diff options
Diffstat (limited to 'target/sh4/op_helper.c')
| -rw-r--r-- | target/sh4/op_helper.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/target/sh4/op_helper.c b/target/sh4/op_helper.c index d0bae0cc00..99394b714c 100644 --- a/target/sh4/op_helper.c +++ b/target/sh4/op_helper.c @@ -177,22 +177,28 @@ void helper_macl(CPUSH4State *env, int32_t arg0, int32_t arg1) env->mac = res; } -void helper_macw(CPUSH4State *env, uint32_t arg0, uint32_t arg1) +void helper_macw(CPUSH4State *env, int32_t arg0, int32_t arg1) { - int64_t res; + /* Inputs are already sign-extended from 16 bits. */ + int32_t mul = arg0 * arg1; - res = ((uint64_t) env->mach << 32) | env->macl; - res += (int64_t) (int16_t) arg0 *(int64_t) (int16_t) arg1; - env->mach = (res >> 32) & 0xffffffff; - env->macl = res & 0xffffffff; if (env->sr & (1u << SR_S)) { - if (res < -0x80000000) { - env->mach = 1; - env->macl = 0x80000000; - } else if (res > 0x000000007fffffff) { + /* + * In saturation arithmetic mode, the accumulator is 32-bit + * with carry. MACH is not considered during the addition + * operation nor the 32-bit saturation logic. + */ + int32_t res, macl = env->macl; + + if (sadd32_overflow(macl, mul, &res)) { + res = macl < 0 ? INT32_MIN : INT32_MAX; + /* If overflow occurs, the MACH register is set to 1. */ env->mach = 1; - env->macl = 0x7fffffff; } + env->macl = res; + } else { + /* In non-saturation arithmetic mode, the accumulator is 64-bit */ + env->mac += mul; } } |