rs6000.c (print_operand): Fix comment and adjust.

	* config/rs6000/rs6000.c (print_operand) <D>: Fix comment and adjust.
	(rs6000_generate_compare): Tweak comments.
	* config/rs6000/rs6000.md (UNSPEC_MV_CR_GT): Fix comment.

From-SVN: r116041

gcc/ChangeLog

+2006-08-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* config/rs6000/rs6000.c (print_operand) <D>: Fix comment and adjust.
+	(rs6000_generate_compare): Tweak comments.
+	* config/rs6000/rs6000.md (UNSPEC_MV_CR_GT): Fix comment.
+
 2006-08-09  Alexandre Oliva  <aoliva@redhat.com>
 
 	* var-tracking.c (enum micro_operation_type): Add MO_COPY.

gcc/config/rs6000/rs6000.c

@@ -10283,13 +10283,14 @@ print_operand (FILE *file, rtx x, int code)
       return;
 
     case 'D':
-      /* Like 'J' but get to the EQ bit.  */
+      /* Like 'J' but get to the GT bit only.  */
       gcc_assert (GET_CODE (x) == REG);
 
-      /* Bit 1 is EQ bit.  */
-      i = 4 * (REGNO (x) - CR0_REGNO) + 2;
+      /* Bit 1 is GT bit.  */
+      i = 4 * (REGNO (x) - CR0_REGNO) + 1;
 
-      fprintf (file, "%d", i);
+      /* Add one for shift count in rlinm for scc.  */
+      fprintf (file, "%d", i + 1);
       return;
 
     case 'E':
@@ -11086,7 +11087,7 @@ rs6000_generate_compare (enum rtx_code code)
   /* First, the compare.  */
   compare_result = gen_reg_rtx (comp_mode);
 
-  /* SPE FP compare instructions on the GPRs.  Yuck!  */
+  /* E500 FP compare instructions on the GPRs.  Yuck!  */
   if ((TARGET_E500 && !TARGET_FPRS && TARGET_HARD_FLOAT)
       && rs6000_compare_fp_p)
     {
@@ -11096,8 +11097,8 @@ rs6000_generate_compare (enum rtx_code code)
       if (op_mode == VOIDmode)
 	op_mode = GET_MODE (rs6000_compare_op1);
 
-      /* Note: The E500 comparison instructions set the GT bit (x +
-	 1), on success.  This explains the mess.  */
+      /* The E500 FP compare instructions toggle the GT bit (CR bit 1) only.
+	 This explains the following mess.  */
 
       switch (code)
 	{

gcc/config/rs6000/rs6000.md

@@ -55,7 +55,7 @@
    (UNSPEC_TLSGOTTPREL		28)
    (UNSPEC_TLSTLS		29)
    (UNSPEC_FIX_TRUNC_TF		30)	; fadd, rounding towards zero
-   (UNSPEC_MV_CR_GT		31)	; move_from_CR_eq_bit
+   (UNSPEC_MV_CR_GT		31)	; move_from_CR_gt_bit
    (UNSPEC_STFIWX		32)
    (UNSPEC_POPCNTB		33)
    (UNSPEC_FRES			34)