[gcc r9-8937] rtl_data: Add sp_is_clobbered_by_asm

[H.J. Lu]

https://gcc.gnu.org/g:3bec35d813cc706b3334bd0b0edbd51869b0f725

commit r9-8937-g3bec35d813cc706b3334bd0b0edbd51869b0f725
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Mon Sep 14 08:52:27 2020 -0700

    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.
    
    (cherry picked from commit 453a20c65722719b9e2d84339f215e7ec87692dc)

Diff:
---
 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(-)

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index e252975f546..1b0591193c3 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -2879,11 +2879,15 @@ 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 5978e51e8ea..f968d033972 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -12283,10 +12283,12 @@ 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 7b1cecd3c44..b8a07d21d37 100644
--- a/gcc/emit-rtl.h
+++ b/gcc/emit-rtl.h
@@ -266,6 +266,9 @@ 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" } } */