rs6000-builtin.def (BU_P7_MISC_X): New #define.

[gcc]

2018-01-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	* config/rs6000/rs6000-builtin.def (BU_P7_MISC_X): New #define.
	(SPEC_BARRIER): New instantiation of BU_P7_MISC_X.
	* config/rs6000/rs6000.c (rs6000_expand_builtin): Handle
	MISC_BUILTIN_SPEC_BARRIER.
	(rs6000_init_builtins): Likewise.
	* config/rs6000/rs6000.md (UNSPECV_SPEC_BARRIER): New UNSPECV
	enum value.
	(speculation_barrier): New define_insn.
	* doc/extend.texi: Document __builtin_speculation_barrier.

[gcc/testsuite]

2018-01-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	* gcc.target/powerpc/spec-barr-1.c: New file.

From-SVN: r256557

gcc/ChangeLog

+2018-01-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
+
+	* config/rs6000/rs6000-builtin.def (BU_P7_MISC_X): New #define.
+	(SPEC_BARRIER): New instantiation of BU_P7_MISC_X.
+	* config/rs6000/rs6000.c (rs6000_expand_builtin): Handle
+	MISC_BUILTIN_SPEC_BARRIER.
+	(rs6000_init_builtins): Likewise.
+	* config/rs6000/rs6000.md (UNSPECV_SPEC_BARRIER): New UNSPECV
+	enum value.
+	(speculation_barrier): New define_insn.
+	* doc/extend.texi: Document __builtin_speculation_barrier.
+
 2018-01-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/83203

gcc/config/rs6000/rs6000-builtin.def

@@ -638,6 +638,14 @@
 		     | RS6000_BTC_BINARY),				\
 		    CODE_FOR_ ## ICODE)			/* ICODE */
 
+#define BU_P7_MISC_X(ENUM, NAME, ATTR)					\
+  RS6000_BUILTIN_X (MISC_BUILTIN_ ## ENUM,		/* ENUM */	\
+		    "__builtin_" NAME,			/* NAME */	\
+		    RS6000_BTM_POPCNTD,			/* MASK */	\
+		    (RS6000_BTC_ ## ATTR		/* ATTR */	\
+		     | RS6000_BTC_SPECIAL),				\
+		    CODE_FOR_nothing)			/* ICODE */
+
 
 /* Miscellaneous builtins for instructions added in ISA 2.07.  These
    instructions do require the ISA 2.07 vector support, but they aren't vector
@@ -2324,6 +2332,11 @@ BU_DFP_MISC_2 (DSCLIQ,		"dscliq",	CONST,	dfp_dscli_td)
 BU_DFP_MISC_2 (DSCRI,		"dscri",	CONST,	dfp_dscri_dd)
 BU_DFP_MISC_2 (DSCRIQ,		"dscriq",	CONST,	dfp_dscri_td)
 
+/* 0 argument void function that we pretend was added in ISA 2.06.
+   It's a special nop recognized by 2018+ firmware for P7 and up,
+   with speculation barrier semantics.  */
+BU_P7_MISC_X (SPEC_BARRIER,	"rs6000_speculation_barrier",	MISC)
+
 /* 1 argument BCD functions added in ISA 2.06.  */
 BU_P7_MISC_1 (CDTBCD,		"cdtbcd",	CONST,	cdtbcd)
 BU_P7_MISC_1 (CBCDTD,		"cbcdtd",	CONST,	cbcdtd)

gcc/config/rs6000/rs6000.c

@@ -16792,6 +16792,12 @@ rs6000_expand_builtin (tree exp, rtx target, rtx subtarget ATTRIBUTE_UNUSED,
     case RS6000_BUILTIN_CPU_SUPPORTS:
       return cpu_expand_builtin (fcode, exp, target);
 
+    case MISC_BUILTIN_SPEC_BARRIER:
+      {
+	emit_insn (gen_rs6000_speculation_barrier ());
+	return NULL_RTX;
+      }
+
     case ALTIVEC_BUILTIN_MASK_FOR_LOAD:
     case ALTIVEC_BUILTIN_MASK_FOR_STORE:
       {
@@ -17164,6 +17170,8 @@ rs6000_init_builtins (void)
 
   ftype = build_function_type_list (void_type_node, NULL_TREE);
   def_builtin ("__builtin_cpu_init", ftype, RS6000_BUILTIN_CPU_INIT);
+  def_builtin ("__builtin_rs6000_speculation_barrier", ftype,
+	       MISC_BUILTIN_SPEC_BARRIER);
 
   ftype = build_function_type_list (bool_int_type_node, const_ptr_type_node,
 				    NULL_TREE);

gcc/config/rs6000/rs6000.md

@@ -168,6 +168,7 @@
    UNSPECV_MFFS			; Move from FPSCR
    UNSPECV_MTFSF		; Move to FPSCR Fields
    UNSPECV_SPLIT_STACK_RETURN   ; A camouflaged return
+   UNSPECV_SPEC_BARRIER         ; Speculation barrier
   ])
 
 
@@ -12996,6 +12997,11 @@
     return "ori 1,1,0";
   return "ori 2,2,0";
 })
+
+(define_insn "rs6000_speculation_barrier"
+  [(unspec_volatile:BLK [(const_int 0)] UNSPECV_SPEC_BARRIER)]
+  ""
+  "ori 31,31,0")
 
 ;; Define the subtract-one-and-jump insns, starting with the template
 ;; so loop.c knows what to generate.

gcc/doc/extend.texi

@@ -15753,6 +15753,7 @@ unsigned long __builtin_divdeuo (unsigned long, unsigned long);
 unsigned int cdtbcd (unsigned int);
 unsigned int cbcdtd (unsigned int);
 unsigned int addg6s (unsigned int, unsigned int);
+void __builtin_rs6000_speculation_barrier (void);
 @end smallexample
 
 The @code{__builtin_divde}, @code{__builtin_divdeo},

gcc/testsuite/ChangeLog

+2018-01-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
+
+	* gcc.target/powerpc/spec-barr-1.c: New file.
+
 2018-01-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/83330

gcc/testsuite/gcc.target/powerpc/spec-barr-1.c

+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { "-mcpu=power7" } } */
+/* { dg-options "-mcpu=power7" } */
+
+void foo ()
+{
+  __builtin_rs6000_speculation_barrier ();
+}
+
+/* { dg-final { scan-assembler "ori 31,31,0" } } */