target/sh4: Fix mac.l with saturation enabled

The saturation arithmetic logic in helper_macl is not correct.
I tested and verified this behavior on a SH7091.

Signed-off-by: Zack Buhman <zack@buhman.org>
Message-Id: <20240404162641.27528-2-zack@buhman.org>
[rth: Reformat helper_macl, add a test case.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
This commit is contained in:
Zack Buhman 2024-04-05 15:17:39 -10:00 committed by Richard Henderson
parent 7d95db5e78
commit c97e8977dc
4 changed files with 86 additions and 11 deletions

View File

@ -11,7 +11,7 @@ DEF_HELPER_3(movcal, void, env, i32, i32)
DEF_HELPER_1(discard_movcal_backup, void, env)
DEF_HELPER_2(ocbi, void, env, i32)
DEF_HELPER_3(macl, void, env, i32, i32)
DEF_HELPER_3(macl, void, env, s32, s32)
DEF_HELPER_3(macw, void, env, i32, i32)
DEF_HELPER_2(ld_fpscr, void, env, i32)

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@ -158,20 +158,23 @@ void helper_ocbi(CPUSH4State *env, uint32_t address)
}
}
void helper_macl(CPUSH4State *env, uint32_t arg0, uint32_t arg1)
void helper_macl(CPUSH4State *env, int32_t arg0, int32_t arg1)
{
const int64_t min = -(1ll << 47);
const int64_t max = (1ll << 47) - 1;
int64_t mul = (int64_t)arg0 * arg1;
int64_t mac = env->mac;
int64_t res;
res = ((uint64_t) env->mach << 32) | env->macl;
res += (int64_t) (int32_t) arg0 *(int64_t) (int32_t) arg1;
env->mach = (res >> 32) & 0xffffffff;
env->macl = res & 0xffffffff;
if (env->sr & (1u << SR_S)) {
if (res < 0)
env->mach |= 0xffff0000;
else
env->mach &= 0x00007fff;
if (!(env->sr & (1u << SR_S))) {
res = mac + mul;
} else if (sadd64_overflow(mac, mul, &res)) {
res = mac < 0 ? min : max;
} else {
res = MIN(MAX(res, min), max);
}
env->mac = res;
}
void helper_macw(CPUSH4State *env, uint32_t arg0, uint32_t arg1)

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@ -9,3 +9,8 @@ run-signals: signals
$(call skip-test, $<, "BROKEN")
run-plugin-signals-with-%:
$(call skip-test, $<, "BROKEN")
VPATH += $(SRC_PATH)/tests/tcg/sh4
test-macl: CFLAGS += -O -g
TESTS += test-macl

67
tests/tcg/sh4/test-macl.c Normal file
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@ -0,0 +1,67 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#define MACL_S_MIN (-(1ll << 47))
#define MACL_S_MAX ((1ll << 47) - 1)
int64_t mac_l(int64_t mac, const int32_t *a, const int32_t *b)
{
register uint32_t macl __asm__("macl") = mac;
register uint32_t mach __asm__("mach") = mac >> 32;
asm volatile("mac.l @%0+,@%1+"
: "+r"(a), "+r"(b), "+x"(macl), "+x"(mach));
return ((uint64_t)mach << 32) | macl;
}
typedef struct {
int64_t mac;
int32_t a, b;
int64_t res[2];
} Test;
__attribute__((noinline))
void test(const Test *t, int sat)
{
int64_t res;
if (sat) {
asm volatile("sets");
} else {
asm volatile("clrs");
}
res = mac_l(t->mac, &t->a, &t->b);
if (res != t->res[sat]) {
fprintf(stderr, "%#llx + (%#x * %#x) = %#llx -- got %#llx\n",
t->mac, t->a, t->b, t->res[sat], res);
abort();
}
}
int main()
{
static const Test tests[] = {
{ 0x00007fff12345678ll, INT32_MAX, INT32_MAX,
{ 0x40007ffe12345679ll, MACL_S_MAX } },
{ MACL_S_MIN, -1, 1,
{ 0xffff7fffffffffffll, MACL_S_MIN } },
{ INT64_MIN, -1, 1,
{ INT64_MAX, MACL_S_MIN } },
{ 0x00007fff00000000ll, INT32_MAX, INT32_MAX,
{ 0x40007ffe00000001ll, MACL_S_MAX } },
{ 4, 1, 2, { 6, 6 } },
{ -4, -1, -2, { -2, -2 } },
};
for (int i = 0; i < sizeof(tests) / sizeof(tests[0]); ++i) {
for (int j = 0; j < 2; ++j) {
test(&tests[i], j);
}
}
return 0;
}