diff --git a/src/opcodes/effects.asm b/src/opcodes/effects.asm
index d391b27..4df9f60 100644
--- a/src/opcodes/effects.asm
+++ b/src/opcodes/effects.asm
@@ -462,7 +462,7 @@ su_op_compressor_mono:
     fucomi  st0, st1
     setnb   al                                  ; if (st0 >= st1) al = 1; else al = 0;
     fsubp   st1, st0                            ; x^2-l x
-    call    su_env_map                          ; c x^2-l x, c is either attack or release parameter mapped in a nonlinear way
+    call    su_nonlinear_map                    ; c x^2-l x, c is either attack or release parameter mapped in a nonlinear way
     fmulp   st1, st0                            ; c*(x^2-l) x
     fadd    dword [WRK+su_compres_wrk.level]    ; l+c*(x^2-l) x   // we could've kept level in the stack and save a few bytes, but su_env_map uses 3 stack (c + 2 temp), so the stack was getting quite big.
     fst     dword [WRK+su_compres_wrk.level]    ; l'=l+c*(x^2-l), l' x
diff --git a/src/opcodes/sources.asm b/src/opcodes/sources.asm
index e4411d8..51cb6d4 100644
--- a/src/opcodes/sources.asm
+++ b/src/opcodes/sources.asm
@@ -29,7 +29,7 @@ kmENV_func_process:
 kmENV_func_attac:
     cmp     al, ENV_STATE_ATTAC                 ; if (al!=ATTAC)
     jne     short kmENV_func_decay              ;   goto decay
-    call    su_env_map                          ; a x, where a=attack
+    call    su_nonlinear_map                    ; a x, where a=attack
     faddp   st1, st0                            ; a+x
     fld1                                        ; 1 a+x
     fucomi  st1                                 ; if (a+x<=1) // is attack complete?
@@ -38,7 +38,7 @@ kmENV_func_attac:
 kmENV_func_decay:
     cmp     al, ENV_STATE_DECAY                 ; if (al!=DECAY)
     jne     short kmENV_func_release            ;   goto release
-    call    su_env_map                          ; d x, where d=decay
+    call    su_nonlinear_map                    ; d x, where d=decay
     fsubp   st1, st0                            ; x-d
     fld     dword [INP+su_env_ports.sustain]       ; s x-d, where s=sustain
     fucomi  st1                                 ; if (x-d>s) // is decay complete?
@@ -47,7 +47,7 @@ kmENV_func_decay:
 kmENV_func_release:
     cmp     al, ENV_STATE_RELEASE               ; if (al!=RELEASE)
     jne     short kmENV_func_leave              ;   goto leave
-    call    su_env_map                            ; r x, where r=release
+    call    su_nonlinear_map                    ; r x, where r=release
     fsubp   st1, st0                            ; x-r
     fldz                                        ; 0 x-r
     fucomi  st1                                 ; if (x-r>0) // is release complete?
diff --git a/src/sointu.asm b/src/sointu.asm
index cf72767..6f5464f 100644
--- a/src/sointu.asm
+++ b/src/sointu.asm
@@ -219,16 +219,16 @@ su_transform_values_out:
     ret
 
 ;-------------------------------------------------------------------------------
-;   su_env_map function: computes 2^(-24*x) of the envelope parameter
+;   su_nonlinear_map function: returns 2^(-24*x) of parameter number _AX
 ;-------------------------------------------------------------------------------
-;   Input:      eax     :   envelope parameter (0 = attac, 1 = decay...)
-;               edx     :   pointer to su_transformed_values
+;   Input:      _AX     :   parameter number (e.g. for envelope: 0 = attac, 1 = decay...)
+;               INP     :   pointer to transformed values
 ;   Output:     st0     :   2^(-24*x), where x is the parameter in the range 0-1
 ;-------------------------------------------------------------------------------
 SECT_TEXT(supower)
 
-%if ENVELOPE_ID > -1 ; TODO: compressor also uses this, so should be compiled if either
-su_env_map:
+%if ENVELOPE_ID > -1 || COMPRES_ID > -1
+su_nonlinear_map:
     fld     dword [INP+_AX*4]   ; x, where x is the parameter in the range 0-1
  do fimul   dword [,c_24,]      ; 24*x
     fchs                        ; -24*x