Based on Bill Verners' Inside the Java Virtual Machine, McGraw Hill Companies, 1997

getfield - Fetch field from object
  opcode:  180 (0xb4)
  usage: getfield field-spec descriptor
  stack before: ..., objectref
stack after: ..., value

or

stack before: ..., objectref
stack after:
..., value.word1, value.word2

 
description: This instruction gets value from a non static field of the object on the top of the stack. field-spec is composed of two parts, a classname and field name (f.e. foo/bar/ClassName/fieldName). descriptor is the Java type descriptor of the field.

getstatic - Fetch static field from class
  opcode:  178 (0xb2)
  usage: getstatic field-spec descriptor
  stack before: ...
stack after: ..., value

or

stack before: ...
stack after: ..., value.word1, value.word2

 
description: This instruction gets value from a static field of the object on the top of the stack. field-spec is composed of two parts, a classname and field name (f.e. foo/bar/ClassName/fieldName). descriptor is the Java type descriptor of the field.

goto - Branch always
  opcode:  167 (0xa7)
  usage: goto label
  stack: No change
 
description: This instruction causes a jump to label label.

goto_w - Branch always (wide index)
  opcode:  200 (0xc8)
  usage: goto_w label
  stack: no change
 
description:

This instruction causes a jump to label label.