diff options
Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 32 |
1 files changed, 12 insertions, 20 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index dbe3d1278f9..327e05d66e7 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -4424,10 +4424,6 @@ to return a nonzero value when it is required, the compiler will run out of spill registers and print a fatal error message. @end deftypefn -@deftypevr {Target Hook} {unsigned int} TARGET_FLAGS_REGNUM -If the target has a dedicated flags register, and it needs to use the post-reload comparison elimination pass, then this value should be set appropriately. -@end deftypevr - @node Scalar Return @subsection How Scalar Function Values Are Returned @cindex return values in registers @@ -5901,7 +5897,6 @@ interested in most macros in this section. @menu * CC0 Condition Codes:: Old style representation of condition codes. * MODE_CC Condition Codes:: Modern representation of condition codes. -* Cond Exec Macros:: Macros to control conditional execution. @end menu @node CC0 Condition Codes @@ -6014,10 +6009,11 @@ for comparisons whose argument is a @code{plus}: @smallexample #define SELECT_CC_MODE(OP,X,Y) \ - (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT \ - ? ((OP == EQ || OP == NE) ? CCFPmode : CCFPEmode) \ - : ((GET_CODE (X) == PLUS || GET_CODE (X) == MINUS \ - || GET_CODE (X) == NEG) \ + (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT \ + ? ((OP == LT || OP == LE || OP == GT || OP == GE) \ + ? CCFPEmode : CCFPmode) \ + : ((GET_CODE (X) == PLUS || GET_CODE (X) == MINUS \ + || GET_CODE (X) == NEG || GET_CODE (x) == ASHIFT) \ ? CC_NOOVmode : CCmode)) @end smallexample @@ -6060,10 +6056,11 @@ then @code{REVERSIBLE_CC_MODE (@var{mode})} must be zero. You need not define this macro if it would always returns zero or if the floating-point format is anything other than @code{IEEE_FLOAT_FORMAT}. For example, here is the definition used on the SPARC, where floating-point -inequality comparisons are always given @code{CCFPEmode}: +inequality comparisons are given either @code{CCFPEmode} or @code{CCFPmode}: @smallexample -#define REVERSIBLE_CC_MODE(MODE) ((MODE) != CCFPEmode) +#define REVERSIBLE_CC_MODE(MODE) \ + ((MODE) != CCFPEmode && (MODE) != CCFPmode) @end smallexample @end defmac @@ -6073,7 +6070,7 @@ comparison done in CC_MODE @var{mode}. The macro is used only in case @code{REVERSIBLE_CC_MODE (@var{mode})} is nonzero. Define this macro in case machine has some non-standard way how to reverse certain conditionals. For instance in case all floating point conditions are non-trapping, compiler may -freely convert unordered compares to ordered one. Then definition may look +freely convert unordered compares to ordered ones. Then definition may look like: @smallexample @@ -6111,14 +6108,9 @@ same. If they are, it returns that mode. If they are different, it returns @code{VOIDmode}. @end deftypefn -@node Cond Exec Macros -@subsection Macros to control conditional execution -@findex conditional execution -@findex predication - -There is one macro that may need to be defined for targets -supporting conditional execution, independent of how they -represent conditional branches. +@deftypevr {Target Hook} {unsigned int} TARGET_FLAGS_REGNUM +If the target has a dedicated flags register, and it needs to use the post-reload comparison elimination pass, then this value should be set appropriately. +@end deftypevr @node Costs @section Describing Relative Costs of Operations |