diff --git a/cranelift/codegen/src/write.rs b/cranelift/codegen/src/write.rs
index abdc5992ad..08a723c16f 100644
--- a/cranelift/codegen/src/write.rs
+++ b/cranelift/codegen/src/write.rs
@@ -7,7 +7,7 @@ use crate::entity::SecondaryMap;
 use crate::ir::entities::AnyEntity;
 use crate::ir::{Block, DataFlowGraph, Function, Inst, SigRef, Type, Value, ValueDef};
 use crate::packed_option::ReservedValue;
-use alloc::string::String;
+use alloc::string::{String, ToString};
 use alloc::vec::Vec;
 use core::fmt::{self, Write};
 
@@ -530,7 +530,26 @@ pub fn write_operands(w: &mut dyn Write, dfg: &DataFlowGraph, inst: Inst) -> fmt
         FloatCondTrap {
             cond, arg, code, ..
         } => write!(w, " {} {}, {}", cond, arg, code),
+    }?;
+
+    let mut sep = "  ; ";
+    for &arg in dfg.inst_args(inst) {
+        if let ValueDef::Result(src, _) = dfg.value_def(arg) {
+            let imm = match dfg[src] {
+                UnaryImm { imm, .. } => imm.to_string(),
+                UnaryIeee32 { imm, .. } => imm.to_string(),
+                UnaryIeee64 { imm, .. } => imm.to_string(),
+                UnaryBool { imm, .. } => imm.to_string(),
+                UnaryConst {
+                    constant_handle, ..
+                } => constant_handle.to_string(),
+                _ => continue,
+            };
+            write!(w, "{}{} = {}", sep, arg, imm)?;
+            sep = ", ";
+        }
     }
+    Ok(())
 }
 
 /// Write block args using optional parantheses.
diff --git a/cranelift/filetests/filetests/verifier/type_check.clif b/cranelift/filetests/filetests/verifier/type_check.clif
index c708ca76ad..b5933f8acb 100644
--- a/cranelift/filetests/filetests/verifier/type_check.clif
+++ b/cranelift/filetests/filetests/verifier/type_check.clif
@@ -48,11 +48,9 @@ function %fn_call_too_few_args() {
         return
 }
 
-function %fn_call_too_many_args() {
+function %fn_call_too_many_args(i64, f32) {
     fn5 = %best_fn()
-    block0:
-        v0 = iconst.i64 56
-        v1 = f32const 0.0
+    block0(v0: i64, v1: f32):
         call fn5(v0, v1) ; error: mismatched argument count for `call fn5(v0, v1)`: got 2, expected 0
         return
 }
diff --git a/cranelift/frontend/src/frontend.rs b/cranelift/frontend/src/frontend.rs
index af2240ff6e..e4f5840249 100644
--- a/cranelift/frontend/src/frontend.rs
+++ b/cranelift/frontend/src/frontend.rs
@@ -1232,6 +1232,17 @@ mod tests {
         sample_function(true)
     }
 
+    #[track_caller]
+    fn check(func: &Function, expected_ir: &str) {
+        let actual_ir = func.display().to_string();
+        assert!(
+            expected_ir == actual_ir,
+            "Expected:\n{}\nGot:\n{}",
+            expected_ir,
+            actual_ir
+        );
+    }
+
     /// Helper function to construct a fixed frontend configuration.
     fn systemv_frontend_config() -> TargetFrontendConfig {
         TargetFrontendConfig {
@@ -1271,8 +1282,8 @@ mod tests {
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
     sig0 = (i64, i64, i64) system_v
     fn0 = %Memcpy sig0
@@ -1282,10 +1293,10 @@ block0:
     v1 -> v3
     v2 = iconst.i64 0
     v0 -> v2
-    call fn0(v1, v0, v1)
-    return v1
+    call fn0(v1, v0, v1)  ; v1 = 0, v0 = 0, v1 = 0
+    return v1  ; v1 = 0
 }
-"
+",
         );
     }
 
@@ -1327,19 +1338,19 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
 block0:
     v4 = iconst.i64 0
     v1 -> v4
     v3 = iconst.i64 0
     v0 -> v3
-    v2 = load.i64 aligned v0
-    store aligned v2, v1
-    return v1
+    v2 = load.i64 aligned v0  ; v0 = 0
+    store aligned v2, v1  ; v1 = 0
+    return v1  ; v1 = 0
 }
-"
+",
         );
     }
 
@@ -1381,8 +1392,8 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
     sig0 = (i64, i64, i64) system_v
     fn0 = %Memcpy sig0
@@ -1393,10 +1404,10 @@ block0:
     v3 = iconst.i64 0
     v0 -> v3
     v2 = iconst.i64 8192
-    call fn0(v1, v0, v2)
-    return v1
+    call fn0(v1, v0, v2)  ; v1 = 0, v0 = 0, v2 = 8192
+    return v1  ; v1 = 0
 }
-"
+",
         );
     }
 
@@ -1426,17 +1437,17 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
 block0:
     v2 = iconst.i64 0
     v0 -> v2
     v1 = iconst.i64 0x0101_0101_0101_0101
-    store aligned v1, v0
-    return v0
+    store aligned v1, v0  ; v1 = 0x0101_0101_0101_0101, v0 = 0
+    return v0  ; v0 = 0
 }
-"
+",
         );
     }
 
@@ -1466,8 +1477,8 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
     sig0 = (i64, i32, i64) system_v
     fn0 = %Memset sig0
@@ -1477,11 +1488,11 @@ block0:
     v0 -> v4
     v1 = iconst.i8 1
     v2 = iconst.i64 8192
-    v3 = uextend.i32 v1
-    call fn0(v0, v3, v2)
-    return v0
+    v3 = uextend.i32 v1  ; v1 = 1
+    call fn0(v0, v3, v2)  ; v0 = 0, v2 = 8192
+    return v0  ; v0 = 0
 }
-"
+",
         );
     }
 
@@ -1530,8 +1541,8 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i32 system_v {
     sig0 = (i64, i64, i64) -> i32 system_v
     fn0 = %Memcmp sig0
@@ -1543,10 +1554,10 @@ block0:
     v1 -> v5
     v4 = iconst.i64 0
     v0 -> v4
-    v3 = call fn0(v0, v1, v2)
+    v3 = call fn0(v0, v1, v2)  ; v0 = 0, v1 = 0, v2 = 0
     return v3
 }
-"
+",
         );
     }
 
@@ -1561,7 +1572,7 @@ block0:
     v3 = iconst.i64 0
     v0 -> v3
     v2 = bconst.b1 true
-    return v2",
+    return v2  ; v2 = true",
             |builder, target, x, y| {
                 builder.emit_small_memory_compare(
                     target.frontend_config(),
@@ -1587,8 +1598,8 @@ block0:
     v1 -> v6
     v5 = iconst.i64 0
     v0 -> v5
-    v2 = load.i8 aligned v0
-    v3 = load.i8 aligned v1
+    v2 = load.i8 aligned v0  ; v0 = 0
+    v3 = load.i8 aligned v1  ; v1 = 0
     v4 = icmp ugt v2, v3
     return v4",
             |builder, target, x, y| {
@@ -1616,8 +1627,8 @@ block0:
     v1 -> v6
     v5 = iconst.i64 0
     v0 -> v5
-    v2 = load.i32 aligned v0
-    v3 = load.i32 aligned v1
+    v2 = load.i32 aligned v0  ; v0 = 0
+    v3 = load.i32 aligned v1  ; v1 = 0
     v4 = icmp eq v2, v3
     return v4",
             |builder, target, x, y| {
@@ -1645,8 +1656,8 @@ block0:
     v1 -> v6
     v5 = iconst.i64 0
     v0 -> v5
-    v2 = load.i128 v0
-    v3 = load.i128 v1
+    v2 = load.i128 v0  ; v0 = 0
+    v3 = load.i128 v1  ; v1 = 0
     v4 = icmp ne v2, v3
     return v4",
             |builder, target, x, y| {
@@ -1678,7 +1689,7 @@ block0:
     v5 = iconst.i64 0
     v0 -> v5
     v2 = iconst.i64 3
-    v3 = call fn0(v0, v1, v2)
+    v3 = call fn0(v0, v1, v2)  ; v0 = 0, v1 = 0, v2 = 3
     v4 = icmp_imm sge v3, 0
     return v4",
             |builder, target, x, y| {
@@ -1740,13 +1751,9 @@ block0:
             builder.finalize();
         }
 
-        let actual_ir = func.display().to_string();
-        let expected_ir = format!("function %sample() -> b1 system_v {{{}\n}}\n", expected);
-        assert!(
-            expected_ir == actual_ir,
-            "Expected\n{}, but got\n{}",
-            expected_ir,
-            actual_ir
+        check(
+            &func,
+            &format!("function %sample() -> b1 system_v {{{}\n}}\n", expected),
         );
     }
 
@@ -1780,22 +1787,22 @@ block0:
             builder.finalize();
         }
 
-        assert_eq!(
-            func.display().to_string(),
+        check(
+            &func,
             "function %sample() -> i8x16, b8x16, f32x4 system_v {
     const0 = 0x00000000000000000000000000000000
 
 block0:
     v5 = f32const 0.0
-    v6 = splat.f32x4 v5
+    v6 = splat.f32x4 v5  ; v5 = 0.0
     v2 -> v6
     v4 = vconst.b8x16 const0
     v1 -> v4
     v3 = vconst.i8x16 const0
     v0 -> v3
-    return v0, v1, v2
+    return v0, v1, v2  ; v0 = const0, v1 = const0
 }
-"
+",
         );
     }
 
diff --git a/cranelift/frontend/src/switch.rs b/cranelift/frontend/src/switch.rs
index 232337474f..2ccb9bba9a 100644
--- a/cranelift/frontend/src/switch.rs
+++ b/cranelift/frontend/src/switch.rs
@@ -391,7 +391,7 @@ mod tests {
             func,
             "block0:
     v0 = iconst.i8 0
-    brz v0, block1
+    brz v0, block1  ; v0 = 0
     jump block0"
         );
     }
@@ -403,7 +403,7 @@ mod tests {
             func,
             "block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm eq v0, 1
+    v1 = icmp_imm eq v0, 1  ; v0 = 0
     brnz v1, block1
     jump block0"
         );
@@ -421,7 +421,7 @@ block0:
     jump block3
 
 block3:
-    v1 = uextend.i32 v0
+    v1 = uextend.i32 v0  ; v0 = 0
     br_table v1, block0, jt0"
         );
     }
@@ -433,12 +433,12 @@ block3:
             func,
             "block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm eq v0, 2
+    v1 = icmp_imm eq v0, 2  ; v0 = 0
     brnz v1, block2
     jump block3
 
 block3:
-    brz.i8 v0, block1
+    brz.i8 v0, block1  ; v0 = 0
     jump block0"
         );
     }
@@ -453,31 +453,31 @@ block3:
 
 block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm uge v0, 7
+    v1 = icmp_imm uge v0, 7  ; v0 = 0
     brnz v1, block9
     jump block8
 
 block9:
-    v2 = icmp_imm.i8 uge v0, 10
+    v2 = icmp_imm.i8 uge v0, 10  ; v0 = 0
     brnz v2, block10
     jump block11
 
 block11:
-    v3 = icmp_imm.i8 eq v0, 7
+    v3 = icmp_imm.i8 eq v0, 7  ; v0 = 0
     brnz v3, block4
     jump block0
 
 block8:
-    v4 = icmp_imm.i8 eq v0, 5
+    v4 = icmp_imm.i8 eq v0, 5  ; v0 = 0
     brnz v4, block3
     jump block12
 
 block12:
-    v5 = uextend.i32 v0
+    v5 = uextend.i32 v0  ; v0 = 0
     br_table v5, block0, jt0
 
 block10:
-    v6 = iadd_imm.i8 v0, -10
+    v6 = iadd_imm.i8 v0, -10  ; v0 = 0
     v7 = uextend.i32 v6
     br_table v7, block0, jt1"
         );
@@ -490,12 +490,12 @@ block10:
             func,
             "block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm eq v0, 128
+    v1 = icmp_imm eq v0, 128  ; v0 = 0
     brnz v1, block1
     jump block3
 
 block3:
-    v2 = icmp_imm.i8 eq v0, 1
+    v2 = icmp_imm.i8 eq v0, 1  ; v0 = 0
     brnz v2, block2
     jump block0"
         );
@@ -508,12 +508,12 @@ block3:
             func,
             "block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm eq v0, 127
+    v1 = icmp_imm eq v0, 127  ; v0 = 0
     brnz v1, block1
     jump block3
 
 block3:
-    v2 = icmp_imm.i8 eq v0, 1
+    v2 = icmp_imm.i8 eq v0, 1  ; v0 = 0
     brnz v2, block2
     jump block0"
         )
@@ -528,12 +528,12 @@ block3:
 
 block0:
     v0 = iconst.i8 0
-    v1 = icmp_imm eq v0, 255
+    v1 = icmp_imm eq v0, 255  ; v0 = 0
     brnz v1, block1
     jump block4
 
 block4:
-    v2 = uextend.i32 v0
+    v2 = uextend.i32 v0  ; v0 = 0
     br_table v2, block0, jt0"
         );
     }
@@ -626,12 +626,12 @@ block0:
     jump block4
 
 block4:
-    v1 = icmp_imm.i64 ugt v0, 0xffff_ffff
+    v1 = icmp_imm.i64 ugt v0, 0xffff_ffff  ; v0 = 0
     brnz v1, block3
     jump block5
 
 block5:
-    v2 = ireduce.i32 v0
+    v2 = ireduce.i32 v0  ; v0 = 0
     br_table v2, block3, jt0"
         );
     }
@@ -667,12 +667,12 @@ block0:
     jump block4
 
 block4:
-    v1 = icmp_imm.i128 ugt v0, 0xffff_ffff
+    v1 = icmp_imm.i128 ugt v0, 0xffff_ffff  ; v0 = 0
     brnz v1, block3
     jump block5
 
 block5:
-    v2 = ireduce.i32 v0
+    v2 = ireduce.i32 v0  ; v0 = 0
     br_table v2, block3, jt0"
         );
     }
diff --git a/cranelift/src/bugpoint.rs b/cranelift/src/bugpoint.rs
index a4673227a1..702f0e8133 100644
--- a/cranelift/src/bugpoint.rs
+++ b/cranelift/src/bugpoint.rs
@@ -1073,9 +1073,13 @@ mod tests {
                 "reduction wasn't maximal for insts"
             );
 
-            assert_eq!(
-                format!("{}", reduced_func),
-                expected_str.replace("\r\n", "\n")
+            let actual_ir = format!("{}", reduced_func);
+            let expected_ir = expected_str.replace("\r\n", "\n");
+            assert!(
+                expected_ir == actual_ir,
+                "Expected:\n{}\nGot:\n{}",
+                expected_ir,
+                actual_ir,
             );
         }
     }
diff --git a/cranelift/tests/bugpoint_consts_expected.clif b/cranelift/tests/bugpoint_consts_expected.clif
index e4de6b9b95..cd5b0de2f1 100644
--- a/cranelift/tests/bugpoint_consts_expected.clif
+++ b/cranelift/tests/bugpoint_consts_expected.clif
@@ -21,6 +21,6 @@ block1:
     v12 = vconst.b8x16 const2
     v13 = vconst.i16x4 const1
     v14 = vconst.f32x16 const0
-    call fn0(v0, v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14)
+    call fn0(v0, v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14)  ; v0 = 0.0, v1 = 0.0, v2 = 0, v3 = 0, v4 = 0, v5 = 0, v6 = 0, v7 = false, v8 = false, v9 = false, v12 = const2, v13 = const1, v14 = const0
     trap user0
 }
diff --git a/cranelift/tests/bugpoint_test_expected.clif b/cranelift/tests/bugpoint_test_expected.clif
index 308863d9f7..982fcb0011 100644
--- a/cranelift/tests/bugpoint_test_expected.clif
+++ b/cranelift/tests/bugpoint_test_expected.clif
@@ -30,6 +30,6 @@ block0:
     v990 -> v1052
     v1051 -> v1052
     v1055 -> v1052
-    call fn0(v0, v105, v1052, v883, v829, v987, v951, v842)
+    call fn0(v0, v105, v1052, v883, v829, v987, v951, v842)  ; v0 = 0, v105 = 0, v1052 = 0, v883 = 0, v829 = 0, v987 = 0, v951 = 0, v842 = 0
     trap user0
 }