binutils-gdb/gdb/testsuite/lib/aarch64-scalable.exp

# Copyright 2023-2024 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/>.  */

# Support routines for aarch64 scalable extension tests

# Load generic aarch64 test dependencies.
load_lib aarch64.exp

#
# Return a regular expression that matches what gdb would print for a
# SVE Z register of length VL in state STATE.  The Z register should be filled
# with BYTE_SVE and the FPSIMD registers should be filled with BYTE_FPSIMD.
#
# The pattern is of the form
#
# {BYTE_FPSIMD <repeats 16 times>}
#
# or
#
# {BYTE_FPSIMD <repeats 16 times>, 0 <repeats ... times>}
#
# or
#
# {BYTE_SVE <repeats VL times>}
#
proc sve_value_pattern { state vl byte_fpsimd byte_sve } {
    set brace_open "{"
    set brace_close "}"

    append data $brace_open
    if { $state == "fpsimd" || $state == "za" } {
	if { $vl > 16 } {
	    set sve_repeat_count [expr $vl - 16]
	    append data "$byte_fpsimd <repeats 16 times>, 0 <repeats $sve_repeat_count times>"
	} else {
	    append data "$byte_fpsimd <repeats 16 times>"
	}
    } else {
	append data "$byte_sve <repeats $vl times>"
    }
    append data $brace_close

    verbose -log "sve_value_pattern pattern string is..."
    verbose -log $data
    return $data
}

#
# Return the SVCR value based on STATE.
# SVCR is only available when SME is available.
#
proc get_svcr_value { state } {
    if { $state == "ssve" } {
      return "= \\\[ SM \\\]"
    } elseif { $state == "za" } {
      return "= \\\[ ZA \\\]"
    } elseif { $state == "za_ssve" } {
      return "= \\\[ SM ZA \\\]"
    }

  return "= \\\[ \\\]"
}

#
# 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)]
}

#
# Validate the values of the SVE registers.
#
proc check_sve_regs { byte state vl svl } {

    # If streaming mode is enabled, the vector length is the streaming
    # vector length.
    set z_pattern ""
    set z_size 0
    if {$state == "ssve" || $state == "za_ssve"} {
	set z_pattern [string_to_regexp [1d_array_value_pattern $byte $svl]]
	set z_size $svl
    } else {
	set z_size $vl

	if {$state == "fpsimd" || $state == "za"} {
	    # If there is no SVE/SSVE state, the contents of the Z/P/FFR registers
	    # are zero.
	    if {$vl == 16} {
		set z_pattern [string_to_regexp [1d_array_value_pattern $byte $vl]]
	    } else {
		set z_repeats [expr $vl - 16]
		set z_pattern [string_to_regexp "{$byte <repeats 16 times>, 0 <repeats $z_repeats times>}"]
	      }
	} else {
	    set z_pattern [string_to_regexp [1d_array_value_pattern $byte $vl]]
	}
    }
    set p_size [expr $z_size / 8]

    # If there is no SVE/SSVE state, the contents of the Z/P/FFR registers
    # are zero.
    set p_byte $byte
    if {$state == "fpsimd" || $state == "za"} {
	set p_byte 0
    }
    set p_pattern [string_to_regexp [1d_array_value_pattern $p_byte $p_size]]

    for {set number 0} {$number < 32} {incr number} {
	set register_name "\$z${number}\.b\.u"
	gdb_test "print sizeof $register_name" " = $z_size"
	gdb_test "print $register_name" $z_pattern
    }

    for {set number 0} {$number < 16} {incr number} {
	set register_name "\$p${number}"
	gdb_test "print sizeof $register_name" " = $p_size"
	gdb_test "print $register_name" $p_pattern
    }

    gdb_test "print \$ffr" $p_pattern
}

#
# Validate the values of the SME registers.
#
proc check_sme_regs { byte state svl } {
    # ZA contents are only available when the ZA state is enabled.  Otherwise
    # the ZA contents are unavailable (zeroed out).
    set za_pattern ""
    set expected_za_size [expr $svl * $svl]

    if {$state != "za" && $state != "za_ssve"} {
	set byte 0
    }

    set za_pattern [string_to_regexp [2d_array_value_pattern $byte $svl $svl]]

    gdb_test "print sizeof \$za" " = $expected_za_size"
    gdb_test "print \$za" $za_pattern
}

#
# Validate the values of the SME2 registers.
#
proc check_sme2_regs { byte } {
    # The size of the ZT registers should always be fixed to 64 bytes.
    set zt_size 64
    gdb_test "print sizeof \$zt0" " = $zt_size"
    # Check that we have the expected pattern of bytes for the ZT registers.
    set zt_pattern [string_to_regexp [1d_array_value_pattern $byte $zt_size]]
    gdb_test "print \$zt0" $zt_pattern
}

#
# 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.
    #
    # The SME2 (ZT) registers are initialized with a value of 0xff (255) 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

    # Check SME2 registers
    if [is_sme2_available] {
	# The SME2 ZT0 register will always be zero, except when ZA is active.
	set sme2_byte 0
	if {$state == "za" || $state == "za_ssve"} {
	    set sme2_byte 255
	}

	# The target supports SME2, so check the ZT register values.
	check_sme2_regs $sme2_byte
    }
}

#
# Return 1 if SME2 is available (meaning the ZT0 register exists).
# Return 0 otherwise.
#
proc is_sme2_available { } {

    # Does the ZT0 register exist?
    gdb_test_multiple "print \$zt0" "" {
	-re " = void.*${::gdb_prompt} $" {
	    # SME2 is not available.
	    return 0
	}
	-re " = {.*}\r\n${::gdb_prompt} $" {
	    # SME2 is available.
	    return 1
	}
    }
}