meta-xilinx/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0009-Patch-microblaze-Fix-atomic-side-effects.patch

From 8711bdfe27bce04d35ba93a1d18ccccd61371829 Mon Sep 17 00:00:00 2001
From: Mahesh Bodapati <mbodapat@xilinx.com>
Date: Thu, 12 Jan 2017 16:41:43 +0530
Subject: [PATCH 09/54] [Patch, microblaze]: Fix atomic side effects. In
 atomic_compare_and_swapsi, add side effects to prevent incorrect assumptions
 during optimization. Previously, the outputs were considered unused; this
 generated assembly code with undefined side effects after invocation of the
 atomic.

Signed-off-by: Kirk Meyer <kirk.meyer@sencore.com>
Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
---
 gcc/config/microblaze/microblaze.md |  3 +++
 gcc/config/microblaze/sync.md       | 21 +++++++++++++--------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/gcc/config/microblaze/microblaze.md b/gcc/config/microblaze/microblaze.md
index f698e54..93f5fa2 100644
--- a/gcc/config/microblaze/microblaze.md
+++ b/gcc/config/microblaze/microblaze.md
@@ -41,6 +41,9 @@
   (UNSPEC_CMP		104)    ;; signed compare
   (UNSPEC_CMPU		105)    ;; unsigned compare
   (UNSPEC_TLS           106)    ;; jump table
+  (UNSPECV_CAS_BOOL     201)    ;; compare and swap (bool)
+  (UNSPECV_CAS_VAL      202)    ;; compare and swap (val)
+  (UNSPECV_CAS_MEM      203)    ;; compare and swap (mem)
 ])
 
 (define_c_enum "unspec" [
diff --git a/gcc/config/microblaze/sync.md b/gcc/config/microblaze/sync.md
index b34bd54..8e694e9 100644
--- a/gcc/config/microblaze/sync.md
+++ b/gcc/config/microblaze/sync.md
@@ -18,14 +18,19 @@
 ;; <http://www.gnu.org/licenses/>.
 
 (define_insn "atomic_compare_and_swapsi"
-  [(match_operand:SI 0 "register_operand" "=&d")	;; bool output
-   (match_operand:SI 1 "register_operand" "=&d")	;; val output
-   (match_operand:SI 2 "nonimmediate_operand" "+Q")	;; memory
-   (match_operand:SI 3 "register_operand" "d")		;; expected value
-   (match_operand:SI 4 "register_operand" "d")		;; desired value
-   (match_operand:SI 5 "const_int_operand" "")		;; is_weak
-   (match_operand:SI 6 "const_int_operand" "")		;; mod_s
-   (match_operand:SI 7 "const_int_operand" "")		;; mod_f
+  [(set (match_operand:SI 0 "register_operand" "=&d")		;; bool output
+        (unspec_volatile:SI
+          [(match_operand:SI 2 "nonimmediate_operand" "+Q")	;; memory
+           (match_operand:SI 3 "register_operand" "d")		;; expected value
+           (match_operand:SI 4 "register_operand" "d")]		;; desired value
+          UNSPECV_CAS_BOOL))
+   (set (match_operand:SI 1 "register_operand" "=&d")		;; val output
+        (unspec_volatile:SI [(const_int 0)] UNSPECV_CAS_VAL))
+   (set (match_dup 2)
+        (unspec_volatile:SI [(const_int 0)] UNSPECV_CAS_MEM))
+   (match_operand:SI 5 "const_int_operand" "")			;; is_weak
+   (match_operand:SI 6 "const_int_operand" "")			;; mod_s
+   (match_operand:SI 7 "const_int_operand" "")			;; mod_f
    (clobber (match_scratch:SI 8 "=&d"))]
   ""
   {
-- 
2.7.4