CALL_INSN may not be a real function call.

Use "used" flag for CALL_INSN to indicate it's a fake call. If it's a
fake call, it won't have its own function stack.

gcc/ChangeLog

	PR target/82735
	* df-scan.c (df_get_call_refs): When call_insn is a fake call,
	it won't use stack pointer reg.
	* final.c (leaf_function_p): When call_insn is a fake call, it
	won't affect caller as a leaf function.
	* reg-stack.c (callee_clobbers_any_stack_reg): New.
	(subst_stack_regs): When call_insn doesn't clobber any stack
	reg, don't clear the arguments.
	* rtl.c (shallow_copy_rtx): Don't clear flag used when orig is
	a insn.
	* shrink-wrap.c (requires_stack_frame_p): No need for stack
	frame for a fake call.
	* rtl.h (FAKE_CALL_P): New macro.

1 files changed, 5 insertions, 0 deletions

diff --git a/gcc/rtl.h b/gcc/rtl.h
index 35178b5..5ed0d6d 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -839,6 +839,11 @@ struct GTY(()) rtvec_def {
 /* Predicate yielding nonzero iff X is a call insn.  */
 #define CALL_P(X) (GET_CODE (X) == CALL_INSN)
 
+/* 1 if RTX is a call_insn for a fake call.
+   CALL_INSN use "used" flag to indicate it's a fake call.  */
+#define FAKE_CALL_P(RTX)                                        \
+  (RTL_FLAG_CHECK1 ("FAKE_CALL_P", (RTX), CALL_INSN)->used)
+
 /* Predicate yielding nonzero iff X is an insn that cannot jump.  */
 #define NONJUMP_INSN_P(X) (GET_CODE (X) == INSN)