gcc (ARC): Prevent stores to the frame before the stack adjustment.

Bugfix: Fixes the problem of the ARC GCC compiler generating incorrect code
when using the "-fno-omit-frame-pointer" option.

ZEP-1243
ZEP-1403

Change-Id: Ied420305a81eb56f57eff00048a425c39278ef85
Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>

recipes-devtools-arc/gcc/files/cbd8e54244cd02bdcf4f1057be3ce96631f35ac3.patch

@@ -0,0 +1,83 @@
+From cbd8e54244cd02bdcf4f1057be3ce96631f35ac3 Mon Sep 17 00:00:00 2001
+From: Claudiu Zissulescu <claziss@gmail.com>
+Date: Tue, 3 Jan 2017 12:06:28 -0500
+Subject: [PATCH] [ARC] Prevent moving stores to the frame before the stack
+ adjustment.
+
+If the stack pointer is needed, emit a special barrier that will prevent
+the scheduler from moving stores to the frame before the stack adjustment.
+
+2017-01-03  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* config/arc/arc.c (arc_expand_prologue): Emit a special barrier
+	to prevent store reordering.
+	* config/arc/arc.md (UNSPEC_ARC_STKTIE): Define.
+	(type): Add block type.
+	(stack_tie): Define special instruction to be used in
+	expand_prologue.
+---
+ gcc/config/arc/arc.c  | 10 +++++++++-
+ gcc/config/arc/arc.md | 15 ++++++++++++++-
+ 2 files changed, 23 insertions(+), 2 deletions(-)
+
+diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
+index 6f21fc3..110556c 100644
+--- a/gcc/config/arc/arc.c
++++ b/gcc/config/arc/arc.c
+@@ -3101,7 +3101,15 @@ arc_expand_prologue (void)
+   frame_size_to_allocate -= first_offset;
+   /* Allocate the stack frame.  */
+   if (frame_size_to_allocate > 0)
+-    frame_stack_add ((HOST_WIDE_INT) 0 - frame_size_to_allocate);
++    {
++      frame_stack_add ((HOST_WIDE_INT) 0 - frame_size_to_allocate);
++      /* If the frame pointer is needed, emit a special barrier that
++	 will prevent the scheduler from moving stores to the frame
++	 before the stack adjustment.  */
++      if (arc_frame_pointer_needed ())
++	emit_insn (gen_stack_tie (stack_pointer_rtx,
++				  hard_frame_pointer_rtx));
++    }
+
+   /* Setup the gp register, if needed.  */
+   if (crtl->uses_pic_offset_table)
+diff --git a/gcc/config/arc/arc.md b/gcc/config/arc/arc.md
+index 16f71b3..448157c 100644
+--- a/gcc/config/arc/arc.md
++++ b/gcc/config/arc/arc.md
+@@ -135,6 +135,7 @@
+   UNSPEC_ARC_VMAC2HU
+   UNSPEC_ARC_VMPY2H
+   UNSPEC_ARC_VMPY2HU
++  UNSPEC_ARC_STKTIE
+   ])
+
+ (define_c_enum "vunspec" [
+@@ -204,7 +205,7 @@
+    simd_vcompare, simd_vpermute, simd_vpack, simd_vpack_with_acc,
+    simd_valign, simd_valign_with_acc, simd_vcontrol,
+    simd_vspecial_3cycle, simd_vspecial_4cycle, simd_dma, mul16_em, div_rem,
+-   fpu"
++   fpu, block"
+   (cond [(eq_attr "is_sfunc" "yes")
+ 	 (cond [(match_test "!TARGET_LONG_CALLS_SET && (!TARGET_MEDIUM_CALLS || GET_CODE (PATTERN (insn)) != COND_EXEC)") (const_string "call")
+ 		(match_test "flag_pic") (const_string "sfunc")]
+@@ -6480,6 +6481,18 @@
+   (set_attr "predicable" "yes,no,no,yes,no")
+   (set_attr "cond" "canuse,nocond,nocond,canuse_limm,nocond")])
+
++(define_insn "stack_tie"
++  [(set (mem:BLK (scratch))
++	(unspec:BLK [(match_operand:SI 0 "register_operand" "rb")
++		     (match_operand:SI 1 "register_operand" "rb")]
++		    UNSPEC_ARC_STKTIE))]
++  ""
++  ""
++  [(set_attr "length" "0")
++   (set_attr "iscompact" "false")
++   (set_attr "type" "block")]
++  )
++
+ ;; include the arc-FPX instructions
+ (include "fpx.md")
+

recipes-devtools-arc/gcc/gcc-6.x.arc.inc

@@ -30,6 +30,7 @@ SRC_URI = "\
     git://github.com/foss-for-synopsys-dwc-arc-processors/gcc.git;protocol=https;nobranch=1 \
     file://0036-libcc1-fix-libcc1-s-install-path-and-rpath.patch \
     file://0039-Fix-various-_FOR_BUILD-and-related-variables.patch \
+    file://cbd8e54244cd02bdcf4f1057be3ce96631f35ac3.patch \
 "
 
 S = "${TMPDIR}/work-shared/gcc-${PV}-${PR}/git"