https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120732
Bug ID: 120732
Summary: Compiler doesn't generate a call to a vector function
Product: gcc
Version: 15.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ibogosavljevic at gmail dot com
Target Milestone: ---
Created attachment 61671
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61671&action=edit
Test example
The compiler doesn't generate a call to a vector function. The example is
attached.
I declared a function
__attribute__ ((__simd__ ("notinbranch")))
double square(double x);
However, the loop which is lower
for (size_t i = 0; i < s; i++) {
d[i] = square(d[i]);
}
doesn't call vectorized version of sqaure, but just a plain old scalar version.
If I put #pragma omp simd before the loop, the compiler generates a call to
vector version of square.
Compilation line:
g++ -c -O3 -fopenmp-simd -ffast-math -mavx2 test.cpp -S -o test.asm
Why doesn't the compiler generate a call to vectorized version of square, since
all prerequisites are met?
