diff --git a/cranelift/src/filetest/binemit.rs b/cranelift/src/filetest/binemit.rs
index 2f695bff1e..15f5b0a982 100644
--- a/cranelift/src/filetest/binemit.rs
+++ b/cranelift/src/filetest/binemit.rs
@@ -127,7 +127,7 @@ impl SubTest for TestBinEmit {
                     AnyEntity::Inst(inst) => {
                         if let Some(prev) = bins.insert(inst, want) {
                             return Err(format!("multiple 'bin:' directives on {}: '{}' and '{}'",
-                                               func.dfg.display_inst(inst),
+                                               func.dfg.display_inst(inst, isa),
                                                prev,
                                                want));
                         }
@@ -166,7 +166,7 @@ impl SubTest for TestBinEmit {
                                encinfo.bytes(enc),
                                "Inconsistent size for [{}] {}",
                                encinfo.display(enc),
-                               func.dfg.display_inst(inst));
+                               func.dfg.display_inst(inst, isa));
                 }
 
                 // Check against bin: directives.
@@ -174,13 +174,13 @@ impl SubTest for TestBinEmit {
                     if !enc.is_legal() {
                         return Err(format!("{} can't be encoded: {}",
                                            inst,
-                                           func.dfg.display_inst(inst)));
+                                           func.dfg.display_inst(inst, isa)));
                     }
                     let have = sink.text.trim();
                     if have != want {
                         return Err(format!("Bad machine code for {}: {}\nWant: {}\nGot:  {}",
                                            inst,
-                                           func.dfg.display_inst(inst),
+                                           func.dfg.display_inst(inst, isa),
                                            want,
                                            have));
                     }
diff --git a/cranelift/src/utils.rs b/cranelift/src/utils.rs
index f620f5f316..3bc8e7b1df 100644
--- a/cranelift/src/utils.rs
+++ b/cranelift/src/utils.rs
@@ -42,7 +42,7 @@ pub fn pretty_verifier_error(func: &ir::Function,
     let mut msg = err.to_string();
     match err.location {
         AnyEntity::Inst(inst) => {
-            write!(msg, "\n{}: {}\n\n", inst, func.dfg.display_inst(inst)).unwrap()
+            write!(msg, "\n{}: {}\n\n", inst, func.dfg.display_inst(inst, isa)).unwrap()
         }
         _ => msg.push('\n'),
     }
diff --git a/lib/cretonne/src/binemit/mod.rs b/lib/cretonne/src/binemit/mod.rs
index 33cce8d2b0..eaa721d510 100644
--- a/lib/cretonne/src/binemit/mod.rs
+++ b/lib/cretonne/src/binemit/mod.rs
@@ -53,5 +53,5 @@ pub trait CodeSink {
 pub fn bad_encoding(func: &Function, inst: Inst) -> ! {
     panic!("Bad encoding {} for {}",
            func.encodings[inst],
-           func.dfg.display_inst(inst));
+           func.dfg.display_inst(inst, None));
 }
diff --git a/lib/cretonne/src/binemit/relaxation.rs b/lib/cretonne/src/binemit/relaxation.rs
index 53b7fd0112..d80d17d7bb 100644
--- a/lib/cretonne/src/binemit/relaxation.rs
+++ b/lib/cretonne/src/binemit/relaxation.rs
@@ -135,7 +135,7 @@ fn relax_branch(dfg: &mut DataFlowGraph,
     let inst = pos.current_inst().unwrap();
     dbg!("Relaxing [{}] {} for {:#x}-{:#x} range",
          encinfo.display(encodings[inst]),
-         dfg.display_inst(inst),
+         dfg.display_inst(inst, None),
          offset,
          dest_offset);
     unimplemented!();
diff --git a/lib/cretonne/src/ir/dfg.rs b/lib/cretonne/src/ir/dfg.rs
index 85e971a9fc..ad67f7722b 100644
--- a/lib/cretonne/src/ir/dfg.rs
+++ b/lib/cretonne/src/ir/dfg.rs
@@ -1,6 +1,7 @@
 //! Data flow graph tracking Instructions, Values, and EBBs.
 
 use entity_map::{EntityMap, PrimaryEntityData};
+use isa::TargetIsa;
 use ir::builder::{InsertBuilder, ReplaceBuilder};
 use ir::extfunc::ExtFuncData;
 use ir::instructions::{Opcode, InstructionData, CallInfo};
@@ -162,7 +163,7 @@ impl DataFlowGraph {
                            self.results[inst].get(num as usize, &self.value_lists),
                            "Dangling result value {}: {}",
                            v,
-                           self.display_inst(inst));
+                           self.display_inst(inst, None));
                 ValueDef::Res(inst, num as usize)
             }
             ValueData::Arg { ebb, num, .. } => {
@@ -376,8 +377,11 @@ impl DataFlowGraph {
     }
 
     /// Returns an object that displays `inst`.
-    pub fn display_inst(&self, inst: Inst) -> DisplayInst {
-        DisplayInst(self, inst)
+    pub fn display_inst<'a, I: Into<Option<&'a TargetIsa>>>(&'a self,
+                                                            inst: Inst,
+                                                            isa: I)
+                                                            -> DisplayInst<'a> {
+        DisplayInst(self, isa.into(), inst)
     }
 
     /// Get all value arguments on `inst` as a slice.
@@ -552,7 +556,7 @@ impl DataFlowGraph {
                    old_value,
                    "{} wasn't detached from {}",
                    old_value,
-                   self.display_inst(inst));
+                   self.display_inst(inst, None));
         new_value
     }
 
@@ -830,14 +834,15 @@ impl EbbData {
 }
 
 /// Object that can display an instruction.
-pub struct DisplayInst<'a>(&'a DataFlowGraph, Inst);
+pub struct DisplayInst<'a>(&'a DataFlowGraph, Option<&'a TargetIsa>, Inst);
 
 impl<'a> fmt::Display for DisplayInst<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let dfg = self.0;
-        let inst = &dfg[self.1];
+        let isa = self.1;
+        let inst = self.2;
 
-        if let Some((first, rest)) = dfg.inst_results(self.1).split_first() {
+        if let Some((first, rest)) = dfg.inst_results(inst).split_first() {
             write!(f, "{}", first)?;
             for v in rest {
                 write!(f, ", {}", v)?;
@@ -846,13 +851,13 @@ impl<'a> fmt::Display for DisplayInst<'a> {
         }
 
 
-        let typevar = dfg.ctrl_typevar(self.1);
+        let typevar = dfg.ctrl_typevar(inst);
         if typevar.is_void() {
-            write!(f, "{}", inst.opcode())?;
+            write!(f, "{}", dfg[inst].opcode())?;
         } else {
-            write!(f, "{}.{}", inst.opcode(), typevar)?;
+            write!(f, "{}.{}", dfg[inst].opcode(), typevar)?;
         }
-        write_operands(f, dfg, None, self.1)
+        write_operands(f, dfg, isa, inst)
     }
 }
 
@@ -870,7 +875,7 @@ mod tests {
         let inst = dfg.make_inst(idata);
         dfg.make_inst_results(inst, types::I32);
         assert_eq!(inst.to_string(), "inst0");
-        assert_eq!(dfg.display_inst(inst).to_string(), "v0 = iconst.i32");
+        assert_eq!(dfg.display_inst(inst, None).to_string(), "v0 = iconst.i32");
 
         // Immutable reference resolution.
         {
@@ -902,7 +907,7 @@ mod tests {
 
         let idata = InstructionData::Nullary { opcode: Opcode::Trap };
         let inst = dfg.make_inst(idata);
-        assert_eq!(dfg.display_inst(inst).to_string(), "trap");
+        assert_eq!(dfg.display_inst(inst, None).to_string(), "trap");
 
         // Result slice should be empty.
         assert_eq!(dfg.inst_results(inst), &[]);
diff --git a/lib/cretonne/src/legalizer/boundary.rs b/lib/cretonne/src/legalizer/boundary.rs
index b65eea0984..3f22694eb8 100644
--- a/lib/cretonne/src/legalizer/boundary.rs
+++ b/lib/cretonne/src/legalizer/boundary.rs
@@ -474,7 +474,7 @@ pub fn handle_call_abi(dfg: &mut DataFlowGraph, cfg: &ControlFlowGraph, pos: &mu
 
     debug_assert!(check_call_signature(dfg, inst).is_ok(),
                   "Signature still wrong: {}, {}{}",
-                  dfg.display_inst(inst),
+                  dfg.display_inst(inst, None),
                   sig_ref,
                   dfg.signatures[sig_ref]);
 
@@ -523,7 +523,7 @@ pub fn handle_return_abi(dfg: &mut DataFlowGraph,
     if special_args > 0 {
         dbg!("Adding {} special-purpose arguments to {}",
              special_args,
-             dfg.display_inst(inst));
+             dfg.display_inst(inst, None));
         let mut vlist = dfg[inst].take_value_list().unwrap();
         for arg in &sig.return_types[abi_args..] {
             match arg.purpose {
@@ -550,7 +550,7 @@ pub fn handle_return_abi(dfg: &mut DataFlowGraph,
 
     debug_assert!(check_return_signature(dfg, inst, sig),
                   "Signature still wrong: {} / signature {}",
-                  dfg.display_inst(inst),
+                  dfg.display_inst(inst, None),
                   sig);
 
     // Yes, we changed stuff.
diff --git a/lib/cretonne/src/legalizer/split.rs b/lib/cretonne/src/legalizer/split.rs
index cbca25c9c2..3e3a36f619 100644
--- a/lib/cretonne/src/legalizer/split.rs
+++ b/lib/cretonne/src/legalizer/split.rs
@@ -123,7 +123,7 @@ fn split_any(dfg: &mut DataFlowGraph,
             let branch_opc = dfg[inst].opcode();
             assert!(branch_opc.is_branch(),
                     "Predecessor not a branch: {}",
-                    dfg.display_inst(inst));
+                    dfg.display_inst(inst, None));
             let fixed_args = branch_opc.constraints().fixed_value_arguments();
             let mut args = dfg[inst]
                 .take_value_list()
diff --git a/lib/cretonne/src/regalloc/coalescing.rs b/lib/cretonne/src/regalloc/coalescing.rs
index 634f0c0a32..08ecf12589 100644
--- a/lib/cretonne/src/regalloc/coalescing.rs
+++ b/lib/cretonne/src/regalloc/coalescing.rs
@@ -399,7 +399,7 @@ impl<'a> Context<'a> {
             dbg!("Checking {}: {}: {}",
                  pred_val,
                  pred_ebb,
-                 self.func.dfg.display_inst(pred_inst));
+                 self.func.dfg.display_inst(pred_inst, self.isa));
 
             // Never coalesce incoming function arguments on the stack. These arguments are
             // pre-spilled, and the rest of the virtual register would be forced to spill to the
@@ -474,9 +474,9 @@ impl<'a> Context<'a> {
         let ty = self.func.dfg.value_type(copy);
 
         dbg!("Inserted {}, before {}: {}",
-             self.func.dfg.display_inst(inst),
+             self.func.dfg.display_inst(inst, self.isa),
              pred_ebb,
-             self.func.dfg.display_inst(pred_inst));
+             self.func.dfg.display_inst(pred_inst, self.isa));
 
         // Give it an encoding.
         let encoding = self.isa
@@ -519,7 +519,7 @@ impl<'a> Context<'a> {
         self.liveness.move_def_locally(succ_val, inst);
 
         dbg!("Inserted {}, following {}({}: {})",
-             self.func.dfg.display_inst(inst),
+             self.func.dfg.display_inst(inst, self.isa),
              ebb,
              new_val,
              ty);
diff --git a/lib/cretonne/src/regalloc/coloring.rs b/lib/cretonne/src/regalloc/coloring.rs
index f61e88e9b7..85911efd0b 100644
--- a/lib/cretonne/src/regalloc/coloring.rs
+++ b/lib/cretonne/src/regalloc/coloring.rs
@@ -73,6 +73,7 @@ pub struct Coloring {
 /// Immutable context information and mutable references that don't need to be borrowed across
 /// method calls should go in this struct.
 struct Context<'a> {
+    isa: &'a TargetIsa,
     // Cached ISA information.
     // We save it here to avoid frequent virtual function calls on the `TargetIsa` trait object.
     reginfo: RegInfo,
@@ -111,6 +112,7 @@ impl Coloring {
                tracker: &mut LiveValueTracker) {
         dbg!("Coloring for:\n{}", func.display(isa));
         let mut ctx = Context {
+            isa,
             reginfo: isa.register_info(),
             encinfo: isa.encoding_info(),
             domtree,
@@ -279,7 +281,7 @@ impl<'a> Context<'a> {
                   locations: &mut ValueLocations,
                   func_signature: &Signature) {
         dbg!("Coloring {}\n          {}",
-             dfg.display_inst(inst),
+             dfg.display_inst(inst, self.isa),
              regs.display(&self.reginfo));
 
         // EBB whose arguments should be colored to match the current branch instruction's
@@ -308,7 +310,7 @@ impl<'a> Context<'a> {
                 assert_eq!(dfg.inst_variable_args(inst).len(),
                            0,
                            "Can't handle EBB arguments: {}",
-                           dfg.display_inst(inst));
+                           dfg.display_inst(inst, self.isa));
                 self.undivert_regs(|lr| !lr.is_local());
             }
         }
diff --git a/lib/cretonne/src/regalloc/spilling.rs b/lib/cretonne/src/regalloc/spilling.rs
index 465efa7856..5733f6e80f 100644
--- a/lib/cretonne/src/regalloc/spilling.rs
+++ b/lib/cretonne/src/regalloc/spilling.rs
@@ -246,7 +246,9 @@ impl<'a> Context<'a> {
                   pos: &mut Cursor,
                   dfg: &mut DataFlowGraph,
                   tracker: &mut LiveValueTracker) {
-        dbg!("Inst {}, {}", dfg.display_inst(inst), self.pressure);
+        dbg!("Inst {}, {}",
+             dfg.display_inst(inst, self.isa),
+             self.pressure);
 
         // We may need to resolve register constraints if there are any noteworthy uses.
         assert!(self.reg_uses.is_empty());
@@ -292,7 +294,7 @@ impl<'a> Context<'a> {
                         None => {
                             panic!("Ran out of {} registers for {}",
                                    op.regclass,
-                                   dfg.display_inst(inst))
+                                   dfg.display_inst(inst, self.isa))
                         }
                     }
                 }
@@ -429,7 +431,7 @@ impl<'a> Context<'a> {
                         None => {
                             panic!("Ran out of {} registers when inserting copy before {}",
                                    rc,
-                                   dfg.display_inst(inst))
+                                   dfg.display_inst(inst, self.isa))
                         }
                     }
                 }