diff --git a/cranelift/filetests/parser/ternary.cton b/cranelift/filetests/parser/ternary.cton
new file mode 100644
index 0000000000..5305126c49
--- /dev/null
+++ b/cranelift/filetests/parser/ternary.cton
@@ -0,0 +1,13 @@
+test cat
+test verifier
+
+function add_i96(i32, i32, i32, i32, i32, i32) -> i32, i32, i32 {
+ebb1(v1: i32, v2: i32, v3: i32, v4: i32, v5: i32, v6: i32):
+    v10, v11 = iadd_cout v1, v4
+    ;check: $v10, $v11 = iadd_cout $v1, $v4
+    v20, v21 = iadd_carry v2, v5, v11
+    ; check: $v20, $v21 = iadd_carry $v2, $v5, $v11
+    v30 = iadd_cin v3, v6, v21
+    ; check: $v30 = iadd_cin $v3, $v6, $v21
+    return v10, v20, v30
+}
diff --git a/cranelift/src/libcretonne/ir/instructions.rs b/cranelift/src/libcretonne/ir/instructions.rs
index c8228d1f43..bfc1fe65f3 100644
--- a/cranelift/src/libcretonne/ir/instructions.rs
+++ b/cranelift/src/libcretonne/ir/instructions.rs
@@ -149,6 +149,11 @@ pub enum InstructionData {
         ty: Type,
         args: [Value; 3],
     },
+    TernaryOverflow {
+        opcode: Opcode,
+        ty: Type,
+        data: Box<TernaryOverflowData>,
+    },
     InsertLane {
         opcode: Opcode,
         ty: Type,
@@ -254,6 +259,19 @@ impl Default for VariableArgs {
     }
 }
 
+/// Payload data for ternary instructions with multiple results, such as `iadd_carry`.
+#[derive(Clone, Debug)]
+pub struct TernaryOverflowData {
+    pub second_result: Value,
+    pub args: [Value; 3],
+}
+
+impl Display for TernaryOverflowData {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}, {}, {}", self.args[0], self.args[1], self.args[2])
+    }
+}
+
 /// Payload data for jump instructions. These need to carry lists of EBB arguments that won't fit
 /// in the allowed InstructionData size.
 #[derive(Clone, Debug)]
diff --git a/cranelift/src/libcretonne/write.rs b/cranelift/src/libcretonne/write.rs
index bfdd13b32f..ea73d18666 100644
--- a/cranelift/src/libcretonne/write.rs
+++ b/cranelift/src/libcretonne/write.rs
@@ -190,6 +190,7 @@ fn write_instruction(w: &mut Write,
         BinaryImmRev { imm, arg, .. } => writeln!(w, " {}, {}", imm, arg),
         BinaryOverflow { args, .. } => writeln!(w, " {}, {}", args[0], args[1]),
         Ternary { args, .. } => writeln!(w, " {}, {}, {}", args[0], args[1], args[2]),
+        TernaryOverflow { ref data, .. } => writeln!(w, " {}", data),
         InsertLane { lane, args, .. } => writeln!(w, " {}, {}, {}", args[0], lane, args[1]),
         ExtractLane { lane, arg, .. } => writeln!(w, " {}, {}", arg, lane),
         IntCompare { cond, args, .. } => writeln!(w, " {}, {}, {}", cond, args[0], args[1]),
diff --git a/cranelift/src/libreader/parser.rs b/cranelift/src/libreader/parser.rs
index 05fa9b831b..723cfb1951 100644
--- a/cranelift/src/libreader/parser.rs
+++ b/cranelift/src/libreader/parser.rs
@@ -13,8 +13,8 @@ use cretonne::ir::{Function, Ebb, Opcode, Value, Type, FunctionName, StackSlotDa
 use cretonne::ir::types::{VOID, Signature, ArgumentType, ArgumentExtension};
 use cretonne::ir::immediates::{Imm64, Ieee32, Ieee64};
 use cretonne::ir::entities::{AnyEntity, NO_EBB, NO_INST, NO_VALUE};
-use cretonne::ir::instructions::{InstructionFormat, InstructionData, VariableArgs, JumpData,
-                                 BranchData, ReturnData};
+use cretonne::ir::instructions::{InstructionFormat, InstructionData, VariableArgs,
+                                 TernaryOverflowData, JumpData, BranchData, ReturnData};
 use cretonne::isa;
 use cretonne::settings;
 use testfile::{TestFile, Details, Comment};
@@ -138,6 +138,10 @@ impl Context {
                         try!(self.map.rewrite_values(args, loc));
                     }
 
+                    InstructionData::TernaryOverflow { ref mut data, .. } => {
+                        try!(self.map.rewrite_values(&mut data.args, loc));
+                    }
+
                     InstructionData::Jump { ref mut data, .. } => {
                         try!(self.map.rewrite_ebb(&mut data.destination, loc));
                         try!(self.map.rewrite_values(&mut data.arguments, loc));
@@ -1066,6 +1070,22 @@ impl<'a> Parser<'a> {
                     args: [ctrl_arg, true_arg, false_arg],
                 }
             }
+            InstructionFormat::TernaryOverflow => {
+                // Names here refer to the `iadd_carry` instruction.
+                let lhs = try!(self.match_value("expected SSA value first operand"));
+                try!(self.match_token(Token::Comma, "expected ',' between operands"));
+                let rhs = try!(self.match_value("expected SSA value second operand"));
+                try!(self.match_token(Token::Comma, "expected ',' between operands"));
+                let cin = try!(self.match_value("expected SSA value third operand"));
+                InstructionData::TernaryOverflow {
+                    opcode: opcode,
+                    ty: VOID,
+                    data: Box::new(TernaryOverflowData {
+                        second_result: NO_VALUE,
+                        args: [lhs, rhs, cin],
+                    }),
+                }
+            }
             InstructionFormat::Jump => {
                 // Parse the destination EBB number. Don't translate source to local numbers yet.
                 let ebb_num = try!(self.match_ebb("expected jump destination EBB"));
diff --git a/meta/cretonne/base.py b/meta/cretonne/base.py
index 30d890b076..f94668da4a 100644
--- a/meta/cretonne/base.py
+++ b/meta/cretonne/base.py
@@ -6,7 +6,7 @@ support.
 """
 from __future__ import absolute_import
 from . import TypeVar, Operand, Instruction, InstructionGroup, variable_args
-from .types import i8, f32, f64
+from .types import i8, f32, f64, b1
 from .immediates import imm64, uimm8, ieee32, ieee64, immvector, intcc, floatcc
 from . import entities
 
@@ -405,6 +405,48 @@ isub_imm = Instruction(
         """,
         ins=(X, y), outs=a)
 
+#
+# Integer arithmetic with carry.
+#
+a = Operand('a', iB)
+x = Operand('x', iB)
+y = Operand('y', iB)
+cin = Operand('cin', b1, doc="Input carry flag")
+cout = Operand('cout', b1, doc="Output carry flag")
+
+iadd_cin = Instruction(
+        'iadd_cin', """
+        Add integers with carry in.
+
+        Same as :inst:`iadd` with an additional carry input.
+
+        Polymorphic over all scalar integer types, but does not support vector
+        types.
+        """,
+        ins=(x, y, cin), outs=a)
+
+iadd_cout = Instruction(
+        'iadd_cout', """
+        Add integers with carry out.
+
+        Same as :inst:`iadd` with an additional carry output.
+
+        Polymorphic over all scalar integer types, but does not support vector
+        types.
+        """,
+        ins=(x, y), outs=(a, cout))
+
+iadd_carry = Instruction(
+        'iadd_carry', """
+        Add integers with carry in and out.
+
+        Same as :inst:`iadd` with an additional carry output.
+
+        Polymorphic over all scalar integer types, but does not support vector
+        types.
+        """,
+        ins=(x, y, cin), outs=(a, cout))
+
 #
 # Bitwise operations.
 #
diff --git a/meta/cretonne/formats.py b/meta/cretonne/formats.py
index 06f4593086..48b9d978af 100644
--- a/meta/cretonne/formats.py
+++ b/meta/cretonne/formats.py
@@ -30,6 +30,10 @@ BinaryOverflow = InstructionFormat(value, value, multiple_results=True)
 # The fma instruction has the same constraint on all inputs.
 Ternary = InstructionFormat(value, value, value, typevar_operand=1)
 
+# Carry in *and* carry out for `iadd_carry` and friends.
+TernaryOverflow = InstructionFormat(
+        value, value, value, multiple_results=True, boxed_storage=True)
+
 InsertLane = InstructionFormat(value, ('lane', uimm8), value)
 ExtractLane = InstructionFormat(value, ('lane', uimm8))
 
diff --git a/meta/gen_instr.py b/meta/gen_instr.py
index 139acf59b7..6c67077cb0 100644
--- a/meta/gen_instr.py
+++ b/meta/gen_instr.py
@@ -153,9 +153,8 @@ def gen_instruction_data_impl(fmt):
                         if f.boxed_storage:
                             fmt.line(
                                     n +
-                                    ' {{ ref data, .. }} => ' +
-                                    'Some(data.args[{}]),'
-                                    .format(i))
+                                    ' { ref data, .. } => ' +
+                                    ('Some(data.args[{}]),'.format(i)))
                         else:
                             fmt.line(
                                     n +