mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

	Commit message (Expand)	Author	Age	Files	Lines
*	2620	Kartik K. Agaram	2016-01-30	1	-6/+6
*	2614	Kartik K. Agaram	2016-01-29	1	-1/+1
*	2570 - recipe variables are now fully type-checked	Kartik K. Agaram	2016-01-18	1	-0/+31
*	2569	Kartik K. Agaram	2016-01-18	1	-0/+14
*	2566 - typecheck 'call' on recipe variables	Kartik K. Agaram	2016-01-18	1	-1/+25
*	2565 - typecheck 'call' on literal recipes	Kartik K. Agaram	2016-01-18	1	-0/+48
*	2563 - bring back 'call'	Kartik K. Agaram	2016-01-18	1	-0/+54
*	2562	Kartik K. Agaram	2016-01-17	1	-11/+12
*	2561	Kartik K. Agaram	2016-01-17	1	-0/+25

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - subx/016index_addressing.cc</title> <meta name="Generator" content="Vim/8.0"> <meta name="plugin-version" content="vim7.4_v2"> <meta name="syntax" content="cpp"> <meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> <meta name="colorscheme" content="minimal"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body onload='JumpToLine();'> <pre id='vimCodeElement'> 1 //: operating on memory at the address provided by some register plus optional scale and offset 2 3 :(scenario add_r32_to_mem_at_r32_with_sib) 4 % Reg[EBX].i = 0x10; 5 % Reg[EAX].i = 0x60; 6 == 0x1 # code segment 7 # op ModR/M SIB displacement immediate 8 01 1c 20 # add EBX to *EAX 9 # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) 10 # SIB in binary: 00 (scale 1) 100 (no index) 000 (base EAX) 11 == 0x60 # data segment 12 01 00 00 00 # 1 13 +run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32 14 +run: effective address is initially 0x60 (EAX) 15 +run: effective address is 0x60 16 +run: storing 0x00000011 17 18 :(before "End Mod 0 Special-cases(addr)") 19 case 4: // exception: mod 0b00 rm 0b100 => incoming SIB (scale-index-base) byte 20 addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a>(mod); 21 break; 22 :(code) 23 uint32_t <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a>(uint8_t mod) { 24 uint8_t sib = <a href='010---vm.cc.html#L214'>next</a>(); 25 uint8_t base = sib&0x7; 26 uint32_t addr = 0; 27 if (base != <a href='010---vm.cc.html#L18'>EBP</a> || mod != 0) { 28 addr = Reg[base].u; 29 <a href='003trace.cc.html#L204'>trace</a>(90, "run") << "effective address is initially 0x" << std::hex << addr << " (" << <a href='013direct_addressing.cc.html#L62'>rname</a>(base) << ")" << <a href='003trace.cc.html#L230'>end</a>(); 30 } 31 else { 32 // base == EBP && mod == 0 33 addr = <a href='011run.cc.html#L315'>next32</a>(); // ignore base 34 <a href='003trace.cc.html#L204'>trace</a>(90, "run") << "effective address is initially 0x" << std::hex << addr << " (disp32)" << <a href='003trace.cc.html#L230'>end</a>(); 35 } 36 uint8_t index = (sib>>3)&0x7; 37 if (index == <a href='010---vm.cc.html#L17'>ESP</a>) { 38 // ignore index and scale 39 <a href='003trace.cc.html#L204'>trace</a>(90, "run") << "effective address is 0x" << std::hex << addr << <a href='003trace.cc.html#L230'>end</a>(); 40 } 41 else { 42 uint8_t scale = (1 << (sib>>6)); 43 addr += Reg[index].i*scale; // treat index register as signed. Maybe base as well? But we'll always ensure it's non-negative. 44 <a href='003trace.cc.html#L204'>trace</a>(90, "run") << "effective address is 0x" << std::hex << addr << " (after adding " << <a href='013direct_addressing.cc.html#L62'>rname</a>(index) << "*" << <a href='010---vm.cc.html#L262'>NUM</a>(scale) << ")" << <a href='003trace.cc.html#L230'>end</a>(); 45 } 46 return addr; 47 } 48 49 :(scenario add_r32_to_mem_at_base_r32_index_r32) 50 % Reg[EBX].i = 0x10; // source 51 % Reg[EAX].i = 0x5e; // dest base 52 % Reg[ECX].i = 0x2; // dest index 53 == 0x1 # code segment 54 # op ModR/M SIB displacement immediate 55 01 1c 08 # add EBX to *(EAX+ECX) 56 # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) 57 # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) 58 == 0x60 # data segment 59 01 00 00 00 # 1 60 +run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32 61 +run: effective address is initially 0x5e (EAX) 62 +run: effective address is 0x60 (after adding ECX*1) 63 +run: storing 0x00000011 64 65 :(scenario add_r32_to_mem_at_displacement_using_sib) 66 % Reg[EBX].i = 0x10; // source 67 == 0x1 # code segment 68 # op ModR/M SIB displacement immediate 69 01 1c 25 60 00 00 00 # add EBX to *0x60 70 # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) 71 # SIB in binary: 00 (scale 1) 100 (no index) 101 (not EBP but disp32) 72 == 0x60 # data segment 73 01 00 00 00 # 1 74 +run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32 75 +run: effective address is initially 0x60 (disp32) 76 +run: effective address is 0x60 77 +run: storing 0x00000011 78 79 //: 80 81 :(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp8) 82 % Reg[EBX].i = 0x10; // source 83 % Reg[EAX].i = 0x59; // dest base 84 % Reg[ECX].i = 0x5; // dest index 85 == 0x1 # code segment 86 # op ModR/M SIB displacement immediate 87 01 5c 08 02 # add EBX to *(EAX+ECX+2) 88 # ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 100 (dest in SIB) 89 # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) 90 == 0x60 # data segment 91 01 00 00 00 # 1 92 +run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32 93 +run: effective address is initially 0x59 (EAX) 94 +run: effective address is 0x5e (after adding ECX*1) 95 +run: effective address is 0x60 (after adding disp8) 96 +run: storing 0x00000011 97 98 :(before "End Mod 1 Special-cases(addr)") 99 case 4: // exception: mod 0b01 rm 0b100 => incoming SIB (scale-index-base) byte 100 addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a>(mod); 101 break; 102 103 //: 104 105 :(scenario add_r32_to_mem_at_base_r32_index_r32_plus_disp32) 106 % Reg[EBX].i = 0x10; // source 107 % Reg[EAX].i = 0x59; // dest base 108 % Reg[ECX].i = 0x5; // dest index 109 == 0x1 # code segment 110 # op ModR/M SIB displacement immediate 111 01 9c 08 02 00 00 00 # add EBX to *(EAX+ECX+2) 112 # ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 100 (dest in SIB) 113 # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) 114 == 0x60 # data segment 115 01 00 00 00 # 1 116 +run: add <a href='010---vm.cc.html#L16'>EBX</a> to r/m32 117 +run: effective address is initially 0x59 (EAX) 118 +run: effective address is 0x5e (after adding ECX*1) 119 +run: effective address is 0x60 (after adding disp32) 120 +run: storing 0x00000011 121 122 :(before "End Mod 2 Special-cases(addr)") 123 case 4: // exception: mod 0b10 rm 0b100 => incoming SIB (scale-index-base) byte 124 addr = <a href='016index_addressing.cc.html#L23'>effective_address_from_sib</a>(mod); 125 break; </pre> </body> </html>