79 lines
2.1 KiB
Python
Executable file
79 lines
2.1 KiB
Python
Executable file
#!/usr/bin/env python
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# This example shows how to use LLVM intrinsics.
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from llvm.core import *
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from llvm.ee import *
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# setup a function and a builder
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mod = Module.new('test')
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functy = Type.function(Type.void(), [])
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func = mod.add_function(functy, "showme")
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block = func.append_basic_block("entry")
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b = Builder.new(block)
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# let's do bswap on a 32-bit integer using llvm.bswap
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val = Constant.int(Type.int(), 42)
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bswap = Function.intrinsic(mod, INTR_BSWAP, [Type.int()])
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b.call(bswap, [val])
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print(mod)
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# the output is:
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#
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# ; ModuleID = 'test'
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#
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# define void @showme() {
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# entry:
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# call i32 @llvm.bswap.i32( i32 42 ) ; <i32>:0 [#uses=0]
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# }
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#
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# declare i32 @llvm.bswap.i32(i32) nounwind readnone
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#
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# mysin(x) = sqrt(1.0 - pow(cos(x), 2))
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float = Type.float()
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mysinty = Type.function( float, [float] )
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mysin = mod.add_function(mysinty, "mysin")
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block = mysin.append_basic_block("entry")
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b = Builder.new(block)
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sqrt = Function.intrinsic(mod, INTR_SQRT, [float])
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pow = Function.intrinsic(mod, INTR_POWI, [float])
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cos = Function.intrinsic(mod, INTR_COS, [float])
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mysin.args[0].name = "x"
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x = mysin.args[0]
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one = Constant.real(float, "1")
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cosx = b.call(cos, [x], "cosx")
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cos2 = b.call(pow, [cosx, Constant.int(Type.int(), 2)], "cos2")
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onemc2 = b.sub(one, cos2, "onemc2")
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sin = b.call(sqrt, [onemc2], "sin")
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b.ret(sin)
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print(mod)
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#
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# ; ModuleID = 'test'
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#
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# define void @showme() {
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# entry:
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# call i32 @llvm.bswap.i32( i32 42 ) ; <i32>:0 [#uses=0]
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# }
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#
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# declare i32 @llvm.bswap.i32(i32) nounwind readnone
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#
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# define float @mysin(float %x) {
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# entry:
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# %cosx = call float @llvm.cos.f32( float %x ) ; <float> [#uses=1]
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# %cos2 = call float @llvm.powi.f32( float %cosx, i32 2 ) ; <float> [#uses=1]
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# %onemc2 = sub float 1.000000e+00, %cos2 ; <float> [#uses=1]
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# %sin = call float @llvm.sqrt.f32( float %onemc2 ) ; <float> [#uses=1]
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# ret float %sin
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# }
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#
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# declare float @llvm.sqrt.f32(float) nounwind readnone
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#
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# declare float @llvm.powi.f32(float, i32) nounwind readnone
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#
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# declare float @llvm.cos.f32(float) nounwind readnone
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#
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