void DVaxpy32(int n, double y0[], double y1[], double y2[], double alpha[],
              double x0[], double x1[]) {
  register double a00, a01, a10, a11, a20, a21;
  register double x0i, x1i;
  int ii;
  a00 = alpha[0];
  a01 = alpha[1];
  a10 = alpha[2];
  a11 = alpha[3];
  a20 = alpha[4];
  a21 = alpha[5];
  for (ii = 0; ii < n; ii++) {
    x0i = x0[ii];
    x1i = x1[ii];
    y0[ii] += a00 * x0i + a01 * x1i;
    y1[ii] += a10 * x0i + a11 * x1i;
    y2[ii] += a20 * x0i + a21 * x1i;
  }
  return;
}


x86 assembly (clang, -O0):
<DVaxpy32>:
push   %rbp
mov    %rsp,%rbp
mov    0x10(%rbp),%rax
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    %rcx,-0x20(%rbp)
mov    %r8,-0x28(%rbp)
mov    %r9,-0x30(%rbp)
mov    -0x28(%rbp),%rax
movsd  (%rax),%xmm0
movsd  %xmm0,-0x38(%rbp)
mov    -0x28(%rbp),%rax
movsd  0x8(%rax),%xmm0
movsd  %xmm0,-0x40(%rbp)
mov    -0x28(%rbp),%rax
movsd  0x10(%rax),%xmm0
movsd  %xmm0,-0x48(%rbp)
mov    -0x28(%rbp),%rax
movsd  0x18(%rax),%xmm0
movsd  %xmm0,-0x50(%rbp)
mov    -0x28(%rbp),%rax
movsd  0x20(%rax),%xmm0
movsd  %xmm0,-0x58(%rbp)
mov    -0x28(%rbp),%rax
movsd  0x28(%rax),%xmm0
movsd  %xmm0,-0x60(%rbp)
movl   $0x0,-0x74(%rbp)
mov    -0x74(%rbp),%eax
cmp    -0x4(%rbp),%eax
jge    1241 <DVaxpy32+0x141>
mov    -0x30(%rbp),%rax
movslq -0x74(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x68(%rbp)
mov    0x10(%rbp),%rax
movslq -0x74(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x70(%rbp)
movsd  -0x38(%rbp),%xmm0
movsd  -0x68(%rbp),%xmm2
movsd  -0x40(%rbp),%xmm1
mulsd  -0x70(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movslq -0x74(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x48(%rbp),%xmm0
movsd  -0x68(%rbp),%xmm2
movsd  -0x50(%rbp),%xmm1
mulsd  -0x70(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x18(%rbp),%rax
movslq -0x74(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x58(%rbp),%xmm0
movsd  -0x68(%rbp),%xmm2
movsd  -0x60(%rbp),%xmm1
mulsd  -0x70(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movslq -0x74(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x74(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x74(%rbp)
jmp    1179 <DVaxpy32+0x79>
pop    %rbp
ret

x86 assembly (clang, -O2):
<DVaxpy32>:
test   %edi,%edi
jle    11a9 <DVaxpy32+0xa9>
mov    0x8(%rsp),%r10
movsd  (%r8),%xmm8
movsd  0x8(%r8),%xmm9
movsd  0x10(%r8),%xmm2
movsd  0x18(%r8),%xmm3
movsd  0x20(%r8),%xmm4
movsd  0x28(%r8),%xmm5
mov    %edi,%edi
xor    %eax,%eax
cs nopw 0x0(%rax,%rax,1)
xchg   %ax,%ax
movsd  (%r9,%rax,8),%xmm6
movsd  (%r10,%rax,8),%xmm7
movapd %xmm9,%xmm1
mulsd  %xmm7,%xmm1
movapd %xmm8,%xmm0
mulsd  %xmm6,%xmm0
addsd  %xmm1,%xmm0
addsd  (%rsi,%rax,8),%xmm0
movsd  %xmm0,(%rsi,%rax,8)
movapd %xmm3,%xmm0
mulsd  %xmm7,%xmm0
movapd %xmm2,%xmm1
mulsd  %xmm6,%xmm1
addsd  %xmm0,%xmm1
addsd  (%rdx,%rax,8),%xmm1
movsd  %xmm1,(%rdx,%rax,8)
mulsd  %xmm5,%xmm7
mulsd  %xmm4,%xmm6
addsd  %xmm7,%xmm6
addsd  (%rcx,%rax,8),%xmm6
movsd  %xmm6,(%rcx,%rax,8)
add    $0x1,%rax
cmp    %rax,%rdi
jne    1140 <DVaxpy32+0x40>
ret

LLVM IR (-O0):
define void @DVaxpy32(i32 %0, double* %1, double* %2, double* %3, double* %4, double* %5, double* %6) {
%8 = alloca i32
%9 = alloca double*
%10 = alloca double*
%11 = alloca double*
%12 = alloca double*
%13 = alloca double*
%14 = alloca double*
%15 = alloca double
%16 = alloca double
%17 = alloca double
%18 = alloca double
%19 = alloca double
%20 = alloca double
%21 = alloca double
%22 = alloca double
%23 = alloca i32
store i32 %0, i32* %8
store double* %1, double** %9
store double* %2, double** %10
store double* %3, double** %11
store double* %4, double** %12
store double* %5, double** %13
store double* %6, double** %14
%24 = load double*, double** %12
%25 = getelementptr inbounds double, double* %24, i64 0
%26 = load double, double* %25
store double %26, double* %15
%27 = load double*, double** %12
%28 = getelementptr inbounds double, double* %27, i64 1
%29 = load double, double* %28
store double %29, double* %16
%30 = load double*, double** %12
%31 = getelementptr inbounds double, double* %30, i64 2
%32 = load double, double* %31
store double %32, double* %17
%33 = load double*, double** %12
%34 = getelementptr inbounds double, double* %33, i64 3
%35 = load double, double* %34
store double %35, double* %18
%36 = load double*, double** %12
%37 = getelementptr inbounds double, double* %36, i64 4
%38 = load double, double* %37
store double %38, double* %19
%39 = load double*, double** %12
%40 = getelementptr inbounds double, double* %39, i64 5
%41 = load double, double* %40
store double %41, double* %20
store i32 0, i32* %23
br label %42
42: ; preds = %93, %7
%43 = load i32, i32* %23
%44 = load i32, i32* %8
%45 = icmp slt i32 %43, %44
br i1 %45, label %46, label %96
46: ; preds = %42
%47 = load double*, double** %13
%48 = load i32, i32* %23
%49 = sext i32 %48 to i64
%50 = getelementptr inbounds double, double* %47, i64 %49
%51 = load double, double* %50
store double %51, double* %21
%52 = load double*, double** %14
%53 = load i32, i32* %23
%54 = sext i32 %53 to i64
%55 = getelementptr inbounds double, double* %52, i64 %54
%56 = load double, double* %55
store double %56, double* %22
%57 = load double, double* %15
%58 = load double, double* %21
%59 = load double, double* %16
%60 = load double, double* %22
%61 = fmul double %59, %60
%62 = call double @llvm.fmuladd.f64(double %57, double %58, double %61)
%63 = load double*, double** %9
%64 = load i32, i32* %23
%65 = sext i32 %64 to i64
%66 = getelementptr inbounds double, double* %63, i64 %65
%67 = load double, double* %66
%68 = fadd double %67, %62
store double %68, double* %66
%69 = load double, double* %17
%70 = load double, double* %21
%71 = load double, double* %18
%72 = load double, double* %22
%73 = fmul double %71, %72
%74 = call double @llvm.fmuladd.f64(double %69, double %70, double %73)
%75 = load double*, double** %10
%76 = load i32, i32* %23
%77 = sext i32 %76 to i64
%78 = getelementptr inbounds double, double* %75, i64 %77
%79 = load double, double* %78
%80 = fadd double %79, %74
store double %80, double* %78
%81 = load double, double* %19
%82 = load double, double* %21
%83 = load double, double* %20
%84 = load double, double* %22
%85 = fmul double %83, %84
%86 = call double @llvm.fmuladd.f64(double %81, double %82, double %85)
%87 = load double*, double** %11
%88 = load i32, i32* %23
%89 = sext i32 %88 to i64
%90 = getelementptr inbounds double, double* %87, i64 %89
%91 = load double, double* %90
%92 = fadd double %91, %86
store double %92, double* %90
br label %93
93: ; preds = %46
%94 = load i32, i32* %23
%95 = add nsw i32 %94, 1
store i32 %95, i32* %23
br label %42
96: ; preds = %42
ret void
}

LLVM IR (-O2):
define void @DVaxpy32(i32 %0, double* nocapture %1, double* nocapture %2, double* nocapture %3, double* nocapture %4, double* nocapture %5, double* nocapture %6) {
%8 = load double, double* %4
%9 = getelementptr inbounds double, double* %4, i64 1
%10 = load double, double* %9
%11 = getelementptr inbounds double, double* %4, i64 2
%12 = load double, double* %11
%13 = getelementptr inbounds double, double* %4, i64 3
%14 = load double, double* %13
%15 = getelementptr inbounds double, double* %4, i64 4
%16 = load double, double* %15
%17 = getelementptr inbounds double, double* %4, i64 5
%18 = load double, double* %17
%19 = icmp sgt i32 %0, 0
br i1 %19, label %20, label %45
20: ; preds = %7
%21 = zext i32 %0 to i64
br label %22
22: ; preds = %20, %22
%23 = phi i64 [ 0, %20 ], [ %43, %22 ]
%24 = getelementptr inbounds double, double* %5, i64 %23
%25 = load double, double* %24
%26 = getelementptr inbounds double, double* %6, i64 %23
%27 = load double, double* %26
%28 = fmul double %10, %27
%29 = tail call double @llvm.fmuladd.f64(double %8, double %25, double %28)
%30 = getelementptr inbounds double, double* %1, i64 %23
%31 = load double, double* %30
%32 = fadd double %31, %29
store double %32, double* %30
%33 = fmul double %14, %27
%34 = tail call double @llvm.fmuladd.f64(double %12, double %25, double %33)
%35 = getelementptr inbounds double, double* %2, i64 %23
%36 = load double, double* %35
%37 = fadd double %34, %36
store double %37, double* %35
%38 = fmul double %18, %27
%39 = tail call double @llvm.fmuladd.f64(double %16, double %25, double %38)
%40 = getelementptr inbounds double, double* %3, i64 %23
%41 = load double, double* %40
%42 = fadd double %39, %41
store double %42, double* %40
%43 = add nuw nsw i64 %23, 1
%44 = icmp eq i64 %43, %21
br i1 %44, label %45, label %22
45: ; preds = %22, %7
ret void
}