tests: Add lib/libgcc-test test case

Add tests for src/lib/libgcc.c __clzsi2() implementation. Unlike GCC
implementation, coreboot one can handle zero input.

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I3f46071d0921e8c5edc5df3c296d11c77de01c88
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56257
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

tests/lib/Makefile.inc

@@ -31,6 +31,7 @@ tests-y += rtc-test
 tests-y += spd_cache-ddr3-test
 tests-y += spd_cache-ddr4-test
 tests-y += cbmem_stage_cache-test
+tests-y += libgcc-test
 
 string-test-srcs += tests/lib/string-test.c
 string-test-srcs += src/lib/string.c
@@ -177,3 +178,5 @@ cbmem_stage_cache-test-srcs += src/lib/imd.c
 cbmem_stage_cache-test-cflags += -I 3rdparty/vboot/firmware/include
 cbmem_stage_cache-test-cflags += -I $(src)/commonlib/include
 cbmem_stage_cache-test-config += CONFIG_CBMEM_STAGE_CACHE=1
+
+libgcc-test-srcs += tests/lib/libgcc-test.c

tests/lib/libgcc-test.c

@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include "../lib/libgcc.c"
+
+#include <tests/test.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct {
+	u32 value;
+	int expected_output;
+} test_data[] = {
+	/* GCC documentation says, __clzsi2() has undefined result for zero as an input value,
+	   but coreboot implementation can handle this. */
+	{ .value = 0, .expected_output = 32 },
+
+	{ .value = 1, .expected_output = 31 },
+	{ .value = 2, .expected_output = 30 },
+	{ .value = 3, .expected_output = 30 },
+	{ .value = 4, .expected_output = 29 },
+	{ .value = 5, .expected_output = 29 },
+	{ .value = 6, .expected_output = 29 },
+	{ .value = 7, .expected_output = 29 },
+
+	{ .value = 0xF, .expected_output = 28 },
+	{ .value = 0x10, .expected_output = 27 },
+	{ .value = 0x25, .expected_output = 26 },
+	{ .value = 0x5D, .expected_output = 25 },
+	{ .value = 0xB7, .expected_output = 24 },
+
+	{ .value = 0x133, .expected_output = 23 },
+	{ .value = 0x3DC, .expected_output = 22 },
+	{ .value = 0x6F1, .expected_output = 21 },
+	{ .value = 0x897, .expected_output = 20 },
+
+	{ .value = 0x1FFF, .expected_output = 19 },
+	{ .value = 0x2222, .expected_output = 18 },
+	{ .value = 0x7BAD, .expected_output = 17 },
+	{ .value = 0xE708, .expected_output = 16 },
+
+	{ .value = 0x1DABD, .expected_output = 15 },
+	{ .value = 0x29876, .expected_output = 14 },
+	{ .value = 0x56665, .expected_output = 13 },
+	{ .value = 0xABCDE, .expected_output = 12 },
+
+	{ .value = 0x18365F, .expected_output = 11 },
+	{ .value = 0x3D0115, .expected_output = 10 },
+	{ .value = 0x4B07EB, .expected_output = 9 },
+	{ .value = 0xCCC74D, .expected_output = 8 },
+
+	{ .value = 0x17933ED, .expected_output = 7 },
+	{ .value = 0x2B00071, .expected_output = 6 },
+	{ .value = 0x4D4C1A5, .expected_output = 5 },
+	{ .value = 0xAD01FFF, .expected_output = 4 },
+
+	{ .value = 0x1C5A8057, .expected_output = 3 },
+	{ .value = 0x35AB23C3, .expected_output = 2 },
+	{ .value = 0x7017013B, .expected_output = 1 },
+	{ .value = 0xAD01EB15, .expected_output = 0 },
+
+	{ .value = 0xFFFFFFFF, .expected_output = 0 },
+	{ .value = 0x80000000, .expected_output = 0 },
+	{ .value = 0x7FFFFFFF, .expected_output = 1 },
+	{ .value = 0x30000000, .expected_output = 2 },
+	{ .value = 0x10000000, .expected_output = 3 },
+	{ .value = 0x0FFFFFFF, .expected_output = 4 },
+
+	{ .value = 0xFF000000, .expected_output = 0 },
+	{ .value = 0x00FF0000, .expected_output = 8 },
+	{ .value = 0x0000FF00, .expected_output = 16 },
+	{ .value = 0x000000FF, .expected_output = 24 },
+
+	{ .value = 0x8F000000, .expected_output = 0 },
+	{ .value = 0x008F0000, .expected_output = 8 },
+	{ .value = 0x00008F00, .expected_output = 16 },
+	{ .value = 0x0000008F, .expected_output = 24 },
+
+	{ .value = 0x7F000000, .expected_output = 1 },
+	{ .value = 0x007F0000, .expected_output = 9 },
+	{ .value = 0x00007F00, .expected_output = 17 },
+	{ .value = 0x0000007F, .expected_output = 25 },
+
+	{ .value = 0x3F000000, .expected_output = 2 },
+	{ .value = 0x003F0000, .expected_output = 10 },
+	{ .value = 0x00003F00, .expected_output = 18 },
+	{ .value = 0x0000003F, .expected_output = 26 },
+
+	{ .value = 0x1F000000, .expected_output = 3 },
+	{ .value = 0x001F0000, .expected_output = 11 },
+	{ .value = 0x00001F00, .expected_output = 19 },
+	{ .value = 0x0000001F, .expected_output = 27 },
+
+	{ .value = 0x0F000000, .expected_output = 4 },
+	{ .value = 0x000F0000, .expected_output = 12 },
+	{ .value = 0x00000F00, .expected_output = 20 },
+	{ .value = 0x0000000F, .expected_output = 28 },
+
+	{ .value = 0x08000000, .expected_output = 4 },
+	{ .value = 0x00080000, .expected_output = 12 },
+	{ .value = 0x00000800, .expected_output = 20 },
+	{ .value = 0x00000008, .expected_output = 28 },
+
+	{ .value = 0x07000000, .expected_output = 5 },
+	{ .value = 0x00070000, .expected_output = 13 },
+	{ .value = 0x00000700, .expected_output = 21 },
+	{ .value = 0x00000007, .expected_output = 29 },
+
+	{ .value = 0x03000000, .expected_output = 6 },
+	{ .value = 0x00030000, .expected_output = 14 },
+	{ .value = 0x00000300, .expected_output = 22 },
+	{ .value = 0x00000003, .expected_output = 30 },
+
+	{ .value = 0x01000000, .expected_output = 7 },
+	{ .value = 0x00010000, .expected_output = 15 },
+	{ .value = 0x00000100, .expected_output = 23 },
+	{ .value = 0x00000001, .expected_output = 31 },
+};
+
+void test_clzsi2_with_data(void **state)
+{
+	for (int i = 0; i < ARRAY_SIZE(test_data); ++i)
+		assert_int_equal(test_data[i].expected_output, __clzsi2(test_data[i].value));
+}
+
+int main(void)
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(test_clzsi2_with_data),
+	};
+
+	return cmocka_run_group_tests(tests, NULL, NULL);
+}