+2002-06-30 Hans-Peter Nilsson <hp@bitrange.com>
+
+ * config/mmix/mmix.md ("return"): New pattern.
+ * config/mmix/mmix.h (TARGET_MASK_USE_RETURN_INSN)
+ (TARGET_USE_RETURN_INSN): New macros.
+ (TARGET_DEFAULT): Include TARGET_MASK_USE_RETURN_INSN.
+ (TARGET_SWITCHES): Add -msingle-exit and -mno-single-exit.
+ * config/mmix/mmix.c (MMIX_OUTPUT_REGNO): Fix spacing.
+ (MMIX_POP_ARGUMENT): New macro.
+ (mmix_target_asm_function_prologue): When no epilogue is executed,
+ just emit a blank line. Use MMIX_POP_ARGUMENT with final POP insn.
+ (mmix_print_operand) <case '.'>: New case.
+ (mmix_print_operand_punct_valid_p): Match '.'.
+ (mmix_use_simple_return): New function.
+ * config/mmix/mmix-protos.h (mmix_use_simple_return): Prototype.
+ * doc/invoke.texi (Option Summary) <MMIX Summary>: Add
+ -msingle-exit, -mno-single-exit.
+ (MMIX Options): Ditto.
+
2002-06-30 Aldy Hernandez <aldyh@redhat.com>
* config/i386/i386.c (ix86_init_mmx_sse_builtins): Fix typos.
increasing rL and clearing unused (unset) registers with lower numbers. */
#define MMIX_OUTPUT_REGNO(N) \
(TARGET_ABI_GNU \
- || (int) (N) < MMIX_RETURN_VALUE_REGNUM \
- || (int) (N) > MMIX_LAST_STACK_REGISTER_REGNUM \
+ || (int) (N) < MMIX_RETURN_VALUE_REGNUM \
+ || (int) (N) > MMIX_LAST_STACK_REGISTER_REGNUM \
? (N) : ((N) - MMIX_RETURN_VALUE_REGNUM \
+ cfun->machine->highest_saved_stack_register + 1))
+/* The %d in "POP %d,0". */
+#define MMIX_POP_ARGUMENT() \
+ ((! TARGET_ABI_GNU \
+ && current_function_return_rtx != NULL \
+ && ! current_function_returns_struct) \
+ ? (GET_CODE (current_function_return_rtx) == PARALLEL \
+ ? GET_NUM_ELEM (XVEC (current_function_return_rtx, 0)) : 1) \
+ : 0)
+
/* The canonical saved comparison operands for non-cc0 machines, set in
the compare expander. */
rtx mmix_compare_op0;
/* The first address to access is beyond the outgoing_args area. */
int offset = current_function_outgoing_args_size;
+ rtx insn = get_last_insn ();
+
+ /* If the last insn was a BARRIER, we don't have to write any code,
+ then all returns were covered by "return" insns. */
+ if (GET_CODE (insn) == NOTE)
+ insn = prev_nonnote_insn (insn);
+ if (insn
+ && (GET_CODE (insn) == BARRIER
+ /* We must make sure that the insn really is a "return" and
+ not a conditional branch. Try to match the return exactly,
+ and if it doesn't match, assume it is a conditional branch
+ (and output an epilogue). */
+ || (GET_CODE (insn) == JUMP_INSN
+ && GET_CODE (PATTERN (insn)) == RETURN)))
+ {
+ /* Emit an extra \n as is done with the normal epilogue. */
+ fputc ('\n', stream);
+ return;
+ }
+
/* Add the space for global non-register-stack registers.
It is assumed that the frame-pointer register can be one of these
registers, in which case it is excluded from the count when needed. */
/* The extra \n is so we have a blank line between the assembly code of
separate functions. */
- fprintf (stream, "\tPOP %d,0\n\n",
- (! TARGET_ABI_GNU
- && current_function_return_rtx != NULL
- && ! current_function_returns_struct)
- ? (GET_CODE (current_function_return_rtx) == PARALLEL
- ? GET_NUM_ELEM (XVEC (current_function_return_rtx, 0)) : 1)
- : 0);
+ fprintf (stream, "\tPOP %d,0\n\n", MMIX_POP_ARGUMENT ());
}
/* ASM_OUTPUT_MI_THUNK. */
}
return;
+ case '.':
+ /* For the %d in POP %d,0. */
+ fprintf (stream, "%d", MMIX_POP_ARGUMENT ());
+ return;
+
case 'B':
if (GET_CODE (x) != CONST_INT)
fatal_insn ("MMIX Internal: Expected a CONST_INT, not this", x);
int code ATTRIBUTE_UNUSED;
{
/* A '+' is used for branch prediction, similar to other ports. */
- return code == '+';
+ return code == '+'
+ /* A '.' is used for the %d in the POP %d,0 return insn. */
+ || code == '.';
}
/* PRINT_OPERAND_ADDRESS. */
Now MMIX's own functions. First the exported ones. */
+/* Non-zero when the function epilogue is simple enough that a single
+ "POP %d,0" should be used. */
+
+int
+mmix_use_simple_return ()
+{
+ int regno;
+
+ int stack_space_to_allocate
+ = (current_function_outgoing_args_size
+ + current_function_pretend_args_size
+ + get_frame_size () + 7) & ~7;
+
+ if (!TARGET_USE_RETURN_INSN || !reload_completed)
+ return 0;
+
+ for (regno = 255;
+ regno >= MMIX_FIRST_GLOBAL_REGNUM;
+ regno--)
+ /* Note that we assume that the frame-pointer-register is one of these
+ registers, in which case we don't count it here. */
+ if ((((regno != MMIX_FRAME_POINTER_REGNUM || !frame_pointer_needed)
+ && regs_ever_live[regno] && !call_used_regs[regno]))
+ || IS_MMIX_EH_RETURN_DATA_REG (regno))
+ return 0;
+
+ if (frame_pointer_needed)
+ stack_space_to_allocate += 8;
+
+ if (MMIX_CFUN_HAS_LANDING_PAD)
+ stack_space_to_allocate += 16;
+ else if (MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS)
+ stack_space_to_allocate += 8;
+
+ return stack_space_to_allocate == 0;
+}
+
/* Output an optimal sequence for setting a register to a specific
constant. Used in an alternative for const_ints in movdi, and when
using large stack-frame offsets.
#define TARGET_MASK_KNUTH_DIVISION 16
#define TARGET_MASK_TOPLEVEL_SYMBOLS 32
#define TARGET_MASK_BRANCH_PREDICT 64
+#define TARGET_MASK_USE_RETURN_INSN 128
/* We use the term "base address" since that's what Knuth uses. The base
address goes in a global register. When addressing, it's more like
#define TARGET_TOPLEVEL_SYMBOLS (target_flags & TARGET_MASK_TOPLEVEL_SYMBOLS)
#define TARGET_BRANCH_PREDICT (target_flags & TARGET_MASK_BRANCH_PREDICT)
#define TARGET_BASE_ADDRESSES (target_flags & TARGET_MASK_BASE_ADDRESSES)
+#define TARGET_USE_RETURN_INSN (target_flags & TARGET_MASK_USE_RETURN_INSN)
#define TARGET_DEFAULT \
- (TARGET_MASK_BRANCH_PREDICT | TARGET_MASK_BASE_ADDRESSES)
+ (TARGET_MASK_BRANCH_PREDICT | TARGET_MASK_BASE_ADDRESSES \
+ | TARGET_MASK_USE_RETURN_INSN)
/* FIXME: Provide a way to *load* the epsilon register. */
#define TARGET_SWITCHES \
N_("Use addresses that allocate global registers")}, \
{"no-base-addresses", -TARGET_MASK_BASE_ADDRESSES, \
N_("Do not use addresses that allocate global registers")}, \
+ {"single-exit", -TARGET_MASK_USE_RETURN_INSN, \
+ N_("Generate a single exit point for each function")}, \
+ {"no-single-exit", TARGET_MASK_USE_RETURN_INSN, \
+ N_("Do not generate a single exit point for each function")}, \
{"", TARGET_DEFAULT, ""}}
/* Unfortunately, this must not reference anything in "mmix.c". */
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