void glmGenerateReverseVector4d(double result[4], const double v[4]) {
  result[0] = -v[0];
  result[1] = -v[1];
  result[2] = -v[2];
  result[3] = -v[3];
}


x86 assembly (clang, -O0):
<glmGenerateReverseVector4d>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x10(%rbp),%rax
movsd  0x8(%rax),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x8(%rax)
mov    -0x10(%rbp),%rax
movsd  0x10(%rax),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x10(%rax)
mov    -0x10(%rbp),%rax
movsd  0x18(%rax),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x18(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<glmGenerateReverseVector4d>:
movsd  (%rsi),%xmm0
movaps 0xef5(%rip),%xmm1
xorps  %xmm1,%xmm0
movlps %xmm0,(%rdi)
movsd  0x8(%rsi),%xmm0
xorps  %xmm1,%xmm0
movlps %xmm0,0x8(%rdi)
movsd  0x10(%rsi),%xmm0
xorps  %xmm1,%xmm0
movlps %xmm0,0x10(%rdi)
movsd  0x18(%rsi),%xmm0
xorps  %xmm1,%xmm0
movlps %xmm0,0x18(%rdi)
ret

LLVM IR (-O0):
define void @glmGenerateReverseVector4d(double* %0, double* %1) {
%3 = alloca double*
%4 = alloca double*
store double* %0, double** %3
store double* %1, double** %4
%5 = load double*, double** %4
%6 = getelementptr inbounds double, double* %5, i64 0
%7 = load double, double* %6
%8 = fneg double %7
%9 = load double*, double** %3
%10 = getelementptr inbounds double, double* %9, i64 0
store double %8, double* %10
%11 = load double*, double** %4
%12 = getelementptr inbounds double, double* %11, i64 1
%13 = load double, double* %12
%14 = fneg double %13
%15 = load double*, double** %3
%16 = getelementptr inbounds double, double* %15, i64 1
store double %14, double* %16
%17 = load double*, double** %4
%18 = getelementptr inbounds double, double* %17, i64 2
%19 = load double, double* %18
%20 = fneg double %19
%21 = load double*, double** %3
%22 = getelementptr inbounds double, double* %21, i64 2
store double %20, double* %22
%23 = load double*, double** %4
%24 = getelementptr inbounds double, double* %23, i64 3
%25 = load double, double* %24
%26 = fneg double %25
%27 = load double*, double** %3
%28 = getelementptr inbounds double, double* %27, i64 3
store double %26, double* %28
ret void
}

LLVM IR (-O2):
define void @glmGenerateReverseVector4d(double* nocapture writeonly %0, double* nocapture %1) {
%3 = load double, double* %1
%4 = fneg double %3
store double %4, double* %0
%5 = getelementptr inbounds double, double* %1, i64 1
%6 = load double, double* %5
%7 = fneg double %6
%8 = getelementptr inbounds double, double* %0, i64 1
store double %7, double* %8
%9 = getelementptr inbounds double, double* %1, i64 2
%10 = load double, double* %9
%11 = fneg double %10
%12 = getelementptr inbounds double, double* %0, i64 2
store double %11, double* %12
%13 = getelementptr inbounds double, double* %1, i64 3
%14 = load double, double* %13
%15 = fneg double %14
%16 = getelementptr inbounds double, double* %0, i64 3
store double %15, double* %16
ret void
}