From 453a20c65722719b9e2d84339f215e7ec87692dc Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 14 Sep 2020 08:52:27 -0700
Subject: [PATCH] rtl_data: Add sp_is_clobbered_by_asm

Add sp_is_clobbered_by_asm to rtl_data to inform backends that the stack
pointer is clobbered by asm statement.

gcc/

	PR target/97032
	* cfgexpand.c (asm_clobber_reg_kind): Set sp_is_clobbered_by_asm
	to true if the stack pointer is clobbered by asm statement.
	* emit-rtl.h (rtl_data): Add sp_is_clobbered_by_asm.
	* config/i386/i386.c (ix86_get_drap_rtx): Set need_drap to true
	if the stack pointer is clobbered by asm statement.

gcc/testsuite/

	PR target/97032
	* gcc.target/i386/pr97032.c: New test.
---
 gcc/cfgexpand.c                         | 14 +++++++++-----
 gcc/config/i386/i386.c                  |  6 ++++--
 gcc/emit-rtl.h                          |  3 +++
 gcc/testsuite/gcc.target/i386/pr97032.c | 23 +++++++++++++++++++++++
 4 files changed, 39 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr97032.c

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index b334ea03c25..1eaa1da11b9 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -2868,11 +2868,15 @@ asm_clobber_reg_is_valid (int regno, int nregs, const char *regname)
      as it was before, so no asm can validly clobber the stack pointer in
      the usual sense.  Adding the stack pointer to the clobber list has
      traditionally had some undocumented and somewhat obscure side-effects.  */
-  if (overlaps_hard_reg_set_p (regset, Pmode, STACK_POINTER_REGNUM)
-      && warning (OPT_Wdeprecated, "listing the stack pointer register"
-		  " %qs in a clobber list is deprecated", regname))
-    inform (input_location, "the value of the stack pointer after an %<asm%>"
-	    " statement must be the same as it was before the statement");
+  if (overlaps_hard_reg_set_p (regset, Pmode, STACK_POINTER_REGNUM))
+    {
+      crtl->sp_is_clobbered_by_asm = true;
+      if (warning (OPT_Wdeprecated, "listing the stack pointer register"
+		   " %qs in a clobber list is deprecated", regname))
+	inform (input_location, "the value of the stack pointer after"
+		" an %<asm%> statement must be the same as it was before"
+		" the statement");
+    }
 
   return is_valid;
 }
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index a15807d91da..c890a733293 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -6968,10 +6968,12 @@ ix86_update_stack_boundary (void)
 static rtx
 ix86_get_drap_rtx (void)
 {
-  /* We must use DRAP if there are outgoing arguments on stack and
+  /* We must use DRAP if there are outgoing arguments on stack or
+     the stack pointer register is clobbered by asm statment and
      ACCUMULATE_OUTGOING_ARGS is false.  */
   if (ix86_force_drap
-      || (cfun->machine->outgoing_args_on_stack
+      || ((cfun->machine->outgoing_args_on_stack
+	   || crtl->sp_is_clobbered_by_asm)
 	  && !ACCUMULATE_OUTGOING_ARGS))
     crtl->need_drap = true;
 
diff --git a/gcc/emit-rtl.h b/gcc/emit-rtl.h
index 3d6565c8a30..92ad0dd6fc0 100644
--- a/gcc/emit-rtl.h
+++ b/gcc/emit-rtl.h
@@ -281,6 +281,9 @@ struct GTY(()) rtl_data {
      pass_stack_ptr_mod has run.  */
   bool sp_is_unchanging;
 
+  /* True if the stack pointer is clobbered by asm statement.  */
+  bool sp_is_clobbered_by_asm;
+
   /* Nonzero if function being compiled doesn't contain any calls
      (ignoring the prologue and epilogue).  This is set prior to
      register allocation in IRA and is valid for the remaining
diff --git a/gcc/testsuite/gcc.target/i386/pr97032.c b/gcc/testsuite/gcc.target/i386/pr97032.c
new file mode 100644
index 00000000000..7cbbe9bc22a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr97032.c
@@ -0,0 +1,23 @@
+/* { dg-do compile { target { ia32 && fstack_protector } } } */
+/* { dg-options "-O2 -mincoming-stack-boundary=2 -fstack-protector-all" } */
+
+#include <stdarg.h>
+
+extern int *__errno_location (void);
+
+long
+sys_socketcall (int op, ...)
+{
+  long int res;
+  va_list ap;
+  va_start (ap, op);
+  asm volatile ("push %%ebx; movl %2, %%ebx; int $0x80; pop %%ebx"
+  /* { dg-warning "listing the stack pointer register" "" { target *-*-* } .-1 } */
+		: "=a" (res) : "0" (102), "ri" (16), "c" (ap) : "memory", "esp");
+  if (__builtin_expect (res > 4294963200UL, 0))
+    *__errno_location () = -res;
+  va_end (ap);
+  return res;
+}
+
+/* { dg-final { scan-assembler "call\[ \t\]*_?__errno_location" } } */
-- 
2.30.2