patch 8.2.3442: Vim9: || and && are not handled at compile time
Problem: Vim9: || and && are not handled at compile time when possible.
Solution: When using constants generate fewer instructions.
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 4807e3a..0d64f01 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2847,7 +2847,7 @@
}
/*
- * Check that the last item of "ppconst" is a bool.
+ * Check that the last item of "ppconst" is a bool, if there is an item.
*/
static int
check_ppconst_bool(ppconst_T *ppconst)
@@ -4845,7 +4845,8 @@
}
else
{
- if (generate_ppconst(cctx, ppconst) == FAIL)
+ if (cctx->ctx_skip != SKIP_YES
+ && generate_ppconst(cctx, ppconst) == FAIL)
return FAIL;
r = compile_load(arg, p, cctx, TRUE, TRUE);
}
@@ -5240,6 +5241,7 @@
{
garray_T *instr = &cctx->ctx_instr;
garray_T end_ga;
+ int save_skip = cctx->ctx_skip;
/*
* Repeat until there is no following "||" or "&&"
@@ -5251,7 +5253,10 @@
long save_sourcing_lnum;
int start_ctx_lnum = cctx->ctx_lnum;
int save_lnum;
+ int const_used;
int status;
+ jumpwhen_T jump_when = opchar == '|'
+ ? JUMP_IF_COND_TRUE : JUMP_IF_COND_FALSE;
if (next != NULL)
{
@@ -5274,14 +5279,38 @@
status = check_ppconst_bool(ppconst);
if (status != FAIL)
{
- // TODO: use ppconst if the value is a constant
- generate_ppconst(cctx, ppconst);
+ // Use the last ppconst if possible.
+ if (ppconst->pp_used > 0)
+ {
+ typval_T *tv = &ppconst->pp_tv[ppconst->pp_used - 1];
+ int is_true = tv2bool(tv);
- // Every part must evaluate to a bool.
- status = bool_on_stack(cctx);
- if (status != FAIL)
- status = ga_grow(&end_ga, 1);
+ if ((is_true && opchar == '|')
+ || (!is_true && opchar == '&'))
+ {
+ // For "false && expr" and "true || expr" the "expr"
+ // does not need to be evaluated.
+ cctx->ctx_skip = SKIP_YES;
+ clear_tv(tv);
+ tv->v_type = VAR_BOOL;
+ tv->vval.v_number = is_true ? VVAL_TRUE : VVAL_FALSE;
+ }
+ else
+ {
+ // For "true && expr" and "false || expr" only "expr"
+ // needs to be evaluated.
+ --ppconst->pp_used;
+ jump_when = JUMP_NEVER;
+ }
+ }
+ else
+ {
+ // Every part must evaluate to a bool.
+ status = bool_on_stack(cctx);
+ }
}
+ if (status != FAIL)
+ status = ga_grow(&end_ga, 1);
cctx->ctx_lnum = save_lnum;
if (status == FAIL)
{
@@ -5289,10 +5318,15 @@
return FAIL;
}
- *(((int *)end_ga.ga_data) + end_ga.ga_len) = instr->ga_len;
- ++end_ga.ga_len;
- generate_JUMP(cctx, opchar == '|'
- ? JUMP_IF_COND_TRUE : JUMP_IF_COND_FALSE, 0);
+ if (jump_when != JUMP_NEVER)
+ {
+ if (cctx->ctx_skip != SKIP_YES)
+ {
+ *(((int *)end_ga.ga_data) + end_ga.ga_len) = instr->ga_len;
+ ++end_ga.ga_len;
+ }
+ generate_JUMP(cctx, jump_when, 0);
+ }
// eval the next expression
SOURCING_LNUM = save_sourcing_lnum;
@@ -5302,6 +5336,7 @@
return FAIL;
}
+ const_used = ppconst->pp_used;
if ((opchar == '|' ? compile_expr3(arg, cctx, ppconst)
: compile_expr4(arg, cctx, ppconst)) == FAIL)
{
@@ -5309,6 +5344,20 @@
return FAIL;
}
+ // "0 || 1" results in true, "1 && 0" results in false.
+ if (ppconst->pp_used == const_used + 1)
+ {
+ typval_T *tv = &ppconst->pp_tv[ppconst->pp_used - 1];
+
+ if (tv->v_type == VAR_NUMBER
+ && (tv->vval.v_number == 1 || tv->vval.v_number == 0))
+ {
+ tv->vval.v_number = tv->vval.v_number == 1
+ ? VVAL_TRUE : VVAL_FALSE;
+ tv->v_type = VAR_BOOL;
+ }
+ }
+
p = may_peek_next_line(cctx, *arg, &next);
}
@@ -5317,26 +5366,32 @@
ga_clear(&end_ga);
return FAIL;
}
- generate_ppconst(cctx, ppconst);
- // Every part must evaluate to a bool.
- if (bool_on_stack(cctx) == FAIL)
+ if (cctx->ctx_skip != SKIP_YES && ppconst->pp_used == 0)
+ // Every part must evaluate to a bool.
+ if (bool_on_stack(cctx) == FAIL)
+ {
+ ga_clear(&end_ga);
+ return FAIL;
+ }
+
+ if (end_ga.ga_len > 0)
{
- ga_clear(&end_ga);
- return FAIL;
- }
+ // Fill in the end label in all jumps.
+ generate_ppconst(cctx, ppconst);
+ while (end_ga.ga_len > 0)
+ {
+ isn_T *isn;
- // Fill in the end label in all jumps.
- while (end_ga.ga_len > 0)
- {
- isn_T *isn;
-
- --end_ga.ga_len;
- isn = ((isn_T *)instr->ga_data)
+ --end_ga.ga_len;
+ isn = ((isn_T *)instr->ga_data)
+ *(((int *)end_ga.ga_data) + end_ga.ga_len);
- isn->isn_arg.jump.jump_where = instr->ga_len;
+ isn->isn_arg.jump.jump_where = instr->ga_len;
+ }
+ ga_clear(&end_ga);
}
- ga_clear(&end_ga);
+
+ cctx->ctx_skip = save_skip;
}
return OK;