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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, 9 Sep 2021 01:45:32 +0800 Greentime Hu wrote: > This patch replacees 2 instructions with 1 instruction to do the same thing > . rs1=x0 with rd != x0 is a special form of the instruction that sets vl to > MAXVL. Similarly, the vector.S is newly introduced in this patch set, so could this optimization be folded into the __vstate_save and __vstate_restore introduction patch? Or it's better to keep this optimizaion in commit log? > > Suggested-by: Andrew Waterman > Co-developed-by: Vincent Chen > Signed-off-by: Vincent Chen > Signed-off-by: Greentime Hu > --- > arch/riscv/kernel/vector.S | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/arch/riscv/kernel/vector.S b/arch/riscv/kernel/vector.S > index 4f0c5a166e4e..f7223c81b11a 100644 > --- a/arch/riscv/kernel/vector.S > +++ b/arch/riscv/kernel/vector.S > @@ -27,8 +27,7 @@ > #define x_vl t2 > #define x_vcsr t3 > #define incr t4 > -#define m_one t5 > -#define status t6 > +#define status t5 > > ENTRY(__vstate_save) > li status, SR_VS > @@ -38,8 +37,7 @@ ENTRY(__vstate_save) > csrr x_vtype, CSR_VTYPE > csrr x_vl, CSR_VL > csrr x_vcsr, CSR_VCSR > - li m_one, -1 > - vsetvli incr, m_one, e8, m8 > + vsetvli incr, x0, e8, m8 > vse8.v v0, (datap) > add datap, datap, incr > vse8.v v8, (datap) > @@ -61,8 +59,7 @@ ENTRY(__vstate_restore) > li status, SR_VS > csrs CSR_STATUS, status > > - li m_one, -1 > - vsetvli incr, m_one, e8, m8 > + vsetvli incr, x0, e8, m8 > vle8.v v0, (datap) > add datap, datap, incr > vle8.v v8, (datap) _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv