mmix.h: Improve comments.

	* config/mmix/mmix.h: Improve comments.
	(CPP_SPEC, CPP_PREDEFINES): Don't define.
	(TARGET_CPU_CPP_BUILTINS): Define.
	(CANONICALIZE_COMPARISON): Don't define, replace with comment.
	(PREDICATE_CODES) <"mmix_reg_or_8bit_or_256_operand">: Remove
	unused predicate.
	* config/mmix/mmix.c (MMIX_OUTPUT_REGNO): Add cast to avoid
	compiler warning.
	(mmix_constant_address_p): Remove another
	redundant test before case.
	(mmix_canonicalize_comparison): Remove unused function.
	(mmix_print_operand_address): Don't test and adjust for operand in
	non-canonical format.
	(mmix_reg_or_8bit_or_256_operand): Remove unused predicate.
	(mmix_gen_compare_reg): Don't use CANONICALIZE_COMPARISON.

From-SVN: r54474

3 files changed, 44 insertions, 77 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 13dbbfa..1bfeb34 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,21 @@
+2002-06-10  Hans-Peter Nilsson  <hp@bitrange.com>
+
+	* config/mmix/mmix.h: Improve comments.
+	(CPP_SPEC, CPP_PREDEFINES): Don't define.
+	(TARGET_CPU_CPP_BUILTINS): Define.
+	(CANONICALIZE_COMPARISON): Don't define, replace with comment.
+	(PREDICATE_CODES) <"mmix_reg_or_8bit_or_256_operand">: Remove
+	unused predicate.
+	* config/mmix/mmix.c (MMIX_OUTPUT_REGNO): Add cast to avoid
+	compiler warning.
+	(mmix_constant_address_p): Remove another
+	redundant test before case.
+	(mmix_canonicalize_comparison): Remove unused function.
+	(mmix_print_operand_address): Don't test and adjust for operand in
+	non-canonical format.
+	(mmix_reg_or_8bit_or_256_operand): Remove unused predicate.
+	(mmix_gen_compare_reg): Don't use CANONICALIZE_COMPARISON.
+
 2002-06-10  Zack Weinberg  <zack@codesourcery.com>
 
 	* config/m32r/m32r.h: Don't define SELECT_CC_MODE.
diff --git a/gcc/config/mmix/mmix.c b/gcc/config/mmix/mmix.c
index 6e66c9f..038a67a 100644
--- a/gcc/config/mmix/mmix.c
+++ b/gcc/config/mmix/mmix.c
@@ -71,8 +71,8 @@ Boston, MA 02111-1307, USA.  */
    increasing rL and clearing unused (unset) registers with lower numbers.  */
 #define MMIX_OUTPUT_REGNO(N)					\
  (TARGET_ABI_GNU 						\
-  || (N) < MMIX_RETURN_VALUE_REGNUM				\
-  || (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))
 
@@ -1454,10 +1454,6 @@ mmix_constant_address_p (x)
   /* When using "base addresses", anything constant goes.  */
   int constant_ok = TARGET_BASE_ADDRESSES != 0;
 
-  if (code == CONSTANT_P_RTX || code == HIGH)
-    /* FIXME: Don't know how to dissect these.  Avoid them for now.  */
-    return constant_ok;
-
   switch (code)
     {
     case LABEL_REF:
@@ -1620,37 +1616,6 @@ mmix_select_cc_mode (op, x, y)
   return CCmode;
 }
 
-/* CANONICALIZE_COMPARISON.
-   FIXME: Check if the number adjustments trig.  */
-
-void
-mmix_canonicalize_comparison (codep, op0p, op1p)
-     RTX_CODE * codep;
-     rtx * op0p ATTRIBUTE_UNUSED;
-     rtx * op1p;
-{
-  /* Change -1 to zero, if possible.  */
-  if ((*codep == LE || *codep == GT)
-      && GET_CODE (*op1p) == CONST_INT
-      && *op1p == constm1_rtx)
-    {
-      *codep = *codep == LE ? LT : GE;
-      *op1p = const0_rtx;
-    }
-
-  /* Fix up 256 to 255, if possible.  */
-  if ((*codep == LT || *codep == LTU || *codep == GE || *codep == GEU)
-      && GET_CODE (*op1p) == CONST_INT
-      && INTVAL (*op1p) == 256)
-    {
-      /* FIXME: Remove when I know this trigs.  */
-      fatal_insn ("oops, not debugged; fixing up value:", *op1p);
-      *codep = *codep == LT ? LE : *codep == LTU ? LEU : *codep
-	== GE ? GT : GTU;
-      *op1p = GEN_INT (255);
-    }
-}
-
 /* REVERSIBLE_CC_MODE.  */
 
 int
@@ -2360,14 +2325,6 @@ mmix_print_operand_address (stream, x)
       rtx x1 = XEXP (x, 0);
       rtx x2 = XEXP (x, 1);
 
-      /* Try swap the order.  FIXME: Do we need this?  */
-      if (! REG_P (x1))
-	{
-	  rtx tem = x1;
-	  x1 = x2;
-	  x2 = tem;
-	}
-
       if (REG_P (x1))
 	{
 	  fprintf (stream, "%s,", reg_names[MMIX_OUTPUT_REGNO (REGNO (x1))]);
@@ -2787,20 +2744,6 @@ mmix_reg_or_8bit_operand (op, mode)
 	&& CONST_OK_FOR_LETTER_P (INTVAL (op), 'I'));
 }
 
-/* True if this is a register or an int 0..256.  We include 256,
-   because it can be canonicalized into 255 for comparisons, which is
-   currently the only use of this predicate.
-   FIXME:  Check that this happens and does TRT.  */
-
-int
-mmix_reg_or_8bit_or_256_operand (op, mode)
-     rtx op;
-     enum machine_mode mode;
-{
-  return mmix_reg_or_8bit_operand (op, mode)
-    || (GET_CODE (op) == CONST_INT && INTVAL (op) == 256);
-}
-
 /* Returns zero if code and mode is not a valid condition from a
    compare-type insn.  Nonzero if it is.  The parameter op, if non-NULL,
    is the comparison of mode is CC-somethingmode.  */
@@ -2860,8 +2803,6 @@ mmix_gen_compare_reg (code, x, y)
   if (! REG_P (x) && ! REG_P (y))
     x = force_reg (mode, x);
 
-  CANONICALIZE_COMPARISON (code, x, y);
-
   /* If it's not quite right yet, put y in a register.  */
   if (! REG_P (y)
       && (GET_CODE (y) != CONST_INT
diff --git a/gcc/config/mmix/mmix.h b/gcc/config/mmix/mmix.h
index d553aea..4ac2c2f 100644
--- a/gcc/config/mmix/mmix.h
+++ b/gcc/config/mmix/mmix.h
@@ -105,14 +105,6 @@ struct machine_function GTY(())
 
 /* Node: Driver */
 
-/* When both ABI:s work, this is how we tell them apart in code.  The
-   GNU abi is implied the default.  Also implied in TARGET_DEFAULT.  */
-#define CPP_SPEC \
- "%{mabi=gnu:-D__MMIX_ABI_GNU__\
-    %{mabi=mmixware:\
-      %eoptions -mabi=mmixware and -mabi=gnu are mutually exclusive}}\
-  %{!mabi=gnu:-D__MMIX_ABI_MMIXWARE__}"
-
 /* User symbols are in the same name-space as built-in symbols, but we
    don't need the built-in symbols, so remove those and instead apply
    stricter operand checking.  Don't warn when expanding insns.  */
@@ -148,7 +140,18 @@ extern const char *mmix_cc1_ignored_option;
 /* Node: Run-time Target */
 
 /* Define __LONG_MAX__, since we're advised not to change glimits.h.  */
-#define CPP_PREDEFINES "-D__mmix__ -D__MMIX__ -D__LONG_MAX__=9223372036854775807L"
+#define TARGET_CPU_CPP_BUILTINS()				\
+  do								\
+    {								\
+      builtin_define ("__mmix__");				\
+      builtin_define ("__MMIX__");				\
+      builtin_define ("__LONG_MAX__=9223372036854775807L");	\
+      if (TARGET_ABI_GNU)					\
+	builtin_define ("__MMIX_ABI_GNU__");			\
+      else							\
+	builtin_define ("__MMIX_ABI_MMIXWARE__");		\
+    }								\
+  while (0)
 
 extern int target_flags;
 
@@ -167,7 +170,9 @@ extern int target_flags;
    a constant pool in global registers, code offseting from those
    registers (automatically causing a request for a suitable constant base
    address register) without having to know the specific register or the
-   specific offset.  */
+   specific offset.  The setback is that there's a limited number of
+   registers, and you'll not find out until link time whether you
+   should've compiled with -mno-base-addresses.  */
 #define TARGET_MASK_BASE_ADDRESSES 128
 
 /* FIXME: Get rid of this one.  */
@@ -855,8 +860,13 @@ typedef struct { int regs; int lib; int now_varargs; } CUMULATIVE_ARGS;
 #define SELECT_CC_MODE(OP, X, Y)		\
  mmix_select_cc_mode (OP, X, Y)
 
-#define CANONICALIZE_COMPARISON(CODE, OP0, OP1)		\
- mmix_canonicalize_comparison (&(CODE), &(OP0), &(OP1));
+/* A definition of CANONICALIZE_COMPARISON that changed LE and GT
+   comparisons with -1 to LT and GE respectively, and LT, LTU, GE or GEU
+   comparisons with 256 to 255 and LE, LEU, GT and GTU has been
+   ineffective; the code path for performing the changes did not trig for
+   neither the GCC test-suite nor ghostscript-6.52 nor Knuth's mmix.tar.gz
+   itself (core GCC functionality supposedly handling it) with sources
+   from 2002-06-06.  */
 
 #define REVERSIBLE_CC_MODE(MODE)		\
  mmix_reversible_cc_mode (MODE)
@@ -999,8 +1009,8 @@ typedef struct { int regs; int lib; int now_varargs; } CUMULATIVE_ARGS;
 
 
 /* Node: Macros for Initialization */
-/* We're compiling to ELF and linking to MMO; all ELF features that GCC
-   care for are there.  FIXME: Are they?  */
+/* We're compiling to ELF and linking to MMO; fundamental ELF features
+   that GCC depend on are there.  */
 
 /* These must be constant strings, since they're used in crtstuff.c.  */
 #define INIT_SECTION_ASM_OP "\t.section .init,\"ax\" ! mmixal-incompatible"
@@ -1127,8 +1137,6 @@ typedef struct { int regs; int lib; int now_varargs; } CUMULATIVE_ARGS;
    SUBREG, REG, PLUS}},				\
  {"mmix_reg_or_constant_operand",		\
   {CONST_INT, CONST_DOUBLE, SUBREG, REG}},	\
- {"mmix_reg_or_8bit_or_256_operand",		\
-  {CONST_INT, CONST_DOUBLE, SUBREG, REG}},	\
  {"mmix_reg_or_8bit_operand",			\
   {CONST_INT, CONST_DOUBLE, SUBREG, REG}},	\
  {"mmix_reg_or_0_operand",			\