Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference
A newer version of this document is available. Customers should click here to go to the newest version.
Visible to Intel only — GUID: GUID-0ECDCF52-2977-4857-9A74-2472E634FD88
Visible to Intel only — GUID: GUID-0ECDCF52-2977-4857-9A74-2472E634FD88
inline, noinline, forceinline
Specifies inlining of all calls in a statement. This also describes pragmas forceinline and noinline.
#pragma inline [recursive] #pragma forceinline [recursive] #pragma noinline |
recursive |
Indicates that the pragma applies to all of the calls that are called by these calls, recursively, down the call chain. |
inline, forceinline, and noinline are statement-specific inlining pragmas. Each can be placed before a C/C++ statement, and it will then apply to all of the calls within a statement and all calls within statements nested within that statement.
The forceinline pragma indicates that the calls in question should be inlined whenever the compiler is capable of doing so.
The inline pragma is a hint to the compiler that the user prefers that the calls in question be inlined, but expects the compiler not to inline them if its heuristics determine that the inlining would be overly aggressive and might slow down the compilation of the source code excessively, create too large of an executable, or degrade performance.
The noinline pragma indicates that the calls in question should not be inlined.
These statement-specific pragmas take precedence over the corresponding function-specific pragmas.
The inline, forceinline, and noinline pragmas are supported in host code only.
Examples
Use the forceinline recursive pragma:
#include <stdio.h> static void fun(float a[100][100], float b[100][100]) { inti , j; for (i = 0; i < 100; i++) { for (j = 0; j < 100; j++) { a[i][j] = 2 * i; b[i][j] = 4 * j; } } } static void sun(float a[100][100], float b[100][100]) { int i, j; for (i = 0; i < 100; i++) { for (j = 0; j < 100; j++) { a[i][j] = 2 * i; b[i][j] = 4 * j; } fun(a, b); } } static float a[100][100]; static float b[100][100]; extern int main() { int i, j; for (i = 0; i < 100; i++) { for (j = 0; j < 100; j++) { a[i][j] = i + j; b[i][j] = i - j; } } for (i = 0; i < 99; i++) { fun(a, b); #pragma forceinline recursive for (j = 0; j < 99; j++) { sun(a, b); } } fprintf(stderr, "%d %d\n", a[99][9], b[99][99]); }
The forceinline recursive pragma applies to the call 'sun(a,b)' as well as the call 'fun(a,b)' called inside 'sun(a,b)'.