[DTrace-devel] [PATCH 08/12] cg: integrate dvar lookup into dt_cg_prep_dvar()
Kris Van Hees
kris.van.hees at oracle.com
Fri Jan 5 05:29:24 UTC 2024
The loading and storing of dynamic variables was implemented using a
function dt_cg_prep_dvar_args() to prepare the arguments for a function
call, followed by performing the actual function call in the respective
callers. Those calls are identical, so it makes sense to consolidate
argument setup and call into a single function.
Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
libdtrace/dt_cg.c | 47 +++++++++++++++++++++++++++--------------------
1 file changed, 27 insertions(+), 20 deletions(-)
diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index 615ebdbf..39a3b4e8 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -2848,11 +2848,12 @@ dt_cg_arglist(dt_ident_t *idp, dt_node_t *args, dt_irlist_t *dlp,
dt_regset_t *drp);
static void
-dt_cg_prep_dvar_args(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
- dt_ident_t *idp, int isstore, dt_ident_t **fnpp)
+dt_cg_prep_dvar(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
+ dt_ident_t *idp, int isstore)
{
uint_t varid = idp->di_id - DIF_VAR_OTHER_UBASE;
const char *fn;
+ dt_ident_t *fnp;
if (idp->di_kind == DT_IDENT_ARRAY) {
/* Associative (global or TLS) array. Cannot be in alloca space. */
@@ -2869,9 +2870,14 @@ dt_cg_prep_dvar_args(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
emit(dlp, BPF_MOV_REG(BPF_REG_2, args->dn_args->dn_reg));
dt_regset_free(drp, args->dn_args->dn_reg);
emit(dlp, BPF_MOV_IMM(BPF_REG_3, isstore));
- if (isstore)
- emit(dlp, BPF_MOV_REG(BPF_REG_4, dnp->dn_reg));
- else
+ if (isstore) {
+ dt_node_t *rp = dnp->dn_right;
+
+ if (rp->dn_kind == DT_NODE_INT && rp->dn_value == 0)
+ emit(dlp, BPF_MOV_IMM(BPF_REG_4, 0));
+ else
+ emit(dlp, BPF_MOV_REG(BPF_REG_4, dnp->dn_reg));
+ } else
emit(dlp, BPF_MOV_IMM(BPF_REG_4, 0));
dt_cg_zerosptr(BPF_REG_5, dlp, drp);
} else if (idp->di_flags & DT_IDFLG_TLS) {
@@ -2883,16 +2889,26 @@ dt_cg_prep_dvar_args(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
emit(dlp, BPF_MOV_IMM(BPF_REG_1, varid));
emit(dlp, BPF_MOV_IMM(BPF_REG_2, isstore));
- if (isstore)
+ if (isstore) {
emit(dlp, BPF_MOV_REG(BPF_REG_3, dnp->dn_reg));
- else
+ dt_node_t *rp = dnp->dn_right;
+
+ if (rp->dn_kind == DT_NODE_INT && rp->dn_value == 0)
+ emit(dlp, BPF_MOV_IMM(BPF_REG_3, 0));
+ else
+ emit(dlp, BPF_MOV_REG(BPF_REG_3, dnp->dn_reg));
+ } else
emit(dlp, BPF_MOV_IMM(BPF_REG_3, 0));
dt_cg_zerosptr(BPF_REG_4, dlp, drp);
} else
assert(0);
- *fnpp = dt_dlib_get_func(yypcb->pcb_hdl, fn);
- assert(*fnpp);
+ fnp = dt_dlib_get_func(yypcb->pcb_hdl, fn);
+ assert(fnp);
+
+ dt_regset_xalloc(drp, BPF_REG_0);
+ emite(dlp, BPF_CALL_FUNC(fnp->di_id), fnp);
+ dt_regset_free_args(drp);
}
static void
@@ -2905,11 +2921,7 @@ dt_cg_load_var(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
/* First handle dvars. */
if (idp->di_kind == DT_IDENT_ARRAY || idp->di_flags & DT_IDFLG_TLS) {
- dt_cg_prep_dvar_args(dnp, dlp, drp, idp, 0, &fnp);
-
- dt_regset_xalloc(drp, BPF_REG_0);
- emite(dlp, BPF_CALL_FUNC(fnp->di_id), fnp);
- dt_regset_free_args(drp);
+ dt_cg_prep_dvar(dnp, dlp, drp, idp, 0);
if ((dnp->dn_reg = dt_regset_alloc(drp)) == -1)
longjmp(yypcb->pcb_jmpbuf, EDT_NOREG);
@@ -3606,7 +3618,6 @@ dt_cg_store_var(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
{
int reg;
size_t size;
- dt_ident_t *fnp;
idp->di_flags |= DT_IDFLG_DIFW;
@@ -3631,11 +3642,7 @@ dt_cg_store_var(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
uint_t lbl_notnull = dt_irlist_label(dlp);
dt_node_t *rp = dnp->dn_right;
- dt_cg_prep_dvar_args(dnp, dlp, drp, idp, 1, &fnp);
-
- dt_regset_xalloc(drp, BPF_REG_0);
- emite(dlp, BPF_CALL_FUNC(fnp->di_id), fnp);
- dt_regset_free_args(drp);
+ dt_cg_prep_dvar(dnp, dlp, drp, idp, 1);
/*
* Special case: a store of a literal 0 causes the dynamic
--
2.42.0
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