[PATCH 15/17] [PowerPC] Add tests for HTM registers

[Pedro Franco de Carvalho <pedromfc@linux.ibm.com>]

This patch adds a test for acces to checkpointed HTM registers in
GDB.

The tests records the values of the regular registers before stepping
the inferior through a "tbegin." instruction to start a transaction,
then the checkpointed registers are checked against the recorded
pre-transactional values. New values are written to the checkpointed
registers and recorded, the inferior continues until the transaction
aborts (which is usually immediately when it is resumed), and the
regular registers are checked against the recorded values, because the
abort should have reverted the registers to these values.

gdb/testsuite/ChangeLog:
YYYY-MM-DD  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* gdb.arch/powerpc-htm-regs.c: New file.
	* gdb.arch/powerpc-htm-regs.exp: New file.
---
 gdb/testsuite/gdb.arch/powerpc-htm-regs.c   |  34 +++
 gdb/testsuite/gdb.arch/powerpc-htm-regs.exp | 311 ++++++++++++++++++++++++++++
 2 files changed, 345 insertions(+)
 create mode 100644 gdb/testsuite/gdb.arch/powerpc-htm-regs.c
 create mode 100644 gdb/testsuite/gdb.arch/powerpc-htm-regs.exp

diff --git a/gdb/testsuite/gdb.arch/powerpc-htm-regs.c b/gdb/testsuite/gdb.arch/powerpc-htm-regs.c
new file mode 100644
index 0000000000..14992039db
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/powerpc-htm-regs.c
@@ -0,0 +1,34 @@
+/* This test is part of GDB, the GNU debugger.
+
+   Copyright 2018 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/>.  */
+
+int main (void)
+{
+  /* Touch DSCR. Some kernels won't schedule the thread with a DSCR
+     altered by ptrace unless the register was used at some point.  */
+  unsigned long dscr = 0x0;
+  asm volatile ("mtdscr %0" : : "r" (dscr));
+
+  asm volatile ("tbegin."); // first marker
+  asm volatile goto ("bc 12,2,%l[end]"
+		     :
+		     :
+		     :
+		     : end);
+  asm volatile ("tabort. 0");
+end:
+  asm volatile ("nop"); // second marker
+}
diff --git a/gdb/testsuite/gdb.arch/powerpc-htm-regs.exp b/gdb/testsuite/gdb.arch/powerpc-htm-regs.exp
new file mode 100644
index 0000000000..07db95e71c
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/powerpc-htm-regs.exp
@@ -0,0 +1,311 @@
+# Copyright 2018 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 access to HTM (hardware transactional memory) registers.
+
+if {![istarget "powerpc*-*-linux*"]} then {
+    verbose "Skipping PowerPC test for HTM registers."
+    return
+}
+
+standard_testfile .c .gen.c
+
+# First check if our processor and kernel support access to
+# the registers we need and to the HTM facility.
+
+set gen_src [standard_output_file $srcfile2]
+
+gdb_produce_source $gen_src {
+    int main() {
+	asm volatile ("tbegin."); // marker
+	asm volatile ("nop");
+	return 0;
+    }
+}
+
+if {[build_executable "compile" $binfile $gen_src {debug}] == -1} {
+    return
+}
+
+clean_restart $binfile
+
+set bp_line [gdb_get_line_number "marker" "$gen_src"]
+
+# Displaced-stepping a tbegin. causes problems,
+# so we make the breakpoint temporary.
+gdb_breakpoint ${gen_src}:${bp_line} {temporary}
+
+gdb_run_cmd
+
+# Wait for the prompt.
+if {[gdb_test "" "Temporary breakpoint.*"] != 0 } {
+    return
+}
+
+# Make sure that we stopped at the right place (just before tbegin. is
+# executed).
+if { [gdb_test "x/i \$pc" "=> $hex.*:.*tbegin\\..*" "disassemble tbegin"] != 0} {
+    return
+}
+
+proc check_register_access { regname } {
+    global gdb_prompt
+
+    set test "$regname register access"
+    gdb_test_multiple "info reg $regname" "$test" {
+	-re "Invalid register.*\r\n$gdb_prompt $" {
+	    unsupported "$test"
+	    return 0
+	}
+	-re "\r\n$regname.*\r\n$gdb_prompt $" {
+	    pass "$test"
+	    return 1
+	}
+    }
+    return 0
+}
+
+if {![check_register_access "vs0"]} {
+    return
+}
+
+if {![check_register_access "texasr"]} {
+    return
+}
+
+if {![check_register_access "dscr"]} {
+    return
+}
+
+if {![check_register_access "ppr"]} {
+    return
+}
+
+if {![check_register_access "tar"]} {
+    return
+}
+
+proc check_htm_support {} {
+    global gdb_prompt
+    set test "HTM support"
+
+    gdb_test_multiple "stepi" "$test" {
+	-re "Illegal instruction.*\r\n$gdb_prompt $" {
+	    unsupported $test
+	    return 0
+	}
+	-re "nop.*\r\n$gdb_prompt $"
+	{
+	    pass $test
+	    return 1
+	}
+    }
+    return 0;
+}
+
+if {![check_htm_support]} {
+    return
+}
+
+# Now do the actual test.
+if {[build_executable "compile" $binfile $srcfile {debug}] == -1} {
+    return
+}
+
+clean_restart $binfile
+
+set bp_line [gdb_get_line_number "first marker"]
+
+clean_restart $binfile
+
+gdb_breakpoint ${srcfile}:${bp_line} {temporary}
+
+gdb_run_cmd
+
+# Wait for the prompt.
+gdb_test "Temporary breakpoint.*"
+
+if {[gdb_test "x/i \$pc" "=> $hex.*:.*tbegin\\..*" "disassemble tbegin"] != 0} {
+    return
+}
+
+# Now we write non-zero values to some registers, then read the values
+# of various registers, then stepi to start the transaction.  The
+# checkpointed register state should correspond to the values we read.
+
+# Write to the GPRs
+for {set i 0} {$i < 32} {incr i 1} {
+    gdb_test_no_output "set \$r$i = $i"
+}
+
+gdb_test_no_output "set \$xer = 0xc0000000"
+
+# FPRs
+gdb_test_no_output "set \$f0 = 0.5"
+for {set i 1} {$i < 32} {incr i 1} {
+    gdb_test_no_output "set \$f$i = \$f[expr $i - 1] + 1.0"
+}
+
+gdb_test_no_output "set \$fpscr = 0x84005000"
+
+# VRs
+for {set i 0} {$i < 32} {incr i 1} {
+    for {set j 0} {$j < 4} {incr j 1} {
+	gdb_test_no_output "set \$vr$i.v4_int32\[$j\] = $i"
+    }
+}
+
+gdb_test_no_output "set \$dscr = 0x2"
+gdb_test_no_output "set \$tar = &main"
+
+# Get the pre-transactional value of the registers.
+for {set i 0} {$i < 32} {incr i 1} {
+    set "r$i" [get_hexadecimal_valueof "\$r$i" "default0"]
+}
+
+set cr [get_hexadecimal_valueof "\$cr" "default0"]
+set xer [get_hexadecimal_valueof "\$xer" "default0"]
+set lr [get_hexadecimal_valueof "\$lr" "default0"]
+set ctr [get_hexadecimal_valueof "\$ctr" "default0"]
+
+for {set i 0} {$i < 32} {incr i 1} {
+    set "f$i" [get_valueof "" "\$f$i" "default0"]
+}
+
+set fpscr [get_hexadecimal_valueof "\$fpscr" "default0"]
+
+for {set i 0} {$i < 32} {incr i 1} {
+    set "vr$i" [get_hexadecimal_valueof "\$vr$i.uint128" "default0"]
+}
+
+set vscr [get_hexadecimal_valueof "\$vscr" "default0"]
+set vrsave [get_hexadecimal_valueof "\$vrsave" "default0"]
+
+for {set i 0} {$i < 64} {incr i 1} {
+    set "vs$i" [get_hexadecimal_valueof "\$vs$i.uint128" "default0"]
+}
+
+set dscr [get_hexadecimal_valueof "\$dscr" "default0"]
+set ppr [get_hexadecimal_valueof "\$ppr" "default0"]
+set tar [get_hexadecimal_valueof "\$tar" "default0"]
+
+gdb_test "stepi" "asm.*bc.*"
+
+proc test_register_match {reg_name reg_var_name hex} {
+    set test "$reg_name matches $reg_var_name"
+
+    upvar $reg_var_name expected_val
+
+    if {$hex} {
+	set actual_val [get_hexadecimal_valueof "\$$reg_name" "default1"]
+    } else {
+	set actual_val [get_valueof "" "\$$reg_name" "default1"]
+    }
+
+    if { "$expected_val" == "$actual_val" } {
+	pass $test
+    } else {
+	fail $test
+    }
+}
+
+for {set i 0} {$i < 32} {incr i 1} {
+    test_register_match "cr$i" "r$i" 1
+}
+
+test_register_match "ccr" "cr" 1
+test_register_match "cxer" "xer" 1
+test_register_match "clr" "lr" 1
+test_register_match "cctr" "ctr" 1
+
+for {set i 0} {$i < 32} {incr i 1} {
+    test_register_match "cf$i" "f$i" 0
+}
+
+test_register_match "cfpscr" "fpscr" 1
+
+for {set i 0} {$i < 32} {incr i 1} {
+    test_register_match "cvr$i.uint128" "vr$i" 1
+}
+
+test_register_match "cvscr" "vscr" 1
+test_register_match "cvrsave" "vrsave" 1
+
+for {set i 0} {$i < 64} {incr i 1} {
+    test_register_match "cvs$i.uint128" "vs$i" 1
+}
+
+test_register_match "cdscr" "dscr" 1
+test_register_match "cppr" "ppr" 1
+test_register_match "ctar" "tar" 1
+
+# Support for writing to the checkpointed registers is not
+# currently available in the gdbserver stub.
+if [target_is_gdbserver] {
+    unsupported "write to checkpointed registers"
+    return
+}
+
+# Now write different values to some of the checkpointed registers and
+# check that the transaction abort reverts the register to these
+# values.
+for {set i 0} {$i < 32} {incr i 1} {
+    gdb_test_no_output "set \$cr$i = $i + 0xC00"
+}
+
+gdb_test_no_output "set \$cf0 = 0.25"
+for {set i 1} {$i < 32} {incr i 1} {
+    gdb_test_no_output "set \$cf$i = \$cf[expr $i - 1] + 1.0"
+}
+
+for {set i 0} {$i < 32} {incr i 1} {
+    for {set j 0} {$j < 4} {incr j 1} {
+	gdb_test_no_output "set \$cvr$i.v4_int32\[$j\] = $i + 0xF00"
+    }
+}
+
+# Read back the values.
+for {set i 0} {$i < 32} {incr i 1} {
+    set "cr$i" [get_hexadecimal_valueof "\$cr$i" "default0"]
+}
+
+for {set i 0} {$i < 32} {incr i 1} {
+    set "cf$i" [get_valueof "" "\$cf$i" "default0"]
+}
+
+for {set i 0} {$i < 64} {incr i 1} {
+    set "cvs$i" [get_hexadecimal_valueof "\$cvs$i.uint128" "default0"]
+}
+
+set bp_line [gdb_get_line_number "second marker"]
+
+gdb_breakpoint ${srcfile}:${bp_line}
+
+gdb_test "continue"
+
+for {set i 0} {$i < 32} {incr i 1} {
+    test_register_match "r$i" "cr$i" 1
+}
+
+for {set i 0} {$i < 32} {incr i 1} {
+    test_register_match "f$i" "cf$i" 0
+}
+
+for {set i 0} {$i < 64} {incr i 1} {
+    test_register_match "vs$i.uint128" "cvs$i" 1
+}
+
-- 
2.13.6