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-rw-r--r--target-s390x/op_helper.c28
1 files changed, 8 insertions, 20 deletions
diff --git a/target-s390x/op_helper.c b/target-s390x/op_helper.c
index 49760a40a2..db03a7971f 100644
--- a/target-s390x/op_helper.c
+++ b/target-s390x/op_helper.c
@@ -1731,25 +1731,15 @@ void HELPER(sqdbr)(uint32_t f1, uint32_t f2)
env->fregs[f1].d = float64_sqrt(env->fregs[f2].d, &env->fpu_status);
}
-static inline uint64_t cksm_overflow(uint64_t cksm)
-{
- if (cksm > 0xffffffffULL) {
- cksm &= 0xffffffffULL;
- cksm++;
- }
- return cksm;
-}
-
/* checksum */
void HELPER(cksm)(uint32_t r1, uint32_t r2)
{
uint64_t src = get_address_31fix(r2);
uint64_t src_len = env->regs[(r2 + 1) & 15];
- uint64_t cksm = 0;
+ uint64_t cksm = (uint32_t)env->regs[r1];
while (src_len >= 4) {
cksm += ldl(src);
- cksm = cksm_overflow(cksm);
/* move to next word */
src_len -= 4;
@@ -1760,26 +1750,24 @@ void HELPER(cksm)(uint32_t r1, uint32_t r2)
case 0:
break;
case 1:
- cksm += ldub(src);
- cksm = cksm_overflow(cksm);
+ cksm += ldub(src) << 24;
break;
case 2:
- cksm += lduw(src);
- cksm = cksm_overflow(cksm);
+ cksm += lduw(src) << 16;
break;
case 3:
- /* XXX check if this really is correct */
- cksm += lduw(src) << 8;
- cksm += ldub(src + 2);
- cksm = cksm_overflow(cksm);
+ cksm += lduw(src) << 16;
+ cksm += ldub(src + 2) << 8;
break;
}
/* indicate we've processed everything */
+ env->regs[r2] = src + src_len;
env->regs[(r2 + 1) & 15] = 0;
/* store result */
- env->regs[r1] = (env->regs[r1] & 0xffffffff00000000ULL) | (uint32_t)cksm;
+ env->regs[r1] = (env->regs[r1] & 0xffffffff00000000ULL) |
+ ((uint32_t)cksm + (cksm >> 32));
}
static inline uint32_t cc_calc_ltgt_32(CPUState *env, int32_t src,