[GCC, AArch64] Enable Transactional Memory Extension

This patch enables the new Transactional Memory Extension announced recently
as part of Arm's new architecture technologies.
We introduce a new optional extension "tme" to enable this. The following
instructions are part of the extension:
   * tstart <Xt>
   * ttest <Xt>
   * tcommit
   * tcancel #<imm>
We have also added ACLE intrinsics for the instructions.

*** gcc/ChangeLog ***

2019-07-31  Sudakshina Das  <sudi.das@arm.com>

	* config/aarch64/aarch64-builtins.c (enum aarch64_builtins): Add
	AARCH64_TME_BUILTIN_TSTART, AARCH64_TME_BUILTIN_TCOMMIT,
	AARCH64_TME_BUILTIN_TTEST and AARCH64_TME_BUILTIN_TCANCEL.
	(aarch64_init_tme_builtins): New.
	(aarch64_init_builtins): Call aarch64_init_tme_builtins.
	(aarch64_expand_builtin_tme): New.
	(aarch64_expand_builtin): Handle TME builtins.
	* config/aarch64/aarch64-c.c (aarch64_update_cpp_builtins): Define
	__ARM_FEATURE_TME when enabled.
	* config/aarch64/aarch64-option-extensions.def: Add "tme".
	* config/aarch64/aarch64.h (AARCH64_FL_TME, AARCH64_ISA_TME): New.
	(TARGET_TME): New.
	* config/aarch64/aarch64.md (define_c_enum "unspec"): Add UNSPEC_TTEST.
	(define_c_enum "unspecv"): Add UNSPECV_TSTART, UNSPECV_TCOMMIT and
	UNSPECV_TCANCEL.
	(tstart, ttest, tcommit, tcancel): New instructions.
	* config/aarch64/arm_acle.h (__tstart, __tcommit): New.
	(__tcancel, __ttest): New.
	(_TMFAILURE_REASON, _TMFAILURE_RTRY, _TMFAILURE_CNCL): New macro.
	(_TMFAILURE_MEM, _TMFAILURE_IMP, _TMFAILURE_ERR): Likewise.
	(_TMFAILURE_SIZE, _TMFAILURE_NEST, _TMFAILURE_DBG): Likewise.
	(_TMFAILURE_INT, _TMFAILURE_TRIVIAL): Likewise.
	* config/arm/types.md: Add new tme type attr.
	* doc/invoke.texi: Document "tme".

*** gcc/testsuite/ChangeLog ***

2019-07-31  Sudakshina Das  <sudi.das@arm.com>

	* gcc.target/aarch64/acle/tme.c: New test.
	* gcc.target/aarch64/pragma_cpp_predefs_2.c: New test.

From-SVN: r273926

gcc/ChangeLog

@@ -1,3 +1,30 @@
+2019-07-31  Sudakshina Das  <sudi.das@arm.com>
+
+	* config/aarch64/aarch64-builtins.c (enum aarch64_builtins): Add
+	AARCH64_TME_BUILTIN_TSTART, AARCH64_TME_BUILTIN_TCOMMIT,
+	AARCH64_TME_BUILTIN_TTEST and AARCH64_TME_BUILTIN_TCANCEL.
+	(aarch64_init_tme_builtins): New.
+	(aarch64_init_builtins): Call aarch64_init_tme_builtins.
+	(aarch64_expand_builtin_tme): New.
+	(aarch64_expand_builtin): Handle TME builtins.
+	* config/aarch64/aarch64-c.c (aarch64_update_cpp_builtins): Define
+	__ARM_FEATURE_TME when enabled.
+	* config/aarch64/aarch64-option-extensions.def: Add "tme".
+	* config/aarch64/aarch64.h (AARCH64_FL_TME, AARCH64_ISA_TME): New.
+	(TARGET_TME): New.
+	* config/aarch64/aarch64.md (define_c_enum "unspec"): Add UNSPEC_TTEST.
+	(define_c_enum "unspecv"): Add UNSPECV_TSTART, UNSPECV_TCOMMIT and
+	UNSPECV_TCANCEL.
+	(tstart, ttest, tcommit, tcancel): New instructions.
+	* config/aarch64/arm_acle.h (__tstart, __tcommit): New.
+	(__tcancel, __ttest): New.
+	(_TMFAILURE_REASON, _TMFAILURE_RTRY, _TMFAILURE_CNCL): New macro.
+	(_TMFAILURE_MEM, _TMFAILURE_IMP, _TMFAILURE_ERR): Likewise.
+	(_TMFAILURE_SIZE, _TMFAILURE_NEST, _TMFAILURE_DBG): Likewise.
+	(_TMFAILURE_INT, _TMFAILURE_TRIVIAL): Likewise.
+	* config/arm/types.md: Add new tme type attr.
+	* doc/invoke.texi: Document "tme".
+
 2019-07-31  Joel Hutton  <Joel.Hutton@arm.com>
 
 	* config/arm/arm_cmse.h (cmse_nonsecure_caller): Add

gcc/config/aarch64/aarch64-builtins.c

@@ -438,6 +438,11 @@ enum aarch64_builtins
   /* Special cased Armv8.3-A Complex FMA by Lane quad Builtins.  */
   AARCH64_SIMD_FCMLA_LANEQ_BUILTIN_BASE,
   AARCH64_SIMD_FCMLA_LANEQ_BUILTINS
+  /* TME builtins.  */
+  AARCH64_TME_BUILTIN_TSTART,
+  AARCH64_TME_BUILTIN_TCOMMIT,
+  AARCH64_TME_BUILTIN_TTEST,
+  AARCH64_TME_BUILTIN_TCANCEL,
   AARCH64_BUILTIN_MAX
 };
 
@@ -1067,6 +1072,35 @@ aarch64_init_pauth_hint_builtins (void)
 			    NULL_TREE);
 }
 
+/* Initialize the transactional memory extension (TME) builtins.  */
+static void
+aarch64_init_tme_builtins (void)
+{
+  tree ftype_uint64_void
+    = build_function_type_list (uint64_type_node, NULL);
+  tree ftype_void_void
+    = build_function_type_list (void_type_node, NULL);
+  tree ftype_void_uint64
+    = build_function_type_list (void_type_node, uint64_type_node, NULL);
+
+  aarch64_builtin_decls[AARCH64_TME_BUILTIN_TSTART]
+    = add_builtin_function ("__builtin_aarch64_tstart", ftype_uint64_void,
+			    AARCH64_TME_BUILTIN_TSTART, BUILT_IN_MD,
+			    NULL, NULL_TREE);
+  aarch64_builtin_decls[AARCH64_TME_BUILTIN_TTEST]
+    = add_builtin_function ("__builtin_aarch64_ttest", ftype_uint64_void,
+			    AARCH64_TME_BUILTIN_TTEST, BUILT_IN_MD,
+			    NULL, NULL_TREE);
+  aarch64_builtin_decls[AARCH64_TME_BUILTIN_TCOMMIT]
+    = add_builtin_function ("__builtin_aarch64_tcommit", ftype_void_void,
+			    AARCH64_TME_BUILTIN_TCOMMIT, BUILT_IN_MD,
+			    NULL, NULL_TREE);
+  aarch64_builtin_decls[AARCH64_TME_BUILTIN_TCANCEL]
+    = add_builtin_function ("__builtin_aarch64_tcancel", ftype_void_uint64,
+			    AARCH64_TME_BUILTIN_TCANCEL, BUILT_IN_MD,
+			    NULL, NULL_TREE);
+}
+
 void
 aarch64_init_builtins (void)
 {
@@ -1104,6 +1138,9 @@ aarch64_init_builtins (void)
      register them.  */
   if (!TARGET_ILP32)
     aarch64_init_pauth_hint_builtins ();
+
+  if (TARGET_TME)
+    aarch64_init_tme_builtins ();
 }
 
 tree
@@ -1507,6 +1544,47 @@ aarch64_expand_fcmla_builtin (tree exp, rtx target, int fcode)
   return target;
 }
 
+/* Function to expand an expression EXP which calls one of the Transactional
+   Memory Extension (TME) builtins FCODE with the result going to TARGET.  */
+static rtx
+aarch64_expand_builtin_tme (int fcode, tree exp, rtx target)
+{
+  switch (fcode)
+    {
+    case AARCH64_TME_BUILTIN_TSTART:
+      target = gen_reg_rtx (DImode);
+      emit_insn (GEN_FCN (CODE_FOR_tstart) (target));
+      break;
+
+    case AARCH64_TME_BUILTIN_TTEST:
+      target = gen_reg_rtx (DImode);
+      emit_insn (GEN_FCN (CODE_FOR_ttest) (target));
+      break;
+
+    case AARCH64_TME_BUILTIN_TCOMMIT:
+      emit_insn (GEN_FCN (CODE_FOR_tcommit) ());
+      break;
+
+    case AARCH64_TME_BUILTIN_TCANCEL:
+      {
+	tree arg0 = CALL_EXPR_ARG (exp, 0);
+	rtx op0 = expand_normal (arg0);
+	if (CONST_INT_P (op0) && UINTVAL (op0) <= 65536)
+	  emit_insn (GEN_FCN (CODE_FOR_tcancel) (op0));
+	else
+	  {
+	    error ("%Kargument must be a 16-bit constant immediate", exp);
+	    return const0_rtx;
+	  }
+      }
+      break;
+
+    default :
+      gcc_unreachable ();
+    }
+    return target;
+}
+
 /* Expand an expression EXP that calls a built-in function,
    with result going to TARGET if that's convenient.  */
 rtx
@@ -1627,6 +1705,12 @@ aarch64_expand_builtin (tree exp,
       || fcode == AARCH64_BUILTIN_RSQRT_V4SF)
     return aarch64_expand_builtin_rsqrt (fcode, exp, target);
 
+  if (fcode == AARCH64_TME_BUILTIN_TSTART
+      || fcode == AARCH64_TME_BUILTIN_TCOMMIT
+      || fcode == AARCH64_TME_BUILTIN_TTEST
+      || fcode == AARCH64_TME_BUILTIN_TCANCEL)
+    return aarch64_expand_builtin_tme (fcode, exp, target);
+
   gcc_unreachable ();
 }
 

gcc/config/aarch64/aarch64-c.c

@@ -157,6 +157,8 @@ aarch64_update_cpp_builtins (cpp_reader *pfile)
   aarch64_def_or_undef (TARGET_SM4, "__ARM_FEATURE_SM4", pfile);
   aarch64_def_or_undef (TARGET_F16FML, "__ARM_FEATURE_FP16_FML", pfile);
 
+  aarch64_def_or_undef (TARGET_TME, "__ARM_FEATURE_TME", pfile);
+
   /* Not for ACLE, but required to keep "float.h" correct if we switch
      target between implementations that do or do not support ARMv8.2-A
      16-bit floating-point extensions.  */

gcc/config/aarch64/aarch64-option-extensions.def

@@ -195,4 +195,7 @@ AARCH64_OPT_EXTENSION("sve2-bitperm", AARCH64_FL_SVE2_BITPERM, AARCH64_FL_SIMD |
 		      AARCH64_FL_F16 | AARCH64_FL_FP | AARCH64_FL_SVE | \
 		      AARCH64_FL_SVE2, 0, false, "")
 
+/* Enabling or disabling "tme" only changes "tme".  */
+AARCH64_OPT_EXTENSION("tme", AARCH64_FL_TME, 0, 0, false, "")
+
 #undef AARCH64_OPT_EXTENSION

gcc/config/aarch64/aarch64.h

@@ -199,6 +199,9 @@ extern unsigned aarch64_architecture_version;
 #define AARCH64_FL_SVE2_SHA3	(1ULL << 31)
 #define AARCH64_FL_SVE2_BITPERM	(1ULL << 32)
 
+/* Transactional Memory Extension.  */
+#define AARCH64_FL_TME	      (1ULL << 33)  /* Has TME instructions.  */
+
 /* Has FP and SIMD.  */
 #define AARCH64_FL_FPSIMD     (AARCH64_FL_FP | AARCH64_FL_SIMD)
 
@@ -243,6 +246,7 @@ extern unsigned aarch64_architecture_version;
 #define AARCH64_ISA_F16FML	   (aarch64_isa_flags & AARCH64_FL_F16FML)
 #define AARCH64_ISA_RCPC8_4	   (aarch64_isa_flags & AARCH64_FL_RCPC8_4)
 #define AARCH64_ISA_V8_5	   (aarch64_isa_flags & AARCH64_FL_V8_5)
+#define AARCH64_ISA_TME		   (aarch64_isa_flags & AARCH64_FL_TME)
 
 /* Crypto is an optional extension to AdvSIMD.  */
 #define TARGET_CRYPTO (TARGET_SIMD && AARCH64_ISA_CRYPTO)
@@ -287,6 +291,9 @@ extern unsigned aarch64_architecture_version;
 /* Armv8.3-a Complex number extension to AdvSIMD extensions.  */
 #define TARGET_COMPLEX (TARGET_SIMD && TARGET_ARMV8_3)
 
+/* TME instructions are enabled.  */
+#define TARGET_TME (AARCH64_ISA_TME)
+
 /* Make sure this is always defined so we don't have to check for ifdefs
    but rather use normal ifs.  */
 #ifndef TARGET_FIX_ERR_A53_835769_DEFAULT

gcc/config/aarch64/aarch64.md

@@ -236,6 +236,7 @@
     UNSPEC_REV_SUBREG
     UNSPEC_SPECULATION_TRACKER
     UNSPEC_COPYSIGN
+    UNSPEC_TTEST		; Represent transaction test.
 ])
 
 (define_c_enum "unspecv" [
@@ -251,6 +252,9 @@
     UNSPECV_BTI_C		; Represent BTI c.
     UNSPECV_BTI_J		; Represent BTI j.
     UNSPECV_BTI_JC		; Represent BTI jc.
+    UNSPECV_TSTART		; Represent transaction start.
+    UNSPECV_TCOMMIT		; Represent transaction commit.
+    UNSPECV_TCANCEL		; Represent transaction cancel.
   ]
 )
 
@@ -7242,6 +7246,43 @@
    (set_attr "speculation_barrier" "true")]
 )
 
+;; Transactional Memory Extension (TME) instructions.
+
+(define_insn "tstart"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(unspec_volatile:DI [(const_int 0)] UNSPECV_TSTART))
+   (clobber (mem:BLK (scratch)))]
+  "TARGET_TME"
+  "tstart\\t%0"
+  [(set_attr "type" "tme")]
+)
+
+(define_insn "ttest"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(unspec_volatile:DI [(const_int 0)] UNSPEC_TTEST))
+   (clobber (mem:BLK (scratch)))]
+  "TARGET_TME"
+  "ttest\\t%0"
+  [(set_attr "type" "tme")]
+)
+
+(define_insn "tcommit"
+  [(unspec_volatile:BLK [(const_int 0)] UNSPECV_TCOMMIT)
+   (clobber (mem:BLK (scratch)))]
+  "TARGET_TME"
+  "tcommit"
+  [(set_attr "type" "tme")]
+)
+
+(define_insn "tcancel"
+  [(unspec_volatile:BLK
+     [(match_operand 0 "const_int_operand" "n")] UNSPECV_TCANCEL)
+   (clobber (mem:BLK (scratch)))]
+  "TARGET_TME && (UINTVAL (operands[0]) <= 65535)"
+  "tcancel\\t#%0"
+  [(set_attr "type" "tme")]
+)
+
 ;; AdvSIMD Stuff
 (include "aarch64-simd.md")
 

gcc/config/aarch64/arm_acle.h

@@ -29,14 +29,14 @@
 
 #include <stdint.h>
 
-#pragma GCC push_options
-
-#pragma GCC target ("+nothing+crc")
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#pragma GCC push_options
+
+#pragma GCC target ("+nothing+crc")
+
 __extension__ static __inline uint32_t __attribute__ ((__always_inline__))
 __crc32b (uint32_t __a, uint8_t __b)
 {
@@ -85,10 +85,53 @@ __crc32d (uint32_t __a, uint64_t __b)
   return __builtin_aarch64_crc32x (__a, __b);
 }
 
+#pragma GCC pop_options
+
+#ifdef __ARM_FEATURE_TME
+#pragma GCC push_options
+#pragma GCC target ("+nothing+tme")
+
+#define _TMFAILURE_REASON     0x00007fffu
+#define _TMFAILURE_RTRY       0x00008000u
+#define _TMFAILURE_CNCL       0x00010000u
+#define _TMFAILURE_MEM        0x00020000u
+#define _TMFAILURE_IMP        0x00040000u
+#define _TMFAILURE_ERR        0x00080000u
+#define _TMFAILURE_SIZE       0x00100000u
+#define _TMFAILURE_NEST       0x00200000u
+#define _TMFAILURE_DBG        0x00400000u
+#define _TMFAILURE_INT        0x00800000u
+#define _TMFAILURE_TRIVIAL    0x01000000u
+
+__extension__ static __inline uint64_t __attribute__ ((__always_inline__))
+__tstart (void)
+{
+  return __builtin_aarch64_tstart ();
+}
+
+__extension__ static __inline void __attribute__ ((__always_inline__))
+__tcommit (void)
+{
+  __builtin_aarch64_tcommit ();
+}
+
+__extension__ static __inline void __attribute__ ((__always_inline__))
+__tcancel (const uint64_t __reason)
+{
+  __builtin_aarch64_tcancel (__reason);
+}
+
+__extension__ static __inline uint64_t __attribute__ ((__always_inline__))
+__ttest (void)
+{
+  return __builtin_aarch64_ttest ();
+}
+
+#pragma GCC pop_options
+#endif
+
 #ifdef __cplusplus
 }
 #endif
 
-#pragma GCC pop_options
-
 #endif

gcc/config/arm/types.md

@@ -546,6 +546,10 @@
 ; The classification below is for coprocessor instructions
 ;
 ; coproc
+;
+; The classification below is for TME instructions
+;
+; tme
 
 (define_attr "type"
  "adc_imm,\
@@ -1091,7 +1095,8 @@
   crypto_sha3,\
   crypto_sm3,\
   crypto_sm4,\
-  coproc"
+  coproc,\
+  tme"
    (const_string "untyped"))
 
 ; Is this an (integer side) multiply with a 32-bit (or smaller) result?

gcc/doc/invoke.texi

@@ -16095,6 +16095,8 @@ Enable SVE2 aes instructions.  This also enables SVE2 instructions.
 @item sve2-sha3
 Enable SVE2 sha3 instructions.  This also enables SVE2 instructions.
 @option{-march=armv8.5-a}.
+@item tme
+Enable the Transactional Memory Extension.
 
 @end table
 

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-07-31  Sudakshina Das  <sudi.das@arm.com>
+
+	* gcc.target/aarch64/acle/tme.c: New test.
+	* gcc.target/aarch64/pragma_cpp_predefs_2.c: New test.
+
 2019-07-31  Joel Hutton  <Joel.Hutton@arm.com>
 
 	* gcc.target/arm/cmse/cmse-17.c: New test.

gcc/testsuite/gcc.target/aarch64/acle/tme.c

@@ -0,0 +1,34 @@
+/* Test the TME intrinsics.  */
+
+/* { dg-do compile } */
+/* { dg-options "-save-temps -O2 -march=armv8-a+tme" } */
+
+#include "arm_acle.h"
+
+#define tcancel_reason 0x234
+
+unsigned
+check_tme (void)
+{
+  unsigned status = __tstart ();
+  if (status == 0)
+    {
+      if (__ttest () == 2)
+	{
+	  __tcancel (tcancel_reason & _TMFAILURE_REASON);
+	  return tcancel_reason;
+	}
+
+      __tcommit ();
+      return 0;
+    }
+  else if (status & _TMFAILURE_NEST)
+    return _TMFAILURE_NEST;
+  else if (status & _TMFAILURE_TRIVIAL)
+    return _TMFAILURE_TRIVIAL;
+}
+
+/* { dg-final { scan-assembler "tstart\tx..?\n" } } */
+/* { dg-final { scan-assembler "tcancel\t#564\n" } } */
+/* { dg-final { scan-assembler "ttest\tx..?\n" } } */
+/* { dg-final { scan-assembler "tcommit\n" } } */

gcc/testsuite/gcc.target/aarch64/pragma_cpp_predefs_2.c

@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#pragma GCC push_options
+#pragma GCC target ("arch=armv8-a+tme")
+#ifndef __ARM_FEATURE_TME
+#error "__ARM_FEATURE_TME is not defined but should be!"
+#endif
+
+#pragma GCC pop_options
+
+#ifdef __ARM_FEATURE_TME
+#error "__ARM_FEATURE_TME is defined but should not be!"
+#endif
+
+int
+foo (int a)
+{
+  return a;
+}