Pages 36-37 of lecture notes "08-machine-data.pdf" shows how xmm registers are used for simple floating point arithmetic such as fadd, dadd, an dincr which increments *p, a pointer to double variable by value v.

For Wed-section you have to follow the aforementioned pages.

For both sections, read 3.11 Floating-Point code.

Write a C function for the following assembly. cvtsd2ss converts scalar double precision number (a double number) to scalar single precision (a float number) while cvtss2sd converts scalar single precision number (a float number) to scalar double precision (a double number).

 unknown1: subss %xmm1, %xmm0 ret 

 unknown2: subsd %xmm1, %xmm0 ret 

 unknown3: movaps %xmm0, %xmm1 cvtsd2ss (%rdi), %xmm0 addss %xmm0, %xmm1 cvtss2sd %xmm1, %xmm2 movsd %xmm2, (%rdi) ret 

 unknown4: movsd (%rdi), %xmm1 movapd %xmm1, %xmm2 subsd %xmm0, %xmm2 movsd %xmm2, (%rdi) movapd %xmm1, %xmm0 ret 

 unknown5: pxor %xmm0, %xmm0 movl $0, %eax jmp .L13 .L14: movss (%rdx,%rax,4), %xmm1 mulss (%rsi,%rax,4), %xmm1 addss %xmm1, %xmm0 addq $1, %rax .L13: cmpq %rdi, %rax jb .L14 rep ret 

 unknown6: pxor %xmm0, %xmm0 movl $0, %eax jmp .L10 .L11: movsd (%rdx,%rax,8), %xmm1 mulsd (%rsi,%rax,8), %xmm1 addsd %xmm1, %xmm0 addq $1, %rax .L10: cmpq %rdi, %rax jb .L11 rep ret