4197 - done supporting all indirect addressing modes

1 files changed, 44 insertions, 0 deletions

diff --git a/subx/014index_addressing.cc b/subx/014index_addressing.cc
index 8ab545d3..e811290d 100644
--- a/subx/014index_addressing.cc
+++ b/subx/014index_addressing.cc
@@ -69,3 +69,47 @@ uint32_t effective_address_from_sib(uint8_t mod) {
 +run: effective address is initially 0x60 (disp32)
 +run: effective address is 0x60
 +run: storing 0x00000011
+
+//:
+
+:(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp8)
+% Reg[3].i = 0x10;  // source
+% Reg[0].i = 0x59;  // dest base
+% Reg[1].i = 0x5;  // dest index
+% SET_WORD_IN_MEM(0x60, 1);
+# op  ModR/M  SIB   displacement  immediate
+  01  5c      08    02                       # add EBX to *(EAX+ECX+2)
+# ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 100 (dest in SIB)
+# SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX)
++run: add EBX to r/m32
++run: effective address is initially 0x59 (EAX)
++run: effective address is 0x5e (after adding ECX*1)
++run: effective address is 0x60 (after adding disp8)
++run: storing 0x00000011
+
+:(before "End Mod 1 Special-cases(addr)")
+case 4:  // exception: mod 0b01 rm 0b100 => incoming SIB (scale-index-base) byte
+  addr = effective_address_from_sib(mod);
+  break;
+
+//:
+
+:(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp32)
+% Reg[3].i = 0x10;  // source
+% Reg[0].i = 0x59;  // dest base
+% Reg[1].i = 0x5;  // dest index
+% SET_WORD_IN_MEM(0x60, 1);
+# op  ModR/M  SIB   displacement  immediate
+  01  9c      08    02 00 00 00              # add EBX to *(EAX+ECX+2)
+# ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 100 (dest in SIB)
+# SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX)
++run: add EBX to r/m32
++run: effective address is initially 0x59 (EAX)
++run: effective address is 0x5e (after adding ECX*1)
++run: effective address is 0x60 (after adding disp32)
++run: storing 0x00000011
+
+:(before "End Mod 2 Special-cases(addr)")
+case 4:  // exception: mod 0b10 rm 0b100 => incoming SIB (scale-index-base) byte
+  addr = effective_address_from_sib(mod);
+  break;