diff options
Diffstat (limited to 'libguile/vm-engine.c')
-rw-r--r-- | libguile/vm-engine.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c index 19d35f113..74825818d 100644 --- a/libguile/vm-engine.c +++ b/libguile/vm-engine.c @@ -3376,7 +3376,31 @@ VM_NAME (scm_thread *thread) NEXT (2); } - VM_DEFINE_OP (163, unused_163, NULL, NOP) + /* jtable idx:24 len:32 (_:8 offset:24)... + * + * Branch to an entry in a table, as in C's switch statement. IDX is + * a u64 local, and the immediate LEN indicates the number of entries + * in the table, and should be greater than or equal to 1. The last + * entry in the table is the "catch-all" entry. The OFFSET... values + * are in the usual L24 encoding, indicating a memory address as a + * number of 32-bit words away from the current instruction pointer. + */ + VM_DEFINE_OP (163, jtable, "jtable", OP2 (X8_S24, V32_X8_L24)) + { + uint32_t idx, len; + const uint32_t *offsets; + + UNPACK_24 (op, idx); + len = ip[1]; + offsets = ip + 2; + + uint64_t i = SP_REF_U64 (idx); + VM_ASSERT (len > 0, abort()); + int32_t offset = offsets[i < len ? i : len - 1]; + offset >>= 8; /* Sign-extending shift. */ + NEXT (offset); + } + VM_DEFINE_OP (164, unused_164, NULL, NOP) VM_DEFINE_OP (165, unused_165, NULL, NOP) VM_DEFINE_OP (166, unused_166, NULL, NOP) |