x86: Use DRAP only if there are outgoing arguments on stack

Since DRAP is needed only if there are outgoing arguments on stack, we
should track outgoing arguments on stack and avoid setting need_drap to
true when there are no outgoing arguments on stack.

gcc/

	PR target/81313
	* config/i386/i386.c (ix86_function_arg_advance): Set
	outgoing_args_on_stack to true if there are outgoing arguments
	on stack.
	(ix86_function_arg): Likewise.
	(ix86_get_drap_rtx): Use DRAP only if there are outgoing
	arguments on stack and ACCUMULATE_OUTGOING_ARGS is false.
	* config/i386/i386.h (machine_function): Add
	outgoing_args_on_stack.

gcc/testsuite/

	PR target/81313
	* gcc.target/i386/pr81313-1.c: New test.
	* gcc.target/i386/pr81313-2.c: Likewise.
	* gcc.target/i386/pr81313-3.c: Likewise.
	* gcc.target/i386/pr81313-4.c: Likewise.
	* gcc.target/i386/pr81313-5.c: Likewise.

(cherry picked from commit 84066338f533756496dc8ce09726fe8dad8b0cf5)

7 files changed, 79 insertions, 2 deletions

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7a49aec92c0..c2f55582ff7 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -9798,7 +9798,13 @@ ix86_function_arg_advance (cumulative_args_t cum_v, machine_mode mode,
   /* For pointers passed in memory we expect bounds passed in Bounds
      Table.  */
   if (!nregs)
-    cum->bnds_in_bt = chkp_type_bounds_count (type);
+    {
+      /* Track if there are outgoing arguments on stack.  */
+      if (cum->caller)
+	cfun->machine->outgoing_args_on_stack = true;
+
+      cum->bnds_in_bt = chkp_type_bounds_count (type);
+    }
 }
 
 /* Define where to put the arguments to a function.
@@ -10127,6 +10133,10 @@ ix86_function_arg (cumulative_args_t cum_v, machine_mode omode,
   else
     arg = function_arg_32 (cum, mode, omode, type, bytes, words);
 
+  /* Track if there are outgoing arguments on stack.  */
+  if (arg == NULL_RTX && cum->caller)
+    cfun->machine->outgoing_args_on_stack = true;
+
   return arg;
 }
 
@@ -13137,7 +13147,11 @@ ix86_update_stack_boundary (void)
 static rtx
 ix86_get_drap_rtx (void)
 {
-  if (ix86_force_drap || !ACCUMULATE_OUTGOING_ARGS)
+  /* We must use DRAP if there are outgoing arguments on stack and
+     ACCUMULATE_OUTGOING_ARGS is false.  */
+  if (ix86_force_drap
+      || (cfun->machine->outgoing_args_on_stack
+	  && !ACCUMULATE_OUTGOING_ARGS))
     crtl->need_drap = true;
 
   if (stack_realign_drap)
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 9e5f4d857d9..1c474af49c6 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2565,6 +2565,9 @@ struct GTY(()) machine_function {
      pass arguments and can be used for indirect sibcall.  */
   BOOL_BITFIELD arg_reg_available : 1;
 
+  /* Nonzero if the function places outgoing arguments on stack.  */
+  BOOL_BITFIELD outgoing_args_on_stack : 1;
+
   /* During prologue/epilogue generation, the current frame state.
      Otherwise, the frame state at the end of the prologue.  */
   struct machine_frame_state fs;
diff --git a/gcc/testsuite/gcc.target/i386/pr81313-1.c b/gcc/testsuite/gcc.target/i386/pr81313-1.c
new file mode 100644
index 00000000000..f7650035cac
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81313-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-accumulate-outgoing-args -mincoming-stack-boundary=4 -mpreferred-stack-boundary=6" } */
+
+extern void foo (void);
+
+void
+bar (void)
+{
+  foo ();
+}
+
+/* { dg-final { scan-assembler-not "lea\[lq\]?\[\\t \]*\[0-9\]*\\(%\[er\]sp\\)" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr81313-2.c b/gcc/testsuite/gcc.target/i386/pr81313-2.c
new file mode 100644
index 00000000000..2cdc645dbcc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81313-2.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mno-accumulate-outgoing-args -mincoming-stack-boundary=4 -mpreferred-stack-boundary=6 -mno-iamcu" } */
+
+extern void foo (int, int, int);
+
+void
+bar (void)
+{
+  foo (1, 2, 3);
+}
+
+/* { dg-final { scan-assembler "lea\[l\]?\[\\t \]*\[0-9\]*\\(%esp\\)" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr81313-3.c b/gcc/testsuite/gcc.target/i386/pr81313-3.c
new file mode 100644
index 00000000000..9c1b2326616
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81313-3.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mno-accumulate-outgoing-args -mincoming-stack-boundary=4 -mpreferred-stack-boundary=6" } */
+
+extern void foo (int, int, int) __attribute__ ((regparm(3)));
+
+void
+bar (int i1, int i2, int i3, int i4)
+{
+  foo (i1, i2, i3);
+}
+
+/* { dg-final { scan-assembler-not "lea\[l\]?\[\\t \]*\[0-9\]*\\(%esp\\)" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr81313-4.c b/gcc/testsuite/gcc.target/i386/pr81313-4.c
new file mode 100644
index 00000000000..bad0b3c27db
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81313-4.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-accumulate-outgoing-args -mincoming-stack-boundary=4 -mpreferred-stack-boundary=6" } */
+
+extern void foo (int, int, int, int, int, int, int);
+
+void
+bar (void)
+{
+  foo (1, 2, 3, 4, 5, 6, 7);
+}
+
+/* { dg-final { scan-assembler "lea\[lq\]?\[\\t \]*\[0-9\]*\\(%\[er\]sp\\)" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr81313-5.c b/gcc/testsuite/gcc.target/i386/pr81313-5.c
new file mode 100644
index 00000000000..51a543ca57e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81313-5.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mno-accumulate-outgoing-args -mincoming-stack-boundary=4 -mpreferred-stack-boundary=6" } */
+
+extern void foo (int, int, int, int, int, int);
+
+void
+bar (int i1, int i2, int i3, int i4, int i5, int i6, int i7)
+{
+  foo (i1, i2, i3, i4, i5, i6);
+}
+
+/* { dg-final { scan-assembler-not "lea\[lq\]?\[\\t \]*\[0-9\]*\\(%\[er\]sp\\)" } } */