On 25/06/14 17:50, Jakub Jelinek wrote: > On Wed, Jun 25, 2014 at 05:21:08PM +1000, Kugan wrote: >> The problem with SRP_POINTER 0, SRP_SIGNED 1, SRP_UNSIGNED 2, >> SRP_SIGNED_AND_UNSIGNED 3 (as I understand) is that, it will be >> incompatible with TYPE_UNSIGNED (tree) and defines of >> POINTER_EXTEND_UNSIGNED values. We will have to then translate while >> setting to SRP_* values . Also SUBREG_PROMOTED_SIGNED_P is now checked >> in some cases for != 0 (meaning SRP_POINTER or SRP_UNSIGNED) and in some >> cases > 0 (meaning SRP_UNSIGNED). >> >> Since our aim is to perform single bit checks, why don’t we just use >> this representation internally (i.e. _rtx->unchanging = 1 if SRP_SIGNED >> and _rtx->volatil = 1 if SRP_UNSIGNED). As for SUBREG_PROMOTED_SIGNED_P, >> we still have to return -1 or 1 depending on SRP_POINTER or SRP_UNSIGNED. > > Why don't you make SUBREG_PROMOTED_UNSIGNED_P just return 0/1 (i.e. the > single bit), and for places where it would like to match both > SRP_UNSIGNED and SRP_POINTER use SUBREG_PROMOTED_GET () & SRP_UNSIGNED > or so?
If we use SUBREG_PROMOTED_GET () & SRP_UNSIGNED, we will miss the case SRP_SIGNED_AND_UNSIGNED. Though this is not wrong, we might miss some optimization opportunities here. We can however use (SUBREG_PROMOTED_GET () != SRP_SIGNED) if you like this. Other option is to define another macro that explicilty says some think like SUBREG_PROMOTED_POINTER_OR_UNSIGNED_P. >> --- a/gcc/ifcvt.c >> +++ b/gcc/ifcvt.c >> @@ -1448,8 +1448,11 @@ noce_emit_cmove (struct noce_if_info *if_info, rtx x, >> enum rtx_code code, >> || byte_vtrue != byte_vfalse >> || (SUBREG_PROMOTED_VAR_P (vtrue) >> != SUBREG_PROMOTED_VAR_P (vfalse)) >> - || (SUBREG_PROMOTED_UNSIGNED_P (vtrue) >> - != SUBREG_PROMOTED_UNSIGNED_P (vfalse))) >> + || ((SUBREG_PROMOTED_UNSIGNED_P (vtrue) >> + != SUBREG_PROMOTED_UNSIGNED_P (vfalse)) >> + && (SUBREG_PROMOTED_SIGNED_P (vtrue) >> + != SUBREG_PROMOTED_SIGNED_P (vfalse)))) > > Shouldn't this be SUBREG_PROMOTED_GET (vtrue) != SUBREG_PROMOTED_GET (vfalse) > ? The reason why I checked like this to cover one side with SRP_SIGNED_AND_UNSIGNED and other with SRP_SIGNED or SRP_UNSIGNED. If we check SUBREG_PROMOTED_GET (vtrue) != SUBREG_PROMOTED_GET (vfalse) we will miss that. >> + >> +/* Predicate to check if RTX of SUBREG_PROMOTED_VAR_P() is promoted >> + for UNSIGNED type. In case of SRP_POINTER, SUBREG_PROMOTED_UNSIGNED_P >> + returns -1 as this is in most cases handled like unsigned extension, >> + except for generating instructions where special code is emitted for >> + (ptr_extend insns) on some architectures. */ >> #define SUBREG_PROMOTED_UNSIGNED_P(RTX) \ >> - ((RTL_FLAG_CHECK1 ("SUBREG_PROMOTED_UNSIGNED_P", (RTX), SUBREG)->volatil) >> \ >> - ? -1 : (int) (RTX)->unchanging) >> + ((((RTL_FLAG_CHECK1 ("SUBREG_PROMOTED_UNSIGNED_P", (RTX), >> SUBREG)->volatil)\ >> + + (RTX)->unchanging) == 0) ? -1 : ((RTX)->volatil == 1)) >> + >> +/* Checks if RTX of SUBREG_PROMOTED_VAR_P() is promotd for given SIGN. */ >> +#define SUBREG_CHECK_PROMOTED_SIGN(RTX, SIGN) \ > > Use space rather than tab. Also, why do we need this macro? > Can't you just use SUBREG_PROMOTED_GET () == sign ? I mean, sign in that > case is typically just 0 or 1. Again I wanted to cover SRP_SIGNED_AND_UNSIGNED as well in this case. Thanks, Kugan