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tgt-vvp: Handle assignment operator on real array entries 

The basic structure for supporting assignment operators on real arrays
exists in the tgt-vvp backend. But there are a few problems, most
importantly it generates the wrong instruction for loading data from the
real array.

The instruction it uses is `%load/reala`, but that instruction does not
exist, the correct name is `%load/ar`.

In addition to this there are a few minor problems.
  * Out-of-bounds access on the array triggers an assert
  * Missing `%pop/real` instruction when skipping a write due to
    out-of-bounds access

Address these so assignment operators are supported on real array entries.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This commit is contained in:
Lars-Peter Clausen 2022-05-26 21:19:59 +02:00
parent 8fb38d7046
commit a4eeea75ce
1 changed files with 8 additions and 4 deletions
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12
tgt-vvp/stmt_assign.c
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@ -648,8 +648,10 @@ static void get_real_from_lval(ivl_lval_t lval, struct real_lval_info*slice)
it to select the word, and pay no further heed to the
expression itself. */
if (word_ix && number_is_immediate(word_ix, IMM_WID, 0)) {
assert(! number_is_unknown(word_ix));
use_word = get_number_immediate(word_ix);
if (number_is_unknown(word_ix))
use_word = ULONG_MAX; // The largest valid index is ULONG_MAX - 1
else
use_word = get_number_immediate(word_ix);
word_ix = 0;
}
@ -673,7 +675,8 @@ static void get_real_from_lval(ivl_lval_t lval, struct real_lval_info*slice)
if (use_word < ivl_signal_array_count(sig)) {
fprintf(vvp_out, " %%ix/load 3, %lu, 0;\n",
use_word);
fprintf(vvp_out, " %%load/reala v%p, 3;\n", sig);
fprintf(vvp_out, " %%flag_set/imm 4, 0;\n");
fprintf(vvp_out, " %%load/ar v%p, 3;\n", sig);
} else {
fprintf(vvp_out, " %%pushi/real 0, 0;\n");
}
@ -688,7 +691,7 @@ static void get_real_from_lval(ivl_lval_t lval, struct real_lval_info*slice)
draw_eval_expr_into_integer(word_ix, slice->u_.memory_word_dynamic.word_idx_reg);
fprintf(vvp_out, " %%flag_mov %u, 4;\n", slice->u_.memory_word_dynamic.x_flag);
fprintf(vvp_out, " %%load/reala v%p, %d;\n", sig, slice->u_.memory_word_dynamic.word_idx_reg);
fprintf(vvp_out, " %%load/ar v%p, %d;\n", sig, slice->u_.memory_word_dynamic.word_idx_reg);
} else {
assert(0);
@ -728,6 +731,7 @@ static void put_real_to_lval(ivl_lval_t lval, struct real_lval_info*slice)
clr_word(word_idx);
} else {
fprintf(vvp_out," ; Skip this slice write to v%p [%lu]\n", sig, slice->u_.memory_word_static.use_word);
fprintf(vvp_out," %%pop/real 1;\n");
}
break;