This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
> -----Original Message----- > From: Richard Sandiford [mailto:rdsandiford@googlemail.com] > Sent: Tuesday, March 05, 2013 4:06 PM > To: Moore, Catherine > Cc: gcc-patches@gcc.gnu.org; Rozycki, Maciej > Subject: Re: FW: [PATCH] [MIPS] microMIPS gcc support: > > We have a few internal-only undocumented constraints that aren't used > much, so we should be able to move them to the "Y" space instead. The > patch below does this for "T" and "U". Then we could use "U" for new, > longer constraints. > > > U<type><factor><bits> > > where <type> is: > > s for signed > u for unsigned > d for decremented unsigned (-1 ... N) > i for incremented unsigned (1 ... N) > > where <factor> is: > > b for "byte" (*1) > h for "halfwords" (*2) > w for "words" (*4) > d for "doublewords" (*8) -- useful for 64-bit MIPS16 but probably not > needed for 32-bit microMIPS > > and where <bits> is the number of bits. <type> and <factor> could be > replaced with an ad-hoc two-letter combination for special cases. > E.g. "Uas9" ("add stack") for ADDISUP. > > Just a suggestion though. I'm not saying these names are totally intuitive or > anything, but they should at least be better than arbitrary letters. > > Also, <bits> could be two digits if necessary, or we could just use hex digits. I extended this proposal a bit by: 1. Adding a <type> e for encoded. The constraint will start with Ue, when the operand is an encoded value. 2. I decided to use two digits for <bits>. 3. The ad-hoc combination is used for anything else. Patch is attached. WDYT? I'm still testing, but results so far look really good. Catherine
Attachment:
short-delay.cl
Description: short-delay.cl
Attachment:
short-delay.patch
Description: short-delay.patch
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |