[SPARC] Errata workaround for GRLIB-TN-0011

This patch provides a workaround for the errata described in GRLIB-TN-0011.

If the workaround is enabled it will:

 * Insert .align 16 before atomic instructions (swap, ldstub, casa).

It is applicable to GR712RC.

2017-11-29  Daniel Cederman  <cederman@gaisler.com>

gcc/
	* config/sparc/sync.md (swapsi): 16-byte align if sparc_fix_gr712rc.
	(atomic_compare_and_swap_leon3_1): Likewise.
	(ldstub): Likewise.

From-SVN: r255235

gcc/ChangeLog

 2017-11-29  Daniel Cederman  <cederman@gaisler.com>
 
+	* config/sparc/sync.md (swapsi): 16-byte align if sparc_fix_gr712rc.
+	(atomic_compare_and_swap_leon3_1): Likewise.
+	(ldstub): Likewise.
+
+2017-11-29  Daniel Cederman  <cederman@gaisler.com>
+
 	* config/sparc/sparc.c (fpop_insn_p): New function.
 	(sparc_do_work_around_errata): Insert NOP instructions to
 	prevent sequences that could trigger the TN-0012 errata for

gcc/config/sparc/sync.md

@@ -222,12 +222,16 @@
 	  UNSPECV_CAS))]
   "TARGET_LEON3"
 {
+  if (sparc_fix_gr712rc)
+    output_asm_insn (".align\t16", operands);
   if (TARGET_SV_MODE)
     return "casa\t%1 0xb, %2, %0"; /* ASI for supervisor data space.  */
   else
     return "casa\t%1 0xa, %2, %0"; /* ASI for user data space.  */
 }
-  [(set_attr "type" "multi")])
+  [(set_attr "type" "multi")
+   (set (attr "length") (if_then_else (eq_attr "fix_gr712rc" "true")
+		      (const_int 4) (const_int 1)))])
 
 (define_insn "*atomic_compare_and_swapdi_v8plus"
   [(set (match_operand:DI 0 "register_operand" "=h")
@@ -275,8 +279,15 @@
    (set (match_dup 1)
 	(match_operand:SI 2 "register_operand" "0"))]
   "(TARGET_V8 || TARGET_V9) && !sparc_fix_ut699"
-  "swap\t%1, %0"
-  [(set_attr "type" "multi")])
+{
+  if (sparc_fix_gr712rc)
+    return ".align\t16\n\tswap\t%1, %0";
+  else
+    return "swap\t%1, %0";
+}
+  [(set_attr "type" "multi")
+   (set (attr "length") (if_then_else (eq_attr "fix_gr712rc" "true")
+		      (const_int 4) (const_int 1)))])
 
 (define_expand "atomic_test_and_set"
   [(match_operand:QI 0 "register_operand" "")
@@ -307,5 +318,12 @@
 			    UNSPECV_LDSTUB))
    (set (match_dup 1) (const_int -1))]
   "!sparc_fix_ut699"
-  "ldstub\t%1, %0"
-  [(set_attr "type" "multi")])
+{
+  if (sparc_fix_gr712rc)
+    return ".align\t16\n\tldstub\t%1, %0";
+  else
+    return "ldstub\t%1, %0";
+}
+  [(set_attr "type" "multi")
+   (set (attr "length") (if_then_else (eq_attr "fix_gr712rc" "true")
+		      (const_int 4) (const_int 1)))])