diff --git a/editors/kate/finch.xml b/editors/kate/finch.xml
index 883a6e0..f9f2642 100644
--- a/editors/kate/finch.xml
+++ b/editors/kate/finch.xml
@@ -5,7 +5,7 @@
   Install: copy to ~/.local/share/org.kde.syntax-highlighting/syntax/finch.xml
   (or run editors/kate/install.sh), then restart Kate.
 -->
-<language name="Finch" version="4" kateversion="5.0" section="Sources" extensions="*.fch"
+<language name="Finch" version="5" kateversion="5.0" section="Sources" extensions="*.fch"
           mimetype="text/x-finch" indenter="cstyle" author="The Finch authors" license="Apache-2.0">
   <highlighting>
     <list name="keywords">
@@ -103,6 +103,8 @@
         <keyword String="imports" attribute="Import"/>
         <keyword String="constants" attribute="Constant"/>
         <keyword String="types" attribute="Data Type"/>
+        <!-- vectors: f32x8, i8x32, u16x16, f64x4 ... -->
+        <RegExpr String="\b[iuf](8|16|32|64)x(2|4|8|16|32|64)\b" attribute="Data Type"/>
         <keyword String="builtins" attribute="Built-in"/>
 
         <RegExpr String="\b0[xX][0-9a-fA-F_]+\b" attribute="Hex"/>
diff --git a/editors/vscode/CHANGELOG.md b/editors/vscode/CHANGELOG.md
index 195374b..a0a750c 100644
--- a/editors/vscode/CHANGELOG.md
+++ b/editors/vscode/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.6.0
+
+- Vector types (`f32x8`, `i8x32`, `f64x4`, …) highlighted as types; completion of their methods (`sum`, `dot`, `fma`, `store`, …).
+
 ## 2.5.0
 
 - Highlighting for code inside text (`"hp \(hp)"`), `test "…" { }` blocks, `const`, `"""` text, `1e9`.
diff --git a/editors/vscode/package-lock.json b/editors/vscode/package-lock.json
index f98d8ad..5a0404d 100644
--- a/editors/vscode/package-lock.json
+++ b/editors/vscode/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "finch-lang",
-  "version": "2.4.0",
+  "version": "2.6.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "finch-lang",
-      "version": "2.4.0",
+      "version": "2.6.0",
       "license": "Apache-2.0",
       "dependencies": {
         "vscode-languageclient": "^9.0.1"
diff --git a/editors/vscode/package.json b/editors/vscode/package.json
index 40c7715..9c17bd1 100644
--- a/editors/vscode/package.json
+++ b/editors/vscode/package.json
@@ -2,7 +2,7 @@
   "name": "finch-lang",
   "displayName": "Finch",
   "description": "The Finch programming language: highlighting, errors as you type, completion, hover, go to definition, and a Run button.",
-  "version": "2.5.0",
+  "version": "2.6.0",
   "publisher": "nexoniarz",
   "license": "Apache-2.0",
   "icon": "images/icon.png",
diff --git a/editors/vscode/syntaxes/finch.tmLanguage.json b/editors/vscode/syntaxes/finch.tmLanguage.json
index 9154a4e..e3c2dea 100644
--- a/editors/vscode/syntaxes/finch.tmLanguage.json
+++ b/editors/vscode/syntaxes/finch.tmLanguage.json
@@ -148,7 +148,7 @@
         },
         {
           "name": "storage.type.primitive.finch",
-          "match": "\\b(int|float|bool|char|str|ptr|map|i8|i16|i32|i64|u8|u16|u32|u64|f32|f64)\\b"
+          "match": "\\b(int|float|bool|char|str|ptr|map|i8|i16|i32|i64|u8|u16|u32|u64|f32|f64|[iuf](?:8|16|32|64)x(?:2|4|8|16|32|64))\\b"
         },
         {
           "match": "\\b(print|input|read_file|write_file|file_exists|delete_file|shell|exit|addr|new|free|error|min|max|abs|clamp|assert|atomic_add|atomic_sub|atomic_load|atomic_store|atomic_swap|atomic_cas)\\s*(?=\\()",
diff --git a/editors/vscode/test/grammar.js b/editors/vscode/test/grammar.js
index bf2aae7..0903ec5 100644
--- a/editors/vscode/test/grammar.js
+++ b/editors/vscode/test/grammar.js
@@ -29,6 +29,7 @@ const code = [
   'test "lives \\(hp + f(1)) left" {',
   '    assert(clamp(x, 0, 9) == 3)',
   '}',
+  'fn dot(f32x8 a, i8x32 b) {',
 ];
 const expect = [  // [line, token text, scope that must be present]
   [0, 'import', 'keyword.control.import'], [0, '"stdio.h"', 'string.quoted.double'],
@@ -49,6 +50,7 @@ const expect = [  // [line, token text, scope that must be present]
   [17, 'test', 'keyword.other.test'], [17, '\\(', 'punctuation.section.embedded.begin'], [17, 'hp', 'meta.embedded.line'],
   [17, 'f', 'meta.embedded.line'], [17, 'left', 'string.quoted.double'],
   [18, 'assert', 'support.function.builtin'], [18, 'clamp', 'support.function.builtin'],
+  [20, 'f32x8', 'storage.type.primitive'], [20, 'i8x32', 'storage.type.primitive'],
 ];
 registry.loadGrammar('source.finch').then((g) => {
   let state = vsctm.INITIAL, toks = [];
diff --git a/src/ast.fch b/src/ast.fch
index 0870037..4c60451 100644
--- a/src/ast.fch
+++ b/src/ast.fch
@@ -36,6 +36,41 @@ fn ptrTo(Type t) -> Type {
     return out
 }
 
+// f32x8, i8x32, u16x16, f64x4: N numbers of one type side by side, worked on all at once (SIMD).
+// Its kind is "vec", elem[0] the type of one lane, count the number of lanes. kind "" if `name` is no such type.
+fn vecType(str name) -> Type {
+    x := name.find("x")
+    if x < 2 || x + 1 >= name.len {
+        return Type()
+    }
+    lane := name.sub(0, x)
+    if !["i8", "i16", "i32", "i64", "u8", "u16", "u32", "u64", "f32", "f64"].contains(lane) {
+        return Type()
+    }
+    n := 0
+    for c in name.sub(x + 1, name.len) {
+        if c < '0' || c > '9' {
+            return Type()
+        }
+        n = n * 10 + (int(c) - int('0'))
+    }
+    if n != 2 && n != 4 && n != 8 && n != 16 && n != 32 && n != 64 {
+        return Type()
+    }
+    bits := int(lane.sub(1, lane.len)) or 0
+    if n * bits > 512 {
+        return Type()           // the widest registers (AVX-512) hold 512 bits
+    }
+    if lane == "i64" {
+        lane = "int"
+    } else if lane == "f64" {
+        lane = "float"
+    }
+    out := Type(kind: "vec", count: n)
+    out.elem.push(simple(lane))
+    return out
+}
+
 fn same(Type a, Type b) -> bool {
     if a.kind != b.kind {
         return false
@@ -43,10 +78,10 @@ fn same(Type a, Type b) -> bool {
     if a.kind == "struct" || a.kind == "named" || a.kind == "enum" {
         return a.name == b.name && a.module == b.module
     }
-    if a.kind == "fixed" && a.count != b.count {
+    if (a.kind == "fixed" || a.kind == "vec") && a.count != b.count {
         return false
     }
-    if a.kind == "array" || a.kind == "ptr" || a.kind == "map" || a.kind == "fixed" {
+    if a.kind == "array" || a.kind == "ptr" || a.kind == "map" || a.kind == "fixed" || a.kind == "vec" {
         if a.elem.len != b.elem.len {
             return false
         }
@@ -67,6 +102,15 @@ fn show(Type t) -> str {
     if t.kind == "fixed" {
         return "[" + str(t.count) + "]" + show(t.elem[0])
     }
+    if t.kind == "vec" {
+        lane := t.elem[0].kind
+        if lane == "int" {
+            lane = "i64"
+        } else if lane == "float" {
+            lane = "f64"
+        }
+        return lane + "x" + str(t.count)
+    }
     if t.kind == "map" {
         return "map[" + show(t.elem[0]) + "]" + show(t.elem[1])
     }
diff --git a/src/docs.fch b/src/docs.fch
index 977f0de..04dc13e 100644
--- a/src/docs.fch
+++ b/src/docs.fch
@@ -40,7 +40,8 @@ fn builtins() -> []Doc {
         doc("float", "float(x) -> float", "Converts to a decimal number; parses text (int(s) or 0.0 handles bad text)."),
         doc("char", "char(int n) -> char", "The character with this code."),
         doc("bool", "bool(int n) -> bool", "true for any number but 0."),
-        doc("ptr", "ptr(x) -> ptr", "An untyped pointer: from a typed pointer, or from a number (an address or offset for C).")
+        doc("ptr", "ptr(x) -> ptr", "An untyped pointer: from a typed pointer, or from a number (an address or offset for C)."),
+        doc("f32x8", "f32x8(x) / f32x8(a, b, ...) / f32x8(list, i) / f32x8(v)", "A vector: 8 f32 side by side, worked on all at once (SIMD). Every lane x; one value per lane; 8 numbers from list[i]; or another 8-lane vector converted. The same goes for i8x16, i32x8, f64x4 and the rest.")
     ]
 }
 
@@ -94,13 +95,32 @@ fn mapMethods() -> []Doc {
     ]
 }
 
+fn vecMethods() -> []Doc {
+    return [
+        doc("len", ".len -> int", "The number of lanes."),
+        doc("sum", "sum() -> T", "All the lanes added up (floats: in whatever order is fastest)."),
+        doc("min", "min() -> T", "The smallest lane."),
+        doc("max", "max() -> T", "The biggest lane."),
+        doc("dot", "dot(V w) -> T", "Lane times lane, added up: (v * w).sum()."),
+        doc("sqrt", "sqrt() -> V", "The square root of every lane (f32/f64 lanes)."),
+        doc("floor", "floor() -> V", "Every lane rounded down (f32/f64 lanes)."),
+        doc("ceil", "ceil() -> V", "Every lane rounded up (f32/f64 lanes)."),
+        doc("round", "round() -> V", "Every lane rounded to the nearest whole number, halves away from 0 (f32/f64 lanes)."),
+        doc("abs", "abs() -> V", "Every lane without its minus sign."),
+        doc("fma", "fma(V b, V c) -> V", "v * b + c in one step, with one rounding (f32/f64 lanes)."),
+        doc("store", "store([]T list, int i)", "Writes the lanes into list[i], list[i+1], ... (or through a ptr[T]).")
+    ]
+}
+
 fn keywords() -> []str {
     return ["fn", "return", "if", "else", "while", "for", "in", "break", "continue", "true", "false", "null", "import",
             "link", "struct", "enum", "match", "export", "defer", "or", "try", "self", "const"]
 }
 
 fn typeNames() -> []str {
-    return ["int", "float", "bool", "char", "str", "ptr", "map", "i8", "i16", "i32", "i64", "u8", "u16", "u32", "u64", "f32", "f64"]
+    return ["int", "float", "bool", "char", "str", "ptr", "map", "i8", "i16", "i32", "i64", "u8", "u16", "u32", "u64", "f32", "f64",
+            "f32x4", "f32x8", "f32x16", "f64x2", "f64x4", "f64x8", "i8x16", "i8x32", "i8x64", "u8x16", "u8x32", "u8x64",
+            "i16x8", "i16x16", "i16x32", "i32x4", "i32x8", "i32x16", "u32x4", "u32x8", "u32x16", "i64x2", "i64x4", "i64x8"]
 }
 
 // the entry called `name`, or an empty Doc
diff --git a/src/gen.fch b/src/gen.fch
index 4768440..7aba27c 100644
--- a/src/gen.fch
+++ b/src/gen.fch
@@ -206,6 +206,7 @@ struct Gen {
     str cwd
     []str md            // the metadata, numbered by position: !0 = md[0]
     map[str]int mdcache // metadata made already: types by key, locations by line:column
+    map[str]int wide    // LLVM types that want more than the 16 bytes malloc and the stack promise: loaded with align 16
     []int mdfiles       // the DIFile of each source file
     int dbgScope        // the DISubprogram of the function being built, or -1 (helpers have none)
     int dbgLine
@@ -367,7 +368,7 @@ fn byteSize(ptr[Gen] g, ast.Type t) -> int {
         }
         return n
     }
-    if k == "fixed" && t.elem.len > 0 {
+    if (k == "fixed" || k == "vec") && t.elem.len > 0 {
         return t.count * byteSize(g, t.elem[0])
     }
     if k == "str" || k == "array" || k == "map" {
@@ -436,12 +437,22 @@ fn alloca(ptr[Gen] g, str ty) -> str {
 
 fn load(ptr[Gen] g, str ty, str at) -> str {
     t := tmpName(g)
-    emit(g, t + " = load " + ty + ", ptr " + at)
+    emit(g, t + " = load " + ty + ", ptr " + at + alignFor(g, ty))
     return t
 }
 
 fn store(ptr[Gen] g, str ty, str v, str at) {
-    emit(g, "store " + ty + " " + v + ", ptr " + at)
+    emit(g, "store " + ty + " " + v + ", ptr " + at + alignFor(g, ty))
+}
+
+// A vector of 32 or 64 bytes (f32x8, i8x64) wants to sit at an address that many bytes apart, and so does a struct
+// that holds one; memory from malloc and the stack is 16 apart. Telling LLVM so keeps it from using the
+// instructions that crash on a smaller alignment.
+fn alignFor(ptr[Gen] g, str ty) -> str {
+    if g.wide.len > 0 && g.wide.has(ty) {
+        return ", align 16"
+    }
+    return ""
 }
 
 fn spill(ptr[Gen] g, Val v) -> str {
@@ -703,6 +714,13 @@ fn llty(ptr[Gen] g, ast.Type t) -> str {
     if k == "fixed" {
         return "[" + str(t.count) + " x " + llty(g, t.elem[0]) + "]"
     }
+    if k == "vec" {
+        out := "<" + str(t.count) + " x " + llty(g, t.elem[0]) + ">"
+        if t.count * bitsOf(t.elem[0]) > 128 && !g.wide.has(out) {
+            g.wide[out] = 1
+        }
+        return out
+    }
     if k == "enum" {
         return "i32"
     }
@@ -774,6 +792,9 @@ fn typeKey(ast.Type t) -> str {
     if t.kind == "enum" {
         return "E_" + modName(t.module) + "_" + t.name
     }
+    if t.kind == "vec" {
+        return ast.show(t)
+    }
     if t.kind == "struct" {
         return "S_" + modName(t.module) + "_" + mangle(t.name)
     }
@@ -1221,7 +1242,19 @@ fn formatFn(ptr[Gen] g, ast.Type t) -> str {
     }
     g.done.push(name)
     s := beginHelper(g)
-    if t.kind == "array" {
+    if t.kind == "vec" {
+        // f32x4(1, 2.5, 3, 4)
+        v := load(g, llty(g, t), "%a")
+        bufText(g, "%buf", ast.show(t) + "(")
+        for k in 0..t.count {
+            if k > 0 {
+                bufText(g, "%buf", ", ")
+            }
+            lane := op(g, "extractelement " + llty(g, t) + " " + v + ", i64 " + str(k))
+            emitFormat(g, "%buf", lane, t.elem[0], false)
+        }
+        bufText(g, "%buf", ")")
+    } else if t.kind == "array" {
         et := t.elem[0]
         d := load(g, "ptr", "%a")
         len := load(g, "i64", op(g, "getelementptr inbounds { ptr, i64, i64 }, ptr %a, i32 0, i32 1"))
@@ -1428,6 +1461,12 @@ fn coerce(ptr[Gen] g, Val v, ast.Type want, ast.Node at, str what) -> Val {
     if want.kind == "str" && (isNumber(v.ty) || v.ty.kind == "bool" || v.ty.kind == "char") {
         msg = msg + " (turn it into text with str(...))"
     }
+    if want.kind == "vec" && isNumber(v.ty) {
+        msg = msg + " (" + ast.show(want) + "(x) puts x in every lane)"
+    }
+    if want.kind == "vec" && v.ty.kind == "vec" {
+        msg = msg + " (convert it: " + ast.show(want) + "(...))"
+    }
     fail(g, at, msg)
     return v
 }
@@ -2054,7 +2093,13 @@ fn resolveStructBody(ptr[Gen] g, int i) {
     g.structs[i].owning = owns
     g.module = saved
     g.structs[i].state = 2
-    g.head.push("%S." + modName(g.structs[i].module) + "." + mangle(g.structs[i].name) + " = type { " + fields.join(", ") + " }")
+    name := "%S." + modName(g.structs[i].module) + "." + mangle(g.structs[i].name)
+    for f in fields {
+        if g.wide.has(f) {
+            g.wide[name] = 1            // it holds a wide vector (or a struct that does)
+        }
+    }
+    g.head.push(name + " = type { " + fields.join(", ") + " }")
 }
 
 // ---------- debug info (-g) ----------
@@ -2108,6 +2153,10 @@ fn sizeAlign(ptr[Gen] g, ast.Type t) -> SizeAlign {
         e := sizeAlign(g, t.elem[0])
         return SizeAlign(size: e.size * t.count, align: e.align)
     }
+    if k == "vec" {
+        n := t.count * sizeAlign(g, t.elem[0]).size
+        return SizeAlign(size: n, align: n)         // LLVM lays a vector out at a multiple of its size
+    }
     if k == "struct" {
         sd := g.structs[findStruct(g, t.module, t.name)]
         if sd.isC {
@@ -2196,6 +2245,10 @@ fn diType(ptr[Gen] g, ast.Type t) -> int {
                 base = diType(g, t.elem[0])
             }
             g.md[id] = "!DIDerivedType(tag: DW_TAG_pointer_type, baseType: " + mdRef(base) + ", size: 64)"
+        } else if k == "vec" {
+            e := sizeAlign(g, t.elem[0])
+            sub := md(g, "!DISubrange(count: " + str(t.count) + ")")
+            g.md[id] = "!DICompositeType(tag: DW_TAG_array_type, baseType: " + mdRef(diType(g, t.elem[0])) + ", size: " + str(e.size * t.count * 8) + ", flags: DIFlagVector, elements: !{!" + str(sub) + "})"
         } else if k == "fixed" {
             e := sizeAlign(g, t.elem[0])
             sub := md(g, "!DISubrange(count: " + str(t.count) + ")")
@@ -3628,6 +3681,9 @@ fn expr(ptr[Gen] g, ast.Node e) -> Val {
 
 fn unary(ptr[Gen] g, ast.Node e) -> Val {
     v := expr(g, e.kids[0])
+    if v.ty.kind == "vec" && e.name != "!" {
+        return vecUnary(g, e, v)
+    }
     if e.name == "!" {
         c := coerce(g, v, T("bool"), e.kids[0], "the value after '!'")
         return Val(v: op(g, "xor i1 " + c.v + ", true"), ty: T("bool"))
@@ -3651,6 +3707,13 @@ fn unary(ptr[Gen] g, ast.Node e) -> Val {
         return Val(v: op(g, "sub " + llty(g, v.ty) + " 0, " + v.v), ty: v.ty)
     }
     if isFloat(v.ty) {
+        if v.lit {
+            // -1.5 is still a number written in the code: f32 x = -1.5 works like f32 x = 1.5
+            if v.v.starts_with("-") {
+                return Val(v: v.v.sub(1, v.v.len), ty: v.ty, lit: true)
+            }
+            return Val(v: "-" + v.v, ty: v.ty, lit: true)
+        }
         return Val(v: op(g, "fneg " + llty(g, v.ty) + " " + v.v), ty: v.ty)
     }
     fail(g, e, "can't put '-' in front of " + ast.show(v.ty))
@@ -3746,6 +3809,9 @@ fn arith(ptr[Gen] g, str o, Val l, Val r, ast.Node at) -> Val {
         release(g, r)
         return Val(v: load(g, "{ ptr, i64, i64 }", out), ty: T("str"), fresh: true)
     }
+    if l.ty.kind == "vec" || r.ty.kind == "vec" {
+        return vecArith(g, o, l, r, at)
+    }
     if !unify(g, addr(l), addr(r)) {
         badOperands(g, o, l, r, at)
     }
@@ -3847,6 +3913,9 @@ fn compare(ptr[Gen] g, str o, Val l, Val r, ast.Node at) -> Val {
         release(g, r)
         return Val(v: res, ty: T("bool"))
     }
+    if l.ty.kind == "vec" || r.ty.kind == "vec" {
+        return vecCompare(g, o, l, r, at)
+    }
     if !unify(g, addr(l), addr(r)) {
         badOperands(g, o, l, r, at)
     }
@@ -4281,6 +4350,15 @@ fn member(ptr[Gen] g, ast.Node m, bool write) -> Ref {
         obj = Ref(isPlace: true, pl: Place(addr: pv, ty: target))
         t = target
     }
+    if t.kind == "vec" {
+        if m.name != "len" {
+            fail(g, m, "a " + ast.show(t) + " has .len and [i] (and methods like .sum()), not '." + m.name + "'")
+        }
+        if write {
+            fail(g, m, ".len can't be changed")
+        }
+        return Ref(isPlace: false, val: Val(v: str(t.count), ty: T("int"), lit: true))
+    }
     if t.kind == "fixed" {
         if write {
             fail(g, m, "." + m.name + " can't be changed directly")
@@ -4376,6 +4454,15 @@ fn indexOf(ptr[Gen] g, ast.Node e, Ref obj, bool write) -> Ref {
         return mapIndex(g, e, obj, t, write)
     }
     i := coerce(g, expr(g, e.kids[1]), T("int"), e.kids[1], "an index").v
+    if t.kind == "vec" {
+        // a lane: v[2], v[i] = x
+        boundsCheck(g, i, str(t.count), e)
+        if obj.isPlace {
+            ep := op(g, "getelementptr inbounds " + llty(g, t.elem[0]) + ", ptr " + obj.pl.addr + ", i64 " + i)
+            return Ref(isPlace: true, pl: Place(addr: ep, ty: t.elem[0]))
+        }
+        return Ref(isPlace: false, val: Val(v: op(g, "extractelement " + llty(g, t) + " " + obj.val.v + ", i64 " + i), ty: t.elem[0]))
+    }
     if t.kind == "fixed" {
         base := ""
         if obj.isPlace {
@@ -5307,7 +5394,7 @@ fn call(ptr[Gen] g, ast.Node c) -> Val {
             store(g, "{ ptr, i64, i64 }", "zeroinitializer", out)
             emit(g, "call void @finch_str_from_bytes(ptr " + out + ", ptr " + spill(g, v) + ")")
             release(g, v)
-        } else if k == "bool" || k == "char" || k == "array" || k == "map" || k == "struct" || k == "enum" {
+        } else if k == "bool" || k == "char" || k == "array" || k == "map" || k == "struct" || k == "enum" || k == "vec" {
             store(g, "{ ptr, i64, i64 }", "zeroinitializer", out)
             emitFormat(g, out, v.v, v.ty, false)
             release(g, v)
@@ -5320,6 +5407,10 @@ fn call(ptr[Gen] g, ast.Node c) -> Val {
     if to.len > 0 {
         return convert(g, c, T(to))
     }
+    vt := ast.vecType(n)
+    if vt.kind.len > 0 {
+        return vecMake(g, c, vt)
+    }
     if n == "read_file" || n == "file_exists" {
         checkArgs(g, c, 0, 1, n)
         pv := strArg(g, c.kids[0], "the file name")
@@ -5570,7 +5661,7 @@ fn mathCall(ptr[Gen] g, ast.Node c) -> Val {
     []Val vals
     for a in c.kids {
         v := expr(g, a)
-        if !isNumber(v.ty) {
+        if !isNumber(v.ty) && v.ty.kind != "vec" {
             fail(g, a, n + "(...) is for numbers, but this is " + ast.show(v.ty))
         }
         vals.push(v)
@@ -5578,6 +5669,9 @@ fn mathCall(ptr[Gen] g, ast.Node c) -> Val {
     if n == "abs" {
         checkArgs(g, c, 0, 1, n)
         x := vals[0]
+        if x.ty.kind == "vec" {
+            return vecAbs(g, x)
+        }
         if isUnsigned(x.ty) {
             return x
         }
@@ -5659,6 +5753,9 @@ fn atomicCall(ptr[Gen] g, ast.Node c) -> Val {
 
 // the smaller (o "<") or bigger (o ">") of two numbers, in the type both fit
 fn pick(ptr[Gen] g, str o, Val a, Val b, ast.Node at) -> Val {
+    if a.ty.kind == "vec" || b.ty.kind == "vec" {
+        return vecPick(g, o, a, b, at)
+    }
     l := a
     r := b
     if !unify(g, addr(l), addr(r)) {
@@ -5902,6 +5999,15 @@ fn method(ptr[Gen] g, ast.Node m) -> Val {
     if r.isPlace {
         t = r.pl.ty
     }
+    if t.kind == "vec" {
+        v := r.val
+        if r.isPlace {
+            v = Val(v: load(g, llty(g, t), r.pl.addr), ty: t)
+        }
+        noteMethod(g, m, docs.vecMethods())
+        heldEnd(g, mark)
+        return vecMethod(g, m, v)
+    }
     if t.kind == "array" {
         a := ""
         if r.isPlace {
@@ -6530,3 +6636,396 @@ fn generate([]ast.Program progs, []str files, cimport.CImports ci, Options opt)
     g.out.push("define i32 @main(i32 %argc, ptr %argv) {\nentry:\n" + traceInit() + pre + "  " + callText + "\n" + after + ret + "}\n")
     return assemble(g)
 }
+
+// ---------- vectors: f32x8, i8x32, f64x4, ... (SIMD) ----------
+//
+// A vector is N numbers of one type side by side: <8 x float> in LLVM. + - * / work on every lane at once, and
+// LLVM picks the instructions: SSE, AVX2 or AVX-512 on x86-64, NEON on ARM64 (with --cpu native, the ones of the
+// machine that builds it). A plain number next to a vector counts for every lane: v * 2.0.
+
+fn laneBytes(ast.Type vt) -> str {
+    return str(bitsOf(vt.elem[0]) / 8)
+}
+
+// v8f32, v32i8: how LLVM's vector intrinsics are named for this type
+fn vecSuffix(ast.Type vt) -> str {
+    if isFloat(vt.elem[0]) {
+        return "v" + str(vt.count) + "f" + str(bitsOf(vt.elem[0]))
+    }
+    return "v" + str(vt.count) + "i" + str(bitsOf(vt.elem[0]))
+}
+
+fn declareOnce(ptr[Gen] g, str decl) {
+    if !has(g.done, decl) {
+        g.done.push(decl)
+        g.head.push(decl)
+    }
+}
+
+// call @llvm.<name>.<suffix>(args...), declared the first time
+fn vecIntrinsic(ptr[Gen] g, str ret, str name, ast.Type vt, []str argTypes, []str args, str flags) -> str {
+    fname := "@llvm." + name + "." + vecSuffix(vt)
+    declareOnce(g, "declare " + ret + " " + fname + "(" + argTypes.join(", ") + ")")
+    []str both
+    for i in 0..args.len {
+        both.push(argTypes[i] + " " + args[i])
+    }
+    return op(g, "call " + flags + ret + " " + fname + "(" + both.join(", ") + ")")
+}
+
+// the same number in every lane
+fn splat(ptr[Gen] g, str v, ast.Type vt) -> str {
+    lt := llty(g, vt)
+    one := op(g, "insertelement " + lt + " poison, " + llty(g, vt.elem[0]) + " " + v + ", i64 0")
+    return op(g, "shufflevector " + lt + " " + one + ", " + lt + " poison, <" + str(vt.count) + " x i32> zeroinitializer")
+}
+
+// a value next to a vector: the vector itself, or a number put in every lane
+fn asVec(ptr[Gen] g, Val v, ast.Type vt, str o, ast.Node at) -> Val {
+    if v.ty.kind == "vec" {
+        if !ast.same(v.ty, vt) {
+            fail(g, at, "can't use '" + o + "' on " + ast.show(vt) + " and " + ast.show(v.ty) + " (convert one: " + ast.show(vt) + "(...))")
+        }
+        return v
+    }
+    s := coerce(g, v, vt.elem[0], at, "a number used with " + ast.show(vt))
+    return Val(v: splat(g, s.v, vt), ty: vt)
+}
+
+fn vecOf(Val l, Val r) -> ast.Type {
+    if l.ty.kind == "vec" {
+        return l.ty
+    }
+    return r.ty
+}
+
+// i, i+1, ..., i+n-1 are all in a list of `len`
+fn vecBounds(ptr[Gen] g, str i, int n, str len, ast.Node at) {
+    end := op(g, "add i64 " + i + ", " + str(n))
+    before := op(g, "icmp slt i64 " + i + ", 0")
+    after := op(g, "icmp sgt i64 " + end + ", " + len)
+    panicIf(g, op(g, "or i1 " + before + ", " + after), "the " + str(n) + " numbers of the vector don't all fit in the list there", at)
+}
+
+// f32x8(x), f32x8(a, b, ..., h), f32x8(list, i), f32x8(i32x8 v)
+fn vecMake(ptr[Gen] g, ast.Node c, ast.Type vt) -> Val {
+    if g.index {
+        noteRef(g, c, c.col, c.name.len, docs.hover(docs.find(docs.builtins(), "f32x8")), "", 0, 0)
+    }
+    for nm in c.names {
+        if nm.len > 0 {
+            fail(g, c, "named arguments (" + nm + ": ...) are only for creating structs")
+        }
+    }
+    shown := ast.show(vt)
+    lane := vt.elem[0]
+    lt := llty(g, vt)
+    n := vt.count
+    usage := shown + "(x) puts x in every lane, " + shown + "(a, b, ...) takes " + str(n) + " numbers, " + shown + "(list, i) loads them from a list"
+    if c.kids.len == 0 {
+        fail(g, c, usage)
+    }
+    first := ref(g, c.kids[0], false)
+    ft := first.val.ty
+    if first.isPlace {
+        ft = first.pl.ty
+    }
+    if ft.kind == "array" || ft.kind == "ptr" {
+        if c.kids.len != 2 {
+            fail(g, c, shown + "(list, i): which index to start at? (" + shown + "(list, 0) for the first " + str(n) + ")")
+        }
+        if ft.elem.len == 0 || !ast.same(ft.elem[0], lane) {
+            fail(g, c.kids[0], shown + "(list, i) loads " + ast.show(lane) + " numbers, but this is " + ast.show(ft))
+        }
+        mark := g.pending.len
+        if !first.isPlace {
+            hold(g, first.val)
+        }
+        i := coerce(g, expr(g, c.kids[1]), T("int"), c.kids[1], "an index").v
+        heldEnd(g, mark)
+        data := ""
+        if ft.kind == "ptr" {
+            data = first.val.v
+            if first.isPlace {
+                data = load(g, "ptr", first.pl.addr)
+            }
+        } else {
+            av := first.val.v
+            if first.isPlace {
+                av = load(g, "{ ptr, i64, i64 }", first.pl.addr)
+            }
+            vecBounds(g, i, n, op(g, "extractvalue { ptr, i64, i64 } " + av + ", 1"), c)
+            data = op(g, "extractvalue { ptr, i64, i64 } " + av + ", 0")
+        }
+        ep := op(g, "getelementptr inbounds " + llty(g, lane) + ", ptr " + data + ", i64 " + i)
+        out := op(g, "load " + lt + ", ptr " + ep + ", align " + laneBytes(vt))
+        if !first.isPlace {
+            release(g, first.val)
+        }
+        return Val(v: out, ty: vt)
+    }
+    v := first.val
+    if first.isPlace {
+        v = Val(v: load(g, llty(g, ft), first.pl.addr), ty: ft)
+    }
+    if c.kids.len == 1 {
+        if ft.kind == "vec" {
+            return vecConvert(g, v, vt, c.kids[0])
+        }
+        if !isNumber(ft) {
+            fail(g, c.kids[0], usage + "; this is " + ast.show(ft))
+        }
+        s := coerce(g, v, lane, c.kids[0], "the number for every lane")
+        return Val(v: splat(g, s.v, vt), ty: vt)
+    }
+    if c.kids.len != n {
+        fail(g, c, usage + "; this has " + str(c.kids.len) + " values")
+    }
+    cur := "poison"
+    for k in 0..n {
+        x := v
+        if k > 0 {
+            x = expr(g, c.kids[k])
+        }
+        s := coerce(g, x, lane, c.kids[k], "lane " + str(k))
+        cur = op(g, "insertelement " + lt + " " + cur + ", " + llty(g, lane) + " " + s.v + ", i64 " + str(k))
+    }
+    return Val(v: cur, ty: vt)
+}
+
+// every lane converted, as the same conversion of one number would: f32x8(ints), i32x8(floats) cuts fractions
+fn vecConvert(ptr[Gen] g, Val v, ast.Type to, ast.Node at) -> Val {
+    from := v.ty
+    if ast.same(from, to) {
+        return v
+    }
+    if from.count != to.count {
+        fail(g, at, "can't turn " + ast.show(from) + " into " + ast.show(to) + ": they have a different number of lanes")
+    }
+    fl := from.elem[0]
+    tl := to.elem[0]
+    inst := ""
+    if isInt(fl) && isInt(tl) {
+        if bitsOf(fl) == bitsOf(tl) {
+            return Val(v: v.v, ty: to)          // i32x8 <-> u32x8: the same bits
+        }
+        if bitsOf(tl) < bitsOf(fl) {
+            inst = "trunc"
+        } else if isSigned(fl) {
+            inst = "sext"
+        } else {
+            inst = "zext"
+        }
+    } else if isInt(fl) {
+        inst = "uitofp"
+        if isSigned(fl) {
+            inst = "sitofp"
+        }
+    } else if isInt(tl) {
+        inst = "fptoui"
+        if isSigned(tl) {
+            inst = "fptosi"
+        }
+    } else if bitsOf(tl) > bitsOf(fl) {
+        inst = "fpext"
+    } else {
+        inst = "fptrunc"
+    }
+    return Val(v: op(g, inst + " " + llty(g, from) + " " + v.v + " to " + llty(g, to)), ty: to)
+}
+
+fn vecUnary(ptr[Gen] g, ast.Node e, Val v) -> Val {
+    lane := v.ty.elem[0]
+    lt := llty(g, v.ty)
+    if e.name == "~" {
+        if !isInt(lane) {
+            fail(g, e, "'~' flips the bits of whole numbers, not of " + ast.show(v.ty))
+        }
+        return Val(v: op(g, "xor " + lt + " " + v.v + ", " + splat(g, "-1", v.ty)), ty: v.ty)
+    }
+    if isUnsigned(lane) {
+        fail(g, e, ast.show(v.ty) + " can't be negative (its lanes are unsigned)")
+    }
+    if isFloat(lane) {
+        return Val(v: op(g, "fneg " + lt + " " + v.v), ty: v.ty)
+    }
+    return Val(v: op(g, "sub " + lt + " zeroinitializer, " + v.v), ty: v.ty)
+}
+
+fn vecArith(ptr[Gen] g, str o, Val l, Val r, ast.Node at) -> Val {
+    vt := vecOf(l, r)
+    a := asVec(g, l, vt, o, at)
+    b := asVec(g, r, vt, o, at)
+    lane := vt.elem[0]
+    names := ["+", "-", "*", "/", "&", "|", "^", "<<", ">>"]
+    insts := ["add", "sub", "mul", "", "and", "or", "xor", "shl", "ashr"]
+    if isUnsigned(lane) {
+        insts[8] = "lshr"
+    }
+    if isFloat(lane) {
+        names = ["+", "-", "*", "/"]
+        insts = ["fadd", "fsub", "fmul", "fdiv"]
+    }
+    k := names.find(o)
+    if k < 0 || insts[k].len == 0 {
+        msg := "can't use '" + o + "' on " + ast.show(vt)
+        if o == "/" || o == "%" {
+            msg = msg + " (x86 and ARM have no instruction that divides whole numbers lane by lane; convert to floats: f32x" + str(vt.count) + "(v))"
+        } else if isFloat(lane) {
+            msg = msg + " (bit operators work on whole numbers only)"
+        }
+        fail(g, at, msg)
+    }
+    return Val(v: op(g, insts[k] + " " + llty(g, vt) + " " + a.v + ", " + b.v), ty: vt)
+}
+
+// v == w: every lane is equal. (Lane by lane: min, max, or v[i] < w[i].)
+fn vecCompare(ptr[Gen] g, str o, Val l, Val r, ast.Node at) -> Val {
+    vt := vecOf(l, r)
+    if o != "==" && o != "!=" {
+        fail(g, at, "'" + o + "' on " + ast.show(vt) + " would have an answer for every lane; use min(v, w), max(v, w), or compare lanes: v[i] " + o + " w[i]")
+    }
+    a := asVec(g, l, vt, o, at)
+    b := asVec(g, r, vt, o, at)
+    cmp := ""
+    if isFloat(vt.elem[0]) {
+        cmp = op(g, "fcmp oeq " + llty(g, vt) + " " + a.v + ", " + b.v)
+    } else {
+        cmp = op(g, "icmp eq " + llty(g, vt) + " " + a.v + ", " + b.v)
+    }
+    bits := ast.Type(kind: "vec", count: vt.count)
+    bits.elem.push(T("bool"))
+    all := vecIntrinsic(g, "i1", "vector.reduce.and", bits, ["<" + str(vt.count) + " x i1>"], [cmp], "")
+    if o == "!=" {
+        return Val(v: op(g, "xor i1 " + all + ", true"), ty: T("bool"))
+    }
+    return Val(v: all, ty: T("bool"))
+}
+
+// min(v, w) and max(v, w), lane by lane (clamp is the two)
+fn vecPick(ptr[Gen] g, str o, Val l, Val r, ast.Node at) -> Val {
+    vt := vecOf(l, r)
+    a := asVec(g, l, vt, o, at)
+    b := asVec(g, r, vt, o, at)
+    lane := vt.elem[0]
+    name := ""
+    if isFloat(lane) {
+        name = "minnum"
+        if o == ">" {
+            name = "maxnum"
+        }
+    } else {
+        sign := "u"
+        if isSigned(lane) {
+            sign = "s"
+        }
+        name = sign + "min"
+        if o == ">" {
+            name = sign + "max"
+        }
+    }
+    lt := llty(g, vt)
+    return Val(v: vecIntrinsic(g, lt, name, vt, [lt, lt], [a.v, b.v], ""), ty: vt)
+}
+
+fn vecAbs(ptr[Gen] g, Val v) -> Val {
+    lane := v.ty.elem[0]
+    lt := llty(g, v.ty)
+    if isUnsigned(lane) {
+        return v
+    }
+    if isFloat(lane) {
+        return Val(v: vecIntrinsic(g, lt, "fabs", v.ty, [lt], [v.v], ""), ty: v.ty)
+    }
+    return Val(v: vecIntrinsic(g, lt, "abs", v.ty, [lt, "i1"], [v.v, "false"], ""), ty: v.ty)
+}
+
+// all the lanes made into one number: "add", "min" or "max"
+fn vecReduce(ptr[Gen] g, Val v, str how) -> Val {
+    lane := v.ty.elem[0]
+    lt := llty(g, v.ty)
+    et := llty(g, lane)
+    if isFloat(lane) {
+        if how == "add" {
+            // reassoc: the lanes may be added in any order, which is what makes it fast
+            return Val(v: vecIntrinsic(g, et, "vector.reduce.fadd", v.ty, [et, lt], ["-0.0", v.v], "reassoc "), ty: lane)
+        }
+        return Val(v: vecIntrinsic(g, et, "vector.reduce.f" + how, v.ty, [lt], [v.v], ""), ty: lane)
+    }
+    if how == "add" {
+        return Val(v: vecIntrinsic(g, et, "vector.reduce.add", v.ty, [lt], [v.v], ""), ty: lane)
+    }
+    sign := "u"
+    if isSigned(lane) {
+        sign = "s"
+    }
+    return Val(v: vecIntrinsic(g, et, "vector.reduce." + sign + how, v.ty, [lt], [v.v], ""), ty: lane)
+}
+
+fn vecMethod(ptr[Gen] g, ast.Node m, Val v) -> Val {
+    vt := v.ty
+    lane := vt.elem[0]
+    lt := llty(g, vt)
+    n := m.name
+    if n == "sum" || n == "min" || n == "max" {
+        need(g, m, 0)
+        how := n
+        if n == "sum" {
+            how = "add"
+        }
+        return vecReduce(g, v, how)
+    }
+    if n == "dot" {
+        need(g, m, 1)
+        w := asVec(g, expr(g, m.kids[1]), vt, "dot", m.kids[1])
+        return vecReduce(g, vecArith(g, "*", v, w, m), "add")
+    }
+    if n == "abs" {
+        need(g, m, 0)
+        return vecAbs(g, v)
+    }
+    if n == "sqrt" || n == "floor" || n == "ceil" || n == "round" || n == "fma" {
+        if !isFloat(lane) {
+            fail(g, m, n + "() is for f32 and f64 lanes, but this is " + ast.show(vt))
+        }
+        if n == "fma" {
+            need(g, m, 2)
+            b := asVec(g, expr(g, m.kids[1]), vt, "fma", m.kids[1])
+            c := asVec(g, expr(g, m.kids[2]), vt, "fma", m.kids[2])
+            return Val(v: vecIntrinsic(g, lt, "fma", vt, [lt, lt, lt], [v.v, b.v, c.v], ""), ty: vt)
+        }
+        need(g, m, 0)
+        return Val(v: vecIntrinsic(g, lt, n, vt, [lt], [v.v], ""), ty: vt)
+    }
+    if n == "store" {
+        need(g, m, 2)
+        dst := ref(g, m.kids[1], true)
+        dt := dst.val.ty
+        if dst.isPlace {
+            dt = dst.pl.ty
+        }
+        if (dt.kind != "array" && dt.kind != "ptr") || dt.elem.len == 0 || !ast.same(dt.elem[0], lane) {
+            fail(g, m.kids[1], "store(list, i) writes " + ast.show(lane) + " numbers into a []" + ast.show(lane) + " or a ptr[" + ast.show(lane) + "], but this is " + ast.show(dt))
+        }
+        if dt.kind == "array" && !dst.isPlace {
+            fail(g, m.kids[1], "store(list, i) needs a list in a variable (this one would be thrown away)")
+        }
+        i := coerce(g, expr(g, m.kids[2]), T("int"), m.kids[2], "an index").v
+        data := ""
+        if dt.kind == "ptr" {
+            data = dst.val.v
+            if dst.isPlace {
+                data = load(g, "ptr", dst.pl.addr)
+            }
+        } else {
+            av := load(g, "{ ptr, i64, i64 }", dst.pl.addr)
+            vecBounds(g, i, vt.count, op(g, "extractvalue { ptr, i64, i64 } " + av + ", 1"), m)
+            data = op(g, "extractvalue { ptr, i64, i64 } " + av + ", 0")
+        }
+        ep := op(g, "getelementptr inbounds " + llty(g, lane) + ", ptr " + data + ", i64 " + i)
+        emit(g, "store " + lt + " " + v.v + ", ptr " + ep + ", align " + laneBytes(vt))
+        return Val(ty: T("void"))
+    }
+    fail(g, m, "a " + ast.show(vt) + " has no method '" + n + "' (it has: sum, min, max, dot, abs, sqrt, floor, ceil, round, fma, store)")
+    return v
+}
diff --git a/src/lsp.fch b/src/lsp.fch
index 0bc0fcc..fc8299d 100644
--- a/src/lsp.fch
+++ b/src/lsp.fch
@@ -7,6 +7,7 @@
 import json
 import host
 import docs
+import ast
 import fmt
 import "stdio.h"
 import "stdlib.h"
@@ -621,6 +622,8 @@ fn completionAt(Analysis a, str text, str path, int line, int col) -> json.Json
             methodItems(addr(items), docs.strMethods())
         } else if type.starts_with("map[") {
             methodItems(addr(items), docs.mapMethods())
+        } else if ast.vecType(type).kind.len > 0 {
+            methodItems(addr(items), docs.vecMethods())     // f32x8, i8x32, ...
         } else {
             base := type
             for st in a.structs {
diff --git a/src/main.fch b/src/main.fch
index f4c4f00..7c59c14 100644
--- a/src/main.fch
+++ b/src/main.fch
@@ -174,6 +174,9 @@ fn usage() {
     print("  --trace           runtime errors show the chain of calls (finch run, finch test, -g and -O0 do it anyway)")
     print("  --no-trace        they don't (finch build without -g or -O0 doesn't, it costs speed)")
     print("  --target <name>   build for another system: windows, linux, arm64 (Linux), macos, or an LLVM triple")
+    print("  --cpu <name>      use all of this processor's instructions (AVX2, AVX-512, NEON...): native is the one")
+    print("                    building it; or x86-64-v3 (AVX2), x86-64-v4 (AVX-512), apple-m1, ... The program then")
+    print("                    needs such a processor. Default: any processor of the target system")
     exit(1)
 }
 
@@ -243,7 +246,7 @@ fn format([]str args) -> int {
 
 fn main([]str args) -> int {
     if args.len == 2 && (args[1] == "version" || args[1] == "--version") {
-        print("Finch 2.5.0 (the compiler is written in Finch)")
+        print("Finch 2.6.0 (the compiler is written in Finch)")
         return 0
     }
     if args.len >= 2 && args[1] == "fmt" {
@@ -293,6 +296,7 @@ fn main([]str args) -> int {
     trace := cmd != "build"         // finch build: only with --trace, -g or -O0 (the chain costs speed)
     traceGiven := false
     targetName := ""
+    cpu := ""
     opt := "-O2"
     []str extraLibs
     []str extraDirs
@@ -335,6 +339,9 @@ fn main([]str args) -> int {
         } else if a == "--target" && ai + 1 < args.len {
             targetName = args[ai + 1]
             ai += 1
+        } else if a == "--cpu" && ai + 1 < args.len {
+            cpu = args[ai + 1]
+            ai += 1
         } else if cmd == "run" {
             progArgs.push(a)
         } else {
@@ -418,6 +425,9 @@ fn main([]str args) -> int {
         for f in man.list("cflags", targets) {
             cflags = cflags + " " + linker.quote(f)
         }
+        if cpu.len == 0 {
+            cpu = man.value("cpu", "")
+        }
     }
     for d in getenv("FINCH_PATH").split(host.pathSeparator()) {
         if d.len > 0 {
@@ -494,6 +504,14 @@ fn main([]str args) -> int {
     if debug {
         extra = extra + " -g"      // or clang drops the debug info that is in the IR
     }
+    if cpu.len > 0 {
+        // x86-64 names a processor with -march, ARM with -mcpu
+        if tg.arm64 {
+            extra = extra + " -mcpu=" + linker.quote(cpu)
+        } else {
+            extra = extra + " -march=" + linker.quote(cpu)
+        }
+    }
     []str cflagList
     for d in dirs {
         cflagList.push(" -I" + linker.quote(d))      // also the program's own folders (its headers, for inline C functions)
diff --git a/src/parser.fch b/src/parser.fch
index ce3aff3..db97175 100644
--- a/src/parser.fch
+++ b/src/parser.fch
@@ -86,7 +86,7 @@ fn node(ptr[Parser] p, str kind) -> ast.Node {
 
 fn isTypeName(str n) -> bool {
     names := ["int", "float", "bool", "char", "str", "ptr", "i8", "i16", "i32", "i64", "u8", "u16", "u32", "u64", "f32", "f64"]
-    return names.contains(n)
+    return names.contains(n) || ast.vecType(n).kind.len > 0
 }
 
 // int, str, ptr[T], []T, Name, module.Name
@@ -117,6 +117,10 @@ fn parseType(ptr[Parser] p) -> ast.Type {
         if name == "f64" {
             return ast.simple("float")
         }
+        vt := ast.vecType(name)
+        if vt.kind.len > 0 {
+            return vt
+        }
         return ast.simple(name)
     }
     t := ast.Type(kind: "named", name: name)
diff --git a/tests/fail/vec_intdiv.fch b/tests/fail/vec_intdiv.fch
new file mode 100644
index 0000000..146aa49
--- /dev/null
+++ b/tests/fail/vec_intdiv.fch
@@ -0,0 +1,5 @@
+// expect: no instruction that divides whole numbers lane by lane
+fn main() {
+    a := i32x4(8)
+    print(a / 2)
+}
diff --git a/tests/fail/vec_lane_index.fch b/tests/fail/vec_lane_index.fch
new file mode 100644
index 0000000..8d71340
--- /dev/null
+++ b/tests/fail/vec_lane_index.fch
@@ -0,0 +1,6 @@
+// expect: index 4
+fn main() {
+    v := i32x4(1)
+    i := 4
+    print(v[i])
+}
diff --git a/tests/fail/vec_lanes.fch b/tests/fail/vec_lanes.fch
new file mode 100644
index 0000000..3e4d0f2
--- /dev/null
+++ b/tests/fail/vec_lanes.fch
@@ -0,0 +1,4 @@
+// expect: f32x4(a, b, ...) takes 4 numbers
+fn main() {
+    print(f32x4(1.0, 2.0, 3.0))
+}
diff --git a/tests/fail/vec_less.fch b/tests/fail/vec_less.fch
new file mode 100644
index 0000000..e9dadb0
--- /dev/null
+++ b/tests/fail/vec_less.fch
@@ -0,0 +1,5 @@
+// expect: use min(v, w), max(v, w), or compare lanes: v[i] < w[i]
+fn main() {
+    a := f32x4(1.0)
+    print(a < a)
+}
diff --git a/tests/fail/vec_load_end.fch b/tests/fail/vec_load_end.fch
new file mode 100644
index 0000000..aa5cb71
--- /dev/null
+++ b/tests/fail/vec_load_end.fch
@@ -0,0 +1,5 @@
+// expect: the 8 numbers of the vector don't all fit in the list there
+fn main() {
+    []f32 data = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]
+    print(f32x8(data, 2))
+}
diff --git a/tests/fail/vec_mix.fch b/tests/fail/vec_mix.fch
new file mode 100644
index 0000000..4b05a3c
--- /dev/null
+++ b/tests/fail/vec_mix.fch
@@ -0,0 +1,6 @@
+// expect: can't use '+' on f32x8 and i32x8 (convert one: f32x8(...))
+fn main() {
+    a := f32x8(1.0)
+    b := i32x8(1)
+    print(a + b)
+}
diff --git a/tests/fail/vec_type.fch b/tests/fail/vec_type.fch
new file mode 100644
index 0000000..0f44299
--- /dev/null
+++ b/tests/fail/vec_type.fch
@@ -0,0 +1,5 @@
+// expect: f32x8(x) puts x in every lane
+fn main() {
+    f32x8 v = 1.0
+    print(v)
+}
diff --git a/tests/run/vectors.fch b/tests/run/vectors.fch
new file mode 100644
index 0000000..2d7d95f
--- /dev/null
+++ b/tests/run/vectors.fch
@@ -0,0 +1,69 @@
+// Vectors: N numbers side by side, worked on all at once (SIMD)
+
+struct Particle {
+    f32x8 pos
+    int id = 7
+}
+
+fn scale(f32x8 v, f32 k) -> f32x8 {
+    return v * k
+}
+
+// a dot product of two lists, 8 at a time, with the rest one by one
+fn dot([]f32 a, []f32 b) -> f32 {
+    acc := f32x8(0.0)
+    i := 0
+    while i + 8 <= a.len {
+        acc = f32x8(a, i).fma(f32x8(b, i), acc)
+        i += 8
+    }
+    total := acc.sum()
+    while i < a.len {
+        total += a[i] * b[i]
+        i += 1
+    }
+    return total
+}
+
+fn main() {
+    a := f32x4(1.0, 2.0, 3.0, 4.0)
+    b := f32x4(0.5)
+    print(a + b, a * 2.0, 10.0 - a, -a)
+    print(a.sum(), a.min(), a.max(), a.dot(a), a.len)
+    print((a * a).sqrt(), f32x4(1.5, -1.5, 2.5, -0.2).round(), f32x4(1.7).floor(), f32x4(1.2).ceil())
+    print(abs(f32x4(-1.0, 2.0, -3.0, 4.0)), min(a, 2.5), max(a, f32x4(2.0)), clamp(a, 1.5, 3.5))
+
+    // lanes
+    a[0] = 9.0
+    print(a[0], a[3], a)
+    print(a == f32x4(9.0, 2.0, 3.0, 4.0), a != a)
+
+    // whole numbers, bits, conversions
+    n := i32x8(1, 2, 3, 4, 5, 6, 7, 8)
+    print(n * 3 - 1, n << 2, n & 1, ~n, n.sum(), n.max())
+    print(f32x8(n) / 2.0, i32x8(f32x8(2.9)), i16x8(n), u8x16(200).sum())
+    print(abs(i32x4(-3, 3, -7, 0)), min(u8x16(5), u8x16(9)).max())
+
+    // from lists and back
+    []f32 data
+    for i in 0..20 {
+        data.push(f32(i))
+    }
+    v := f32x8(data, 4)
+    print(v)
+    (v * 10.0).store(data, 12)
+    print(data)
+    print(dot(data, data))
+
+    // in structs, arrays, functions, and str()
+    p := Particle(pos: f32x8(1.0))
+    p.pos = scale(p.pos, 3.0)
+    p.pos[7] = 0.5
+    print(p)
+    []f64x4 list
+    list.push(f64x4(1.0, 2.0, 3.0, 4.0))
+    list.push(list[0] * list[0])
+    print(list, str(list[1]).len)
+    i64x2 big = i64x2(1 << 40, -5)
+    print(big + big)
+}
diff --git a/tests/run/vectors.out b/tests/run/vectors.out
new file mode 100644
index 0000000..8e130e6
--- /dev/null
+++ b/tests/run/vectors.out
@@ -0,0 +1,15 @@
+f32x4(1.5, 2.5, 3.5, 4.5) f32x4(2, 4, 6, 8) f32x4(9, 8, 7, 6) f32x4(-1, -2, -3, -4)
+10 1 4 30 4
+f32x4(1, 2, 3, 4) f32x4(2, -2, 3, -0) f32x4(1, 1, 1, 1) f32x4(2, 2, 2, 2)
+f32x4(1, 2, 3, 4) f32x4(1, 2, 2.5, 2.5) f32x4(2, 2, 3, 4) f32x4(1.5, 2, 3, 3.5)
+9 4 f32x4(9, 2, 3, 4)
+true false
+i32x8(2, 5, 8, 11, 14, 17, 20, 23) i32x8(4, 8, 12, 16, 20, 24, 28, 32) i32x8(1, 0, 1, 0, 1, 0, 1, 0) i32x8(-2, -3, -4, -5, -6, -7, -8, -9) 36 8
+f32x8(0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4) i32x8(2, 2, 2, 2, 2, 2, 2, 2) i16x8(1, 2, 3, 4, 5, 6, 7, 8) 128
+i32x4(3, 3, 7, 0) 5
+f32x8(4, 5, 6, 7, 8, 9, 10, 11)
+[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 40, 50, 60, 70, 80, 90, 100, 110]
+49706
+Particle(pos: f32x8(3, 3, 3, 3, 3, 3, 3, 0.5), id: 7)
+[f64x4(1, 2, 3, 4), f64x4(1, 4, 9, 16)] 18
+i64x2(2199023255552, -10)