commit e7519110827a59eb7275591db640bdbdfd31ba15

Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>

Date:   Wed Sep 20 05:43:28 2017 +0000

            * combine-stack-adj.c (combine_stack_adjustments_for_block): Do

            nothing for stack adjustments with REG_STACK_CHECK.

            * sched-deps.c (parse_add_or_inc): Reject insns with

            REG_STACK_CHECK from dependency breaking.

            * config/i386/i386.c (pro_epilogue_adjust_stack): Return insn.

            (ix86_adjust_satck_and_probe_stack_clash): Add REG_STACK_NOTEs.

            * reg-notes.def (STACK_CHECK): New note.

            * gcc.target/i386/stack-check-11.c: New test.

    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252999 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/combine-stack-adj.c b/gcc/combine-stack-adj.c

index 9ec14a3e443..82d6dba856f 100644

--- a/gcc/combine-stack-adj.c

+++ b/gcc/combine-stack-adj.c

@@ -508,6 +508,8 @@ combine_stack_adjustments_for_block (basic_block bb)

 	continue;

       set = single_set_for_csa (insn);

+      if (set && find_reg_note (insn, REG_STACK_CHECK, NULL_RTX))

+	set = NULL_RTX;

       if (set)

 	{

 	  rtx dest = SET_DEST (set);

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c

index 088dca2001f..5aff9b9d113 100644

--- a/gcc/config/i386/i386.c

+++ b/gcc/config/i386/i386.c

@@ -12900,7 +12900,7 @@ ix86_add_queued_cfa_restore_notes (rtx insn)

    zero if %r11 register is live and cannot be freely used and positive

    otherwise.  */

-static void

+static rtx

 pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset,

 			   int style, bool set_cfa)

 {

@@ -12987,6 +12987,7 @@ pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset,

       m->fs.sp_offset = ooffset - INTVAL (offset);

       m->fs.sp_valid = valid;

     }

+  return insn;

 }

 /* Find an available register to be used as dynamic realign argument

@@ -13333,9 +13334,11 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)

       for (i = probe_interval; i <= size; i += probe_interval)

 	{

 	  /* Allocate PROBE_INTERVAL bytes.  */

-	  pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,

-				     GEN_INT (-probe_interval), -1,

-				     m->fs.cfa_reg == stack_pointer_rtx);

+	  rtx insn

+	    = pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,

+					 GEN_INT (-PROBE_INTERVAL), -1,

+					 m->fs.cfa_reg == stack_pointer_rtx);

+	  add_reg_note (insn, REG_STACK_CHECK, const0_rtx);

 	  /* And probe at *sp.  */

 	  emit_stack_probe (stack_pointer_rtx);

diff --git a/gcc/reg-notes.def b/gcc/reg-notes.def

index 8734d26e5b4..18cf7e3cfc0 100644

--- a/gcc/reg-notes.def

+++ b/gcc/reg-notes.def

@@ -223,6 +223,10 @@ REG_NOTE (ARGS_SIZE)

    pseudo reg.  */

 REG_NOTE (RETURNED)

+/* Indicates the instruction is a stack check probe that should not

+   be combined with other stack adjustments.  */

+REG_NOTE (STACK_CHECK)

+

 /* Used to mark a call with the function decl called by the call.

    The decl might not be available in the call due to splitting of the call

    insn.  This note is a SYMBOL_REF.  */

diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c

index b2393bf28fb..564f3fb1559 100644

--- a/gcc/sched-deps.c

+++ b/gcc/sched-deps.c

@@ -4717,6 +4717,11 @@ parse_add_or_inc (struct mem_inc_info *mii, rtx_insn *insn, bool before_mem)

   if (RTX_FRAME_RELATED_P (insn) || !pat)

     return false;

+  /* Do not allow breaking data dependencies for insns that are marked

+     with REG_STACK_CHECK.  */

+  if (find_reg_note (insn, REG_STACK_CHECK, NULL))

+    return false;

+

   /* Result must be single reg.  */

   if (!REG_P (SET_DEST (pat)))

     return false;

diff --git a/gcc/testsuite/gcc.target/i386/stack-check-11.c b/gcc/testsuite/gcc.target/i386/stack-check-11.c

new file mode 100644

index 00000000000..183103f01e5

--- /dev/null

+++ b/gcc/testsuite/gcc.target/i386/stack-check-11.c

@@ -0,0 +1,16 @@

+/* { dg-do compile } */

+/* { dg-options "-O2 -fstack-clash-protection" } */

+/* { dg-require-effective-target supports_stack_clash_protection } */

+

+extern void arf (unsigned long int *, unsigned long int *);

+void

+frob ()

+{

+  unsigned long int num[859];

+  unsigned long int den[859];

+  arf (den, num);

+}

+

+/* { dg-final { scan-assembler-times "subq" 4 } } */

+/* { dg-final { scan-assembler-times "orq" 3 } } */

+