SAVEUSR Compiler Directive

Abbreviation		None.
Arguments		None.
Default		SAVESYS
µVision		Options — C166 — Save Temporary Variables on User Stack.
Description		The SAVEUSR directive instructs the C166 Compiler to save temporary results and saved-by-callee variables on the user stack. This option may be necessary if you run out of system stack space. The system stack is always located in on-chip RAM, which is faster than external RAM but is limited in size.
See Also		SAVESYS
Example		1 extern void func (void); 2 3 #pragma SAVESYS // Save to SYS STACK (default) 4 int func1 (int i1, int i2) { 5 1 func (); 6 1 return (i1 + i2); 7 1 } 8 9 10 #pragma SAVEUSR // Save to USER STACK 11 int func2 (int i1, int i2) { 12 1 func (); 13 1 return (i1 + i2); 14 1 } ASSEMBLY LISTING OF GENERATED OBJECT CODE ; FUNCTION func1 (BEGIN RMASK = @0x7FFF) ; SOURCE LINE # 4 0000 ECFD PUSH R13 0002 ECFE PUSH R14 0004 F0D9 MOV R13,R9 ;---- Variable 'i2' assigned to Register 'R13' ---- 0006 F0E8 MOV R14,R8 ;---- Variable 'i1' assigned to Register 'R14' ---- ; SOURCE LINE # 5 0008 CA000000 E CALLA cc_UC,func ; SOURCE LINE # 6 000C F04E MOV R4,R14 000E 004D ADD R4,R13 ; SOURCE LINE # 7 0010 FCFE POP R14 0012 FCFD POP R13 0014 CB00 RET ; FUNCTION func1 (END RMASK = @0x7FFF) ; FUNCTION func2 (BEGIN RMASK = @0x7FFF) ; SOURCE LINE # 11 0016 88D0 MOV [-R0],R13 0018 88E0 MOV [-R0],R14 001A F0D9 MOV R13,R9 ;---- Variable 'i2' assigned to Register 'R13' ---- 001C F0E8 MOV R14,R8 ;---- Variable 'i1' assigned to Register 'R14' ---- ; SOURCE LINE # 12 001E CA000000 E CALLA cc_UC,func ; SOURCE LINE # 13 0022 F04E MOV R4,R14 0024 004D ADD R4,R13 ; SOURCE LINE # 14 0026 98E0 MOV R14,[R0+] 0028 98D0 MOV R13,[R0+] 002A CB00 RET ; FUNCTION func2 (END RMASK = @0x7FFF)