Prevent scheduling from interfering with the epilogue instructions, as soon

as any of the stack or frame pointers are modified.

Allow narrower-than-register types to be kept in registers in wider modes,
as was the case with gcc 3.

This now seems to produce reliable code with -O1. -O2 is not safe yet.

2 files changed, 29 insertions, 2 deletions

diff --git a/gnu/gcc/gcc/config/m88k/m88k.c b/gnu/gcc/gcc/config/m88k/m88k.c
index fa9925c9083..a140773a843 100644
--- a/gnu/gcc/gcc/config/m88k/m88k.c
+++ b/gnu/gcc/gcc/config/m88k/m88k.c
@@ -115,6 +115,12 @@ static void m88k_output_file_start (void);
 #undef TARGET_PROMOTE_PROTOTYPES
 #define TARGET_PROMOTE_PROTOTYPES hook_bool_tree_true
 
+#undef TARGET_PROMOTE_FUNCTION_ARGS
+#define TARGET_PROMOTE_FUNCTION_ARGS hook_bool_tree_true
+
+#undef TARGET_PROMOTE_FUNCTION_RETURN
+#define TARGET_PROMOTE_FUNCTION_RETURN hook_bool_tree_true
+
 #undef TARGET_SETUP_INCOMING_VARARGS
 #define TARGET_SETUP_INCOMING_VARARGS m88k_setup_incoming_varargs
 
@@ -1394,14 +1400,25 @@ void
 m88k_expand_epilogue (void)
 {
   if (frame_pointer_needed)
-    emit_add (stack_pointer_rtx, frame_pointer_rtx, -m88k_fp_offset);
+    {
+      emit_insn (gen_blockage ());
+      emit_add (stack_pointer_rtx, frame_pointer_rtx, -m88k_fp_offset);
+    }
 
   if (nregs || nxregs)
     preserve_registers (m88k_fp_offset + 4, 0);
 
   if (m88k_stack_size)
-    emit_add (stack_pointer_rtx, stack_pointer_rtx, m88k_stack_size);
+    {
+      emit_insn (gen_blockage ());
+      emit_add (stack_pointer_rtx, stack_pointer_rtx, m88k_stack_size);
+    }
 
+  /* This should not be necessary, but when there are several epilogues
+     in the function after the optimizer shuffles things around, the
+     extra epilogues will lack this extremely important instruction if
+     it is not explicitly generated. */
+  emit_insn (gen_blockage ());
   emit_insn (gen_indirect_jump (INCOMING_RETURN_ADDR_RTX));
 }
 
diff --git a/gnu/gcc/gcc/config/m88k/m88k.h b/gnu/gcc/gcc/config/m88k/m88k.h
index 82f232a8688..da96462c89b 100644
--- a/gnu/gcc/gcc/config/m88k/m88k.h
+++ b/gnu/gcc/gcc/config/m88k/m88k.h
@@ -209,6 +209,16 @@ extern enum processor_type m88k_cpu;
 
 /* A bit-field declared as `int' forces `int' alignment for the struct.  */
 #define PCC_BITFIELD_TYPE_MATTERS 1
+
+/* Define this macro if it is advisable to hold scalars in registers
+   in a wider mode than that declared by the program.  In such cases,
+   the value is constrained to be within the bounds of the declared
+   type, but kept valid in the wider mode.  The signedness of the
+   extension may differ from that of the type.  */
+#define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)	\
+  if (GET_MODE_CLASS (MODE) == MODE_INT		\
+      && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)	\
+    (MODE) = SImode;
 
 /*** Register Usage ***/