Skip to main content

Return to Answer

added 1 character in body
Source Link
RobertS supports Monica Cellio
RobertS supports Monica Cellio
  • 15.2k
  • 13
  • 47
  • 94

Assuming:

sizeof(unsigned short) == 2 sizeof(int) == 4

Then I personally would use the following (your compiler may differ):

unsigned shorts are aligned to 2 byte boundaries int will be aligned to 4 byte boundaries. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset } myStruct; // End 6 bytes. // No part is required to align tighter than 2 bytes. // So whole structure can be 2 byte aligned. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset /// Padding // 6-7 padding (so i is 4 byte aligned) int i; // 8 bytes offset } myStruct; // End 12 bytes // Whole structure needs to be 4 byte aligned. // So that i is correctly aligned.

Assuming:

sizeof(unsigned short) == 2 sizeof(int) == 4

Then I personally would use the following (your compiler may differ):

unsigned shorts are aligned to 2 byte boundaries int will be aligned to 4 byte boundaries. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset } myStruct; // End 6 bytes. // No part is required to align tighter than 2 bytes. // So whole structure can be 2 byte aligned. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset /// Padding // 6-7 padding (so i is 4 byte aligned int i; // 8 bytes offset } myStruct; // End 12 bytes // Whole structure needs to be 4 byte aligned. // So that i is correctly aligned.

Assuming:

sizeof(unsigned short) == 2 sizeof(int) == 4

Then I personally would use the following (your compiler may differ):

unsigned shorts are aligned to 2 byte boundaries int will be aligned to 4 byte boundaries. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset } myStruct; // End 6 bytes. // No part is required to align tighter than 2 bytes. // So whole structure can be 2 byte aligned. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset /// Padding // 6-7 padding (so i is 4 byte aligned) int i; // 8 bytes offset } myStruct; // End 12 bytes // Whole structure needs to be 4 byte aligned. // So that i is correctly aligned.
Source Link
Loki Astari
Loki Astari
  • 266.5k
  • 87
  • 344
  • 575

Assuming:

sizeof(unsigned short) == 2 sizeof(int) == 4

Then I personally would use the following (your compiler may differ):

unsigned shorts are aligned to 2 byte boundaries int will be aligned to 4 byte boundaries. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset } myStruct; // End 6 bytes. // No part is required to align tighter than 2 bytes. // So whole structure can be 2 byte aligned. typedef struct { unsigned short v1; // 0 bytes offset unsigned short v2; // 2 bytes offset unsigned short v3; // 4 bytes offset /// Padding // 6-7 padding (so i is 4 byte aligned int i; // 8 bytes offset } myStruct; // End 12 bytes // Whole structure needs to be 4 byte aligned. // So that i is correctly aligned.