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8268366: Incorrect calculation of has_fpu_registers in C1 linear scan
Reviewed-by: phh
Backport-of: 702e3ff
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TheRealMDoerr committed Jul 1, 2021
1 parent 3ed6237 commit e56abcaaeedcb510537eee92a57109525a7e5951
Showing 2 changed files with 73 additions and 5 deletions.
@@ -645,7 +645,8 @@ void LinearScan::compute_local_live_sets() {
CodeEmitInfo* info = visitor.info_at(k);
ValueStack* stack = info->stack();
for_each_state_value(stack, value,
set_live_gen_kill(value, op, live_gen, live_kill)
set_live_gen_kill(value, op, live_gen, live_kill);
local_has_fpu_registers = local_has_fpu_registers || value->type()->is_float_kind();
);
}

@@ -1658,22 +1659,33 @@ void LinearScan::allocate_registers() {
Interval* precolored_cpu_intervals, *not_precolored_cpu_intervals;
Interval* precolored_fpu_intervals, *not_precolored_fpu_intervals;

// allocate cpu registers
// collect cpu intervals
create_unhandled_lists(&precolored_cpu_intervals, &not_precolored_cpu_intervals,
is_precolored_cpu_interval, is_virtual_cpu_interval);

// allocate fpu registers
// collect fpu intervals
create_unhandled_lists(&precolored_fpu_intervals, &not_precolored_fpu_intervals,
is_precolored_fpu_interval, is_virtual_fpu_interval);

// the fpu interval allocation cannot be moved down below with the fpu section as
// this fpu interval collection cannot be moved down below with the allocation section as
// the cpu_lsw.walk() changes interval positions.

if (!has_fpu_registers()) {
#ifdef ASSERT
assert(not_precolored_fpu_intervals == Interval::end(), "missed an uncolored fpu interval");
#else
if (not_precolored_fpu_intervals != Interval::end()) {
BAILOUT("missed an uncolored fpu interval");
}
#endif
}

// allocate cpu registers
LinearScanWalker cpu_lsw(this, precolored_cpu_intervals, not_precolored_cpu_intervals);
cpu_lsw.walk();
cpu_lsw.finish_allocation();

if (has_fpu_registers()) {
// allocate fpu registers
LinearScanWalker fpu_lsw(this, precolored_fpu_intervals, not_precolored_fpu_intervals);
fpu_lsw.walk();
fpu_lsw.finish_allocation();
@@ -0,0 +1,56 @@
/*
* Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/

/*
* @test
* @bug 8268366
* @run main/othervm -Xbatch -XX:+TieredCompilation -XX:TieredStopAtLevel=1
* compiler.c1.TestLinearScanHasFPURegisters
*/

package compiler.c1;

public class TestLinearScanHasFPURegisters {
void test(String[] args) {
String arr[] = new String[4];
float f = -1;
try {
arr[0] = "-1"; // exception edge 1 with value -1
if (args.length > 1) {
f = 42;
arr[1] = "42"; // exception edge 2 with value 42
}
} catch (Exception e) {
// exception handler block with incoming phi for "f"
for (int i = 0; i < 1; ++i) {
f = f; // generates bytecodes, but no JIT IR
}
}
}
public static void main(String[] args) {
TestLinearScanHasFPURegisters t = new TestLinearScanHasFPURegisters();
for (int i = 0; i < 1000; ++i) {
t.test(args);
}
}
}

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