Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 29.11.2017 13:31, Bin Meng wrote: Hi Stefan, On Wed, Nov 29, 2017 at 6:01 PM, Stefan Roesewrote: Hi Bin, On 29.11.2017 10:23, Bin Meng wrote: On Wed, Nov 29, 2017 at 4:42 PM, Stefan Roese wrote: Hi Bin, On 29.11.2017 09:30, Bin Meng wrote: I wrote some codes soemthing like: s64 a, b, c; c = a/b; The compiler will generate codes to call __divdi3. This works before your patch. Yes, I understand this. But right now, we don't have any code generating this error. And if this will happen at some time, I would prefer to investigate this code sequence introducing this division, to use the division functions / macros available in U-Boot (as mentioned above) and in the kernel instead. Here a short explanation, why this new version is preferred to the currently available functions pulled from libgcc: We are fixing an "ugly" Yocto build problem with this patch, related to 32bit binaries with 64bit toolchains (multilib) building by not relying on anything from libgcc. Please see this thread for some more details: https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html I hope this helps a bit to understand the motivation behind this patch. Thanks for the background. I am not familiar with yocto project, but is the build broken due to the gcc on the build host does not ship with multilib? Please take a look at the email thread mentioned above for a detailed explanation. Especially this post should answer your questions: https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html Now I see. Thank you. I am using a 64-bit host with gcc multilib, and there is no such build error observed. Right. This issue is only seen on Yocto builds (AFAIK). But again, I would really like to see U-Boot x86 being self-contained without any host libgcc dependencies as on other architectures as well. So to completely resolve such issue to make U-Boot self-contained, we should remove the reference to the host libgcc.a in arch/x86/lib/Makefile, and use CONFIG_USE_PRIVATE_GCC to include the build for div64.o. Thoughts? I was under the impression, that I already removed the host libgcc reference completely for x86 with my patch. But you are correct - there still is a reference in this Makefile which is used by the standalone code, AFAICT. Any quick idea on how to rid of this one as well? I believe we need change obj-y += div64.o to lib-$(CONFIG_USE_PRIVATE_LIBGCC) += div64.o To remove the libgcc dependency completely. Yep. Thanks. I've posted v3 with this additional removal. Thanks, Stefan ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Wed, Nov 29, 2017 at 6:01 PM, Stefan Roesewrote: > Hi Bin, > > > On 29.11.2017 10:23, Bin Meng wrote: >> >> On Wed, Nov 29, 2017 at 4:42 PM, Stefan Roese wrote: >>> >>> Hi Bin, >>> >>> On 29.11.2017 09:30, Bin Meng wrote: >>> >>> >>> >> I wrote some codes soemthing like: >> >> s64 a, b, c; >> c = a/b; >> >> The compiler will generate codes to call __divdi3. This works before >> your >> patch. > > > > > Yes, I understand this. But right now, we don't have any code > generating this error. And if this will happen at some time, I would > prefer to investigate this code sequence introducing this division, to > use the division functions / macros available in U-Boot (as mentioned > above) and in the kernel instead. > > Here a short explanation, why this new version is preferred to the > currently available functions pulled from libgcc: We are fixing an > "ugly" Yocto build problem with this patch, related to 32bit binaries > with 64bit toolchains (multilib) building by not relying on anything > from libgcc. Please see this thread for some more details: > > https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html > > I hope this helps a bit to understand the motivation behind this patch. > Thanks for the background. I am not familiar with yocto project, but is the build broken due to the gcc on the build host does not ship with multilib? >>> >>> >>> >>> Please take a look at the email thread mentioned above for a detailed >>> explanation. Especially this post should answer your questions: >>> >>> https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html >> >> >> Now I see. Thank you. >> >>> I am using a 64-bit host with gcc multilib, and there is no such build error observed. >>> >>> >>> >>> Right. This issue is only seen on Yocto builds (AFAIK). But again, >>> I would really like to see U-Boot x86 being self-contained without >>> any host libgcc dependencies as on other architectures as well. >> >> >> So to completely resolve such issue to make U-Boot self-contained, we >> should remove the reference to the host libgcc.a in >> arch/x86/lib/Makefile, and use CONFIG_USE_PRIVATE_GCC to include the >> build for div64.o. Thoughts? > > > I was under the impression, that I already removed the host libgcc > reference completely for x86 with my patch. But you are correct - there > still is a reference in this Makefile which is used by the standalone > code, AFAICT. > > Any quick idea on how to rid of this one as well? > I believe we need change obj-y += div64.o to lib-$(CONFIG_USE_PRIVATE_LIBGCC) += div64.o To remove the libgcc dependency completely. Regards, Bin ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 29.11.2017 10:23, Bin Meng wrote: On Wed, Nov 29, 2017 at 4:42 PM, Stefan Roesewrote: Hi Bin, On 29.11.2017 09:30, Bin Meng wrote: I wrote some codes soemthing like: s64 a, b, c; c = a/b; The compiler will generate codes to call __divdi3. This works before your patch. Yes, I understand this. But right now, we don't have any code generating this error. And if this will happen at some time, I would prefer to investigate this code sequence introducing this division, to use the division functions / macros available in U-Boot (as mentioned above) and in the kernel instead. Here a short explanation, why this new version is preferred to the currently available functions pulled from libgcc: We are fixing an "ugly" Yocto build problem with this patch, related to 32bit binaries with 64bit toolchains (multilib) building by not relying on anything from libgcc. Please see this thread for some more details: https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html I hope this helps a bit to understand the motivation behind this patch. Thanks for the background. I am not familiar with yocto project, but is the build broken due to the gcc on the build host does not ship with multilib? Please take a look at the email thread mentioned above for a detailed explanation. Especially this post should answer your questions: https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html Now I see. Thank you. I am using a 64-bit host with gcc multilib, and there is no such build error observed. Right. This issue is only seen on Yocto builds (AFAIK). But again, I would really like to see U-Boot x86 being self-contained without any host libgcc dependencies as on other architectures as well. So to completely resolve such issue to make U-Boot self-contained, we should remove the reference to the host libgcc.a in arch/x86/lib/Makefile, and use CONFIG_USE_PRIVATE_GCC to include the build for div64.o. Thoughts? I was under the impression, that I already removed the host libgcc reference completely for x86 with my patch. But you are correct - there still is a reference in this Makefile which is used by the standalone code, AFAICT. Any quick idea on how to rid of this one as well? Thanks, Stefan ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Wed, Nov 29, 2017 at 4:42 PM, Stefan Roesewrote: > Hi Bin, > > On 29.11.2017 09:30, Bin Meng wrote: > > > I wrote some codes soemthing like: s64 a, b, c; c = a/b; The compiler will generate codes to call __divdi3. This works before your patch. >>> >>> >>> >>> Yes, I understand this. But right now, we don't have any code >>> generating this error. And if this will happen at some time, I would >>> prefer to investigate this code sequence introducing this division, to >>> use the division functions / macros available in U-Boot (as mentioned >>> above) and in the kernel instead. >>> >>> Here a short explanation, why this new version is preferred to the >>> currently available functions pulled from libgcc: We are fixing an >>> "ugly" Yocto build problem with this patch, related to 32bit binaries >>> with 64bit toolchains (multilib) building by not relying on anything >>> from libgcc. Please see this thread for some more details: >>> >>> https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html >>> >>> I hope this helps a bit to understand the motivation behind this patch. >>> >> >> Thanks for the background. I am not familiar with yocto project, but >> is the build broken due to the gcc on the build host does not ship >> with multilib? > > > Please take a look at the email thread mentioned above for a detailed > explanation. Especially this post should answer your questions: > > https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html Now I see. Thank you. > >> I am using a 64-bit host with gcc multilib, and there is no such build >> error observed. > > > Right. This issue is only seen on Yocto builds (AFAIK). But again, > I would really like to see U-Boot x86 being self-contained without > any host libgcc dependencies as on other architectures as well. So to completely resolve such issue to make U-Boot self-contained, we should remove the reference to the host libgcc.a in arch/x86/lib/Makefile, and use CONFIG_USE_PRIVATE_GCC to include the build for div64.o. Thoughts? Regards, Bin ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 29.11.2017 09:30, Bin Meng wrote: I wrote some codes soemthing like: s64 a, b, c; c = a/b; The compiler will generate codes to call __divdi3. This works before your patch. Yes, I understand this. But right now, we don't have any code generating this error. And if this will happen at some time, I would prefer to investigate this code sequence introducing this division, to use the division functions / macros available in U-Boot (as mentioned above) and in the kernel instead. Here a short explanation, why this new version is preferred to the currently available functions pulled from libgcc: We are fixing an "ugly" Yocto build problem with this patch, related to 32bit binaries with 64bit toolchains (multilib) building by not relying on anything from libgcc. Please see this thread for some more details: https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html I hope this helps a bit to understand the motivation behind this patch. Thanks for the background. I am not familiar with yocto project, but is the build broken due to the gcc on the build host does not ship with multilib? Please take a look at the email thread mentioned above for a detailed explanation. Especially this post should answer your questions: https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html I am using a 64-bit host with gcc multilib, and there is no such build error observed. Right. This issue is only seen on Yocto builds (AFAIK). But again, I would really like to see U-Boot x86 being self-contained without any host libgcc dependencies as on other architectures as well. Thanks, Stefan ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Tue, Nov 28, 2017 at 12:34 AM, Stefan Roesewrote: > Hi Bin, > > > On 27.11.2017 10:46, Bin Meng wrote: >> >> On Fri, Nov 24, 2017 at 5:29 PM, Stefan Roese wrote: >>> >>> Hi Bin, >>> >>> >>> On 24.11.2017 09:29, Bin Meng wrote: On Mon, Nov 20, 2017 at 6:43 PM, Stefan Roese wrote: > > > Hi Bin, > > > On 20.11.2017 08:24, Bin Meng wrote: >> >> >> >> On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roese wrote: >>> >>> >>> >>> This patch removes the inclusion of the libgcc math functions and >>> replaces them by functions coded in C, taken from the coreboot >>> project. This makes U-Boot building more independent from the >>> toolchain >>> installed / available on the build system. >>> >>> The code taken from coreboot is authored from Vadim Bendebury >>> on 2014-11-28 and committed with commit >>> ID e63990ef [libpayload: provide basic 64bit division implementation] >>> (coreboot git repository located here [1]). >>> >>> I modified the code so that its checkpatch clean without any >>> functional changes. >>> >>> [1] git://github.com/coreboot/coreboot.git >>> >>> Signed-off-by: Stefan Roese >>> Cc: Simon Glass >>> Cc: Bin Meng >>> --- >>> v2: >>> - Added coreboot git repository link to commit message >>> >>> arch/x86/config.mk| 3 -- >>> arch/x86/lib/Makefile | 2 +- >>> arch/x86/lib/div64.c | 113 >>> ++ >>> arch/x86/lib/gcc.c| 29 - >>> 4 files changed, 114 insertions(+), 33 deletions(-) >>> create mode 100644 arch/x86/lib/div64.c >>> delete mode 100644 arch/x86/lib/gcc.c >>> >>> diff --git a/arch/x86/config.mk b/arch/x86/config.mk >>> index 8835dcf36f..472ada5490 100644 >>> --- a/arch/x86/config.mk >>> +++ b/arch/x86/config.mk >>> @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections >>> -fvisibility=hidden >>> PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions >>> PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) >>> >>> -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 >>> -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 >>> - >>> # This is used in the top-level Makefile which does not include >>> # PLATFORM_LDFLAGS >>> LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared >>> --no-undefined >>> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile >>> index fe00d7573f..d9b23f5cc4 100644 >>> --- a/arch/x86/lib/Makefile >>> +++ b/arch/x86/lib/Makefile >>> @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o >>> obj-y += early_cmos.o >>> obj-$(CONFIG_EFI) += efi/ >>> obj-y += e820.o >>> -obj-y += gcc.o >>> +obj-y += div64.o >>> obj-y += init_helpers.o >>> obj-y += interrupts.o >>> obj-y += lpc-uclass.o >>> diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c >>> new file mode 100644 >>> index 00..4efed74037 >>> --- /dev/null >>> +++ b/arch/x86/lib/div64.c >>> @@ -0,0 +1,113 @@ >>> +/* >>> + * This file is copied from the coreboot repository as part of >>> + * the libpayload project: >>> + * >>> + * Copyright 2014 Google Inc. >>> + * >>> + * SPDX-License-Identifier: BSD-3-Clause >>> + */ >>> + >>> +#include >>> + >>> +union overlay64 { >>> + u64 longw; >>> + struct { >>> + u32 lower; >>> + u32 higher; >>> + } words; >>> +}; >>> + >>> +u64 __ashldi3(u64 num, unsigned int shift) >>> +{ >>> + union overlay64 output; >>> + >>> + output.longw = num; >>> + if (shift >= 32) { >>> + output.words.higher = output.words.lower << (shift - >>> 32); >>> + output.words.lower = 0; >>> + } else { >>> + if (!shift) >>> + return num; >>> + output.words.higher = (output.words.higher << shift) >>> | >>> + (output.words.lower >> (32 - shift)); >>> + output.words.lower = output.words.lower << shift; >>> + } >>> + return output.longw; >>> +} >>> + >>> +u64 __lshrdi3(u64 num, unsigned int shift) >>> +{ >>> + union overlay64 output; >>> + >>> + output.longw = num; >>> + if (shift >= 32) { >>> + output.words.lower = output.words.higher >> (shift - >>> 32); >>> + output.words.higher = 0; >>> + } else { >>> +
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 27.11.2017 10:46, Bin Meng wrote: On Fri, Nov 24, 2017 at 5:29 PM, Stefan Roesewrote: Hi Bin, On 24.11.2017 09:29, Bin Meng wrote: On Mon, Nov 20, 2017 at 6:43 PM, Stefan Roese wrote: Hi Bin, On 20.11.2017 08:24, Bin Meng wrote: On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roese wrote: This patch removes the inclusion of the libgcc math functions and replaces them by functions coded in C, taken from the coreboot project. This makes U-Boot building more independent from the toolchain installed / available on the build system. The code taken from coreboot is authored from Vadim Bendebury on 2014-11-28 and committed with commit ID e63990ef [libpayload: provide basic 64bit division implementation] (coreboot git repository located here [1]). I modified the code so that its checkpatch clean without any functional changes. [1] git://github.com/coreboot/coreboot.git Signed-off-by: Stefan Roese Cc: Simon Glass Cc: Bin Meng --- v2: - Added coreboot git repository link to commit message arch/x86/config.mk| 3 -- arch/x86/lib/Makefile | 2 +- arch/x86/lib/div64.c | 113 ++ arch/x86/lib/gcc.c| 29 - 4 files changed, 114 insertions(+), 33 deletions(-) create mode 100644 arch/x86/lib/div64.c delete mode 100644 arch/x86/lib/gcc.c diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 8835dcf36f..472ada5490 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 - # This is used in the top-level Makefile which does not include # PLATFORM_LDFLAGS LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index fe00d7573f..d9b23f5cc4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o -obj-y += gcc.o +obj-y += div64.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.o diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c new file mode 100644 index 00..4efed74037 --- /dev/null +++ b/arch/x86/lib/div64.c @@ -0,0 +1,113 @@ +/* + * This file is copied from the coreboot repository as part of + * the libpayload project: + * + * Copyright 2014 Google Inc. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include + +union overlay64 { + u64 longw; + struct { + u32 lower; + u32 higher; + } words; +}; + +u64 __ashldi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.higher = output.words.lower << (shift - 32); + output.words.lower = 0; + } else { + if (!shift) + return num; + output.words.higher = (output.words.higher << shift) | + (output.words.lower >> (32 - shift)); + output.words.lower = output.words.lower << shift; + } + return output.longw; +} + +u64 __lshrdi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.lower = output.words.higher >> (shift - 32); + output.words.higher = 0; + } else { + if (!shift) + return num; + output.words.lower = output.words.lower >> shift | + (output.words.higher << (32 - shift)); + output.words.higher = output.words.higher >> shift; + } + return output.longw; +} + +#define MAX_32BIT_UINT u64)1) << 32) - 1) + +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) +{ + u64 result = 0; + + /* +* If divider is zero - let the rest of the system care about the +* exception. +*/ + if (!divider) + return 1 / (u32)divider; + + /* As an optimization, let's not use 64 bit division unless we must. */ + if (dividend <= MAX_32BIT_UINT) { + if (divider > MAX_32BIT_UINT) { + result = 0; + if (rem_p) + *rem_p = divider; + } else { + result = (u32)dividend / (u32)divider; + if (rem_p) + *rem_p = (u32)dividend % (u32)divider; + } +
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Fri, Nov 24, 2017 at 5:29 PM, Stefan Roesewrote: > Hi Bin, > > > On 24.11.2017 09:29, Bin Meng wrote: >> >> On Mon, Nov 20, 2017 at 6:43 PM, Stefan Roese wrote: >>> >>> Hi Bin, >>> >>> >>> On 20.11.2017 08:24, Bin Meng wrote: On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roese wrote: > > > This patch removes the inclusion of the libgcc math functions and > replaces them by functions coded in C, taken from the coreboot > project. This makes U-Boot building more independent from the toolchain > installed / available on the build system. > > The code taken from coreboot is authored from Vadim Bendebury > on 2014-11-28 and committed with commit > ID e63990ef [libpayload: provide basic 64bit division implementation] > (coreboot git repository located here [1]). > > I modified the code so that its checkpatch clean without any > functional changes. > > [1] git://github.com/coreboot/coreboot.git > > Signed-off-by: Stefan Roese > Cc: Simon Glass > Cc: Bin Meng > --- > v2: > - Added coreboot git repository link to commit message > >arch/x86/config.mk| 3 -- >arch/x86/lib/Makefile | 2 +- >arch/x86/lib/div64.c | 113 > ++ >arch/x86/lib/gcc.c| 29 - >4 files changed, 114 insertions(+), 33 deletions(-) >create mode 100644 arch/x86/lib/div64.c >delete mode 100644 arch/x86/lib/gcc.c > > diff --git a/arch/x86/config.mk b/arch/x86/config.mk > index 8835dcf36f..472ada5490 100644 > --- a/arch/x86/config.mk > +++ b/arch/x86/config.mk > @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections > -fvisibility=hidden >PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions >PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) > > -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 > -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 > - ># This is used in the top-level Makefile which does not include ># PLATFORM_LDFLAGS >LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared > --no-undefined > diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile > index fe00d7573f..d9b23f5cc4 100644 > --- a/arch/x86/lib/Makefile > +++ b/arch/x86/lib/Makefile > @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o >obj-y += early_cmos.o >obj-$(CONFIG_EFI) += efi/ >obj-y += e820.o > -obj-y += gcc.o > +obj-y += div64.o >obj-y += init_helpers.o >obj-y += interrupts.o >obj-y += lpc-uclass.o > diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c > new file mode 100644 > index 00..4efed74037 > --- /dev/null > +++ b/arch/x86/lib/div64.c > @@ -0,0 +1,113 @@ > +/* > + * This file is copied from the coreboot repository as part of > + * the libpayload project: > + * > + * Copyright 2014 Google Inc. > + * > + * SPDX-License-Identifier: BSD-3-Clause > + */ > + > +#include > + > +union overlay64 { > + u64 longw; > + struct { > + u32 lower; > + u32 higher; > + } words; > +}; > + > +u64 __ashldi3(u64 num, unsigned int shift) > +{ > + union overlay64 output; > + > + output.longw = num; > + if (shift >= 32) { > + output.words.higher = output.words.lower << (shift - > 32); > + output.words.lower = 0; > + } else { > + if (!shift) > + return num; > + output.words.higher = (output.words.higher << shift) | > + (output.words.lower >> (32 - shift)); > + output.words.lower = output.words.lower << shift; > + } > + return output.longw; > +} > + > +u64 __lshrdi3(u64 num, unsigned int shift) > +{ > + union overlay64 output; > + > + output.longw = num; > + if (shift >= 32) { > + output.words.lower = output.words.higher >> (shift - > 32); > + output.words.higher = 0; > + } else { > + if (!shift) > + return num; > + output.words.lower = output.words.lower >> shift | > + (output.words.higher << (32 - shift)); > + output.words.higher = output.words.higher >> shift; > + } > + return output.longw; > +} > + > +#define MAX_32BIT_UINT u64)1) << 32) - 1) > + > +static u64 _64bit_divide(u64 dividend, u64
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 24.11.2017 09:29, Bin Meng wrote: On Mon, Nov 20, 2017 at 6:43 PM, Stefan Roesewrote: Hi Bin, On 20.11.2017 08:24, Bin Meng wrote: On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roese wrote: This patch removes the inclusion of the libgcc math functions and replaces them by functions coded in C, taken from the coreboot project. This makes U-Boot building more independent from the toolchain installed / available on the build system. The code taken from coreboot is authored from Vadim Bendebury on 2014-11-28 and committed with commit ID e63990ef [libpayload: provide basic 64bit division implementation] (coreboot git repository located here [1]). I modified the code so that its checkpatch clean without any functional changes. [1] git://github.com/coreboot/coreboot.git Signed-off-by: Stefan Roese Cc: Simon Glass Cc: Bin Meng --- v2: - Added coreboot git repository link to commit message arch/x86/config.mk| 3 -- arch/x86/lib/Makefile | 2 +- arch/x86/lib/div64.c | 113 ++ arch/x86/lib/gcc.c| 29 - 4 files changed, 114 insertions(+), 33 deletions(-) create mode 100644 arch/x86/lib/div64.c delete mode 100644 arch/x86/lib/gcc.c diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 8835dcf36f..472ada5490 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 - # This is used in the top-level Makefile which does not include # PLATFORM_LDFLAGS LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index fe00d7573f..d9b23f5cc4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o -obj-y += gcc.o +obj-y += div64.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.o diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c new file mode 100644 index 00..4efed74037 --- /dev/null +++ b/arch/x86/lib/div64.c @@ -0,0 +1,113 @@ +/* + * This file is copied from the coreboot repository as part of + * the libpayload project: + * + * Copyright 2014 Google Inc. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include + +union overlay64 { + u64 longw; + struct { + u32 lower; + u32 higher; + } words; +}; + +u64 __ashldi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.higher = output.words.lower << (shift - 32); + output.words.lower = 0; + } else { + if (!shift) + return num; + output.words.higher = (output.words.higher << shift) | + (output.words.lower >> (32 - shift)); + output.words.lower = output.words.lower << shift; + } + return output.longw; +} + +u64 __lshrdi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.lower = output.words.higher >> (shift - 32); + output.words.higher = 0; + } else { + if (!shift) + return num; + output.words.lower = output.words.lower >> shift | + (output.words.higher << (32 - shift)); + output.words.higher = output.words.higher >> shift; + } + return output.longw; +} + +#define MAX_32BIT_UINT u64)1) << 32) - 1) + +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) +{ + u64 result = 0; + + /* +* If divider is zero - let the rest of the system care about the +* exception. +*/ + if (!divider) + return 1 / (u32)divider; + + /* As an optimization, let's not use 64 bit division unless we must. */ + if (dividend <= MAX_32BIT_UINT) { + if (divider > MAX_32BIT_UINT) { + result = 0; + if (rem_p) + *rem_p = divider; + } else { + result = (u32)dividend / (u32)divider; + if (rem_p) + *rem_p = (u32)dividend % (u32)divider; + } + return result; + } + + while (divider <= dividend) { + u64 locald = divider; + u64 limit =
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Mon, Nov 20, 2017 at 6:43 PM, Stefan Roesewrote: > Hi Bin, > > > On 20.11.2017 08:24, Bin Meng wrote: >> >> On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roese wrote: >>> >>> This patch removes the inclusion of the libgcc math functions and >>> replaces them by functions coded in C, taken from the coreboot >>> project. This makes U-Boot building more independent from the toolchain >>> installed / available on the build system. >>> >>> The code taken from coreboot is authored from Vadim Bendebury >>> on 2014-11-28 and committed with commit >>> ID e63990ef [libpayload: provide basic 64bit division implementation] >>> (coreboot git repository located here [1]). >>> >>> I modified the code so that its checkpatch clean without any >>> functional changes. >>> >>> [1] git://github.com/coreboot/coreboot.git >>> >>> Signed-off-by: Stefan Roese >>> Cc: Simon Glass >>> Cc: Bin Meng >>> --- >>> v2: >>> - Added coreboot git repository link to commit message >>> >>> arch/x86/config.mk| 3 -- >>> arch/x86/lib/Makefile | 2 +- >>> arch/x86/lib/div64.c | 113 >>> ++ >>> arch/x86/lib/gcc.c| 29 - >>> 4 files changed, 114 insertions(+), 33 deletions(-) >>> create mode 100644 arch/x86/lib/div64.c >>> delete mode 100644 arch/x86/lib/gcc.c >>> >>> diff --git a/arch/x86/config.mk b/arch/x86/config.mk >>> index 8835dcf36f..472ada5490 100644 >>> --- a/arch/x86/config.mk >>> +++ b/arch/x86/config.mk >>> @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections >>> -fvisibility=hidden >>> PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions >>> PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) >>> >>> -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 >>> -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 >>> - >>> # This is used in the top-level Makefile which does not include >>> # PLATFORM_LDFLAGS >>> LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared >>> --no-undefined >>> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile >>> index fe00d7573f..d9b23f5cc4 100644 >>> --- a/arch/x86/lib/Makefile >>> +++ b/arch/x86/lib/Makefile >>> @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o >>> obj-y += early_cmos.o >>> obj-$(CONFIG_EFI) += efi/ >>> obj-y += e820.o >>> -obj-y += gcc.o >>> +obj-y += div64.o >>> obj-y += init_helpers.o >>> obj-y += interrupts.o >>> obj-y += lpc-uclass.o >>> diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c >>> new file mode 100644 >>> index 00..4efed74037 >>> --- /dev/null >>> +++ b/arch/x86/lib/div64.c >>> @@ -0,0 +1,113 @@ >>> +/* >>> + * This file is copied from the coreboot repository as part of >>> + * the libpayload project: >>> + * >>> + * Copyright 2014 Google Inc. >>> + * >>> + * SPDX-License-Identifier: BSD-3-Clause >>> + */ >>> + >>> +#include >>> + >>> +union overlay64 { >>> + u64 longw; >>> + struct { >>> + u32 lower; >>> + u32 higher; >>> + } words; >>> +}; >>> + >>> +u64 __ashldi3(u64 num, unsigned int shift) >>> +{ >>> + union overlay64 output; >>> + >>> + output.longw = num; >>> + if (shift >= 32) { >>> + output.words.higher = output.words.lower << (shift - 32); >>> + output.words.lower = 0; >>> + } else { >>> + if (!shift) >>> + return num; >>> + output.words.higher = (output.words.higher << shift) | >>> + (output.words.lower >> (32 - shift)); >>> + output.words.lower = output.words.lower << shift; >>> + } >>> + return output.longw; >>> +} >>> + >>> +u64 __lshrdi3(u64 num, unsigned int shift) >>> +{ >>> + union overlay64 output; >>> + >>> + output.longw = num; >>> + if (shift >= 32) { >>> + output.words.lower = output.words.higher >> (shift - 32); >>> + output.words.higher = 0; >>> + } else { >>> + if (!shift) >>> + return num; >>> + output.words.lower = output.words.lower >> shift | >>> + (output.words.higher << (32 - shift)); >>> + output.words.higher = output.words.higher >> shift; >>> + } >>> + return output.longw; >>> +} >>> + >>> +#define MAX_32BIT_UINT u64)1) << 32) - 1) >>> + >>> +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) >>> +{ >>> + u64 result = 0; >>> + >>> + /* >>> +* If divider is zero - let the rest of the system care about the >>> +* exception. >>> +*/ >>> + if (!divider) >>> + return 1 / (u32)divider; >>> + >>> + /* As an optimization, let's not use 64 bit division unless we >>> must. */ >>> + if (dividend <= MAX_32BIT_UINT) { >>> + if
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Bin, On 20.11.2017 08:24, Bin Meng wrote: On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roesewrote: This patch removes the inclusion of the libgcc math functions and replaces them by functions coded in C, taken from the coreboot project. This makes U-Boot building more independent from the toolchain installed / available on the build system. The code taken from coreboot is authored from Vadim Bendebury on 2014-11-28 and committed with commit ID e63990ef [libpayload: provide basic 64bit division implementation] (coreboot git repository located here [1]). I modified the code so that its checkpatch clean without any functional changes. [1] git://github.com/coreboot/coreboot.git Signed-off-by: Stefan Roese Cc: Simon Glass Cc: Bin Meng --- v2: - Added coreboot git repository link to commit message arch/x86/config.mk| 3 -- arch/x86/lib/Makefile | 2 +- arch/x86/lib/div64.c | 113 ++ arch/x86/lib/gcc.c| 29 - 4 files changed, 114 insertions(+), 33 deletions(-) create mode 100644 arch/x86/lib/div64.c delete mode 100644 arch/x86/lib/gcc.c diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 8835dcf36f..472ada5490 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 - # This is used in the top-level Makefile which does not include # PLATFORM_LDFLAGS LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index fe00d7573f..d9b23f5cc4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o -obj-y += gcc.o +obj-y += div64.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.o diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c new file mode 100644 index 00..4efed74037 --- /dev/null +++ b/arch/x86/lib/div64.c @@ -0,0 +1,113 @@ +/* + * This file is copied from the coreboot repository as part of + * the libpayload project: + * + * Copyright 2014 Google Inc. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include + +union overlay64 { + u64 longw; + struct { + u32 lower; + u32 higher; + } words; +}; + +u64 __ashldi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.higher = output.words.lower << (shift - 32); + output.words.lower = 0; + } else { + if (!shift) + return num; + output.words.higher = (output.words.higher << shift) | + (output.words.lower >> (32 - shift)); + output.words.lower = output.words.lower << shift; + } + return output.longw; +} + +u64 __lshrdi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.lower = output.words.higher >> (shift - 32); + output.words.higher = 0; + } else { + if (!shift) + return num; + output.words.lower = output.words.lower >> shift | + (output.words.higher << (32 - shift)); + output.words.higher = output.words.higher >> shift; + } + return output.longw; +} + +#define MAX_32BIT_UINT u64)1) << 32) - 1) + +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) +{ + u64 result = 0; + + /* +* If divider is zero - let the rest of the system care about the +* exception. +*/ + if (!divider) + return 1 / (u32)divider; + + /* As an optimization, let's not use 64 bit division unless we must. */ + if (dividend <= MAX_32BIT_UINT) { + if (divider > MAX_32BIT_UINT) { + result = 0; + if (rem_p) + *rem_p = divider; + } else { + result = (u32)dividend / (u32)divider; + if (rem_p) + *rem_p = (u32)dividend % (u32)divider; + } + return result; + } + + while (divider <= dividend) { + u64 locald = divider; + u64 limit = __lshrdi3(dividend, 1); + int shifts = 0; + + while (locald <= limit) { + shifts++; +
Re: [U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
Hi Stefan, On Fri, Nov 17, 2017 at 2:02 PM, Stefan Roesewrote: > This patch removes the inclusion of the libgcc math functions and > replaces them by functions coded in C, taken from the coreboot > project. This makes U-Boot building more independent from the toolchain > installed / available on the build system. > > The code taken from coreboot is authored from Vadim Bendebury > on 2014-11-28 and committed with commit > ID e63990ef [libpayload: provide basic 64bit division implementation] > (coreboot git repository located here [1]). > > I modified the code so that its checkpatch clean without any > functional changes. > > [1] git://github.com/coreboot/coreboot.git > > Signed-off-by: Stefan Roese > Cc: Simon Glass > Cc: Bin Meng > --- > v2: > - Added coreboot git repository link to commit message > > arch/x86/config.mk| 3 -- > arch/x86/lib/Makefile | 2 +- > arch/x86/lib/div64.c | 113 > ++ > arch/x86/lib/gcc.c| 29 - > 4 files changed, 114 insertions(+), 33 deletions(-) > create mode 100644 arch/x86/lib/div64.c > delete mode 100644 arch/x86/lib/gcc.c > > diff --git a/arch/x86/config.mk b/arch/x86/config.mk > index 8835dcf36f..472ada5490 100644 > --- a/arch/x86/config.mk > +++ b/arch/x86/config.mk > @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden > PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions > PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) > > -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 > -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 > - > # This is used in the top-level Makefile which does not include > # PLATFORM_LDFLAGS > LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined > diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile > index fe00d7573f..d9b23f5cc4 100644 > --- a/arch/x86/lib/Makefile > +++ b/arch/x86/lib/Makefile > @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o > obj-y += early_cmos.o > obj-$(CONFIG_EFI) += efi/ > obj-y += e820.o > -obj-y += gcc.o > +obj-y += div64.o > obj-y += init_helpers.o > obj-y += interrupts.o > obj-y += lpc-uclass.o > diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c > new file mode 100644 > index 00..4efed74037 > --- /dev/null > +++ b/arch/x86/lib/div64.c > @@ -0,0 +1,113 @@ > +/* > + * This file is copied from the coreboot repository as part of > + * the libpayload project: > + * > + * Copyright 2014 Google Inc. > + * > + * SPDX-License-Identifier: BSD-3-Clause > + */ > + > +#include > + > +union overlay64 { > + u64 longw; > + struct { > + u32 lower; > + u32 higher; > + } words; > +}; > + > +u64 __ashldi3(u64 num, unsigned int shift) > +{ > + union overlay64 output; > + > + output.longw = num; > + if (shift >= 32) { > + output.words.higher = output.words.lower << (shift - 32); > + output.words.lower = 0; > + } else { > + if (!shift) > + return num; > + output.words.higher = (output.words.higher << shift) | > + (output.words.lower >> (32 - shift)); > + output.words.lower = output.words.lower << shift; > + } > + return output.longw; > +} > + > +u64 __lshrdi3(u64 num, unsigned int shift) > +{ > + union overlay64 output; > + > + output.longw = num; > + if (shift >= 32) { > + output.words.lower = output.words.higher >> (shift - 32); > + output.words.higher = 0; > + } else { > + if (!shift) > + return num; > + output.words.lower = output.words.lower >> shift | > + (output.words.higher << (32 - shift)); > + output.words.higher = output.words.higher >> shift; > + } > + return output.longw; > +} > + > +#define MAX_32BIT_UINT u64)1) << 32) - 1) > + > +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) > +{ > + u64 result = 0; > + > + /* > +* If divider is zero - let the rest of the system care about the > +* exception. > +*/ > + if (!divider) > + return 1 / (u32)divider; > + > + /* As an optimization, let's not use 64 bit division unless we must. > */ > + if (dividend <= MAX_32BIT_UINT) { > + if (divider > MAX_32BIT_UINT) { > + result = 0; > + if (rem_p) > + *rem_p = divider; > + } else { > + result = (u32)dividend / (u32)divider; > + if (rem_p) > + *rem_p = (u32)dividend % (u32)divider; > + } > + return result; > + } > + > +
[U-Boot] [PATCH v2] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones
This patch removes the inclusion of the libgcc math functions and replaces them by functions coded in C, taken from the coreboot project. This makes U-Boot building more independent from the toolchain installed / available on the build system. The code taken from coreboot is authored from Vadim Bendeburyon 2014-11-28 and committed with commit ID e63990ef [libpayload: provide basic 64bit division implementation] (coreboot git repository located here [1]). I modified the code so that its checkpatch clean without any functional changes. [1] git://github.com/coreboot/coreboot.git Signed-off-by: Stefan Roese Cc: Simon Glass Cc: Bin Meng --- v2: - Added coreboot git repository link to commit message arch/x86/config.mk| 3 -- arch/x86/lib/Makefile | 2 +- arch/x86/lib/div64.c | 113 ++ arch/x86/lib/gcc.c| 29 - 4 files changed, 114 insertions(+), 33 deletions(-) create mode 100644 arch/x86/lib/div64.c delete mode 100644 arch/x86/lib/gcc.c diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 8835dcf36f..472ada5490 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64) -LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 - # This is used in the top-level Makefile which does not include # PLATFORM_LDFLAGS LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index fe00d7573f..d9b23f5cc4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o -obj-y += gcc.o +obj-y += div64.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.o diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c new file mode 100644 index 00..4efed74037 --- /dev/null +++ b/arch/x86/lib/div64.c @@ -0,0 +1,113 @@ +/* + * This file is copied from the coreboot repository as part of + * the libpayload project: + * + * Copyright 2014 Google Inc. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include + +union overlay64 { + u64 longw; + struct { + u32 lower; + u32 higher; + } words; +}; + +u64 __ashldi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.higher = output.words.lower << (shift - 32); + output.words.lower = 0; + } else { + if (!shift) + return num; + output.words.higher = (output.words.higher << shift) | + (output.words.lower >> (32 - shift)); + output.words.lower = output.words.lower << shift; + } + return output.longw; +} + +u64 __lshrdi3(u64 num, unsigned int shift) +{ + union overlay64 output; + + output.longw = num; + if (shift >= 32) { + output.words.lower = output.words.higher >> (shift - 32); + output.words.higher = 0; + } else { + if (!shift) + return num; + output.words.lower = output.words.lower >> shift | + (output.words.higher << (32 - shift)); + output.words.higher = output.words.higher >> shift; + } + return output.longw; +} + +#define MAX_32BIT_UINT u64)1) << 32) - 1) + +static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p) +{ + u64 result = 0; + + /* +* If divider is zero - let the rest of the system care about the +* exception. +*/ + if (!divider) + return 1 / (u32)divider; + + /* As an optimization, let's not use 64 bit division unless we must. */ + if (dividend <= MAX_32BIT_UINT) { + if (divider > MAX_32BIT_UINT) { + result = 0; + if (rem_p) + *rem_p = divider; + } else { + result = (u32)dividend / (u32)divider; + if (rem_p) + *rem_p = (u32)dividend % (u32)divider; + } + return result; + } + + while (divider <= dividend) { + u64 locald = divider; + u64 limit = __lshrdi3(dividend, 1); + int shifts = 0; + + while (locald <= limit) { + shifts++; + locald = locald + locald; + } + result |= __ashldi3(1, shifts); +