diff --git a/cranelift/codegen/meta/src/gen_legalizer.rs b/cranelift/codegen/meta/src/gen_legalizer.rs
index 67959b3c7c..344bad7472 100644
--- a/cranelift/codegen/meta/src/gen_legalizer.rs
+++ b/cranelift/codegen/meta/src/gen_legalizer.rs
@@ -415,6 +415,11 @@ fn gen_transform<'a>(
             fmt.line("let removed = pos.remove_inst();");
             fmt.line("debug_assert_eq!(removed, inst);");
         }
+
+        if transform.def_pool.get(transform.src).apply.inst.is_branch {
+            fmt.line("cfg.recompute_ebb(pos.func, pos.current_ebb().unwrap());");
+        }
+
         fmt.line("return true;");
     });
     fmt.line("}");
diff --git a/cranelift/codegen/meta/src/shared/legalize.rs b/cranelift/codegen/meta/src/shared/legalize.rs
index 90fe47d0fd..57ad9c89b8 100644
--- a/cranelift/codegen/meta/src/shared/legalize.rs
+++ b/cranelift/codegen/meta/src/shared/legalize.rs
@@ -4,7 +4,7 @@ use crate::cdsl::xform::{TransformGroupBuilder, TransformGroups};
 
 use crate::shared::immediates::Immediates;
 use crate::shared::types::Float::{F32, F64};
-use crate::shared::types::Int::{I16, I32, I64, I8};
+use crate::shared::types::Int::{I16, I128, I32, I64, I8};
 
 pub(crate) fn define(insts: &InstructionGroup, imm: &Immediates) -> TransformGroups {
     let mut narrow = TransformGroupBuilder::new(
@@ -49,6 +49,8 @@ pub(crate) fn define(insts: &InstructionGroup, imm: &Immediates) -> TransformGro
     let bor = insts.by_name("bor");
     let bor_imm = insts.by_name("bor_imm");
     let bor_not = insts.by_name("bor_not");
+    let brnz = insts.by_name("brnz");
+    let brz = insts.by_name("brz");
     let br_icmp = insts.by_name("br_icmp");
     let br_table = insts.by_name("br_table");
     let bxor = insts.by_name("bxor");
@@ -177,9 +179,11 @@ pub(crate) fn define(insts: &InstructionGroup, imm: &Immediates) -> TransformGro
     let al = var("al");
     let ah = var("ah");
     let cc = var("cc");
+    let ebb = var("ebb");
     let ptr = var("ptr");
     let flags = var("flags");
     let offset = var("off");
+    let vararg = var("vararg");
 
     narrow.legalize(
         def!(a = iadd(x, y)),
@@ -227,6 +231,26 @@ pub(crate) fn define(insts: &InstructionGroup, imm: &Immediates) -> TransformGro
         ],
     );
 
+    narrow.legalize(
+        def!(brz.I128(x, ebb, vararg)),
+        vec![
+            def!((xl, xh) = isplit(x)),
+            def!(a = icmp_imm(Literal::enumerator_for(intcc, "eq"), xl, Literal::constant(imm64, 0))),
+            def!(b = icmp_imm(Literal::enumerator_for(intcc, "eq"), xh, Literal::constant(imm64, 0))),
+            def!(c = band(a, b)),
+            def!(brz(c, ebb, vararg)),
+        ],
+    );
+
+    narrow.legalize(
+        def!(brnz.I128(x, ebb, vararg)),
+        vec![
+            def!((xl, xh) = isplit(x)),
+            def!(brnz(xl, ebb, vararg)),
+            def!(brnz(xh, ebb, vararg)),
+        ],
+    );
+
     // Widen instructions with one input operand.
     for &op in &[bnot, popcnt] {
         for &int_ty in &[I8, I16] {
diff --git a/cranelift/filetests/filetests/isa/x86/br-i128.clif b/cranelift/filetests/filetests/isa/x86/br-i128.clif
new file mode 100644
index 0000000000..a09db3f41b
--- /dev/null
+++ b/cranelift/filetests/filetests/isa/x86/br-i128.clif
@@ -0,0 +1,24 @@
+test compile
+target x86_64
+
+function u0:0(i128) -> i8 fast {
+ebb0(v0: i128):
+    brz v0, ebb1
+    v1 = iconst.i8 0
+    return v1
+
+ebb1:
+    v2 = iconst.i8 1
+    return v2
+}
+
+function u0:1(i128) -> i8 fast {
+ebb0(v0: i128):
+    brnz v0, ebb1
+    v1 = iconst.i8 0
+    return v1
+
+ebb1:
+    v2 = iconst.i8 1
+    return v2
+}