GCC vs ICC

Hi all, I'm interested in knowing how GCC differs from Intel's ICC in terms of the optimization levels and catering to specific processor architecture. I'm using GCC 4.1.2 20070626 and ICC v11.1 for Linux. How does ICC's optimization levels (O1 to O3) differ from GCC, if they differ at all?

Re: GCC vs ICC

On 3/22/2010 7:46 PM, Rayne wrote: Hi all, I'm interested in knowing how GCC differs from Intel's ICC in terms of the optimization levels and catering to specific processor architecture. I'm using GCC 4.1.2 20070626 and ICC v11.1 for Linux. How does ICC's optimization levels (O1 to O3)

[Bug c/36869] OpenMP issue in gcc vs icc

--- Comment #1 from singler at gcc dot gnu dot org 2008-07-24 15:02 --- The test program is wrong. The loop counter i is not mentioned in the parallel clause, so it is *shared*. Thus, the two loops interfere and the calculation of pi goes wrong. Add private(i) to the clause or declare

[Bug c/36869] New: OpenMP issue in gcc vs icc

20080312 Let me know if you need more detail. God bless your work! PS: I saw this bug(!) on another web page too!!! Kemal Kilic [EMAIL PROTECTED] -- Summary: OpenMP issue in gcc vs icc Product: gcc Version: 4.3.1 Status: UNCONFIRMED

openMP gcc vs icc, erratic results with gcc

Hi everybody, I just started working with openMP, i installed first gcc-4.2.3 and then gcc-4.3.0, both of them having support for openMP. I tried a code to calculate the product \pi*\e. When i compile the code with gcc (both 4.2.3 and 4.3.0) withtout -fopenmp the result is correct. When i

Re: openMP gcc vs icc, erratic results with gcc

diego sandoval wrote: Hi everybody, I just started working with openMP, i installed first gcc-4.2.3 and then gcc-4.3.0, both of them having support for openMP. I tried a code to calculate the product \pi*\e. When i compile the code with gcc (both 4.2.3 and 4.3.0) withtout -fopenmp the

Re: openMP gcc vs icc, erratic results with gcc

Dear Diego, As I understand it (which is not necessarily correct), your code is slightly incorrect, since variable are by default shared between parallel sections. Therefore, the int i is shared between threads, and hence the erratic results if both loops execute at the same time. To fix it, you

Re: openMP gcc vs icc, erratic results with gcc

On Wed, May 21, 2008 at 11:21:27AM +0100, Ed Brambley wrote: As I understand it (which is not necessarily correct), your code is slightly incorrect, since variable are by default shared between parallel sections. Therefore, the int i is shared between threads, and hence the erratic results if