diff --git a/src/tint/ir/disassembler.cc b/src/tint/ir/disassembler.cc
index 4c02bda6ef..03e21a2711 100644
--- a/src/tint/ir/disassembler.cc
+++ b/src/tint/ir/disassembler.cc
@@ -110,12 +110,12 @@ void Disassembler::Walk(const Block* blk) {
         blk,
         [&](const ir::FunctionTerminator* t) {
             TINT_ASSERT(IR, in_function_);
-            Indent() << "%fn" << IdOf(t) << " = func_terminator" << std::endl;
+            Indent() << "%b" << IdOf(t) << " = func_terminator" << std::endl;
             in_function_ = false;
         },
         [&](const ir::RootTerminator* t) {
             TINT_ASSERT(IR, !in_function_);
-            Indent() << "%fn" << IdOf(t) << " = root_terminator" << std::endl << std::endl;
+            Indent() << "%b" << IdOf(t) << " = root_terminator" << std::endl << std::endl;
         },
         [&](const ir::Block* b) {
             // If this block is dead, nothing to do
@@ -123,7 +123,7 @@ void Disassembler::Walk(const Block* blk) {
                 return;
             }
 
-            Indent() << "%fn" << IdOf(b) << " = block";
+            Indent() << "%b" << IdOf(b) << " = block";
             if (!b->Params().IsEmpty()) {
                 out_ << " (";
                 for (auto* p : b->Params()) {
@@ -181,7 +181,7 @@ void Disassembler::EmitFunction(const Function* func) {
 
         out_ << "]";
     }
-    out_ << " -> %fn" << IdOf(func->StartTarget()) << " {" << std::endl;
+    out_ << " -> %b" << IdOf(func->StartTarget()) << " {" << std::endl;
 
     {
         ScopedIndent si(indent_size_);
@@ -319,16 +319,16 @@ void Disassembler::EmitIf(const If* i) {
 
     out_ << " [";
     if (has_true) {
-        out_ << "t: %fn" << IdOf(i->True());
+        out_ << "t: %b" << IdOf(i->True());
     }
     if (has_false) {
         if (has_true) {
             out_ << ", ";
         }
-        out_ << "f: %fn" << IdOf(i->False());
+        out_ << "f: %b" << IdOf(i->False());
     }
     if (i->Merge()->HasBranchTarget()) {
-        out_ << ", m: %fn" << IdOf(i->Merge());
+        out_ << ", m: %b" << IdOf(i->Merge());
     }
     out_ << "]" << std::endl;
 
@@ -349,13 +349,13 @@ void Disassembler::EmitIf(const If* i) {
 }
 
 void Disassembler::EmitLoop(const Loop* l) {
-    out_ << "loop [s: %fn" << IdOf(l->Start());
+    out_ << "loop [s: %b" << IdOf(l->Start());
 
     if (l->Continuing()->HasBranchTarget()) {
-        out_ << ", c: %fn" << IdOf(l->Continuing());
+        out_ << ", c: %b" << IdOf(l->Continuing());
     }
     if (l->Merge()->HasBranchTarget()) {
-        out_ << ", m: %fn" << IdOf(l->Merge());
+        out_ << ", m: %b" << IdOf(l->Merge());
     }
     out_ << "]" << std::endl;
 
@@ -395,10 +395,10 @@ void Disassembler::EmitSwitch(const Switch* s) {
                 EmitValue(selector.val);
             }
         }
-        out_ << ", %fn" << IdOf(c.Start()) << ")";
+        out_ << ", %b" << IdOf(c.Start()) << ")";
     }
     if (s->Merge()->HasBranchTarget()) {
-        out_ << ", m: %fn" << IdOf(s->Merge());
+        out_ << ", m: %b" << IdOf(s->Merge());
     }
     out_ << "]" << std::endl;
 
@@ -415,7 +415,7 @@ void Disassembler::EmitSwitch(const Switch* s) {
 
 void Disassembler::EmitBranch(const Branch* b) {
     std::string suffix = "";
-    out_ << "br %fn" << IdOf(b->To());
+    out_ << "br %b" << IdOf(b->To());
     if (b->To()->Is<FunctionTerminator>()) {
         suffix = "return";
     } else if (b->To()->Is<RootTerminator>()) {
diff --git a/src/tint/ir/from_program_binary_test.cc b/src/tint/ir/from_program_binary_test.cc
index 76fc46c955..cdd62274c4 100644
--- a/src/tint/ir/from_program_binary_test.cc
+++ b/src/tint/ir/from_program_binary_test.cc
@@ -34,19 +34,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Add) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = add %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -60,21 +60,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Increment) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = add %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -88,21 +88,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundAdd) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = add %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -115,19 +115,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Subtract) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = sub %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -141,21 +141,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Decrement) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, i32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:i32 = load %v1
     %4:i32 = sub %3, 1i
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -169,21 +169,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundSubtract) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = sub %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -196,19 +196,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Multiply) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = mul %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -222,21 +222,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundMultiply) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = mul %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -249,19 +249,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Div) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = div %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -275,21 +275,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundDiv) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = div %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -302,19 +302,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Modulo) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = mod %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -328,21 +328,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundModulo) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = mod %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -355,19 +355,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_And) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = and %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -381,21 +381,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundAnd) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, bool, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:bool = load %v1
     %4:bool = and %3, false
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -408,19 +408,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Or) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = or %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -434,21 +434,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundOr) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, bool, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:bool = load %v1
     %4:bool = or %3, false
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -461,19 +461,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Xor) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = xor %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -487,21 +487,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundXor) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = xor %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -514,42 +514,42 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LogicalAnd) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %fn1 {
-  %fn1 = block {
-    br %fn2 true  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %b1 {
+  %b1 = block {
+    br %b2 true  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:bool = call %my_func
-    if %3 [t: %fn4, f: %fn5, m: %fn6]
+    if %3 [t: %b4, f: %b5, m: %b6]
       # True block
-      %fn4 = block {
-        br %fn6 false
+      %b4 = block {
+        br %b6 false
       }
 
       # False block
-      %fn5 = block {
-        br %fn6 %3
+      %b5 = block {
+        br %b6 %3
       }
 
     # Merge block
-    %fn6 = block (%4:bool) {
-      if %4:bool [t: %fn7, f: %fn8, m: %fn9]
+    %b6 = block (%4:bool) {
+      if %4:bool [t: %b7, f: %b8, m: %b9]
         # True block
-        %fn7 = block {
-          br %fn9
+        %b7 = block {
+          br %b9
         }
 
         # False block
-        %fn8 = block {
-          br %fn9
+        %b8 = block {
+          br %b9
         }
 
       # Merge block
-      %fn9 = block {
-        br %fn10  # return
+      %b9 = block {
+        br %b10  # return
       }
 
     }
@@ -557,7 +557,7 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LogicalAnd) {
 
   }
 
-  %fn10 = func_terminator
+  %b10 = func_terminator
 }
 )");
 }
@@ -570,42 +570,42 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LogicalOr) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %fn1 {
-  %fn1 = block {
-    br %fn2 true  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %b1 {
+  %b1 = block {
+    br %b2 true  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:bool = call %my_func
-    if %3 [t: %fn4, f: %fn5, m: %fn6]
+    if %3 [t: %b4, f: %b5, m: %b6]
       # True block
-      %fn4 = block {
-        br %fn6 %3
+      %b4 = block {
+        br %b6 %3
       }
 
       # False block
-      %fn5 = block {
-        br %fn6 true
+      %b5 = block {
+        br %b6 true
       }
 
     # Merge block
-    %fn6 = block (%4:bool) {
-      if %4:bool [t: %fn7, f: %fn8, m: %fn9]
+    %b6 = block (%4:bool) {
+      if %4:bool [t: %b7, f: %b8, m: %b9]
         # True block
-        %fn7 = block {
-          br %fn9
+        %b7 = block {
+          br %b9
         }
 
         # False block
-        %fn8 = block {
-          br %fn9
+        %b8 = block {
+          br %b9
         }
 
       # Merge block
-      %fn9 = block {
-        br %fn10  # return
+      %b9 = block {
+        br %b10  # return
       }
 
     }
@@ -613,7 +613,7 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LogicalOr) {
 
   }
 
-  %fn10 = func_terminator
+  %b10 = func_terminator
 }
 )");
 }
@@ -626,19 +626,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Equal) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = eq %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -651,19 +651,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_NotEqual) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = neq %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -676,19 +676,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LessThan) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = lt %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -701,19 +701,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_GreaterThan) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = gt %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -726,19 +726,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_LessThanEqual) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = lte %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -751,19 +751,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_GreaterThanEqual) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:bool = gte %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -776,19 +776,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_ShiftLeft) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = shiftl %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -802,21 +802,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundShiftLeft) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = shiftl %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -829,19 +829,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_ShiftRight) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 0u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = shiftr %3, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -855,21 +855,21 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_CompoundShiftRight) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v1:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = load %v1
     %4:u32 = shiftr %3, 1u
     store %v1, %4
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -884,40 +884,40 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Compound) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 -> %b1 {
+  %b1 = block {
+    br %b2 0.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:f32 = call %my_func
     %4:bool = lt %3, 2.0f
-    if %4 [t: %fn4, f: %fn5, m: %fn6]
+    if %4 [t: %b4, f: %b5, m: %b6]
       # True block
-      %fn4 = block {
+      %b4 = block {
         %5:f32 = call %my_func
         %6:f32 = call %my_func
         %7:f32 = mul 2.29999995231628417969f, %6
         %8:f32 = div %5, %7
         %9:bool = gt 2.5f, %8
-        br %fn6 %9
+        br %b6 %9
       }
 
       # False block
-      %fn5 = block {
-        br %fn6 %4
+      %b5 = block {
+        br %b6 %4
       }
 
     # Merge block
-    %fn6 = block (%tint_symbol:bool) {
-      br %fn7  # return
+    %b6 = block (%tint_symbol:bool) {
+      br %b7  # return
     }
 
   }
 
-  %fn7 = func_terminator
+  %b7 = func_terminator
 }
 )");
 }
@@ -931,18 +931,18 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Binary_Compound_WithConstEval) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:bool):bool -> %fn1 {
-  %fn1 = block {
-    br %fn2 true  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:bool):bool -> %b1 {
+  %b1 = block {
+    br %b2 true  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %tint_symbol:bool = call %my_func, false
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_builtin_test.cc b/src/tint/ir/from_program_builtin_test.cc
index 84a85912f6..37505ef3cb 100644
--- a/src/tint/ir/from_program_builtin_test.cc
+++ b/src/tint/ir/from_program_builtin_test.cc
@@ -35,20 +35,20 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Builtin) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %i:ptr<private, f32, read_write> = var, 1.0f
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:f32 = load %i
     %tint_symbol:f32 = asin %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_call_test.cc b/src/tint/ir/from_program_call_test.cc
index b6985e1508..efd90ccf60 100644
--- a/src/tint/ir/from_program_call_test.cc
+++ b/src/tint/ir/from_program_call_test.cc
@@ -35,19 +35,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Bitcast) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 0.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():f32 -> %b1 {
+  %b1 = block {
+    br %b2 0.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:f32 = call %my_func
     %tint_symbol:f32 = bitcast %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -62,12 +62,12 @@ TEST_F(IR_BuilderImplTest, EmitStatement_Discard) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = func():void [@fragment] -> %fn1 {
-  %fn1 = block {
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = func():void [@fragment] -> %b1 {
+  %b1 = block {
     discard
-    br %fn2  # return
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -80,18 +80,18 @@ TEST_F(IR_BuilderImplTest, EmitStatement_UserFunction) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:f32):void -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func(%p:f32):void -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %4:void = call %my_func, 6.0f
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -105,20 +105,20 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Convert) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %i:ptr<private, i32, read_write> = var, 1i
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:i32 = load %i
     %tint_symbol:f32 = convert i32, %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -131,12 +131,12 @@ TEST_F(IR_BuilderImplTest, EmitExpression_ConstructEmpty) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %i:ptr<private, vec3<f32>, read_write> = var, vec3<f32> 0.0f
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
 )");
 }
@@ -150,20 +150,20 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Construct) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %i:ptr<private, f32, read_write> = var, 1.0f
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:f32 = load %i
     %tint_symbol:vec3<f32> = construct 2.0f, 3.0f, %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_function_test.cc b/src/tint/ir/from_program_function_test.cc
index 3161e4a2f5..d5ae1068f3 100644
--- a/src/tint/ir/from_program_function_test.cc
+++ b/src/tint/ir/from_program_function_test.cc
@@ -34,11 +34,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_Vertex) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec4<f32> [@vertex ra: @position] -> %fn1 {
-  %fn1 = block {
-    br %fn2 vec4<f32> 0.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec4<f32> [@vertex ra: @position] -> %b1 {
+  %b1 = block {
+    br %b2 vec4<f32> 0.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -50,11 +50,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_Fragment) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():void [@fragment] -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():void [@fragment] -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -67,11 +67,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_Compute) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test = func():void [@compute @workgroup_size(8, 4, 2)] -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+              R"(%test = func():void [@compute @workgroup_size(8, 4, 2)] -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -83,11 +83,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_Return) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec3<f32> -> %fn1 {
-  %fn1 = block {
-    br %fn2 vec3<f32> 0.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec3<f32> -> %b1 {
+  %b1 = block {
+    br %b2 vec3<f32> 0.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -100,11 +100,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_ReturnPosition) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec4<f32> [@vertex ra: @position] -> %fn1 {
-  %fn1 = block {
-    br %fn2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():vec4<f32> [@vertex ra: @position] -> %b1 {
+  %b1 = block {
+    br %b2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -118,11 +118,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_ReturnPositionInvariant) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test = func():vec4<f32> [@vertex ra: @position @invariant] -> %fn1 {
-  %fn1 = block {
-    br %fn2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
+              R"(%test = func():vec4<f32> [@vertex ra: @position @invariant] -> %b1 {
+  %b1 = block {
+    br %b2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -135,11 +135,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_ReturnLocation) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test = func():vec4<f32> [@fragment ra: @location(1)] -> %fn1 {
-  %fn1 = block {
-    br %fn2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
+              R"(%test = func():vec4<f32> [@fragment ra: @location(1)] -> %b1 {
+  %b1 = block {
+    br %b2 vec4<f32> 1.0f, 2.0f, 3.0f, 4.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -152,11 +152,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_ReturnFragDepth) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():f32 [@fragment ra: @frag_depth] -> %fn1 {
-  %fn1 = block {
-    br %fn2 1.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():f32 [@fragment ra: @frag_depth] -> %b1 {
+  %b1 = block {
+    br %b2 1.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -169,11 +169,11 @@ TEST_F(IR_BuilderImplTest, EmitFunction_ReturnSampleMask) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():u32 [@fragment ra: @sample_mask] -> %fn1 {
-  %fn1 = block {
-    br %fn2 1u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test = func():u32 [@fragment ra: @sample_mask] -> %b1 {
+  %b1 = block {
+    br %b2 1u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_materialize_test.cc b/src/tint/ir/from_program_materialize_test.cc
index 8d524991c5..1fdc5ab564 100644
--- a/src/tint/ir/from_program_materialize_test.cc
+++ b/src/tint/ir/from_program_materialize_test.cc
@@ -34,11 +34,11 @@ TEST_F(IR_BuilderImplTest, EmitExpression_MaterializedCall) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = func():f32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 2.0f  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%test_function = func():f32 -> %b1 {
+  %b1 = block {
+    br %b2 2.0f  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_store_test.cc b/src/tint/ir/from_program_store_test.cc
index 9fbb5e408a..bebd300d92 100644
--- a/src/tint/ir/from_program_store_test.cc
+++ b/src/tint/ir/from_program_store_test.cc
@@ -36,19 +36,19 @@ TEST_F(IR_BuilderImplTest, EmitStatement_Assign) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %a:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     store %a, 4u
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_test.cc b/src/tint/ir/from_program_test.cc
index 5892701a1a..89fa102d0b 100644
--- a/src/tint/ir/from_program_test.cc
+++ b/src/tint/ir/from_program_test.cc
@@ -70,11 +70,11 @@ TEST_F(IR_BuilderImplTest, Func) {
 
     EXPECT_EQ(m->functions[0]->Stage(), Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():void -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func():void -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -95,11 +95,11 @@ TEST_F(IR_BuilderImplTest, Func_WithParam) {
 
     EXPECT_EQ(m->functions[0]->Stage(), Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32):u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 %a  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32):u32 -> %b1 {
+  %b1 = block {
+    br %b2 %a  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -121,11 +121,11 @@ TEST_F(IR_BuilderImplTest, Func_WithMultipleParam) {
 
     EXPECT_EQ(m->functions[0]->Stage(), Function::PipelineStage::kUndefined);
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32, %b:i32, %c:bool):void -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%f = func(%a:u32, %b:i32, %c:bool):void -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -159,27 +159,27 @@ TEST_F(IR_BuilderImplTest, IfStatement) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    if true [t: %fn2, f: %fn3, m: %fn4]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    if true [t: %b2, f: %b3, m: %b4]
       # True block
-      %fn2 = block {
-        br %fn4
+      %b2 = block {
+        br %b4
       }
 
       # False block
-      %fn3 = block {
-        br %fn4
+      %b3 = block {
+        br %b4
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -203,26 +203,26 @@ TEST_F(IR_BuilderImplTest, IfStatement_TrueReturns) {
     EXPECT_EQ(2u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    if true [t: %fn2, f: %fn3, m: %fn4]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    if true [t: %b2, f: %b3, m: %b4]
       # True block
-      %fn2 = block {
-        br %fn5  # return
+      %b2 = block {
+        br %b5  # return
       }
       # False block
-      %fn3 = block {
-        br %fn4
+      %b3 = block {
+        br %b4
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -246,26 +246,26 @@ TEST_F(IR_BuilderImplTest, IfStatement_FalseReturns) {
     EXPECT_EQ(2u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    if true [t: %fn2, f: %fn3, m: %fn4]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    if true [t: %b2, f: %b3, m: %b4]
       # True block
-      %fn2 = block {
-        br %fn4
+      %b2 = block {
+        br %b4
       }
 
       # False block
-      %fn3 = block {
-        br %fn5  # return
+      %b3 = block {
+        br %b5  # return
       }
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -289,21 +289,21 @@ TEST_F(IR_BuilderImplTest, IfStatement_BothReturn) {
     EXPECT_EQ(2u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    if true [t: %fn2, f: %fn3]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    if true [t: %b2, f: %b3]
       # True block
-      %fn2 = block {
-        br %fn4  # return
+      %b2 = block {
+        br %b4  # return
       }
       # False block
-      %fn3 = block {
-        br %fn4  # return
+      %b3 = block {
+        br %b4  # return
       }
 
   }
 
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -324,42 +324,42 @@ TEST_F(IR_BuilderImplTest, IfStatement_JumpChainToMerge) {
     ASSERT_NE(loop_flow, nullptr);
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    if true [t: %fn2, f: %fn3, m: %fn4]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    if true [t: %b2, f: %b3, m: %b4]
       # True block
-      %fn2 = block {
-        loop [s: %fn5, c: %fn6, m: %fn7]
-          %fn5 = block {
-            br %fn7
+      %b2 = block {
+        loop [s: %b5, c: %b6, m: %b7]
+          %b5 = block {
+            br %b7
           }
 
           # Continuing block
-          %fn6 = block {
-            br %fn5
+          %b6 = block {
+            br %b5
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn4
+        %b7 = block {
+          br %b4
         }
 
 
       }
 
       # False block
-      %fn3 = block {
-        br %fn4
+      %b3 = block {
+        br %b4
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -383,26 +383,26 @@ TEST_F(IR_BuilderImplTest, Loop_WithBreak) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        br %fn4
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        br %b4
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -432,42 +432,42 @@ TEST_F(IR_BuilderImplTest, Loop_WithContinue) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        if true [t: %fn5, f: %fn6, m: %fn7]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        if true [t: %b5, f: %b6, m: %b7]
           # True block
-          %fn5 = block {
-            br %fn4
+          %b5 = block {
+            br %b4
           }
 
           # False block
-          %fn6 = block {
-            br %fn7
+          %b6 = block {
+            br %b7
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn3
+        %b7 = block {
+          br %b3
         }
 
 
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -496,42 +496,42 @@ TEST_F(IR_BuilderImplTest, Loop_WithContinuing_BreakIf) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        br %fn3
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        br %b3
       }
 
       # Continuing block
-      %fn3 = block {
-        if true [t: %fn5, f: %fn6, m: %fn7]
+      %b3 = block {
+        if true [t: %b5, f: %b6, m: %b7]
           # True block
-          %fn5 = block {
-            br %fn4
+          %b5 = block {
+            br %b4
           }
 
           # False block
-          %fn6 = block {
-            br %fn7
+          %b6 = block {
+            br %b7
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn2
+        %b7 = block {
+          br %b2
         }
 
 
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -547,42 +547,42 @@ TEST_F(IR_BuilderImplTest, Loop_Continuing_Body_Scope) {
 
     auto m = res.Move();
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        br %fn3
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        br %b3
       }
 
       # Continuing block
-      %fn3 = block {
-        if true [t: %fn5, f: %fn6, m: %fn7]
+      %b3 = block {
+        if true [t: %b5, f: %b6, m: %b7]
           # True block
-          %fn5 = block {
-            br %fn4
+          %b5 = block {
+            br %b4
           }
 
           # False block
-          %fn6 = block {
-            br %fn7
+          %b6 = block {
+            br %b7
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn2
+        %b7 = block {
+          br %b2
         }
 
 
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -611,37 +611,37 @@ TEST_F(IR_BuilderImplTest, Loop_WithReturn) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3]
-      %fn2 = block {
-        if true [t: %fn4, f: %fn5, m: %fn6]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3]
+      %b2 = block {
+        if true [t: %b4, f: %b5, m: %b6]
           # True block
-          %fn4 = block {
-            br %fn7  # return
+          %b4 = block {
+            br %b7  # return
           }
           # False block
-          %fn5 = block {
-            br %fn6
+          %b5 = block {
+            br %b6
           }
 
         # Merge block
-        %fn6 = block {
-          br %fn3
+        %b6 = block {
+          br %b3
         }
 
 
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
 
   }
 
-  %fn7 = func_terminator
+  %b7 = func_terminator
 }
 )");
 }
@@ -665,21 +665,21 @@ TEST_F(IR_BuilderImplTest, Loop_WithOnlyReturn) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3]
-      %fn2 = block {
-        br %fn4  # return
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3]
+      %b2 = block {
+        br %b4  # return
       }
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
 
   }
 
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -712,48 +712,48 @@ TEST_F(IR_BuilderImplTest, Loop_WithOnlyReturn_ContinuingBreakIf) {
     EXPECT_EQ(3u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        br %fn5  # return
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        br %b5  # return
       }
       # Continuing block
-      %fn3 = block {
-        if true [t: %fn6, f: %fn7, m: %fn8]
+      %b3 = block {
+        if true [t: %b6, f: %b7, m: %b8]
           # True block
-          %fn6 = block {
-            br %fn4
+          %b6 = block {
+            br %b4
           }
 
           # False block
-          %fn7 = block {
-            br %fn8
+          %b7 = block {
+            br %b8
           }
 
         # Merge block
-        %fn8 = block {
-          br %fn2
+        %b8 = block {
+          br %b2
         }
 
 
       }
 
     # Merge block
-    %fn4 = block {
-      if true [t: %fn9, f: %fn10, m: %fn11]
+    %b4 = block {
+      if true [t: %b9, f: %b10, m: %b11]
         # True block
-        %fn9 = block {
-          br %fn5  # return
+        %b9 = block {
+          br %b5  # return
         }
         # False block
-        %fn10 = block {
-          br %fn11
+        %b10 = block {
+          br %b11
         }
 
       # Merge block
-      %fn11 = block {
-        br %fn5  # return
+      %b11 = block {
+        br %b5  # return
       }
 
     }
@@ -761,7 +761,7 @@ TEST_F(IR_BuilderImplTest, Loop_WithOnlyReturn_ContinuingBreakIf) {
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -790,37 +790,37 @@ TEST_F(IR_BuilderImplTest, Loop_WithIf_BothBranchesBreak) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        if true [t: %fn5, f: %fn6]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        if true [t: %b5, f: %b6]
           # True block
-          %fn5 = block {
-            br %fn4
+          %b5 = block {
+            br %b4
           }
 
           # False block
-          %fn6 = block {
-            br %fn4
+          %b6 = block {
+            br %b4
           }
 
 
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn7  # return
+    %b4 = block {
+      br %b7  # return
     }
 
   }
 
-  %fn7 = func_terminator
+  %b7 = func_terminator
 }
 )");
 }
@@ -843,39 +843,39 @@ TEST_F(IR_BuilderImplTest, Loop_Nested) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        loop [s: %fn5, c: %fn6, m: %fn7]
-          %fn5 = block {
-            if true [t: %fn8, f: %fn9, m: %fn10]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        loop [s: %b5, c: %b6, m: %b7]
+          %b5 = block {
+            if true [t: %b8, f: %b9, m: %b10]
               # True block
-              %fn8 = block {
-                br %fn7
+              %b8 = block {
+                br %b7
               }
 
               # False block
-              %fn9 = block {
-                br %fn10
+              %b9 = block {
+                br %b10
               }
 
             # Merge block
-            %fn10 = block {
-              if true [t: %fn11, f: %fn12, m: %fn13]
+            %b10 = block {
+              if true [t: %b11, f: %b12, m: %b13]
                 # True block
-                %fn11 = block {
-                  br %fn6
+                %b11 = block {
+                  br %b6
                 }
 
                 # False block
-                %fn12 = block {
-                  br %fn13
+                %b12 = block {
+                  br %b13
                 }
 
               # Merge block
-              %fn13 = block {
-                br %fn6
+              %b13 = block {
+                br %b6
               }
 
 
@@ -885,48 +885,48 @@ TEST_F(IR_BuilderImplTest, Loop_Nested) {
           }
 
           # Continuing block
-          %fn6 = block {
-            loop [s: %fn14, c: %fn15, m: %fn16]
-              %fn14 = block {
-                br %fn16
+          %b6 = block {
+            loop [s: %b14, c: %b15, m: %b16]
+              %b14 = block {
+                br %b16
               }
 
               # Continuing block
-              %fn15 = block {
-                br %fn14
+              %b15 = block {
+                br %b14
               }
 
             # Merge block
-            %fn16 = block {
-              loop [s: %fn17, c: %fn18, m: %fn19]
-                %fn17 = block {
-                  br %fn18
+            %b16 = block {
+              loop [s: %b17, c: %b18, m: %b19]
+                %b17 = block {
+                  br %b18
                 }
 
                 # Continuing block
-                %fn18 = block {
-                  if true [t: %fn20, f: %fn21, m: %fn22]
+                %b18 = block {
+                  if true [t: %b20, f: %b21, m: %b22]
                     # True block
-                    %fn20 = block {
-                      br %fn19
+                    %b20 = block {
+                      br %b19
                     }
 
                     # False block
-                    %fn21 = block {
-                      br %fn22
+                    %b21 = block {
+                      br %b22
                     }
 
                   # Merge block
-                  %fn22 = block {
-                    br %fn17
+                  %b22 = block {
+                    br %b17
                   }
 
 
                 }
 
               # Merge block
-              %fn19 = block {
-                br %fn5
+              %b19 = block {
+                br %b5
               }
 
 
@@ -936,21 +936,21 @@ TEST_F(IR_BuilderImplTest, Loop_Nested) {
           }
 
         # Merge block
-        %fn7 = block {
-          if true [t: %fn23, f: %fn24, m: %fn25]
+        %b7 = block {
+          if true [t: %b23, f: %b24, m: %b25]
             # True block
-            %fn23 = block {
-              br %fn4
+            %b23 = block {
+              br %b4
             }
 
             # False block
-            %fn24 = block {
-              br %fn25
+            %b24 = block {
+              br %b25
             }
 
           # Merge block
-          %fn25 = block {
-            br %fn3
+          %b25 = block {
+            br %b3
           }
 
 
@@ -960,18 +960,18 @@ TEST_F(IR_BuilderImplTest, Loop_Nested) {
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn26  # return
+    %b4 = block {
+      br %b26  # return
     }
 
   }
 
-  %fn26 = func_terminator
+  %b26 = func_terminator
 }
 )");
 }
@@ -1002,42 +1002,42 @@ TEST_F(IR_BuilderImplTest, While) {
     EXPECT_EQ(2u, if_flow->Merge()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        if false [t: %fn5, f: %fn6, m: %fn7]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        if false [t: %b5, f: %b6, m: %b7]
           # True block
-          %fn5 = block {
-            br %fn7
+          %b5 = block {
+            br %b7
           }
 
           # False block
-          %fn6 = block {
-            br %fn4
+          %b6 = block {
+            br %b4
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn3
+        %b7 = block {
+          br %b3
         }
 
 
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -1068,41 +1068,41 @@ TEST_F(IR_BuilderImplTest, While_Return) {
     EXPECT_EQ(2u, if_flow->Merge()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        if true [t: %fn5, f: %fn6, m: %fn7]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        if true [t: %b5, f: %b6, m: %b7]
           # True block
-          %fn5 = block {
-            br %fn7
+          %b5 = block {
+            br %b7
           }
 
           # False block
-          %fn6 = block {
-            br %fn4
+          %b6 = block {
+            br %b4
           }
 
         # Merge block
-        %fn7 = block {
-          br %fn8  # return
+        %b7 = block {
+          br %b8  # return
         }
 
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn8  # return
+    %b4 = block {
+      br %b8  # return
     }
 
   }
 
-  %fn8 = func_terminator
+  %b8 = func_terminator
 }
 )");
 }
@@ -1167,26 +1167,26 @@ TEST_F(IR_BuilderImplTest, For_NoInitCondOrContinuing) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    loop [s: %fn2, c: %fn3, m: %fn4]
-      %fn2 = block {
-        br %fn4
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    loop [s: %b2, c: %b3, m: %b4]
+      %b2 = block {
+        br %b4
       }
 
       # Continuing block
-      %fn3 = block {
-        br %fn2
+      %b3 = block {
+        br %b2
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -1230,32 +1230,32 @@ TEST_F(IR_BuilderImplTest, Switch) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    switch 1i [c: (0i, %fn2), c: (1i, %fn3), c: (default, %fn4), m: %fn5]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    switch 1i [c: (0i, %b2), c: (1i, %b3), c: (default, %b4), m: %b5]
       # Case block
-      %fn2 = block {
-        br %fn5
+      %b2 = block {
+        br %b5
       }
 
       # Case block
-      %fn3 = block {
-        br %fn5
+      %b3 = block {
+        br %b5
       }
 
       # Case block
-      %fn4 = block {
-        br %fn5
+      %b4 = block {
+        br %b5
       }
 
     # Merge block
-    %fn5 = block {
-      br %fn6  # return
+    %b5 = block {
+      br %b6  # return
     }
 
   }
 
-  %fn6 = func_terminator
+  %b6 = func_terminator
 }
 )");
 }
@@ -1295,22 +1295,22 @@ TEST_F(IR_BuilderImplTest, Switch_MultiSelector) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    switch 1i [c: (0i 1i default, %fn2), m: %fn3]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    switch 1i [c: (0i 1i default, %b2), m: %b3]
       # Case block
-      %fn2 = block {
-        br %fn3
+      %b2 = block {
+        br %b3
       }
 
     # Merge block
-    %fn3 = block {
-      br %fn4  # return
+    %b3 = block {
+      br %b4  # return
     }
 
   }
 
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -1338,22 +1338,22 @@ TEST_F(IR_BuilderImplTest, Switch_OnlyDefault) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    switch 1i [c: (default, %fn2), m: %fn3]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    switch 1i [c: (default, %b2), m: %b3]
       # Case block
-      %fn2 = block {
-        br %fn3
+      %b2 = block {
+        br %b3
       }
 
     # Merge block
-    %fn3 = block {
-      br %fn4  # return
+    %b3 = block {
+      br %b4  # return
     }
 
   }
 
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -1390,27 +1390,27 @@ TEST_F(IR_BuilderImplTest, Switch_WithBreak) {
     EXPECT_EQ(1u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    switch 1i [c: (0i, %fn2), c: (default, %fn3), m: %fn4]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    switch 1i [c: (0i, %b2), c: (default, %b3), m: %b4]
       # Case block
-      %fn2 = block {
-        br %fn4
+      %b2 = block {
+        br %b4
       }
 
       # Case block
-      %fn3 = block {
-        br %fn4
+      %b3 = block {
+        br %b4
       }
 
     # Merge block
-    %fn4 = block {
-      br %fn5  # return
+    %b4 = block {
+      br %b5  # return
     }
 
   }
 
-  %fn5 = func_terminator
+  %b5 = func_terminator
 }
 )");
 }
@@ -1449,21 +1449,21 @@ TEST_F(IR_BuilderImplTest, Switch_AllReturn) {
     EXPECT_EQ(2u, func->EndTarget()->InboundBranches().Length());
 
     EXPECT_EQ(Disassemble(m),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    switch 1i [c: (0i, %fn2), c: (default, %fn3)]
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    switch 1i [c: (0i, %b2), c: (default, %b3)]
       # Case block
-      %fn2 = block {
-        br %fn4  # return
+      %b2 = block {
+        br %b4  # return
       }
       # Case block
-      %fn3 = block {
-        br %fn4  # return
+      %b3 = block {
+        br %b4  # return
       }
 
   }
 
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -1476,18 +1476,18 @@ TEST_F(IR_BuilderImplTest, Emit_Phony) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%b = func():i32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 1i  # return
+              R"(%b = func():i32 -> %b1 {
+  %b1 = block {
+    br %b2 1i  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:i32 = call %b
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_unary_test.cc b/src/tint/ir/from_program_unary_test.cc
index 70af4e31c1..bbdb773f0f 100644
--- a/src/tint/ir/from_program_unary_test.cc
+++ b/src/tint/ir/from_program_unary_test.cc
@@ -34,19 +34,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Unary_Not) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %fn1 {
-  %fn1 = block {
-    br %fn2 false  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():bool -> %b1 {
+  %b1 = block {
+    br %b2 false  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:bool = call %my_func
     %tint_symbol:bool = eq %3, false
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -59,19 +59,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Unary_Complement) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 1u  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():u32 -> %b1 {
+  %b1 = block {
+    br %b2 1u  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:u32 = call %my_func
     %tint_symbol:u32 = complement %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -84,19 +84,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Unary_Negation) {
     auto m = Build();
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
-    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():i32 -> %fn1 {
-  %fn1 = block {
-    br %fn2 1i  # return
+    EXPECT_EQ(Disassemble(m.Get()), R"(%my_func = func():i32 -> %b1 {
+  %b1 = block {
+    br %b2 1i  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     %3:i32 = call %my_func
     %tint_symbol:i32 = negation %3
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -111,18 +111,18 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Unary_AddressOf) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v2:ptr<private, i32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
-    br %fn4  # return
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
@@ -139,19 +139,19 @@ TEST_F(IR_BuilderImplTest, EmitExpression_Unary_Indirection) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %v3:ptr<private, i32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
-%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn3 {
-  %fn3 = block {
+%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b3 {
+  %b3 = block {
     store %v3, 42i
-    br %fn4  # return
+    br %b4  # return
   }
-  %fn4 = func_terminator
+  %b4 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/from_program_var_test.cc b/src/tint/ir/from_program_var_test.cc
index 6112390ebb..1f793ef931 100644
--- a/src/tint/ir/from_program_var_test.cc
+++ b/src/tint/ir/from_program_var_test.cc
@@ -33,12 +33,12 @@ TEST_F(IR_BuilderImplTest, Emit_GlobalVar_NoInit) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %a:ptr<private, u32, read_write> = var
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
 )");
 }
@@ -51,12 +51,12 @@ TEST_F(IR_BuilderImplTest, Emit_GlobalVar_Init) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()), R"(# Root block
-%fn1 = block {
+%b1 = block {
   %a:ptr<private, u32, read_write> = var, 2u
-  br %fn2  # root_end
+  br %b2  # root_end
 }
 
-%fn2 = root_terminator
+%b2 = root_terminator
 
 )");
 }
@@ -69,12 +69,12 @@ TEST_F(IR_BuilderImplTest, Emit_Var_NoInit) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
     %a:ptr<function, u32, read_write> = var
-    br %fn2  # return
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
@@ -88,12 +88,12 @@ TEST_F(IR_BuilderImplTest, Emit_Var_Init) {
     ASSERT_TRUE(m) << (!m ? m.Failure() : "");
 
     EXPECT_EQ(Disassemble(m.Get()),
-              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
+              R"(%test_function = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
     %a:ptr<function, u32, read_write> = var, 2u
-    br %fn2  # return
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )");
 }
diff --git a/src/tint/ir/transform/add_empty_entry_point_test.cc b/src/tint/ir/transform/add_empty_entry_point_test.cc
index 172cd5676c..72fde36473 100644
--- a/src/tint/ir/transform/add_empty_entry_point_test.cc
+++ b/src/tint/ir/transform/add_empty_entry_point_test.cc
@@ -25,11 +25,11 @@ using IR_AddEmptyEntryPointTest = TransformTest;
 
 TEST_F(IR_AddEmptyEntryPointTest, EmptyModule) {
     auto* expect = R"(
-%unused_entry_point = func():void [@compute @workgroup_size(1, 1, 1)] -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+%unused_entry_point = func():void [@compute @workgroup_size(1, 1, 1)] -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )";
 
@@ -44,11 +44,11 @@ TEST_F(IR_AddEmptyEntryPointTest, ExistingEntryPoint) {
     mod.functions.Push(ep);
 
     auto* expect = R"(
-%main = func():void [@fragment] -> %fn1 {
-  %fn1 = block {
-    br %fn2  # return
+%main = func():void [@fragment] -> %b1 {
+  %b1 = block {
+    br %b2  # return
   }
-  %fn2 = func_terminator
+  %b2 = func_terminator
 }
 )";