| Message ID | 1322630640-13708-5-git-send-email-tony@bakeyournoodle.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | e32a03290c72773c304ffeebffed0a63c0a672ae |
| Delegated to: | Josh Boyer |
| Headers | show |
On Wed, 2011-11-30 at 16:23 +1100, Tony Breeds wrote: > Code copied from arch/powerpc/kernel/misc_32.S > > Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> > --- > arch/powerpc/boot/div64.S | 52 +++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 52 insertions(+), 0 deletions(-) Should we just link with libgcc ? :-) Cheers, Ben. > diff --git a/arch/powerpc/boot/div64.S b/arch/powerpc/boot/div64.S > index d271ab5..bbcb8a4 100644 > --- a/arch/powerpc/boot/div64.S > +++ b/arch/powerpc/boot/div64.S > @@ -57,3 +57,55 @@ __div64_32: > stw r8,4(r3) > mr r3,r6 # return the remainder in r3 > blr > + > +/* > + * Extended precision shifts. > + * > + * Updated to be valid for shift counts from 0 to 63 inclusive. > + * -- Gabriel > + * > + * R3/R4 has 64 bit value > + * R5 has shift count > + * result in R3/R4 > + * > + * ashrdi3: arithmetic right shift (sign propagation) > + * lshrdi3: logical right shift > + * ashldi3: left shift > + */ > + .globl __ashrdi3 > +__ashrdi3: > + subfic r6,r5,32 > + srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count > + addi r7,r5,32 # could be xori, or addi with -32 > + slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) > + rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 > + sraw r7,r3,r7 # t2 = MSW >> (count-32) > + or r4,r4,r6 # LSW |= t1 > + slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 > + sraw r3,r3,r5 # MSW = MSW >> count > + or r4,r4,r7 # LSW |= t2 > + blr > + > + .globl __ashldi3 > +__ashldi3: > + subfic r6,r5,32 > + slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count > + addi r7,r5,32 # could be xori, or addi with -32 > + srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count) > + slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32) > + or r3,r3,r6 # MSW |= t1 > + slw r4,r4,r5 # LSW = LSW << count > + or r3,r3,r7 # MSW |= t2 > + blr > + > + .globl __lshrdi3 > +__lshrdi3: > + subfic r6,r5,32 > + srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count > + addi r7,r5,32 # could be xori, or addi with -32 > + slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) > + srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32) > + or r4,r4,r6 # LSW |= t1 > + srw r3,r3,r5 # MSW = MSW >> count > + or r4,r4,r7 # LSW |= t2 > + blr
On Wed, Nov 30, 2011 at 12:48 AM, Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > On Wed, 2011-11-30 at 16:23 +1100, Tony Breeds wrote: >> Code copied from arch/powerpc/kernel/misc_32.S >> >> Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> >> --- >> arch/powerpc/boot/div64.S | 52 +++++++++++++++++++++++++++++++++++++++++++++ >> 1 files changed, 52 insertions(+), 0 deletions(-) > > Should we just link with libgcc ? :-) Please tell me you're joking. However, adding this code and wonderful and all but why do we need to add it? Changelog should say why. josh
On Wed, 2011-11-30 at 06:45 -0500, Josh Boyer wrote: > On Wed, Nov 30, 2011 at 12:48 AM, Benjamin Herrenschmidt > <benh@kernel.crashing.org> wrote: > > On Wed, 2011-11-30 at 16:23 +1100, Tony Breeds wrote: > >> Code copied from arch/powerpc/kernel/misc_32.S > >> > >> Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> > >> --- > >> arch/powerpc/boot/div64.S | 52 +++++++++++++++++++++++++++++++++++++++++++++ > >> 1 files changed, 52 insertions(+), 0 deletions(-) > > > > Should we just link with libgcc ? :-) > > Please tell me you're joking. Only half... I wonder what it would look like. Wouldn't ld only pickup what we use anyway ? > However, adding this code and wonderful and all but why do we need to > add it? Changelog should say why. Agreed. Cheers, Ben.
On 11/30/2011 02:21 PM, Benjamin Herrenschmidt wrote: > On Wed, 2011-11-30 at 06:45 -0500, Josh Boyer wrote: >> On Wed, Nov 30, 2011 at 12:48 AM, Benjamin Herrenschmidt >> <benh@kernel.crashing.org> wrote: >>> On Wed, 2011-11-30 at 16:23 +1100, Tony Breeds wrote: >>>> Code copied from arch/powerpc/kernel/misc_32.S >>>> >>>> Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> >>>> --- >>>> arch/powerpc/boot/div64.S | 52 +++++++++++++++++++++++++++++++++++++++++++++ >>>> 1 files changed, 52 insertions(+), 0 deletions(-) >>> >>> Should we just link with libgcc ? :-) >> >> Please tell me you're joking. > > Only half... I wonder what it would look like. Wouldn't ld only pickup > what we use anyway ? We do it in U-Boot... Only problem I see is that it would need to be built as soft-float, and apparently that isn't supported by gcc on 64-bit ppc. Unfortunately there's isn't a "no float" mode. -Scott
On Wed, Nov 30, 2011 at 06:45:37AM -0500, Josh Boyer wrote: > However, adding this code and wonderful and all but why do we need to > add it? Changelog should say why. Okay changelog updated to: powerpc/boot: Add extended precision shifts to the boot wrapper. The upcoming currituck patches will need to do 64-bit shifts which will fail with undefined symbol without this patch. I looked at linking against libgcc but we can't guarantee that libgcc was compiled with soft-float. Also Using ../lib/div64.S or ../kernel/misc_32.S, this will break the build as the .o's need to be built with different flags for the bootwrapper vs the kernel. So for now the easiest option is to just copy code from arch/powerpc/kernel/misc_32.S I don't think this code changes too often ;P Yours Tony
diff --git a/arch/powerpc/boot/div64.S b/arch/powerpc/boot/div64.S index d271ab5..bbcb8a4 100644 --- a/arch/powerpc/boot/div64.S +++ b/arch/powerpc/boot/div64.S @@ -57,3 +57,55 @@ __div64_32: stw r8,4(r3) mr r3,r6 # return the remainder in r3 blr + +/* + * Extended precision shifts. + * + * Updated to be valid for shift counts from 0 to 63 inclusive. + * -- Gabriel + * + * R3/R4 has 64 bit value + * R5 has shift count + * result in R3/R4 + * + * ashrdi3: arithmetic right shift (sign propagation) + * lshrdi3: logical right shift + * ashldi3: left shift + */ + .globl __ashrdi3 +__ashrdi3: + subfic r6,r5,32 + srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count + addi r7,r5,32 # could be xori, or addi with -32 + slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) + rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 + sraw r7,r3,r7 # t2 = MSW >> (count-32) + or r4,r4,r6 # LSW |= t1 + slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 + sraw r3,r3,r5 # MSW = MSW >> count + or r4,r4,r7 # LSW |= t2 + blr + + .globl __ashldi3 +__ashldi3: + subfic r6,r5,32 + slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count + addi r7,r5,32 # could be xori, or addi with -32 + srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count) + slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32) + or r3,r3,r6 # MSW |= t1 + slw r4,r4,r5 # LSW = LSW << count + or r3,r3,r7 # MSW |= t2 + blr + + .globl __lshrdi3 +__lshrdi3: + subfic r6,r5,32 + srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count + addi r7,r5,32 # could be xori, or addi with -32 + slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) + srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32) + or r4,r4,r6 # LSW |= t1 + srw r3,r3,r5 # MSW = MSW >> count + or r4,r4,r7 # LSW |= t2 + blr
Code copied from arch/powerpc/kernel/misc_32.S Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> --- arch/powerpc/boot/div64.S | 52 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 52 insertions(+), 0 deletions(-)