diff --git a/js/src/jit/mips-shared/Assembler-mips-shared.cpp b/js/src/jit/mips-shared/Assembler-mips-shared.cpp
index 65b176b297c0..a8ecdced47da 100644
--- a/js/src/jit/mips-shared/Assembler-mips-shared.cpp
+++ b/js/src/jit/mips-shared/Assembler-mips-shared.cpp
@@ -1282,6 +1282,12 @@ AssemblerMIPSShared::as_truncws(FloatRegister fd, FloatRegister fs)
     return writeInst(InstReg(op_cop1, rs_s, zero, fs, fd, ff_trunc_w_fmt).encode());
 }
 
+BufferOffset
+AssemblerMIPSShared::as_truncls(FloatRegister fd, FloatRegister fs)
+{
+    return writeInst(InstReg(op_cop1, rs_s, zero, fs, fd, ff_trunc_l_fmt).encode());
+}
+
 BufferOffset
 AssemblerMIPSShared::as_ceilwd(FloatRegister fd, FloatRegister fs)
 {
@@ -1306,6 +1312,12 @@ AssemblerMIPSShared::as_truncwd(FloatRegister fd, FloatRegister fs)
     return writeInst(InstReg(op_cop1, rs_d, zero, fs, fd, ff_trunc_w_fmt).encode());
 }
 
+BufferOffset
+AssemblerMIPSShared::as_truncld(FloatRegister fd, FloatRegister fs)
+{
+    return writeInst(InstReg(op_cop1, rs_d, zero, fs, fd, ff_trunc_l_fmt).encode());
+}
+
 BufferOffset
 AssemblerMIPSShared::as_cvtdl(FloatRegister fd, FloatRegister fs)
 {
diff --git a/js/src/jit/mips-shared/Assembler-mips-shared.h b/js/src/jit/mips-shared/Assembler-mips-shared.h
index e8defcdc42e1..ff4046af2aa0 100644
--- a/js/src/jit/mips-shared/Assembler-mips-shared.h
+++ b/js/src/jit/mips-shared/Assembler-mips-shared.h
@@ -1131,11 +1131,13 @@ class AssemblerMIPSShared : public AssemblerShared
     BufferOffset as_floorws(FloatRegister fd, FloatRegister fs);
     BufferOffset as_roundws(FloatRegister fd, FloatRegister fs);
     BufferOffset as_truncws(FloatRegister fd, FloatRegister fs);
+    BufferOffset as_truncls(FloatRegister fd, FloatRegister fs);
 
     BufferOffset as_ceilwd(FloatRegister fd, FloatRegister fs);
     BufferOffset as_floorwd(FloatRegister fd, FloatRegister fs);
     BufferOffset as_roundwd(FloatRegister fd, FloatRegister fs);
     BufferOffset as_truncwd(FloatRegister fd, FloatRegister fs);
+    BufferOffset as_truncld(FloatRegister fd, FloatRegister fs);
 
     BufferOffset as_cvtdl(FloatRegister fd, FloatRegister fs);
     BufferOffset as_cvtds(FloatRegister fd, FloatRegister fs);