Linearscan register allocator for javascript
// Declare some instructionsvarlinearscan=require('linearscan');functiongp(kind,value){return{kind:kind,group:'gp',value:value};}functionfp(kind,value){return{kind:kind,group:'fp',value:value};}varconfig=linearscan.config.create({// Multiple register groups might be specified, they will be allocated// separatelyregisters:{gp:['rax','rbx','rcx','rdx'],fp:['xmm1','xmm2','xmm3','xmm4']},opcodes:{literal:{// 'any' means either 'register' or 'spill'output:gp('any')},'literal-fp':{output:fp('any')},// Set `branch` to `true` to get links to other regionsif:{branch:true},jump:{branch:true},add:{output:gp('any'),inputs:[gp('any'),gp('any')]},'add-fp':{output:fp('any'),inputs:[fp('any'),fp('any')]},floor:{output:gp('any'),inputs:[fp('any')]},return:{// specify particular register that MUST be used hereinputs:[gp('register','rax')]},'rax-out':{inputs:[],output:gp('register','rax'),spills:[]},'rbx-out':{inputs:[],output:gp('register','rbx'),spills:[]},'rbx-call':{inputs:[],output:gp('register','rbx'),// Scratches are similar to spills, but neither input nor output will// be allocated to this value.scratches:[gp('register','rdx')],spills:[gp('register','rax'),gp('register','rbx'),gp('register','rcx')]},call:{output:gp('register','rax'),// 'register' means just any GP registerinputs:[gp('register'),gp('any')],spills:[gp('register','rax'),gp('register','rbx'),gp('register','rcx'),gp('register','rdx')]}}});// Get pipeline from previous stages of compiler// (see json-pipeline npm module)varpipeline=getPipeline();// Make sure that pipeline is properly indexedpipeline.reindex();varout=linearscan.allocate(pipeline,config);console.log(out.render('printable'));Will output something like this:
register{%rax=literal1%rbx=literal2%rcx=literal3%rdx=literal4[0]=ls:move%3%rdx=literal5[1]=ls:move[0][3]=ls:move%1[2]=ls:move%2[0]=ls:move%3%rax=call%rdx,%rax%rax=add[3],[3]%rax=add[2],[2]%rax=add[1],[1]%rax=add[0],[0]}out.spillType is the list of spill ranges of following format:{ type: 'register-group', from: index, to: index }.
This software is licensed under the MIT License.
Copyright Fedor Indutny, 2015.
Permission is hereby granted, free of charge, to any person obtaining acopy of this software and associated documentation files (the"Software"), to deal in the Software without restriction, includingwithout limitation the rights to use, copy, modify, merge, publish,distribute, sublicense, and/or sell copies of the Software, and to permitpersons to whom the Software is furnished to do so, subject to thefollowing conditions:
The above copyright notice and this permission notice shall be includedin all copies or substantial portions of the Software.
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