i386.h (MODE_NEEDED): Calls need UNINITIALIZED mode; add comment.

	* i386.h (MODE_NEEDED): Calls need UNINITIALIZED mode; add comment.
	(EMIT_MODE_SET): UNINITIALIZED mode needs no set.
	* i386.md (i387_cw): Add 'uninitialized' mode.

From-SVN: r87365

gcc/ChangeLog

 2004-09-11  Jan Hubicka  <jh@suse.cz>
 
+	* i386.h (MODE_NEEDED): Calls need UNINITIALIZED mode; add comment.
+	(EMIT_MODE_SET): UNINITIALIZED mode needs no set.
+	* i386.md (i387_cw): Add 'uninitialized' mode.
+
 	* profile.c (BB_TO_GCOV_INDEX): move more to the front.
 	(output_location): Break out from ....
 	(branch_prob): ... here; handle gcov output on trees.

gcc/config/i386/i386.h

@@ -2960,13 +2960,18 @@ extern rtx ix86_compare_op1;	/* operand 1 for comparisons */
    `OPTIMIZE_MODE_SWITCHING' is defined, you must define this macro to
    return an integer value not larger than the corresponding element
    in `NUM_MODES_FOR_MODE_SWITCHING', to denote the mode that ENTITY
-   must be switched into prior to the execution of INSN.  */
+   must be switched into prior to the execution of INSN. 
+   
+   The mode UNINITIALIZED is used to force re-load of possibly previously
+   stored control word after function call.  The mode ANY specify that
+   function has no requirements on the control word and make no changes
+   in the bits we are interested in.  */
 
 #define MODE_NEEDED(ENTITY, I)						\
   (GET_CODE (I) == CALL_INSN						\
    || (GET_CODE (I) == INSN && (asm_noperands (PATTERN (I)) >= 0 	\
 				|| GET_CODE (PATTERN (I)) == ASM_INPUT))\
-   ? I387_CW_ANY 							\
+   ? I387_CW_UNINITIALIZED						\
    : recog_memoized (I) < 0						\
    ? I387_CW_ANY 							\
    : get_attr_i387_cw (I))
@@ -2981,7 +2986,7 @@ extern rtx ix86_compare_op1;	/* operand 1 for comparisons */
    are to be inserted.  */
 
 #define EMIT_MODE_SET(ENTITY, MODE, HARD_REGS_LIVE) 			\
-  ((MODE) != I387_CW_ANY						\
+  ((MODE) != I387_CW_ANY && (MODE) != I387_CW_UNINITIALIZED		\
    ? emit_i387_cw_initialization (assign_386_stack_local (HImode, 1),	\
 				  assign_386_stack_local (HImode, 2),   \
 				  MODE), 0				\

gcc/config/i386/i386.md

@@ -431,7 +431,7 @@
 
 ;; Defines rounding mode of an FP operation.
 
-(define_attr "i387_cw" "floor,ceil,trunc,mask_pm,any"
+(define_attr "i387_cw" "floor,ceil,trunc,mask_pm,uninitialized,any"
   (const_string "any"))
 
 ;; Describe a user's asm statement.