Division test bench
From Zet
This example tests these instructions:
- div, idiv and aam. Examples include:
- word / byte
- positive / positive
- negative / positive
- positive / negative
- negative / negative
- 0, 1, -1 division
- overflow and int 0
- 2 random values
Code
.code16 start: movw $208, %sp # Exception 0 handler movw $0x1000, (0) movw $0xf000, (2) movw $208, %bp # div word tests # easy test movw $0x0, %dx movw $0x14, %ax movw $0x5, %bx movw $0x2, (%bp) divw %bx addw $0x2, %bp movw %ax, (128) movw %bx, (130) movw %dx, (4) pushf movw $0xa320, %dx movw $0xc3da, %ax movw $0xffff, (6) movw $0x4, (%bp) divw (6) addw $0x2, %bp movw %ax, (8) movw %dx, (10) pushf movw $0xffff, %dx movw $0xffff, %ax movw $0x1, %cx movw $0x2, (%bp) divw %cx addw $0x2, %bp movw %ax, (12) movw %cx, (14) movw %dx, (16) pushf movw $0xffff, %dx movw $0xffff, %ax movw $0xffff, (18) movw $0x4, (%bp) divw (18) addw $0x2, %bp movw %ax, (20) movw %dx, (22) pushf movw $0xfbb4, %dx movw $0xc3da, %ax movw $0xae8e, %cx movw $0x2, (%bp) divw %cx addw $0x2, %bp movw %ax, (24) movw %cx, (26) movw %dx, (28) pushf movw $0x25c9, %dx movw $0xf110, %ax movw $0x2, (%bp) divw %ax addw $0x2, %bp movw %ax, (30) movw %dx, (32) pushf # div byte tests # easy test movw $0x14, %ax movw $0x5, %bx movw $0x2, (%bp) divb %bl addw $0x2, %bp movw %ax, (34) movw %bx, (36) movw %dx, (38) pushf movw $0xa320, %dx movw $0xc3da, %ax movw $0xff, (40) movw $0x4, (%bp) divb (40) addw $0x2, %bp movw %ax, (42) movw %dx, (44) pushf movw $0xffff, %ax movb $0x1, %dh movw $0x2, (%bp) divb %dh addw $0x2, %bp movw %ax, (46) movw %dx, (48) pushf movw $0xffff, %ax movw $0xffff, (50) movw $0x4, (%bp) divb (51) addw $0x2, %bp movw %ax, (52) movw %dx, (54) pushf movw $0x008a, %ax movw $0xae8e, %cx movw $0x2, (%bp) divb %cl addw $0x2, %bp movw %ax, (56) movw %cx, (58) pushf movw $0x0669, %dx movw $0x89f3, %ax movw $0x2, (%bp) divb %al addw $0x2, %bp movw %ax, (60) movw %dx, (62) pushf # idiv word tests # easy test movw $0x0, %dx movw $0x14, %ax movw $0xfa, %bx movw $0x2, (%bp) idivw %bx addw $0x2, %bp movw %ax, (64) movw %bx, (66) movw %dx, (68) pushf movw $0xa320, %dx movw $0xc3da, %ax movw $0xffff, (70) movw $0x4, (%bp) idivw (70) addw $0x2, %bp movw %ax, (72) movw %dx, (74) pushf movw $0xffff, %dx movw $0xffff, %ax movw $0x1, %cx movw $0x2, (%bp) idivw %cx addw $0x2, %bp movw %ax, (76) movw %cx, (78) movw %dx, (80) pushf movw $0xffff, %dx movw $0xffff, %ax movw $0xffff, (82) movw $0x4, (%bp) idivw (82) addw $0x2, %bp movw %ax, (84) movw %dx, (86) pushf movw $0xfbb4, %dx movw $0xc3da, %ax movw $0xae8e, %cx movw $0x2, (%bp) idivw %cx addw $0x2, %bp movw %ax, (88) movw %cx, (90) movw %dx, (92) pushf movw $0x25c9, %dx movw $0xf110, %ax movw $0x2, (%bp) idivw %ax addw $0x2, %bp movw %ax, (94) movw %dx, (96) pushf # idiv byte tests # easy test movw $0x14, %ax movw $0x5, %bx movw $0x2, (%bp) idivb %bl addw $0x2, %bp movw %ax, (98) movw %bx, (100) movw %dx, (102) pushf movw $0xa320, %dx movw $0xc3da, %ax movw $0xff, (104) movw $0x4, (%bp) idivb (104) addw $0x2, %bp movw %ax, (106) movw %dx, (108) pushf movw $0xffff, %ax movb $0x1, %dh movw $0x2, (%bp) idivb %dh addw $0x2, %bp movw %ax, (110) movw %dx, (112) pushf movw $0xffff, %ax movw $0xffff, (114) movw $0x4, (%bp) idivb (115) addw $0x2, %bp movw %ax, (116) movw %dx, (118) pushf movw $0x008a, %ax movw $0xae8e, %cx movw $0x2, (%bp) idivb %cl addw $0x2, %bp movw %ax, (120) movw %cx, (122) pushf movw $0x0669, %dx movw $0x89f3, %ax movw $0x2, (%bp) idivb %al addw $0x2, %bp movw %ax, (124) movw %dx, (126) pushf # AAM tests movw $0xffff, %ax movw $0x2, (%bp) aam $0 addw $0x2, %bp movw %ax, (132) pushf movw $0x2, (%bp) aam $1 addw $0x2, %bp movw %ax, (134) pushf movw $0xffff, %ax movw $0x2, (%bp) aam addw $0x2, %bp movw %ax, (136) pushf movw $0xff00, %ax movw $0x2, (%bp) aam $0 addw $0x2, %bp movw %ax, (138) pushf movw $0x2, (%bp) aam $1 addw $0x2, %bp movw %ax, (140) pushf movw $0x3ffb, %ax movw $0x2, (%bp) aam addw $0x2, %bp movw %ax, (142) pushf hlt # Exception handler (int 0) .org 0x1000 push %ax push %di movw (%bp), %ax movw %sp, %si addw $4, %si movw (%si), %si movw %si, (%bp) addw %ax, %si movw %sp, %di addw $4, %di movw %si, (%di) pop %di pop %ax iret .org 65520 jmp start .org 65535 .byte 0xff
Results
Memory contents at the end should be:
0x000: 0x1000 0xf000 0x0000 0xffff 0xa321 0x66fb 0xffff 0x0001 0x010: 0xffff 0xffff 0xffff 0xffff 0xc3da 0xae8e 0xfbb4 0x2821 0x020: 0x5e00 0x0004 0x0005 0x5e00 0x00ff 0x9ec4 0xa320 0xffff 0x030: 0x0120 0xffff 0xffff 0x0120 0x8a00 0xae8e 0x5091 0x0669 0x040: 0x0000 0x00fa 0x0014 0xffff 0xc3da 0xa320 0xffff 0x0001 0x050: 0x0000 0xffff 0x0001 0x0000 0x0d7f 0xae8e 0xf568 0xf110 0x060: 0x25c9 0x0004 0x0005 0x25c9 0x00ff 0xc3da 0xa320 0x00ff 0x070: 0x0120 0xffff 0x0001 0x0120 0x18ff 0xae8e 0x89f3 0x0669 0x080: 0x0004 0x0005 0xffff 0xff00 0x1905 0xff00 0x0000 0x1901 0x090: 0x0000 0xff00 0x0006 0x0006 0x0002 0x0006 0x0002 0x0002 0x0a0: 0x0016 0x0002 0x0006 0x0006 0x0002 0x0006 0x0002 0x0002 0x0b0: 0x0016 0x0006 0x0002 0x0002 0x0006 0x0002 0x0006 0x0006 0x0c0: 0x0012 0x0006 0x0002 0x0002 0x0006 0x0002 0x0006 0x0006 0x0d0: 0x0002 0x0004 0x005f 0x0081 0x009e 0x0002 0x0002 0x0004 0x0e0: 0x010d 0x0128 0x0002 0x0002 0x0002 0x0197 0x0002 0x0004 0x0f0: 0x0002 0x020f 0x0002 0x0249 0x0002 0x0004 0x0002 0x02af 0x100: 0x02c4 0x0002 0x0002 0x02f4 0x0002 0x0002 0xXXXX 0xXXXX
