re PR middle-end/37908 (atomic NAND op generate wrong code; __sync_nand_and_fetch, __sync_fetch_and_nand)

	PR middle-end/37908
	* optabs.c (expand_sync_operation): Properly handle NAND case
	by calculating ~(t1 & val) instead of (~t1 & val).
	* builtins.c (expand_builtin_sync_operation): Warn for changed
	semantics in NAND builtins.
	* c.opt (Wsync-nand): New warning option.  Describe -Wsync-nand.
	
	* doc/invoke.texi (Warning options): Add Wsync-nand.
	* doc/extend.texi (Atomic Builtins) [__sync_fetch_and_nand]: Correct
	__sync_fetch_and_nand builtin operation in the example.  Add a note
	about changed semantics in GCC 4.4.
	[__sync_nand_and_fetch]: Correct __sync_nand_and_fetch builtin
	operation in the example.  Add a note about changed semantics in
	GCC 4.4.

testsuite/ChangeLog:

	PR middle-end/37908
	* gcc.dg/pr37908.c: New test.
	* gcc.dg/ia64-sync-1.c: Correct __sync_fetch_and_nand and
	__sync_nand_and_fetch results.  Add dg-message to look for the warning
	about changed semantics of NAND builtin.
	(init_si, init_di): Change init value for __sync_fetch_and_nand to -1.
	(test_si, test_di): Change expected result of
	__sync_nand_and_fetch to ~7.
	* gcc.dg/ia64-sync-2.c: Correct __sync_fetch_and_nand and
	__sync_nand_and_fetch results.  Add dg-message to look for the warning
	about changed semantics of NAND builtin.
	(init_noret_si, init_noret_di): Change init value for
	__sync_fetch_and_nand to -1.
	(init_noret_si, init_noret_di): Change expected result of
	__sync_nand_and_fetch to ~7.
	* gcc.dg/sync-2.c: Correct __sync_fetch_and_nand and
	__sync_nand_and_fetch results.  Add dg-message to look for the warning
	about changed semantics of NAND builtin.
	(init_qi, init_qi): Change init value for __sync_fetch_and_nand to -1.
	(init_hi, init_hi): Change expected result of
	__sync_nand_and_fetch to ~7.
	* gcc.dg/sync-3.c: Copy from sync-2.c instead of including
	the c source file.
	* gcc.c-torture/compile/sync-1.c: Add dg-message to look for the
	warning about changed semantics of NAND builtin.
	* gcc.c-torture/compile/sync-2.c: Ditto.
	* gcc.c-torture/compile/sync-3.c: Ditto.

From-SVN: r141942

1 files changed, 23 insertions, 12 deletions

diff --git a/gcc/optabs.c b/gcc/optabs.c
index 1273103..ed59f5e 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -7182,12 +7182,13 @@ expand_sync_operation (rtx mem, rtx val, enum rtx_code code)
       t1 = t0;
       if (code == NOT)
 	{
-	  t1 = expand_simple_unop (mode, NOT, t1, NULL_RTX, true);
-	  code = AND;
+	  t1 = expand_simple_binop (mode, AND, t1, val, NULL_RTX,
+				    true, OPTAB_LIB_WIDEN);
+	  t1 = expand_simple_unop (mode, code, t1, NULL_RTX, true);
 	}
-      t1 = expand_simple_binop (mode, code, t1, val, NULL_RTX,
-				true, OPTAB_LIB_WIDEN);
-
+      else
+	t1 = expand_simple_binop (mode, code, t1, val, NULL_RTX,
+				  true, OPTAB_LIB_WIDEN);
       insn = get_insns ();
       end_sequence ();
 
@@ -7315,9 +7316,17 @@ expand_sync_fetch_operation (rtx mem, rtx val, enum rtx_code code,
 		}
 
 	      if (code == NOT)
-		target = expand_simple_unop (mode, NOT, target, NULL_RTX, true);
-	      target = expand_simple_binop (mode, code, target, val, NULL_RTX,
-					    true, OPTAB_LIB_WIDEN);
+		{
+		  target = expand_simple_binop (mode, AND, target, val,
+						NULL_RTX, true,
+						OPTAB_LIB_WIDEN);
+		  target = expand_simple_unop (mode, code, target,
+					       NULL_RTX, true);
+		}
+	      else
+		target = expand_simple_binop (mode, code, target, val,
+					      NULL_RTX, true,
+					      OPTAB_LIB_WIDEN);
 	    }
 
 	  return target;
@@ -7340,11 +7349,13 @@ expand_sync_fetch_operation (rtx mem, rtx val, enum rtx_code code,
       t1 = t0;
       if (code == NOT)
 	{
-	  t1 = expand_simple_unop (mode, NOT, t1, NULL_RTX, true);
-	  code = AND;
+	  t1 = expand_simple_binop (mode, AND, t1, val, NULL_RTX,
+				    true, OPTAB_LIB_WIDEN);
+	  t1 = expand_simple_unop (mode, code, t1, NULL_RTX, true);
 	}
-      t1 = expand_simple_binop (mode, code, t1, val, NULL_RTX,
-				true, OPTAB_LIB_WIDEN);
+      else
+	t1 = expand_simple_binop (mode, code, t1, val, NULL_RTX,
+				  true, OPTAB_LIB_WIDEN);
       if (after)
 	emit_move_insn (target, t1);