arch/loongarch/kernel/fpu.S | 94 +++++++++++++++++++++---------------- 1 file changed, 54 insertions(+), 40 deletions(-)
On LA464 movcf2gr is 7 times slower than movcf2fr + movfr2gr, and
movgr2cf is 15 times (!) slower than movgr2fr + movfr2cf.
On LA664 movcf2fr + movfr2gr has a similar performance with movcf2gr,
and movgr2fr + movfr2cf has a similar performance with movgr2cf.
To use FP registers in sc_save_fcc and sc_restore_fcc we need to save
FP/LSX/LASX registers before sc_save_fcc, and restore FP/LSX/LASX
registers after sc_restore_fcc.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
---
arch/loongarch/kernel/fpu.S | 94 +++++++++++++++++++++----------------
1 file changed, 54 insertions(+), 40 deletions(-)
diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S
index d53ab10f4644..ecb127f9a673 100644
--- a/arch/loongarch/kernel/fpu.S
+++ b/arch/loongarch/kernel/fpu.S
@@ -96,43 +96,57 @@
.endm
.macro sc_save_fcc base, tmp0, tmp1
- movcf2gr \tmp0, $fcc0
- move \tmp1, \tmp0
- movcf2gr \tmp0, $fcc1
- bstrins.d \tmp1, \tmp0, 15, 8
- movcf2gr \tmp0, $fcc2
- bstrins.d \tmp1, \tmp0, 23, 16
- movcf2gr \tmp0, $fcc3
- bstrins.d \tmp1, \tmp0, 31, 24
- movcf2gr \tmp0, $fcc4
- bstrins.d \tmp1, \tmp0, 39, 32
- movcf2gr \tmp0, $fcc5
- bstrins.d \tmp1, \tmp0, 47, 40
- movcf2gr \tmp0, $fcc6
- bstrins.d \tmp1, \tmp0, 55, 48
- movcf2gr \tmp0, $fcc7
- bstrins.d \tmp1, \tmp0, 63, 56
- EX st.d \tmp1, \base, 0
+ movcf2fr ft0, $fcc0
+ movcf2fr ft1, $fcc1
+ movfr2gr.s \tmp0, ft0
+ movfr2gr.s \tmp1, ft1
+ EX st.b \tmp0, \base, 0
+ EX st.b \tmp0, \base, 8
+ movcf2fr ft0, $fcc2
+ movcf2fr ft1, $fcc3
+ movfr2gr.s \tmp0, ft0
+ movfr2gr.s \tmp1, ft1
+ EX st.b \tmp0, \base, 16
+ EX st.b \tmp0, \base, 24
+ movcf2fr ft0, $fcc3
+ movcf2fr ft1, $fcc4
+ movfr2gr.s \tmp0, ft0
+ movfr2gr.s \tmp1, ft1
+ EX st.b \tmp0, \base, 32
+ EX st.b \tmp0, \base, 40
+ movcf2fr ft0, $fcc5
+ movcf2fr ft1, $fcc6
+ movfr2gr.s \tmp0, ft0
+ movfr2gr.s \tmp1, ft1
+ EX st.b \tmp0, \base, 48
+ EX st.b \tmp0, \base, 56
.endm
.macro sc_restore_fcc base, tmp0, tmp1
- EX ld.d \tmp0, \base, 0
- bstrpick.d \tmp1, \tmp0, 7, 0
- movgr2cf $fcc0, \tmp1
- bstrpick.d \tmp1, \tmp0, 15, 8
- movgr2cf $fcc1, \tmp1
- bstrpick.d \tmp1, \tmp0, 23, 16
- movgr2cf $fcc2, \tmp1
- bstrpick.d \tmp1, \tmp0, 31, 24
- movgr2cf $fcc3, \tmp1
- bstrpick.d \tmp1, \tmp0, 39, 32
- movgr2cf $fcc4, \tmp1
- bstrpick.d \tmp1, \tmp0, 47, 40
- movgr2cf $fcc5, \tmp1
- bstrpick.d \tmp1, \tmp0, 55, 48
- movgr2cf $fcc6, \tmp1
- bstrpick.d \tmp1, \tmp0, 63, 56
- movgr2cf $fcc7, \tmp1
+ EX ld.b \tmp0, \base, 0
+ EX ld.b \tmp1, \base, 8
+ movgr2fr.w ft0, \tmp0
+ movgr2fr.w ft1, \tmp1
+ movfr2cf $fcc0, ft0
+ movfr2cf $fcc1, ft1
+ EX ld.b \tmp0, \base, 16
+ EX ld.b \tmp1, \base, 24
+ movgr2fr.w ft0, \tmp0
+ movgr2fr.w ft1, \tmp1
+ movfr2cf $fcc2, ft0
+ movfr2cf $fcc3, ft1
+ EX ld.b \tmp0, \base, 32
+ EX ld.b \tmp1, \base, 40
+ movgr2fr.w ft0, \tmp0
+ movgr2fr.w ft1, \tmp1
+ movfr2cf $fcc4, ft0
+ movfr2cf $fcc5, ft1
+ EX ld.b \tmp0, \base, 48
+ EX ld.b \tmp1, \base, 56
+ movgr2fr.w ft0, \tmp0
+ movgr2fr.w ft1, \tmp1
+ movfr2cf $fcc6, ft0
+ movfr2cf $fcc7, ft1
.endm
.macro sc_save_fcsr base, tmp0
@@ -449,9 +463,9 @@ SYM_FUNC_END(_init_fpu)
* a2: fcsr
*/
SYM_FUNC_START(_save_fp_context)
- sc_save_fcc a1 t1 t2
sc_save_fcsr a2 t1
sc_save_fp a0
+ sc_save_fcc a1 t1 t2
li.w a0, 0 # success
jr ra
SYM_FUNC_END(_save_fp_context)
@@ -462,8 +476,8 @@ SYM_FUNC_END(_save_fp_context)
* a2: fcsr
*/
SYM_FUNC_START(_restore_fp_context)
- sc_restore_fp a0
sc_restore_fcc a1 t1 t2
+ sc_restore_fp a0
sc_restore_fcsr a2 t1
li.w a0, 0 # success
jr ra
@@ -475,9 +489,9 @@ SYM_FUNC_END(_restore_fp_context)
* a2: fcsr
*/
SYM_FUNC_START(_save_lsx_context)
- sc_save_fcc a1, t0, t1
sc_save_fcsr a2, t0
sc_save_lsx a0
+ sc_save_fcc a1, t0, t1
li.w a0, 0 # success
jr ra
SYM_FUNC_END(_save_lsx_context)
@@ -488,8 +502,8 @@ SYM_FUNC_END(_save_lsx_context)
* a2: fcsr
*/
SYM_FUNC_START(_restore_lsx_context)
- sc_restore_lsx a0
sc_restore_fcc a1, t1, t2
+ sc_restore_lsx a0
sc_restore_fcsr a2, t1
li.w a0, 0 # success
jr ra
@@ -501,9 +515,9 @@ SYM_FUNC_END(_restore_lsx_context)
* a2: fcsr
*/
SYM_FUNC_START(_save_lasx_context)
- sc_save_fcc a1, t0, t1
sc_save_fcsr a2, t0
sc_save_lasx a0
+ sc_save_fcc a1, t0, t1
li.w a0, 0 # success
jr ra
SYM_FUNC_END(_save_lasx_context)
@@ -514,8 +528,8 @@ SYM_FUNC_END(_save_lasx_context)
* a2: fcsr
*/
SYM_FUNC_START(_restore_lasx_context)
- sc_restore_lasx a0
sc_restore_fcc a1, t1, t2
+ sc_restore_lasx a0
sc_restore_fcsr a2, t1
li.w a0, 0 # success
jr ra
--
2.43.0Emmm, I want to keep the code simpler. :) Huacai On Thu, Dec 14, 2023 at 9:02 PM Xi Ruoyao <xry111@xry111.site> wrote: > > On LA464 movcf2gr is 7 times slower than movcf2fr + movfr2gr, and > movgr2cf is 15 times (!) slower than movgr2fr + movfr2cf. > > On LA664 movcf2fr + movfr2gr has a similar performance with movcf2gr, > and movgr2fr + movfr2cf has a similar performance with movgr2cf. > > To use FP registers in sc_save_fcc and sc_restore_fcc we need to save > FP/LSX/LASX registers before sc_save_fcc, and restore FP/LSX/LASX > registers after sc_restore_fcc. > > Signed-off-by: Xi Ruoyao <xry111@xry111.site> > --- > arch/loongarch/kernel/fpu.S | 94 +++++++++++++++++++++---------------- > 1 file changed, 54 insertions(+), 40 deletions(-) > > diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S > index d53ab10f4644..ecb127f9a673 100644 > --- a/arch/loongarch/kernel/fpu.S > +++ b/arch/loongarch/kernel/fpu.S > @@ -96,43 +96,57 @@ > .endm > > .macro sc_save_fcc base, tmp0, tmp1 > - movcf2gr \tmp0, $fcc0 > - move \tmp1, \tmp0 > - movcf2gr \tmp0, $fcc1 > - bstrins.d \tmp1, \tmp0, 15, 8 > - movcf2gr \tmp0, $fcc2 > - bstrins.d \tmp1, \tmp0, 23, 16 > - movcf2gr \tmp0, $fcc3 > - bstrins.d \tmp1, \tmp0, 31, 24 > - movcf2gr \tmp0, $fcc4 > - bstrins.d \tmp1, \tmp0, 39, 32 > - movcf2gr \tmp0, $fcc5 > - bstrins.d \tmp1, \tmp0, 47, 40 > - movcf2gr \tmp0, $fcc6 > - bstrins.d \tmp1, \tmp0, 55, 48 > - movcf2gr \tmp0, $fcc7 > - bstrins.d \tmp1, \tmp0, 63, 56 > - EX st.d \tmp1, \base, 0 > + movcf2fr ft0, $fcc0 > + movcf2fr ft1, $fcc1 > + movfr2gr.s \tmp0, ft0 > + movfr2gr.s \tmp1, ft1 > + EX st.b \tmp0, \base, 0 > + EX st.b \tmp0, \base, 8 > + movcf2fr ft0, $fcc2 > + movcf2fr ft1, $fcc3 > + movfr2gr.s \tmp0, ft0 > + movfr2gr.s \tmp1, ft1 > + EX st.b \tmp0, \base, 16 > + EX st.b \tmp0, \base, 24 > + movcf2fr ft0, $fcc3 > + movcf2fr ft1, $fcc4 > + movfr2gr.s \tmp0, ft0 > + movfr2gr.s \tmp1, ft1 > + EX st.b \tmp0, \base, 32 > + EX st.b \tmp0, \base, 40 > + movcf2fr ft0, $fcc5 > + movcf2fr ft1, $fcc6 > + movfr2gr.s \tmp0, ft0 > + movfr2gr.s \tmp1, ft1 > + EX st.b \tmp0, \base, 48 > + EX st.b \tmp0, \base, 56 > .endm > > .macro sc_restore_fcc base, tmp0, tmp1 > - EX ld.d \tmp0, \base, 0 > - bstrpick.d \tmp1, \tmp0, 7, 0 > - movgr2cf $fcc0, \tmp1 > - bstrpick.d \tmp1, \tmp0, 15, 8 > - movgr2cf $fcc1, \tmp1 > - bstrpick.d \tmp1, \tmp0, 23, 16 > - movgr2cf $fcc2, \tmp1 > - bstrpick.d \tmp1, \tmp0, 31, 24 > - movgr2cf $fcc3, \tmp1 > - bstrpick.d \tmp1, \tmp0, 39, 32 > - movgr2cf $fcc4, \tmp1 > - bstrpick.d \tmp1, \tmp0, 47, 40 > - movgr2cf $fcc5, \tmp1 > - bstrpick.d \tmp1, \tmp0, 55, 48 > - movgr2cf $fcc6, \tmp1 > - bstrpick.d \tmp1, \tmp0, 63, 56 > - movgr2cf $fcc7, \tmp1 > + EX ld.b \tmp0, \base, 0 > + EX ld.b \tmp1, \base, 8 > + movgr2fr.w ft0, \tmp0 > + movgr2fr.w ft1, \tmp1 > + movfr2cf $fcc0, ft0 > + movfr2cf $fcc1, ft1 > + EX ld.b \tmp0, \base, 16 > + EX ld.b \tmp1, \base, 24 > + movgr2fr.w ft0, \tmp0 > + movgr2fr.w ft1, \tmp1 > + movfr2cf $fcc2, ft0 > + movfr2cf $fcc3, ft1 > + EX ld.b \tmp0, \base, 32 > + EX ld.b \tmp1, \base, 40 > + movgr2fr.w ft0, \tmp0 > + movgr2fr.w ft1, \tmp1 > + movfr2cf $fcc4, ft0 > + movfr2cf $fcc5, ft1 > + EX ld.b \tmp0, \base, 48 > + EX ld.b \tmp1, \base, 56 > + movgr2fr.w ft0, \tmp0 > + movgr2fr.w ft1, \tmp1 > + movfr2cf $fcc6, ft0 > + movfr2cf $fcc7, ft1 > .endm > > .macro sc_save_fcsr base, tmp0 > @@ -449,9 +463,9 @@ SYM_FUNC_END(_init_fpu) > * a2: fcsr > */ > SYM_FUNC_START(_save_fp_context) > - sc_save_fcc a1 t1 t2 > sc_save_fcsr a2 t1 > sc_save_fp a0 > + sc_save_fcc a1 t1 t2 > li.w a0, 0 # success > jr ra > SYM_FUNC_END(_save_fp_context) > @@ -462,8 +476,8 @@ SYM_FUNC_END(_save_fp_context) > * a2: fcsr > */ > SYM_FUNC_START(_restore_fp_context) > - sc_restore_fp a0 > sc_restore_fcc a1 t1 t2 > + sc_restore_fp a0 > sc_restore_fcsr a2 t1 > li.w a0, 0 # success > jr ra > @@ -475,9 +489,9 @@ SYM_FUNC_END(_restore_fp_context) > * a2: fcsr > */ > SYM_FUNC_START(_save_lsx_context) > - sc_save_fcc a1, t0, t1 > sc_save_fcsr a2, t0 > sc_save_lsx a0 > + sc_save_fcc a1, t0, t1 > li.w a0, 0 # success > jr ra > SYM_FUNC_END(_save_lsx_context) > @@ -488,8 +502,8 @@ SYM_FUNC_END(_save_lsx_context) > * a2: fcsr > */ > SYM_FUNC_START(_restore_lsx_context) > - sc_restore_lsx a0 > sc_restore_fcc a1, t1, t2 > + sc_restore_lsx a0 > sc_restore_fcsr a2, t1 > li.w a0, 0 # success > jr ra > @@ -501,9 +515,9 @@ SYM_FUNC_END(_restore_lsx_context) > * a2: fcsr > */ > SYM_FUNC_START(_save_lasx_context) > - sc_save_fcc a1, t0, t1 > sc_save_fcsr a2, t0 > sc_save_lasx a0 > + sc_save_fcc a1, t0, t1 > li.w a0, 0 # success > jr ra > SYM_FUNC_END(_save_lasx_context) > @@ -514,8 +528,8 @@ SYM_FUNC_END(_save_lasx_context) > * a2: fcsr > */ > SYM_FUNC_START(_restore_lasx_context) > - sc_restore_lasx a0 > sc_restore_fcc a1, t1, t2 > + sc_restore_lasx a0 > sc_restore_fcsr a2, t1 > li.w a0, 0 # success > jr ra > -- > 2.43.0 >
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