }
> +
> +    set compile_flags "{additional_flags=-march=armv8-a+sme}"
> +
> +    # Compile a test program containing SVE instructions.

s/SVE/SME/

> +    set src {
> +	int main() {
> +	    asm volatile ("smstart za");
> +	    return 0;
> +	}
> +    }
> +    if {![gdb_simple_compile $me $src executable $compile_flags]} {


-- 
Thiago