54 lines
2.1 KiB
D
54 lines
2.1 KiB
D
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/**********************************************
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To provide access to features that would be otherwise counterproductive or
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difficult to implement, compilers provide an interface consisting of a set
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of builtins (also called intrinsics) which can be called like normal functions.
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This module exposes builtins both common to all D compilers
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(those provided by the frontend) and specific to the host compiler i.e. those
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specific to either LLVM or GCC (`ldc.intrinsics` and `gcc.builtins` are publicly imported, respectively).
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Host-specific intrinsics cannot be reliably listed here, however listings can be found
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at the documentation for the relevant backends, i.e.
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$(LINK2 https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html, GCC) and
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$(LINK2 https://llvm.org/docs/LangRef.html, LLVM). It should be noted that not all
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builtins listed are necessarily supported by the host compiler, please file a bug
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if this is the case for your workload.
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Use of this module reduces the amount of conditional compilation needed
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to use a given builtin. For example, to write a target independent function
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that uses prefetching we can write the following:
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---
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float usePrefetch(float[] x)
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{
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// There is only one import statement required rather than two (versioned) imports
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import core.builtins;
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version (GNU)
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__builtin_prefetch(x.ptr);
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version (LDC)
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/+
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For the curious: 0, 3, 1 mean `x` will only be read-from (0), it will be used
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very often (3), and it should be fetched to the data-cache (1).
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+/
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llvm_prefetch(x.ptr, 0, 3, 1);
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const doMath = blahBlahBlah;
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return doMath;
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}
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---
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Copyright: Copyright © 2021, The D Language Foundation
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License: $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
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Authors: Walter Bright
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Source: $(DRUNTIMESRC core/builtins.d)
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*/
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module core.builtins;
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version (GNU)
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public import gcc.builtins;
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version (LDC)
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public import ldc.intrinsics;
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/// Writes `s` to `stderr` during CTFE (does nothing at runtime).
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void __ctfeWrite(scope const(char)[] s) @nogc @safe pure nothrow {}
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