From: David Gow Date: Sun, 6 Jul 2014 01:46:52 +0000 (+0800) Subject: now with fewer midnight-isms X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=commitdiff_plain;h=f06cfbc2d5986de9f9489e5cd9424231f310d471;ds=inline now with fewer midnight-isms --- diff --git a/src/div_digits_asm.s b/src/div_digits_asm.s index b11dd92..1ebf86f 100644 --- a/src/div_digits_asm.s +++ b/src/div_digits_asm.s @@ -2,27 +2,25 @@ .globl div_digits .type div_digits, @function -# div_digits(digits, div, size, res, rem) -# divides an arbint in digits by uint64 div into res with remainder rem -# Either res or rem may alias digits -# digits = rdi, div = rsx, size = rdx, res = rcx, rem = r8 +# div_digits(digits, div, size, res) +# divides an arbint in digits by uint64 div into res, returns remainder +# res may alias digits +# digits = rdi, div = rsx, size = rdx, res = rcx, div_digits: - movq %rdx, %r9 - leaq -8(%rdi,%r9,8), %rdi # We want to point to the end of the buffer (LSB) - leaq -8(%rcx,%r9,8), %rcx # We want to point to the end of the buffer (LSB) - leaq -8(%r8,%r9,8), %r8 # We want to point to the end of the buffer (LSB) + movq %rdx, %r8 + leaq -8(%rdi,%r8,8), %rdi # We want to point to the end of the buffer (LSB) + leaq -8(%rcx,%r8,8), %rcx # We want to point to the end of the buffer (LSB) movq \$0, %rdx loop: movq (%rdi), %rax divq %rsi # rdx:rax/rsi => rax, rdx:rax%rsi => rdx movq %rax, (%rcx) - movq %rdx, (%r8) - dec %r9 + dec %r8 leaq -8(%rdi), %rdi leaq -8(%rcx), %rcx - leaq -8(%r8), %r8 jnz loop end: + movq %rdx, %rax # return the remainder ret