[PATCH] Fix PR target/90458

[Eric Botcazou via Gcc-patches]

Hi,

this is the incompatibility of -fstack-clash-protection with Windows SEH.  Now 
the Windows ports always enable TARGET_STACK_PROBE, which means that the stack 
is always probed (out of line) so -fstack-clash-protection does nothing more.

Tested on x86-64/Windows and Linux, OK for all active branches?


2023-02-15  Eric Botcazou  <ebotca...@adacore.com>

        * config/i386/i386.cc (ix86_compute_frame_layout): Disable the
        effects of -fstack-clash-protection for TARGET_STACK_PROBE.
        (ix86_expand_prologue): Likewise.

-- 
Eric Botcazou
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 3cacf738c4a..22f444be23c 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -6876,7 +6876,9 @@ ix86_compute_frame_layout (void)
 	 stack clash protections are enabled and the allocated frame is
 	 larger than the probe interval, then use pushes to save
 	 callee saved registers.  */
-      || (flag_stack_clash_protection && to_allocate > get_probe_interval ()))
+      || (flag_stack_clash_protection
+	  && !ix86_target_stack_probe ()
+	  && to_allocate > get_probe_interval ()))
     frame->save_regs_using_mov = false;
 
   if (ix86_using_red_zone ()
@@ -8761,8 +8763,11 @@ ix86_expand_prologue (void)
       sse_registers_saved = true;
     }
 
-  /* If stack clash protection is requested, then probe the stack.  */
-  if (allocate >= 0 && flag_stack_clash_protection)
+  /* If stack clash protection is requested, then probe the stack, unless it
+     is already probed on the target.  */
+  if (allocate >= 0
+      && flag_stack_clash_protection
+      && !ix86_target_stack_probe ())
     {
       ix86_adjust_stack_and_probe (allocate, int_registers_saved, false);
       allocate = 0;