diff options
Diffstat (limited to 'target-s390x/cpu.h')
| -rw-r--r-- | target-s390x/cpu.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h index 4fb34b598d..4e58cdee3e 100644 --- a/target-s390x/cpu.h +++ b/target-s390x/cpu.h @@ -671,6 +671,13 @@ ObjectClass *s390_cpu_class_by_name(const char *name); /* CC optimization */ +/* Instead of computing the condition codes after each x86 instruction, + * QEMU just stores the result (called CC_DST), the type of operation + * (called CC_OP) and whatever operands are needed (CC_SRC and possibly + * CC_VR). When the condition codes are needed, the condition codes can + * be calculated using this information. Condition codes are not generated + * if they are only needed for conditional branches. + */ enum cc_op { CC_OP_CONST0 = 0, /* CC is 0 */ CC_OP_CONST1, /* CC is 1 */ |