wok annotate linld/stuff/src/pipehole.awk @ rev 20520

Up sshguard (2.2.0)
author Pascal Bellard <pascal.bellard@slitaz.org>
date Mon Nov 05 11:52:27 2018 +0100 (2018-11-05)
parents f5088c165f51
children f0d71e920c5a
rev   line source
pascal@20458 1 BEGIN { hold=0 }
pascal@20458 2 function isnum(n) { return match(n,/^[0-9+-]/) }
pascal@20458 3 {
pascal@20458 4 if (hold == 0) {
pascal@20458 5 s=$0
pascal@20458 6 if (/^ mov .x,bx$/ || /^ mov .x,.i$/) {
pascal@20520 7 r=$2
pascal@20458 8 hold=1; split($2,regs,","); next
pascal@20458 9 }
pascal@20458 10 if (/^ inc e?.[ix]/ || /^ dec e?.[ix]/) {
pascal@20458 11 hold=2; r=$2; next
pascal@20458 12 }
pascal@20458 13 if (/^ mov [abcds][ix],/ && ! /,.s/) {
pascal@20458 14 hold=3; split($2,regs,","); next
pascal@20458 15 }
pascal@20458 16 if (/^ movzx eax,ax$/) { hold=4; next }
pascal@20520 17 if (/^ mov cl,4$/) { hold=8; next }
pascal@20458 18 }
pascal@20458 19 else if (hold == 1) {
pascal@20520 20 if (/^ ;/) { print; next }
pascal@20458 21 hold=0; split($2,args,","); op=""
pascal@20458 22 if ($1 == "add") op="+"
pascal@20458 23 if ($1 == "sub") op="-"
pascal@20458 24 if (op != "" && regs[1] == args[1] && isnum(args[2])) {
pascal@20458 25 print "\tlea\t" regs[1] ",[" regs[2] op args[2] "]"
pascal@20458 26 next
pascal@20458 27 }
pascal@20520 28 if (/^ pop [ds]i/ && regs[2] ~ /^[ds]i$/) {
pascal@20520 29 print " xchg " r
pascal@20520 30 }
pascal@20520 31 else print "\tmov\t" regs[1] "," regs[2]
pascal@20458 32 }
pascal@20458 33 else if (hold == 2) {
pascal@20458 34 hold=0; split($2,args,","); print s
pascal@20458 35 if ($1 == "or" && r == args[1] && r == args[2]) next # don't clear C ...
pascal@20458 36 }
pascal@20458 37 else if (hold == 3) {
pascal@20458 38 hold=0
pascal@20458 39 if (/^ add [abcds][ix],/ || /^ sub [abcds][ix],/) {
pascal@20458 40 split($2,regs2,",")
pascal@20458 41 if (regs[1] == regs2[1] && (regs2[2] == "offset" || isnum(regs2[2]))) {
pascal@20458 42 t=$0; sub(/mov/,$1,s)
pascal@20458 43 if ($1 == "add") sub(/add/,"mov",t); else sub(/sub/,"mov",t)
pascal@20458 44 print t; print s; next
pascal@20458 45 }
pascal@20458 46 }
pascal@20458 47 print s
pascal@20458 48 }
pascal@20458 49 else if (hold == 4) {
pascal@20458 50 hold=0
pascal@20458 51 if (/^ push eax$/) {
pascal@20458 52 print " push 0"; print " push ax"; next
pascal@20458 53 } else { print s }
pascal@20458 54 }
pascal@20520 55 else if (hold == 8) {
pascal@20458 56 hold=0
pascal@20520 57 if (/^ call near ptr N_LXURSH@$/) {
pascal@20520 58 print " extrn N_LXURSH@4:near"
pascal@20520 59 print " call near ptr N_LXURSH@4"
pascal@20520 60 next
pascal@20520 61 }
pascal@20520 62 print s
pascal@20458 63 }
pascal@20458 64 s=$0
pascal@20458 65 # These optimisation may break ZF or CF
pascal@20485 66 if (/^ sub sp,2$/) { print " push ax"; next }
pascal@20485 67 if (/^ sub sp,4$/) { print " push ax"; print " push ax"; next }
pascal@20485 68 if (/^ add sp,4$/) { print " pop cx"; print " pop cx"; next }
pascal@20458 69 if (/^ mov d*word ptr .*,0$/ || /^ mov dword ptr .*,large 0$/) {
pascal@20458 70 sub(/mov/,"and",s); print s; next # slower
pascal@20458 71 }
pascal@20458 72 if (/^ mov d*word ptr .*,-1$/ || /^ mov dword ptr .*,large -1$/) {
pascal@20458 73 sub(/mov/,"or",s); print s; next # slower
pascal@20458 74 }
pascal@20458 75 if (/^ or .*,0$/ || /^ and .*,-1$/) next
pascal@20458 76 if (/^ or [abcd]x,/) {
pascal@20458 77 split($2,args,",")
pascal@20458 78 if (isnum(args[2]) && args[2] >= 0 && args[2] < 256) {
pascal@20458 79 print " or " substr(args[1],1,1) "l," args[2]; next
pascal@20458 80 }
pascal@20458 81 }
pascal@20458 82 if (/^ and [abcd]x,/) {
pascal@20458 83 split($2,args,",")
pascal@20459 84 if (isnum(args[2]) && args[2] >= -256 && args[2] < 0) {
pascal@20458 85 print " and " substr(args[1],1,1) "l," args[2]; next
pascal@20458 86 }
pascal@20458 87 }
pascal@20458 88 if (/^ or e[abcd]x,/) {
pascal@20458 89 split($2,args,",")
pascal@20458 90 if (args[2] == "large") { args[2] = $3 }
pascal@20458 91 if (isnum(args[2]) && args[2] >= 0 && args[2] < 256) {
pascal@20458 92 print " or " substr(args[1],2,1) "l," args[2]; next
pascal@20458 93 }
pascal@20458 94 }
pascal@20458 95 if (/^ and e[abcd]x,/) {
pascal@20458 96 split($2,args,",")
pascal@20458 97 if (args[2] == "large") { args[2] = $3 }
pascal@20459 98 if (isnum(args[2]) && args[2] >= -256 && args[2] < 0) {
pascal@20458 99 print " and " substr(args[1],2,1) "l," args[2]; next
pascal@20458 100 }
pascal@20458 101 }
pascal@20458 102 if (/^ or e[abcds][ix],/) {
pascal@20458 103 split($2,args,",")
pascal@20458 104 if (args[2] == "large") { args[2] = $3 }
pascal@20458 105 if (isnum(args[2]) && args[2] >= 0 && args[2] < 65536) {
pascal@20458 106 print " or " substr(args[1],2) "," args[2]; next
pascal@20458 107 }
pascal@20458 108 }
pascal@20458 109 if (/^ and e[abcds][ix],/) {
pascal@20458 110 split($2,args,",")
pascal@20458 111 if (args[2] == "large") { args[2] = $3 }
pascal@20459 112 if (isnum(args[2]) && args[2] >= -65536 && args[2] < 0) {
pascal@20458 113 print " and " substr(args[1],2) "," args[2]; next
pascal@20458 114 }
pascal@20458 115 }
pascal@20458 116 if (/^ add word ptr/ || /^ sub word ptr/) {
pascal@20458 117 split($0,args,",")
pascal@20458 118 if (isnum(args[2]) && (args[2] % 256 == 0)) {
pascal@20458 119 sub(/word/,"byte",s); sub(/\]/,"+1]",s)
pascal@20458 120 print s "/256"; next
pascal@20458 121 }
pascal@20458 122 }
pascal@20458 123 if (/^ add dword ptr/ || /^ sub dword ptr/) {
pascal@20458 124 split($0,args,",")
pascal@20458 125 if (args[2] == "large") { split(args[2],args," ") }
pascal@20458 126 if (isnum(args[2])) {
pascal@20458 127 if (args[2] % 16777216 == 0) {
pascal@20458 128 sub(/dword/,"byte",s); sub(/\]/,"+3]",s)
pascal@20458 129 print s "/16777216"; next
pascal@20458 130 }
pascal@20458 131 if (args[2] % 65536 == 0) {
pascal@20458 132 sub(/dword/,"word",s); sub(/\]/,"+2]",s)
pascal@20458 133 print s "/65536"; next
pascal@20458 134 }
pascal@20458 135 }
pascal@20458 136 }
pascal@20458 137 if (/^ mov e.x,/) {
pascal@20458 138 split($2,args,",")
pascal@20458 139 r=args[1]
pascal@20458 140 if (args[2] == "large") { args[2] = $3 }
pascal@20458 141 if (isnum(args[2]) && args[2] % 65536 == args[2]) {
pascal@20458 142 if (args[2] % 256 == args[2] || args[2] % 256 == 0) {
pascal@20458 143 print " xor " r "," r
pascal@20458 144 if (args[2] == 0) next
pascal@20458 145 x=" mov " substr(r,2,1)
pascal@20458 146 if (args[2] % 256 == 0) {
pascal@20458 147 print x "h," args[2] "/256"
pascal@20458 148 }
pascal@20458 149 else { print x "l," args[2] }
pascal@20458 150 next
pascal@20458 151 }
pascal@20458 152 }
pascal@20458 153 }
pascal@20458 154 print
pascal@20458 155 }