[llvm-dev] intrinsics

Anastasiya Ruzhanskaya via llvm-dev
Tue, 11 Jul 2017 18:38:35 -0000

great, thank you!

Still, I have tried fast option:
clang -S -O3 -mllvm -ffast-math -emit-llvm sqrt.c -o sqrt.s

and also with specifying this option in opt (not in clang) - it stays the
same sqrt.

#include <stdlib.h>

#include <stdio.h>
int main() {

        int a;
        scanf("%d", &a);
        double b = sqrt(a);
        int c = (b > 10) ? 1 : 0;
        return c;
}


2017-07-11 20:33 GMT+02:00 Friedman, Eli <efriedma at codeaurora.org>:

> On 7/11/2017 11:19 AM, Anastasiya Ruzhanskaya wrote:
>
> And are such intrinsics, as memset, memcpy, memmove replaced by standard
> library calls? This is said in sources, that it looks for such functions in
> global symbol table.
>
>
> The backend will sometimes generate a call to the C library memset,
> memcpy, or memmove to lower a call to the LLVM intrinsics with the same
> name.  Depending on the target/optimization flags/length of the operation,
> in some cases it will generate inline code, or generate a call to a
> function with a different name.
>
> -Eli
>
> --
> Employee of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux
Foundation Collaborative Project
>
>
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