runtime: use builtin memmove directly

    
    We can use the intrinsic memmove directly, without going through
    C.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/170004

	* go-gcc.cc (Gcc_backend::Gcc_backend): Define memmove builtin.

From-SVN: r271016

gcc/go/ChangeLog

+2019-05-08  Cherry Zhang  <cherryyz@google.com>
+
+	* go-gcc.cc (Gcc_backend::Gcc_backend): Define memmove builtin.
+
 2019-05-07  Cherry Zhang  <cherryyz@google.com>
 
 	* lang.opt (-fgo-debug-optimization): New option.

gcc/go/go-gcc.cc

@@ -604,6 +604,15 @@ Gcc_backend::Gcc_backend()
 						NULL_TREE),
 		       false, false);
 
+  // We use __builtin_memmove for copying data.
+  this->define_builtin(BUILT_IN_MEMMOVE, "__builtin_memmove", "memmove",
+		       build_function_type_list(void_type_node,
+						ptr_type_node,
+						const_ptr_type_node,
+						size_type_node,
+						NULL_TREE),
+		       false, false);
+
   // Used by runtime/internal/sys.
   this->define_builtin(BUILT_IN_CTZ, "__builtin_ctz", "ctz",
 		       build_function_type_list(integer_type_node,

gcc/go/gofrontend/MERGE

-0b4cf8ded107ccbfbd4af7f4e056f23f941d0f86
+3a9bccfbf4af1c756978c40967838d9f6a4e7a62
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/Makefile.am

@@ -461,7 +461,6 @@ runtime_files = \
 	runtime/go-memclr.c \
 	runtime/go-memcmp.c \
 	runtime/go-memequal.c \
-	runtime/go-memmove.c \
 	runtime/go-nanotime.c \
 	runtime/go-now.c \
 	runtime/go-nosys.c \

libgo/Makefile.in

@@ -245,16 +245,15 @@ am__objects_3 = runtime/aeshash.lo runtime/go-assert.lo \
 	runtime/go-ffi.lo runtime/go-fieldtrack.lo \
 	runtime/go-matherr.lo runtime/go-memclr.lo \
 	runtime/go-memcmp.lo runtime/go-memequal.lo \
-	runtime/go-memmove.lo runtime/go-nanotime.lo runtime/go-now.lo \
-	runtime/go-nosys.lo runtime/go-reflect-call.lo \
-	runtime/go-runtime-error.lo runtime/go-setenv.lo \
-	runtime/go-signal.lo runtime/go-strslice.lo \
-	runtime/go-typedesc-equal.lo runtime/go-unsafe-pointer.lo \
-	runtime/go-unsetenv.lo runtime/go-unwind.lo \
-	runtime/go-varargs.lo runtime/env_posix.lo runtime/panic.lo \
-	runtime/print.lo runtime/proc.lo runtime/runtime_c.lo \
-	runtime/stack.lo runtime/yield.lo $(am__objects_1) \
-	$(am__objects_2)
+	runtime/go-nanotime.lo runtime/go-now.lo runtime/go-nosys.lo \
+	runtime/go-reflect-call.lo runtime/go-runtime-error.lo \
+	runtime/go-setenv.lo runtime/go-signal.lo \
+	runtime/go-strslice.lo runtime/go-typedesc-equal.lo \
+	runtime/go-unsafe-pointer.lo runtime/go-unsetenv.lo \
+	runtime/go-unwind.lo runtime/go-varargs.lo \
+	runtime/env_posix.lo runtime/panic.lo runtime/print.lo \
+	runtime/proc.lo runtime/runtime_c.lo runtime/stack.lo \
+	runtime/yield.lo $(am__objects_1) $(am__objects_2)
 am_libgo_llgo_la_OBJECTS = $(am__objects_3)
 libgo_llgo_la_OBJECTS = $(am_libgo_llgo_la_OBJECTS)
 AM_V_lt = $(am__v_lt_@AM_V@)
@@ -882,7 +881,6 @@ runtime_files = \
 	runtime/go-memclr.c \
 	runtime/go-memcmp.c \
 	runtime/go-memequal.c \
-	runtime/go-memmove.c \
 	runtime/go-nanotime.c \
 	runtime/go-now.c \
 	runtime/go-nosys.c \
@@ -1337,8 +1335,6 @@ runtime/go-memcmp.lo: runtime/$(am__dirstamp) \
 	runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-memequal.lo: runtime/$(am__dirstamp) \
 	runtime/$(DEPDIR)/$(am__dirstamp)
-runtime/go-memmove.lo: runtime/$(am__dirstamp) \
-	runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-nanotime.lo: runtime/$(am__dirstamp) \
 	runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-now.lo: runtime/$(am__dirstamp) \
@@ -1431,7 +1427,6 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-memclr.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-memcmp.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-memequal.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-memmove.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-nanotime.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-nosys.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-now.Plo@am__quote@

libgo/go/runtime/stubs.go

@@ -100,6 +100,7 @@ func reflect_memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) {
 
 // memmove copies n bytes from "from" to "to".
 //go:noescape
+//extern __builtin_memmove
 func memmove(to, from unsafe.Pointer, n uintptr)
 
 //go:linkname reflect_memmove reflect.memmove

libgo/runtime/go-memmove.c

-/* go-memmove.c -- move one memory buffer to another
-
-   Copyright 2016 The Go Authors. All rights reserved.
-   Use of this source code is governed by a BSD-style
-   license that can be found in the LICENSE file.  */
-
-#include "runtime.h"
-
-void move(void *, void *, uintptr)
-  __asm__ (GOSYM_PREFIX "runtime.memmove");
-
-void
-move (void *p1, void *p2, uintptr len)
-{
-  __builtin_memmove (p1, p2, len);
-}