Julia vectorization

gistfile1.txt

julia> f(x) = for i = 1:length(x); @inbounds x[i] *= 2; end
# methods for generic function f
f(x) at none:1

julia> disassemble(f, (Matrix{Float64},))

define void @julia_f(i8**) {
top:
  %1 = getelementptr i8** %0, i64 2, !dbg !3364
  %2 = load i8** %1, align 8, !dbg !3364
  %3 = icmp slt i8* %2, inttoptr (i64 1 to i8*), !dbg !3369
  br i1 %3, label %L2, label %if.lr.ph, !dbg !3369

if.lr.ph:                                         ; preds = %top
  %4 = ptrtoint i8* %2 to i64, !dbg !3364
  %5 = getelementptr i8** %0, i64 1, !dbg !3364
  %6 = load i8** %5, align 8, !dbg !3364
  %7 = bitcast i8* %6 to double*, !dbg !3370
  %8 = icmp sgt i64 %4, 1
  %smax = select i1 %8, i64 %4, i64 1
  %n.mod.vf = urem i64 %smax, 6
  %cmp.zero = icmp eq i64 %smax, %n.mod.vf
  br i1 %cmp.zero, label %middle.block, label %vector.ph

vector.ph:                                        ; preds = %if.lr.ph
  %n.vec = sub i64 %smax, %n.mod.vf
  %end.idx.rnd.down = add i64 %n.vec, 1
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 1, %vector.ph ], [ %index.next, %vector.body ]
  %9 = add i64 %index, -1
  %10 = getelementptr double* %7, i64 %9, !dbg !3370
  %11 = bitcast double* %10 to <2 x double>*
  %wide.load = load <2 x double>* %11, align 8
  %.sum = add i64 %index, 1
  %12 = getelementptr double* %7, i64 %.sum
  %13 = bitcast double* %12 to <2 x double>*
  %wide.load6 = load <2 x double>* %13, align 8
  %.sum13 = add i64 %index, 3
  %14 = getelementptr double* %7, i64 %.sum13
  %15 = bitcast double* %14 to <2 x double>*
  %wide.load7 = load <2 x double>* %15, align 8
  %16 = fmul <2 x double> %wide.load, <double 2.000000e+00, double 2.000000e+00>
  %17 = fmul <2 x double> %wide.load6, <double 2.000000e+00, double 2.000000e+00>
  %18 = fmul <2 x double> %wide.load7, <double 2.000000e+00, double 2.000000e+00>
  store <2 x double> %16, <2 x double>* %11, align 8
  store <2 x double> %17, <2 x double>* %13, align 8
  store <2 x double> %18, <2 x double>* %15, align 8
  %index.next = add i64 %index, 6
  %19 = icmp eq i64 %index.next, %end.idx.rnd.down
  br i1 %19, label %middle.block, label %vector.body

middle.block:                                     ; preds = %vector.body, %if.lr.ph
  %resume.val = phi i64 [ 1, %if.lr.ph ], [ %end.idx.rnd.down, %vector.body ]
  %end.idx = add i64 %smax, 1
  %cmp.n = icmp eq i64 %end.idx, %resume.val
  br i1 %cmp.n, label %L2, label %if

if:                                               ; preds = %middle.block, %if
  %"#s1.03" = phi i64 [ %24, %if ], [ %resume.val, %middle.block ]
  %20 = add i64 %"#s1.03", -1, !dbg !3370
  %21 = getelementptr double* %7, i64 %20, !dbg !3370
  %22 = load double* %21, align 8, !dbg !3370
  %23 = fmul double %22, 2.000000e+00, !dbg !3370
  store double %23, double* %21, align 8, !dbg !3370
  %24 = add nsw i64 %"#s1.03", 1, !dbg !3371
  %25 = icmp slt i64 %"#s1.03", %4, !dbg !3369
  br i1 %25, label %if, label %L2, !dbg !3369, !llvm.vectorizer.already_vectorized !3372

L2:                                               ; preds = %if, %middle.block, %top
  ret void, !dbg !3371
}