Re: C11 atomics on parisc are broken on gcc-7 and gcc-8

[John David Anglin <dave.anglin@xxxxxxxx>]

On 2018-09-18 7:13 PM, John David Anglin wrote:
> You are correct.  The problem is my fault.  I changed gcc when it was 
> realized that PA 2.0
> executes loads and stores out of order.  I need to add back some code 
> that was there before.
Testing the attached change.

Dave

--
John David Anglin  dave.anglin@xxxxxxxx

Index: config/pa/pa.md
===================================================================
--- config/pa/pa.md	(revision 264413)
+++ config/pa/pa.md	(working copy)
@@ -9960,6 +9960,58 @@
 
 ;; Implement atomic DImode load using 64-bit floating point load.
 
+(define_expand "atomic_storeqi"
+  [(match_operand:QI 0 "memory_operand")                ;; memory
+   (match_operand:QI 1 "register_operand")              ;; val out
+   (match_operand:SI 2 "const_int_operand")]            ;; model
+  ""
+{
+  if (TARGET_SYNC_LIBCALL)
+    {
+      rtx mem = operands[0];
+      rtx val = operands[1];
+      if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
+	DONE;
+    }
+  FAIL;
+})
+
+;; Implement atomic HImode stores using exchange.
+
+(define_expand "atomic_storehi"
+  [(match_operand:HI 0 "memory_operand")                ;; memory
+   (match_operand:HI 1 "register_operand")              ;; val out
+   (match_operand:SI 2 "const_int_operand")]            ;; model
+  ""
+{
+  if (TARGET_SYNC_LIBCALL)
+    {
+      rtx mem = operands[0];
+      rtx val = operands[1];
+      if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
+	DONE;
+    }
+  FAIL;
+})
+
+;; Implement atomic SImode store using exchange.
+
+(define_expand "atomic_storesi"
+  [(match_operand:SI 0 "memory_operand")                ;; memory
+   (match_operand:SI 1 "register_operand")              ;; val out
+   (match_operand:SI 2 "const_int_operand")]            ;; model
+  ""
+{
+  if (TARGET_SYNC_LIBCALL)
+    {
+      rtx mem = operands[0];
+      rtx val = operands[1];
+      if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
+	DONE;
+    }
+  FAIL;
+})
+
 (define_expand "atomic_loaddi"
   [(match_operand:DI 0 "register_operand")              ;; val out
    (match_operand:DI 1 "memory_operand")                ;; memory
@@ -9999,6 +10051,14 @@
 {
   enum memmodel model;
 
+  if (TARGET_SYNC_LIBCALL)
+    {
+      rtx mem = operands[0];
+      rtx val = operands[1];
+      if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
+	DONE;
+    }
+
   if (TARGET_64BIT || TARGET_DISABLE_FPREGS || TARGET_SOFT_FLOAT)
     FAIL;