Add function_abi.{h,cc}

This patch adds new structures and functions for handling
multiple ABIs in a translation unit.  The structures are:

- predefined_function_abi: describes a static, predefined ABI
- function_abi: describes either a predefined ABI or a local
  variant of one (e.g. taking -fipa-ra into account)

The patch adds functions for getting the ABI from a given type
or decl; a later patch will also add a function for getting the
ABI of the target of a call insn.

Although ABIs are about much more than call-clobber/saved choices,
I wanted to keep the name general in case we add more ABI-related
information in future.

2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* Makefile.in (OBJS): Add function-abi.o.
	(GTFILES): Add function-abi.h.
	* function-abi.cc: New file.
	* function-abi.h: Likewise.
	* emit-rtl.h (rtl_data::abi): New field.
	* function.c: Include function-abi.h.
	(prepare_function_start): Initialize crtl->abi.
	* read-rtl-function.c: Include regs.h and function-abi.h.
	(read_rtl_function_body): Initialize crtl->abi.
	(read_rtl_function_body_from_file_range): Likewise.
	* reginfo.c: Include function-abi.h.
	(init_reg_sets_1): Initialize default_function_abi.
	(globalize_reg): Call add_full_reg_clobber for each predefined ABI
	when making a register global.
	* target-globals.h (this_target_function_abi_info): Declare.
	(target_globals::function_abi_info): New field.
	(restore_target_globals): Copy it.
	* target-globals.c: Include function-abi.h.
	(default_target_globals): Initialize the function_abi_info field.
	(target_globals): Allocate it.
	(save_target_globals): Free it.

From-SVN: r276307

1 files changed, 8 insertions, 1 deletions

diff --git a/gcc/reginfo.c b/gcc/reginfo.c
index 22d0e68..a3fbbe6 100644
--- a/gcc/reginfo.c
+++ b/gcc/reginfo.c
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "reload.h"
 #include "output.h"
 #include "tree-pass.h"
+#include "function-abi.h"
 
 /* Maximum register number used in this function, plus one.  */
 
@@ -419,6 +420,8 @@ init_reg_sets_1 (void)
 	       }
 	  }
      }
+
+  default_function_abi.initialize (0, regs_invalidated_by_call);
 }
 
 /* Compute the table of register modes.
@@ -728,7 +731,11 @@ globalize_reg (tree decl, int i)
      appropriate regs_invalidated_by_call bit, even if it's already
      set in fixed_regs.  */
   if (i != STACK_POINTER_REGNUM)
-    SET_HARD_REG_BIT (regs_invalidated_by_call, i);
+    {
+      SET_HARD_REG_BIT (regs_invalidated_by_call, i);
+      for (unsigned int i = 0; i < NUM_ABI_IDS; ++i)
+	function_abis[i].add_full_reg_clobber (i);
+    }
 
   /* If already fixed, nothing else to do.  */
   if (fixed_regs[i])