[DTrace-devel] [PATCH 32/61] Add dt_cg_push_stack()

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

This patch prepares for future, additional uses of this stack.

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 libdtrace/dt_cg.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index 11a9c8c5..b0c2a362 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -2607,6 +2607,22 @@ dt_cg_typecast(const dt_node_t *src, const dt_node_t *dst,
 	}
 }
 
+static void
+dt_cg_push_stack(dt_irlist_t *dlp, dt_regset_t *drp, int reg)
+{
+	int tmp;
+
+	if ((tmp = dt_regset_alloc(drp)) == -1)
+		longjmp(yypcb->pcb_jmpbuf, EDT_NOREG);
+
+	emit(dlp, BPF_LOAD(BPF_DW, tmp, BPF_REG_FP, DT_STK_SP));
+	emit(dlp, BPF_STORE(BPF_DW, tmp, 0, reg));
+	dt_regset_free(drp, reg);
+	emit(dlp, BPF_ALU64_IMM(BPF_ADD, tmp, -DT_STK_SLOT_SZ));
+	emit(dlp, BPF_STORE(BPF_DW, BPF_REG_FP, DT_STK_SP, tmp));
+	dt_regset_free(drp, tmp);
+}
+
 /*
  * Generate code to push the specified argument list on to the tuple stack.
  * We use this routine for handling the index tuple for associative arrays.
@@ -2644,15 +2660,7 @@ dt_cg_arglist(dt_ident_t *idp, dt_node_t *args, dt_irlist_t *dlp,
 			longjmp(yypcb->pcb_jmpbuf, EDT_NOTUPREG);
 
 		dt_cg_node(dnp, dlp, drp);
-
-		/* Push the component (pointer or value) onto the stack. */
-		dt_regset_xalloc(drp, BPF_REG_0);
-		emit(dlp, BPF_LOAD(BPF_DW, BPF_REG_0, BPF_REG_FP, DT_STK_SP));
-		emit(dlp, BPF_STORE(BPF_DW, BPF_REG_0, 0, dnp->dn_reg));
-		dt_regset_free(drp, dnp->dn_reg);
-		emit(dlp, BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, -DT_STK_SLOT_SZ));
-		emit(dlp, BPF_STORE(BPF_DW, BPF_REG_FP, DT_STK_SP, BPF_REG_0));
-		dt_regset_free(drp, BPF_REG_0);
+		dt_cg_push_stack(dlp, drp, dnp->dn_reg);
 	}
 
 	TRACE_REGSET("      arglist: Stack");
-- 
2.18.4