binutils-gdb/gdb/testsuite/gdb.arch/amd64-disp-step-avx.exp

# Copyright 2009-2020 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/>.

# This file is part of the gdb testsuite.

# Test displaced stepping over VEX-encoded RIP-relative AVX
# instructions.

if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
    verbose "Skipping x86_64 displaced stepping tests."
    return
}

standard_testfile .S

set options [list debug \
		 additional_flags=-static \
		 additional_flags=-nostartfiles]
if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile} $options] } {
    return -1
}

# Get things started.

gdb_test "set displaced-stepping on" ""
gdb_test "show displaced-stepping" ".* displaced stepping .* is on.*"

if ![runto_main] then {
    fail "can't run to main"
    return 0
}

# GDB picks a spare register from this list to hold the RIP-relative
# address.
set rip_regs { "rax" "rbx" "rcx" "rdx" "rbp" "rsi" "rdi" }

# Assign VAL to all the RIP_REGS.

proc set_regs { val } {
    global gdb_prompt
    global rip_regs

    foreach reg ${rip_regs} {
	gdb_test_no_output "set \$${reg} = ${val}"
    }
}

# Verify all RIP_REGS print as HEX_VAL_RE in hex.

proc verify_regs { hex_val_re } {
    global rip_regs

    foreach reg ${rip_regs} {
	gdb_test "p /x \$${reg}" " = ${hex_val_re}" "${reg} expected value"
    }
}

# Set a break at FUNC, which starts with a RIP-relative instruction
# that we want to displaced-step over, and then continue over the
# breakpoint, forcing a displaced-stepping sequence.

proc disp_step_func { func } {
    global srcfile

    set test_start_label "${func}"
    set test_end_label "${func}_end"

    gdb_test "break ${test_start_label}" \
	"Breakpoint.*at.* file .*$srcfile, line.*"
    gdb_test "break ${test_end_label}" \
	"Breakpoint.*at.* file .*$srcfile, line.*"

    gdb_test "continue" \
	"Continuing.*Breakpoint.*, ${test_start_label} ().*" \
	"continue to ${test_start_label}"

    # GDB picks a spare register to hold the RIP-relative address.
    # Ensure the spare register value is restored properly (rax-rdi,
    # sans rsp).
    set value "0xdeadbeefd3adb33f"
    set_regs $value

    # Turn "debug displaced" on to make sure a displaced step is actually
    # executed, not an inline step.
    gdb_test_no_output "set debug displaced on"

    gdb_test "continue" \
	"Continuing.*displaced: displaced pc to.*Breakpoint.*, ${test_end_label} ().*" \
	"continue to ${test_end_label}"

    gdb_test_no_output "set debug displaced off"

    verify_regs $value
}

# Test a VEX2-encoded RIP-relative instruction.
with_test_prefix "vex2" {
    # This test writes to the 'xmm0' register.  As the test is
    # statically linked, we know that the XMM registers should all
    # have the default value of 0 at this point in time.  We're about
    # to run an AVX instruction that will modify $xmm0, but lets first
    # confirm that all XMM registers are 0.
    for {set i 0 } { $i < 16 } { incr i } {
	gdb_test "p /x \$xmm${i}.uint128" " = 0x0" \
	    "xmm${i} has expected value before"
    }

    disp_step_func "test_rip_vex2"

    # Confirm the instruction's expected side effects.  It should have
    # modified xmm0.
    gdb_test "p /x \$xmm0.uint128" " = 0x1122334455667788" \
	"xmm0 has expected value after"

    # And all of the other XMM register should still be 0.
    for {set i 1 } { $i < 16 } { incr i } {
	gdb_test "p /x \$xmm${i}.uint128" " = 0x0" \
	    "xmm${i} has expected value after"
    }
}

# Test a VEX3-encoded RIP-relative instruction.
with_test_prefix "vex3" {
    # This case writes to the 'var128' variable.  Confirm the
    # variable's value is what we believe it is before the AVX
    # instruction runs.
    gdb_test "p /x (unsigned long long \[2\]) var128" \
	" = \\{0xaa55aa55aa55aa55, 0x55aa55aa55aa55aa\\}" \
	"var128 has expected value before"

    # Run the AVX instruction.
    disp_step_func "test_rip_vex3"

    # Confirm the instruction's expected side effects.  It should have
    # modifed the 'var128' variable.
    gdb_test "p /x (unsigned long long \[2\]) var128" \
	" = \\{0x1122334455667788, 0x0\\}" \
	"var128 has expected value after"
}

# Done, run program to exit.
gdb_continue_to_end "amd64-disp-step-avx"