Come up with hook libc_has_fast_function (PR middle-end/90263).

2019-05-20  Martin Liska  <mliska@suse.cz>

	PR middle-end/90263
	* builtins.c (expand_builtin_memory_copy_args): When having a
	target with fast mempcpy implementation do now use memcpy.
	* config/i386/i386.c (ix86_libc_has_fast_function): New.
	(TARGET_LIBC_HAS_FAST_FUNCTION): Likewise.
	* doc/tm.texi: Likewise.
	* doc/tm.texi.in: Likewise.
	* target.def:
	* expr.c (emit_block_move_hints): Add 2 new arguments.
	* expr.h (emit_block_move_hints): Bail out when libcall
	to memcpy would be used.
2019-05-20  Martin Liska  <mliska@suse.cz>

	PR middle-end/90263
	* gcc.c-torture/compile/pr90263.c: New test.
	* lib/target-supports.exp: Add check_effective_target_glibc.

From-SVN: r271400

11 files changed, 100 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a4f0e2d..68564af 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,19 @@
 2019-05-20  Martin Liska  <mliska@suse.cz>
 
+	PR middle-end/90263
+	* builtins.c (expand_builtin_memory_copy_args): When having a
+	target with fast mempcpy implementation do now use memcpy.
+	* config/i386/i386.c (ix86_libc_has_fast_function): New.
+	(TARGET_LIBC_HAS_FAST_FUNCTION): Likewise.
+	* doc/tm.texi: Likewise.
+	* doc/tm.texi.in: Likewise.
+	* target.def:
+	* expr.c (emit_block_move_hints): Add 2 new arguments.
+	* expr.h (emit_block_move_hints): Bail out when libcall
+	to memcpy would be used.
+
+2019-05-20  Martin Liska  <mliska@suse.cz>
+
 	* profile-count.c: Add vertical spacing in order
 	to separate functions.
 	* profile-count.h: Likewise.
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 0456a9e..3f32754 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3839,6 +3839,8 @@ expand_builtin_memory_copy_args (tree dest, tree src, tree len,
   unsigned HOST_WIDE_INT max_size;
   unsigned HOST_WIDE_INT probable_max_size;
 
+  bool is_move_done;
+
   /* If DEST is not a pointer type, call the normal function.  */
   if (dest_align == 0)
     return NULL_RTX;
@@ -3888,11 +3890,22 @@ expand_builtin_memory_copy_args (tree dest, tree src, tree len,
   if (CALL_EXPR_TAILCALL (exp)
       && (retmode == RETURN_BEGIN || target == const0_rtx))
     method = BLOCK_OP_TAILCALL;
-  if (retmode == RETURN_END && target != const0_rtx)
+  bool use_mempcpy_call = (targetm.libc_has_fast_function (BUILT_IN_MEMPCPY)
+			   && retmode == RETURN_END
+			   && target != const0_rtx);
+  if (use_mempcpy_call)
     method = BLOCK_OP_NO_LIBCALL_RET;
   dest_addr = emit_block_move_hints (dest_mem, src_mem, len_rtx, method,
 				     expected_align, expected_size,
-				     min_size, max_size, probable_max_size);
+				     min_size, max_size, probable_max_size,
+				     use_mempcpy_call, &is_move_done);
+
+  /* Bail out when a mempcpy call would be expanded as libcall and when
+     we have a target that provides a fast implementation
+     of mempcpy routine.  */
+  if (!is_move_done)
+    return NULL_RTX;
+
   if (dest_addr == pc_rtx)
     return NULL_RTX;
 
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index d3eb7c8..384c633 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -23063,6 +23063,21 @@ ix86_run_selftests (void)
 #define TARGET_GET_MULTILIB_ABI_NAME \
   ix86_get_multilib_abi_name
 
+static bool ix86_libc_has_fast_function (int fcode)
+{
+#ifdef OPTION_GLIBC
+  if (OPTION_GLIBC)
+    return (built_in_function)fcode == BUILT_IN_MEMPCPY;
+  else
+    return false;
+#else
+  return false;
+#endif
+}
+
+#undef TARGET_LIBC_HAS_FAST_FUNCTION
+#define TARGET_LIBC_HAS_FAST_FUNCTION ix86_libc_has_fast_function
+
 #if CHECKING_P
 #undef TARGET_RUN_TARGET_SELFTESTS
 #define TARGET_RUN_TARGET_SELFTESTS selftest::ix86_run_selftests
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 8c8978b..0941039 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -5594,6 +5594,11 @@ This hook determines whether a function from a class of functions
 @var{fn_class} is present at the runtime.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_LIBC_HAS_FAST_FUNCTION (int @var{fcode})
+This hook determines whether a function from a class of functions
+@var{fn_class} has a fast implementation.
+@end deftypefn
+
 @defmac NEXT_OBJC_RUNTIME
 Set this macro to 1 to use the "NeXT" Objective-C message sending conventions
 by default.  This calling convention involves passing the object, the selector
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index fe1194e..17560fc 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -3991,6 +3991,8 @@ macro, a reasonable default is used.
 
 @hook TARGET_LIBC_HAS_FUNCTION
 
+@hook TARGET_LIBC_HAS_FAST_FUNCTION
+
 @defmac NEXT_OBJC_RUNTIME
 Set this macro to 1 to use the "NeXT" Objective-C message sending conventions
 by default.  This calling convention involves passing the object, the selector
diff --git a/gcc/expr.c b/gcc/expr.c
index fa15b7e..c78bc74 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -1561,12 +1561,16 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method,
 		       unsigned int expected_align, HOST_WIDE_INT expected_size,
 		       unsigned HOST_WIDE_INT min_size,
 		       unsigned HOST_WIDE_INT max_size,
-		       unsigned HOST_WIDE_INT probable_max_size)
+		       unsigned HOST_WIDE_INT probable_max_size,
+		       bool bail_out_libcall, bool *is_move_done)
 {
   int may_use_call;
   rtx retval = 0;
   unsigned int align;
 
+  if (is_move_done)
+    *is_move_done = true;
+
   gcc_assert (size);
   if (CONST_INT_P (size) && INTVAL (size) == 0)
     return 0;
@@ -1628,6 +1632,13 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method,
 	   && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (x))
 	   && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (y)))
     {
+      if (bail_out_libcall)
+	{
+	  if (is_move_done)
+	    *is_move_done = false;
+	  return retval;
+	}
+
       if (may_use_call < 0)
 	return pc_rtx;
 
diff --git a/gcc/expr.h b/gcc/expr.h
index 17c3962..6eb70bf 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -114,7 +114,9 @@ extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
 			          unsigned int, HOST_WIDE_INT,
 				  unsigned HOST_WIDE_INT,
 				  unsigned HOST_WIDE_INT,
-				  unsigned HOST_WIDE_INT);
+				  unsigned HOST_WIDE_INT,
+				  bool bail_out_libcall = false,
+				  bool *is_move_done = NULL);
 extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool,
 				 by_pieces_constfn, void *);
 extern bool emit_storent_insn (rtx to, rtx from);
diff --git a/gcc/target.def b/gcc/target.def
index 66cee07..23e260c 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -2547,6 +2547,13 @@ DEFHOOK
  bool, (enum function_class fn_class),
  default_libc_has_function)
 
+DEFHOOK
+(libc_has_fast_function,
+ "This hook determines whether a function from a class of functions\n\
+@var{fn_class} has a fast implementation.",
+ bool, (int fcode),
+ default_libc_has_fast_function)
+
 /* True if new jumps cannot be created, to replace existing ones or
    not, at the current point in the compilation.  */
 DEFHOOK
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ecb4d68..7b3bf73 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2019-05-20  Martin Liska  <mliska@suse.cz>
+
+	PR middle-end/90263
+	* gcc.c-torture/compile/pr90263.c: New test.
+	* lib/target-supports.exp: Add check_effective_target_glibc.
+
 2019-05-20  Richard Biener  <rguenther@suse.de>
 
 	PR testsuite/90518
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr90263.c b/gcc/testsuite/gcc.c-torture/compile/pr90263.c
new file mode 100644
index 0000000..df3ab0f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr90263.c
@@ -0,0 +1,10 @@
+/* PR middle-end/90263 */
+/* { dg-require-effective-target glibc } */
+
+int *f (int *p, int *q, long n)
+{
+  return __builtin_mempcpy (p, q, n);
+}
+
+/* { dg-final { scan-assembler "mempcpy" { target { i?86-*-* x86_64-*-* } } } } */
+/* { dg-final { scan-assembler "memcpy" { target { ! { i?86-*-* x86_64-*-* } } } } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 63bc2cc..3bd6e81 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -9313,6 +9313,17 @@ proc check_effective_target_arm_v8_3a_complex_neon_hw { } {
     } [add_options_for_arm_v8_3a_complex_neon ""]]
 }
 
+# Returns 1 if the target is using glibc, 0 otherwise.
+
+proc check_effective_target_glibc { } {
+    return [check_no_compiler_messages glibc_object assembly {
+  #include <stdlib.h>
+	#if !defined(__GLIBC__)
+	#error undefined
+	#endif
+    }]
+}
+
 # Return 1 if the target plus current options supports a vector
 # complex addition with rotate of half and single float modes, 0 otherwise.
 #