(+ Jason) On Thu, 27 Aug 2020 at 20:31, Uros Bizjak <ubizjak@xxxxxxxxx> wrote: > > x86_64 zero extends 32bit operations, so for 64bit operands, > XORL r32,r32 is functionally equal to XORL r64,r64, but avoids > a REX prefix byte when legacy registers are used. > > Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > --- > arch/x86/crypto/curve25519-x86_64.c | 68 ++++++++++++++--------------- > 1 file changed, 34 insertions(+), 34 deletions(-) > > diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c > index 8acbb6584a37..a9edb6f8a0ba 100644 > --- a/arch/x86/crypto/curve25519-x86_64.c > +++ b/arch/x86/crypto/curve25519-x86_64.c > @@ -45,11 +45,11 @@ static inline u64 add_scalar(u64 *out, const u64 *f1, u64 f2) > > asm volatile( > /* Clear registers to propagate the carry bit */ > - " xor %%r8, %%r8;" > - " xor %%r9, %%r9;" > - " xor %%r10, %%r10;" > - " xor %%r11, %%r11;" > - " xor %1, %1;" > + " xor %%r8d, %%r8d;" > + " xor %%r9d, %%r9d;" > + " xor %%r10d, %%r10d;" > + " xor %%r11d, %%r11d;" > + " xor %k1, %k1;" > > /* Begin addition chain */ > " addq 0(%3), %0;" > @@ -93,7 +93,7 @@ static inline void fadd(u64 *out, const u64 *f1, const u64 *f2) > " cmovc %0, %%rax;" > > /* Step 2: Add carry*38 to the original sum */ > - " xor %%rcx, %%rcx;" > + " xor %%ecx, %%ecx;" > " add %%rax, %%r8;" > " adcx %%rcx, %%r9;" > " movq %%r9, 8(%1);" > @@ -165,28 +165,28 @@ static inline void fmul(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > > /* Compute src1[0] * src2 */ > " movq 0(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " movq %%r8, 0(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " movq %%r8, 0(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " movq %%r10, 8(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" > /* Compute src1[1] * src2 */ > " movq 8(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 8(%0), %%r8;" " movq %%r8, 8(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 8(%0), %%r8;" " movq %%r8, 8(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 16(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[2] * src2 */ > " movq 16(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 16(%0), %%r8;" " movq %%r8, 16(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 16(%0), %%r8;" " movq %%r8, 16(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 24(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[3] * src2 */ > " movq 24(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 24(%0), %%r8;" " movq %%r8, 24(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 24(%0), %%r8;" " movq %%r8, 24(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 32(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " movq %%rbx, 40(%0);" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " movq %%r14, 48(%0);" " mov $0, %%rax;" > @@ -200,7 +200,7 @@ static inline void fmul(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 32(%1), %%r8, %%r13;" > - " xor %3, %3;" > + " xor %k3, %k3;" > " adoxq 0(%1), %%r8;" > " mulxq 40(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > @@ -246,28 +246,28 @@ static inline void fmul2(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > > /* Compute src1[0] * src2 */ > " movq 0(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " movq %%r8, 0(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " movq %%r8, 0(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " movq %%r10, 8(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" > /* Compute src1[1] * src2 */ > " movq 8(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 8(%0), %%r8;" " movq %%r8, 8(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 8(%0), %%r8;" " movq %%r8, 8(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 16(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[2] * src2 */ > " movq 16(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 16(%0), %%r8;" " movq %%r8, 16(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 16(%0), %%r8;" " movq %%r8, 16(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 24(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[3] * src2 */ > " movq 24(%1), %%rdx;" > - " mulxq 0(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 24(%0), %%r8;" " movq %%r8, 24(%0);" > + " mulxq 0(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 24(%0), %%r8;" " movq %%r8, 24(%0);" > " mulxq 8(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 32(%0);" > " mulxq 16(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " movq %%rbx, 40(%0);" " mov $0, %%r8;" > " mulxq 24(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " movq %%r14, 48(%0);" " mov $0, %%rax;" > @@ -277,29 +277,29 @@ static inline void fmul2(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > > /* Compute src1[0] * src2 */ > " movq 32(%1), %%rdx;" > - " mulxq 32(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " movq %%r8, 64(%0);" > - " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " movq %%r10, 72(%0);" > + " mulxq 32(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " movq %%r8, 64(%0);" > + " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " movq %%r10, 72(%0);" > " mulxq 48(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" > " mulxq 56(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" > /* Compute src1[1] * src2 */ > " movq 40(%1), %%rdx;" > - " mulxq 32(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 72(%0), %%r8;" " movq %%r8, 72(%0);" > - " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 80(%0);" > + " mulxq 32(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 72(%0), %%r8;" " movq %%r8, 72(%0);" > + " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 80(%0);" > " mulxq 48(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 56(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[2] * src2 */ > " movq 48(%1), %%rdx;" > - " mulxq 32(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 80(%0), %%r8;" " movq %%r8, 80(%0);" > - " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 88(%0);" > + " mulxq 32(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 80(%0), %%r8;" " movq %%r8, 80(%0);" > + " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 88(%0);" > " mulxq 48(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " mov $0, %%r8;" > " mulxq 56(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" > /* Compute src1[3] * src2 */ > " movq 56(%1), %%rdx;" > - " mulxq 32(%3), %%r8, %%r9;" " xor %%r10, %%r10;" " adcxq 88(%0), %%r8;" " movq %%r8, 88(%0);" > - " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 96(%0);" > + " mulxq 32(%3), %%r8, %%r9;" " xor %%r10d, %%r10d;" " adcxq 88(%0), %%r8;" " movq %%r8, 88(%0);" > + " mulxq 40(%3), %%r10, %%r11;" " adox %%r9, %%r10;" " adcx %%rbx, %%r10;" " movq %%r10, 96(%0);" > " mulxq 48(%3), %%rbx, %%r13;" " adox %%r11, %%rbx;" " adcx %%r14, %%rbx;" " movq %%rbx, 104(%0);" " mov $0, %%r8;" > " mulxq 56(%3), %%r14, %%rdx;" " adox %%r13, %%r14;" " adcx %%rax, %%r14;" " movq %%r14, 112(%0);" " mov $0, %%rax;" > " adox %%rdx, %%rax;" " adcx %%r8, %%rax;" " movq %%rax, 120(%0);" > @@ -312,7 +312,7 @@ static inline void fmul2(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 32(%1), %%r8, %%r13;" > - " xor %3, %3;" > + " xor %k3, %k3;" > " adoxq 0(%1), %%r8;" > " mulxq 40(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > @@ -345,7 +345,7 @@ static inline void fmul2(u64 *out, const u64 *f1, const u64 *f2, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 96(%1), %%r8, %%r13;" > - " xor %3, %3;" > + " xor %k3, %k3;" > " adoxq 64(%1), %%r8;" > " mulxq 104(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > @@ -516,7 +516,7 @@ static inline void fsqr(u64 *out, const u64 *f, u64 *tmp) > > /* Step 1: Compute all partial products */ > " movq 0(%1), %%rdx;" /* f[0] */ > - " mulxq 8(%1), %%r8, %%r14;" " xor %%r15, %%r15;" /* f[1]*f[0] */ > + " mulxq 8(%1), %%r8, %%r14;" " xor %%r15d, %%r15d;" /* f[1]*f[0] */ > " mulxq 16(%1), %%r9, %%r10;" " adcx %%r14, %%r9;" /* f[2]*f[0] */ > " mulxq 24(%1), %%rax, %%rcx;" " adcx %%rax, %%r10;" /* f[3]*f[0] */ > " movq 24(%1), %%rdx;" /* f[3] */ > @@ -526,7 +526,7 @@ static inline void fsqr(u64 *out, const u64 *f, u64 *tmp) > " mulxq 16(%1), %%rax, %%rcx;" " mov $0, %%r14;" /* f[2]*f[1] */ > > /* Step 2: Compute two parallel carry chains */ > - " xor %%r15, %%r15;" > + " xor %%r15d, %%r15d;" > " adox %%rax, %%r10;" > " adcx %%r8, %%r8;" > " adox %%rcx, %%r11;" > @@ -563,7 +563,7 @@ static inline void fsqr(u64 *out, const u64 *f, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 32(%1), %%r8, %%r13;" > - " xor %%rcx, %%rcx;" > + " xor %%ecx, %%ecx;" > " adoxq 0(%1), %%r8;" > " mulxq 40(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > @@ -607,7 +607,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > asm volatile( > /* Step 1: Compute all partial products */ > " movq 0(%1), %%rdx;" /* f[0] */ > - " mulxq 8(%1), %%r8, %%r14;" " xor %%r15, %%r15;" /* f[1]*f[0] */ > + " mulxq 8(%1), %%r8, %%r14;" " xor %%r15d, %%r15d;" /* f[1]*f[0] */ > " mulxq 16(%1), %%r9, %%r10;" " adcx %%r14, %%r9;" /* f[2]*f[0] */ > " mulxq 24(%1), %%rax, %%rcx;" " adcx %%rax, %%r10;" /* f[3]*f[0] */ > " movq 24(%1), %%rdx;" /* f[3] */ > @@ -617,7 +617,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > " mulxq 16(%1), %%rax, %%rcx;" " mov $0, %%r14;" /* f[2]*f[1] */ > > /* Step 2: Compute two parallel carry chains */ > - " xor %%r15, %%r15;" > + " xor %%r15d, %%r15d;" > " adox %%rax, %%r10;" > " adcx %%r8, %%r8;" > " adox %%rcx, %%r11;" > @@ -647,7 +647,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > > /* Step 1: Compute all partial products */ > " movq 32(%1), %%rdx;" /* f[0] */ > - " mulxq 40(%1), %%r8, %%r14;" " xor %%r15, %%r15;" /* f[1]*f[0] */ > + " mulxq 40(%1), %%r8, %%r14;" " xor %%r15d, %%r15d;" /* f[1]*f[0] */ > " mulxq 48(%1), %%r9, %%r10;" " adcx %%r14, %%r9;" /* f[2]*f[0] */ > " mulxq 56(%1), %%rax, %%rcx;" " adcx %%rax, %%r10;" /* f[3]*f[0] */ > " movq 56(%1), %%rdx;" /* f[3] */ > @@ -657,7 +657,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > " mulxq 48(%1), %%rax, %%rcx;" " mov $0, %%r14;" /* f[2]*f[1] */ > > /* Step 2: Compute two parallel carry chains */ > - " xor %%r15, %%r15;" > + " xor %%r15d, %%r15d;" > " adox %%rax, %%r10;" > " adcx %%r8, %%r8;" > " adox %%rcx, %%r11;" > @@ -692,7 +692,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 32(%1), %%r8, %%r13;" > - " xor %%rcx, %%rcx;" > + " xor %%ecx, %%ecx;" > " adoxq 0(%1), %%r8;" > " mulxq 40(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > @@ -725,7 +725,7 @@ static inline void fsqr2(u64 *out, const u64 *f, u64 *tmp) > /* Step 1: Compute dst + carry == tmp_hi * 38 + tmp_lo */ > " mov $38, %%rdx;" > " mulxq 96(%1), %%r8, %%r13;" > - " xor %%rcx, %%rcx;" > + " xor %%ecx, %%ecx;" > " adoxq 64(%1), %%r8;" > " mulxq 104(%1), %%r9, %%rbx;" > " adcx %%r13, %%r9;" > -- > 2.26.2 >
