On 18/12/22 22:18, Philippe Mathieu-Daudé wrote:
From: Richard Henderson <richard.hender...@linaro.org>
We have been allocating a worst case number of arguments
to support calls. Instead, allow the size to vary.
By default leave space for 4 args, to maximize reuse,
but allow calls to increase the number of args to 32.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
[PMD: Split patch in two]
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
accel/tcg/plugin-gen.c | 10 ++++-----
include/exec/helper-head.h | 2 --
include/tcg/tcg.h | 46 +++++++++++++-------------------------
tcg/tcg.c | 35 +++++++++++++++++++++--------
4 files changed, 47 insertions(+), 46 deletions(-)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3f172cb1d6..ccbe947222 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1513,7 +1513,12 @@ void tcg_gen_callN(void *func, TCGTemp *ret, int nargs,
TCGTemp **args)
}
}
- max_args = ARRAY_SIZE(op->args);
+ /*
+ * A Call op needs up to 4 + 2N parameters on 32-bit archs,
+ * and up to 4 + N parameters on 64-bit archs
+ * (N = number of input arguments + output arguments).
+ */
+ max_args = (64 / TCG_TARGET_REG_BITS) * nargs + 4;
op = tcg_emit_op(INDEX_op_call, max_args);
pi = 0;
@@ -2298,19 +2303,31 @@ void tcg_remove_ops_after(TCGOp *op)
static TCGOp *tcg_op_alloc(TCGOpcode opc, unsigned nargs)
{
TCGContext *s = tcg_ctx;
- TCGOp *op;
+ TCGOp *op = NULL;
- assert(nargs < ARRAY_SIZE(op->args));
- if (likely(QTAILQ_EMPTY(&s->free_ops))) {
- op = tcg_malloc(sizeof(TCGOp));
- } else {
- op = QTAILQ_FIRST(&s->free_ops);
- QTAILQ_REMOVE(&s->free_ops, op, link);
+ if (unlikely(!QTAILQ_EMPTY(&s->free_ops))) {
+ QTAILQ_FOREACH(op, &s->free_ops, link) {
+ if (nargs <= op->nargs) {
+ QTAILQ_REMOVE(&s->free_ops, op, link);
+ nargs = op->nargs;
+ goto found;
+ }
+ }
}
+
+ /* Most opcodes have 3 or 4 operands: reduce fragmentation. */
+ nargs = MAX(4, nargs);
+ op = tcg_malloc(sizeof(TCGOp) + sizeof(TCGArg) * nargs);
+
+ found:
memset(op, 0, offsetof(TCGOp, link));
op->opc = opc;
- s->nb_ops++;
+ op->nargs = nargs;
We can move this assignation before the 'found' label.
+ /* Check for bitfield overflow. */
+ tcg_debug_assert(op->nargs == nargs);
+
+ s->nb_ops++;
return op;
}
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
