72 lines
1.7 KiB
Text
72 lines
1.7 KiB
Text
* How to add an llvm intrinsic
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- add enum value llvmintrinsic::foo to llvmintrinsic in xo-expression
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- also add foo to llvmintrinsic2str in xo-expression llvmintrinsic.hpp
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- if we have a built-in Primitive for the same functionality,
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want Primitive::intrinsic_ = llvmintrinsic::foo
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- in MachPipeline::codegen_apply(), look for switch(intrinsic),
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add case llvmintrinsic::foo
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- substitute codegen for the intrinsic
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in place of the catch-all IRBuilder::CreateCall
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** To test from python:
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1. install xo-pyjit and deps somewhere (~/local2 in this example)
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2. PYTHONPATH=~/local2:$PYTHONPATH python
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3. python:
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from xo_pyreflect import *
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from xo_pyexpression import *
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from xo_pyjit import *
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i32_t=TypeDescr.lookup_by_name('double')
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x=make_var('x',i32_t)
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f=make_mul_i32_pm()
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c=make_apply(f,[x,x])
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lm=make_lambda('sq',[x],c)
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mp=MachPipeline.make()
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code=mp.codegen(lm)
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print(code.print())
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4. in our example, get output like:
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define i32 @sq(i32 %x) {
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entry:
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%0 = mul i32 %x, %x
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ret i32 %0
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}
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5. to compile+run via JIT:
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mp.machgen_current_module()
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fn=mp.lookup_fn('int (*)(int)', 'sq')
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fn(16) # -> 256
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** to figure out what 'IR should look like' for something simple
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write some c++:
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#include <cmath>
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struct env_type {
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env_type * parent;
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env_type * (*unwind)(env_type *, int);
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};
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double wrap_sqrt(env_type * env, double x) {
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return ::sqrt(x);
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}
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int main() {
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wrap_sqrt(nullptr, 2.0);
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}
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compile to emit IR
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$ clang -cc1 ex_cpp.cpp -emit-llvm
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inspect
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ex_cpp.ll
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