diff --git a/cranelift/filetests/isa/x86/allones_funcaddrs32.cton b/cranelift/filetests/isa/x86/allones_funcaddrs32.cton
index c4c078470b..cf0036f4d0 100644
--- a/cranelift/filetests/isa/x86/allones_funcaddrs32.cton
+++ b/cranelift/filetests/isa/x86/allones_funcaddrs32.cton
@@ -1,6 +1,6 @@
 ; binary emission of 32-bit code.
 test binemit
-set is_compressed
+set opt_level=best
 set allones_funcaddrs
 isa x86 haswell
 
diff --git a/cranelift/filetests/isa/x86/allones_funcaddrs64.cton b/cranelift/filetests/isa/x86/allones_funcaddrs64.cton
index ca3cf1ab69..3f47c78052 100644
--- a/cranelift/filetests/isa/x86/allones_funcaddrs64.cton
+++ b/cranelift/filetests/isa/x86/allones_funcaddrs64.cton
@@ -1,7 +1,7 @@
 ; binary emission of 64-bit code.
 test binemit
 set is_64bit
-set is_compressed
+set opt_level=best
 set allones_funcaddrs
 isa x86 haswell
 
diff --git a/cranelift/filetests/isa/x86/baseline_clz_ctz_popcount_encoding.cton b/cranelift/filetests/isa/x86/baseline_clz_ctz_popcount_encoding.cton
index f69efd573a..72104272e1 100644
--- a/cranelift/filetests/isa/x86/baseline_clz_ctz_popcount_encoding.cton
+++ b/cranelift/filetests/isa/x86/baseline_clz_ctz_popcount_encoding.cton
@@ -1,7 +1,6 @@
-
 test binemit
 set is_64bit
-set is_compressed
+set opt_level=best
 isa x86 baseline
 
 ; The binary encodings can be verified with the command:
diff --git a/cranelift/filetests/isa/x86/binary32.cton b/cranelift/filetests/isa/x86/binary32.cton
index 842f941779..6eb4565f79 100644
--- a/cranelift/filetests/isa/x86/binary32.cton
+++ b/cranelift/filetests/isa/x86/binary32.cton
@@ -1,6 +1,6 @@
 ; binary emission of x86-32 code.
 test binemit
-set is_compressed
+set opt_level=best
 isa x86 haswell
 
 ; The binary encodings can be verified with the command:
diff --git a/cranelift/filetests/isa/x86/binary64-float.cton b/cranelift/filetests/isa/x86/binary64-float.cton
index df910941cd..e9fcc99e63 100644
--- a/cranelift/filetests/isa/x86/binary64-float.cton
+++ b/cranelift/filetests/isa/x86/binary64-float.cton
@@ -1,7 +1,7 @@
 ; Binary emission of 64-bit floating point code.
 test binemit
 set is_64bit
-set is_compressed
+set opt_level=best
 isa x86 haswell
 
 ; The binary encodings can be verified with the command:
diff --git a/cranelift/filetests/isa/x86/binary64-pic.cton b/cranelift/filetests/isa/x86/binary64-pic.cton
index cc592e0188..ff9cfc42ac 100644
--- a/cranelift/filetests/isa/x86/binary64-pic.cton
+++ b/cranelift/filetests/isa/x86/binary64-pic.cton
@@ -1,7 +1,7 @@
 ; binary emission of 64-bit code.
 test binemit
 set is_64bit
-set is_compressed
+set opt_level=best
 set is_pic
 isa x86 haswell
 
diff --git a/cranelift/filetests/isa/x86/binary64.cton b/cranelift/filetests/isa/x86/binary64.cton
index 2a945ee17c..6417cd26e2 100644
--- a/cranelift/filetests/isa/x86/binary64.cton
+++ b/cranelift/filetests/isa/x86/binary64.cton
@@ -1,7 +1,7 @@
 ; binary emission of x86-64 code.
 test binemit
 set is_64bit
-set is_compressed
+set opt_level=best
 isa x86 haswell
 
 ; The binary encodings can be verified with the command:
diff --git a/cranelift/filetests/isa/x86/legalize-call.cton b/cranelift/filetests/isa/x86/legalize-call.cton
index adcb6a6ad1..0eaaba0dfa 100644
--- a/cranelift/filetests/isa/x86/legalize-call.cton
+++ b/cranelift/filetests/isa/x86/legalize-call.cton
@@ -1,7 +1,7 @@
 ; Test legalization of a non-colocated call in 64-bit non-PIC mode.
 test legalizer
 set is_64bit
-set is_compressed
+set opt_level=best
 isa x86 haswell
 
 function %call() {
diff --git a/cranelift/filetests/isa/x86/prologue-epilogue.cton b/cranelift/filetests/isa/x86/prologue-epilogue.cton
index 9ed37274ca..76aa459f94 100644
--- a/cranelift/filetests/isa/x86/prologue-epilogue.cton
+++ b/cranelift/filetests/isa/x86/prologue-epilogue.cton
@@ -1,6 +1,6 @@
 test compile
 set is_64bit
-set is_compressed
+set opt_level=best
 set is_pic
 isa x86 haswell
 
diff --git a/lib/filetests/src/test_binemit.rs b/lib/filetests/src/test_binemit.rs
index 86058673e3..a0711414d4 100644
--- a/lib/filetests/src/test_binemit.rs
+++ b/lib/filetests/src/test_binemit.rs
@@ -9,6 +9,7 @@ use cretonne_codegen::dbg::DisplayList;
 use cretonne_codegen::ir;
 use cretonne_codegen::ir::entities::AnyEntity;
 use cretonne_codegen::print_errors::pretty_error;
+use cretonne_codegen::settings::OptLevel;
 use cretonne_reader::TestCommand;
 use match_directive::match_directive;
 use std::borrow::Cow;
@@ -121,7 +122,7 @@ impl SubTest for TestBinEmit {
             .min();
         func.stack_slots.frame_size = min_offset.map(|off| (-off) as u32);
 
-        let is_compressed = isa.flags().is_compressed();
+        let opt_level = isa.flags().opt_level();
 
         // Give an encoding to any instruction that doesn't already have one.
         let mut divert = RegDiversions::new();
@@ -141,11 +142,11 @@ impl SubTest for TestBinEmit {
                                 recipe_constraints.satisfied(inst, &divert, &func)
                             });
 
-                        if is_compressed {
+                        if opt_level == OptLevel::Best {
                             // Get the smallest legal encoding
                             legal_encodings.min_by_key(|&e| encinfo.bytes(e))
                         } else {
-                            // If not using compressed, just use the first encoding.
+                            // If not optimizing, just use the first encoding.
                             legal_encodings.next()
                         }
                     }