target: Support heap-based trampolines

Enable -ftrampoline-impl=heap by default if we are on macOS 11
or later.

Co-Authored-By: Maxim Blinov <maxim.blinov@embecosm.com>
Co-Authored-By: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
Co-Authored-By: Iain Sandoe <iain@sandoe.co.uk>
gcc/ChangeLog:

	* config.gcc: Default to heap trampolines on macOS 11 and above.
	* config/i386/darwin.h: Define X86_CUSTOM_FUNCTION_TEST.
	* config/i386/i386.h: Define X86_CUSTOM_FUNCTION_TEST.
	* config/i386/i386.cc: Use X86_CUSTOM_FUNCTION_TEST.

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 0782cbc6e9154eb0aa5130e33097260ca4e419ea..606d3a8513eae1849b338ac22a28559f27fb958a 100644 (file)
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1171,6 +1171,17 @@ case ${target} in
   ;;
 esac
 
+# Figure out if we need to enable heap trampolines by default
+case ${target} in
+*-*-darwin2*)
+  # Currently, we do this for macOS 11 and above.
+  tm_defines="$tm_defines HEAP_TRAMPOLINES_INIT=1"
+  ;;
+*)
+  tm_defines="$tm_defines HEAP_TRAMPOLINES_INIT=0"
+  ;;
+esac
+
 case ${target} in
 aarch64*-*-elf | aarch64*-*-fuchsia* | aarch64*-*-rtems*)
        tm_file="${tm_file} elfos.h newlib-stdint.h"

diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h
index 588bd669bddc9726b5451d160a3a2b79865a3ef8..036eefbbb95f6723bbfd20687915f683d40be442 100644 (file)
--- a/gcc/config/i386/darwin.h
+++ b/gcc/config/i386/darwin.h
@@ -308,3 +308,9 @@ along with GCC; see the file COPYING3.  If not see
 #define CLEAR_INSN_CACHE(beg, end)                             \
   extern void sys_icache_invalidate(void *start, size_t len);  \
   sys_icache_invalidate ((beg), (size_t)((end)-(beg)))
+
+/* Disable custom function descriptors for Darwin when we have off-stack
+   trampolines.  */
+#undef X86_CUSTOM_FUNCTION_TEST
+#define X86_CUSTOM_FUNCTION_TEST \
+  (flag_trampolines && flag_trampoline_impl == TRAMPOLINE_IMPL_HEAP) ? 0 : 1

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 641e768033553be716299de01b158e403048382a..f4772e0cb69824aaf51a60f892ea7bf56bc152c8 100644 (file)
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -26287,7 +26287,7 @@ ix86_libgcc_floating_mode_supported_p
 #define TARGET_HARD_REGNO_SCRATCH_OK ix86_hard_regno_scratch_ok
 
 #undef TARGET_CUSTOM_FUNCTION_DESCRIPTORS
-#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 1
+#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS X86_CUSTOM_FUNCTION_TEST
 
 #undef TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID
 #define TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID ix86_addr_space_zero_address_valid

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 4dd26e35a3e8811a9de7537be60ee429b1e54c42..7e66fa095855c97d3db5f166412f162f9f45a7d8 100644 (file)
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -760,6 +760,12 @@ extern const char *host_detect_local_cpu (int argc, const char **argv);
 /* Minimum allocation boundary for the code of a function.  */
 #define FUNCTION_BOUNDARY 8
 
+/* We will and with this value to test if a custom function descriptor needs
+   a static chain.  The function boundary must the adjusted so that the bit
+   this represents is no longer part of the address.  0 Disables the custom
+   function descriptors.  */
+#define X86_CUSTOM_FUNCTION_TEST 1
+
 /* C++ stores the virtual bit in the lowest bit of function pointers.  */
 #define TARGET_PTRMEMFUNC_VBIT_LOCATION ptrmemfunc_vbit_in_pfn