>-----Original Message----- >From: pixman-boun...@lists.freedesktop.org >[mailto:pixman-boun...@lists.freedesktop.org] On Behalf >Of Shiyou Yin >Sent: Monday, March 9, 2020 9:43 PM >To: 'Matt Turner' >Cc: 'pixman' >Subject: Re: [Pixman] [PATCH v2] build: improve control logic for enabling MMI. > >>-----Original Message----- >>From: Matt Turner [mailto:matts...@gmail.com] >>Sent: Monday, March 9, 2020 9:00 AM >>To: Shiyou Yin >>Cc: pixman >>Subject: Re: [Pixman] [PATCH v2] build: improve control logic for enabling >>MMI. >> >>Thank you for the patch! >> >>On Fri, Mar 6, 2020 at 3:28 AM Shiyou Yin <yinshiyou...@loongson.cn> wrote: >>> >>> From: Yin Shiyou <yinshiyou-hf@loongson> >> >>Should be yinshiyou-hf@loongson*.cn*? > >Yes, will update. > >>> >>> 1. Replace LS_CFLAGS with MMI_CFLAGS to express its intention more >>> accurately. >>> LS_CFLAGS is still available, but it is not recommended. >> >>I'm not aware of any reasons why LS_CFLAGS needs to stay for >>compatibility. Do we know of any distros that set it to override the >>-march=... value? > >No, keep LS_CFLAGS is just considering that users may be used to it. > >> >>> 2. Improve the control logic for enabling MMI. >>> >>> Three essential conditions for enabling MMI: >>> 1) user have not specify --disable-loongson-mmi. >>> 2) MMI options has been specified by MMI_CFLAGS,CC or compiler's default >>> setting. >>> 3) compiler supports these MMI options. >>> --- >>> configure.ac | 69 >>> ++++++++++++++++++++++++++++++++++++++++-------------------- >> >>We should also update meson.build. I expect/hope that the autotools >>build system will go away sometime in the future. > >Will update. > >> >>I'm not sure I entirely understand the patch. I understand that the >>objective is to make it possible to easily build pixman for Loongson3A >>and use the pixman-mmx.c optimizations. > >It's my original goal. In my first patch, I replaced '-march=loongson2f' >with -mloongson-mmi directly. But it raised objections, Yunqiang said it will >cause break on 2F for the different opcode on 2F and 3A. I tried to find a 2F >to verify this, but I havn't found yet. > >>I think it's currently possible to build pixman on mips without >>specifying -march=loongson* in CFLAGS and it will enable the >>pixman-mmx.c paths and choose them at runtime. Is part of the goal to >>keep that working? If so, could we just use the -mloongson-mmi flag to >>compile pixman-mmx.c? > >Yes, from last year, compiler has add '-mloongson-mmi' to support MMI, >It's not recommended to use -march=* to build MMI any more. >What we worry about is -march=loongson2f and -mloongson-mmi will generate >different opcode.(This is not verified yet.) > >>Or does that flag mean the Loongson3A variants of the instructions? >>What happens if you compile with -march=loongson2f -mloongson-mmi? >>Does GCC generate instructions compatible with 2F or 3A? > >I am still trying to find out a 2F to verify this. >If -mloongson-mmi works well on 2F, maybe we can revert to the first version >of my patch. >If -mloongson-mmi caused break of 2F, then this patch may be a suitable option. > Hi, Matt I haven't found an available 2F environment(hardware+ os+ buildtools) to verify yet. But according to the compiler team of loongson, opcode of MMI are consitant on 2F and 3a. So far, I have submitted two proposals: Proposal A: just replace '-march=loongson2f' with '-mloongson-mmi'. Proposal B: improve the hole control logic for enabling MMI.
In fact, Proposal B is equivalent to deleting the default settings for LS_CFLAGS directly. So, I have simplified it。Both patch are in the attachment. Considering loongson compiler team has said that opcode of MMI are consitant on 2F and 3a, I prefer to choose proposal A. please help to merge this patch.
proposal_A_0001-configure.ac-use-mloongson-mmi-for-Loongson-MMI.patch
Description: Binary data
proposal_B_0001-configure.ac-Delete-the-default-setting-of-LS_CFLAGS.patch
Description: Binary data
_______________________________________________ Pixman mailing list Pixman@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/pixman
