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author | Björn Gustavsson <bjorn@erlang.org> | 2016-04-01 14:03:51 +0200 |
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committer | Björn Gustavsson <bjorn@erlang.org> | 2016-04-06 15:55:29 +0200 |
commit | ec26a0c56cb6e28cc5a35ef72116275e5eeef823 (patch) | |
tree | 9731b718e21457bac2517ef7258de76f5cf3dcc5 /erts/emulator | |
parent | 4b507534f27c343fe2b53f07bbe52e94c81e381f (diff) | |
download | otp-ec26a0c56cb6e28cc5a35ef72116275e5eeef823.tar.gz otp-ec26a0c56cb6e28cc5a35ef72116275e5eeef823.tar.bz2 otp-ec26a0c56cb6e28cc5a35ef72116275e5eeef823.zip |
Refactor calls to transform_engine()
We used to set last_op_next and last_op to NULL just in case.
Setting last_op_next to causes a rescan of the instructions
to find the last instruction in the chain, so we would want
to avoid that unless really necessary.
Diffstat (limited to 'erts/emulator')
-rw-r--r-- | erts/emulator/beam/beam_load.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c index 16cbdbffea..2f2b433999 100644 --- a/erts/emulator/beam/beam_load.c +++ b/erts/emulator/beam/beam_load.c @@ -2028,11 +2028,7 @@ load_code(LoaderState* stp) ASSERT(arity == last_op->arity); do_transform: - if (stp->genop == NULL) { - last_op_next = NULL; - goto get_next_instr; - } - + ASSERT(stp->genop != NULL); if (gen_opc[stp->genop->op].transform != -1) { int need; tmp_op = stp->genop; @@ -2045,25 +2041,34 @@ load_code(LoaderState* stp) } switch (transform_engine(stp)) { case TE_FAIL: - last_op_next = NULL; - last_op = NULL; + /* + * No transformation found. stp->genop != NULL and + * last_op_next is still valid. Go ahead and load + * the instruction. + */ break; case TE_OK: + /* + * Some transformation was applied. last_op_next is + * no longer valid and stp->genop may be NULL. + * Try to transform again. + */ + if (stp->genop == NULL) { + last_op_next = &stp->genop; + goto get_next_instr; + } last_op_next = NULL; - last_op = NULL; goto do_transform; case TE_SHORT_WINDOW: - last_op_next = NULL; - last_op = NULL; + /* + * No transformation applied. stp->genop != NULL and + * last_op_next is still valid. Fetch a new instruction + * before trying the transformation again. + */ goto get_next_instr; } } - if (stp->genop == NULL) { - last_op_next = NULL; - goto get_next_instr; - } - /* * From the collected generic instruction, find the specific * instruction. @@ -2584,7 +2589,10 @@ load_code(LoaderState* stp) { GenOp* next = stp->genop->next; FREE_GENOP(stp, stp->genop); - stp->genop = next; + if ((stp->genop = next) == NULL) { + last_op_next = &stp->genop; + goto get_next_instr; + } goto do_transform; } } |