Any ideas about this issue?

Teodor_P_ · ‎05-15-2013

Hi,

I'm trying to port our large application to run natively on the Xeon Phi card.

I've compiled it but there are some problems and I think the problems are related to the compiler and that it generates bad code.

The compiler I'm using is:

$ icpc -V Intel(R) C++ Intel(R) 64 Compiler XE for applications running on Intel(R) 64, Version 13.1.1.163 Build 20130313 Copyright (C) 1985-2013 Intel Corporation. All rights reserved.

And the build options are something like:

Compiler: icpc
Optimizations: -gxx-name=g++412 -gcc-name=gcc412 -O0 -g -fPIC -mmic -D_REENTRANT -static-intel -fvisibility=hidden
Link flags: -static-intel -lpthread -lrt -lc -Wl,--gc-sections -fPIC -mmic

The compiler has produced this code and the crash happens on the last instruction (rax=0x7ff15418330e and k1=1)

0x00007ff176d056f8 <init>:   pushq %rbp
0x00007ff176d056f9 <init+1>:   mov %rsp, %rbp
0x00007ff176d056fc <init+4>:   sub $0x20, %rsp
0x00007ff176d05700 <init+8>:   movq %rdi, -0x20(%rbp)
0x00007ff176d05704 <init+12>:   movq -0x20(%rbp), %rax
0x00007ff176d05708 <init+16>:   movq %rax, -0x18(%rbp)
0x00007ff176d0570c <init+20>:   vbroadcastssl 0xb3651e(%rip), %k0, %zmm0
0x00007ff176d05716 <init+30>:   movq -0x18(%rbp), %rax
0x00007ff176d0571a <init+34>:   mov $0x1, %edx
0x00007ff176d0571f <init+39>:   kmov %rdx, %k1
0x00007ff176d05723 <init+43>:   vpackstorelps %zmm0, %k1, (%rax)

As far as I could understand from the Instruction set reference the vpackstorelps requires the address to be 64-byte aligned, which is not the case here. Am I correct in this understanding? Is this a bug in the compiler or something is wrong in my code?

The function looks like this:

void init() {

pmin.set(some_const, some_const, some_const);

pmax.set(some_const, some_const, some_const);

}

pmin and pmax are Vectors and the set function looks like this:

__forceinline void set(float ix, float iy, float iz) {

     x=ix;

     y=iy;

     z=iz;

}

Could this __forceinline call mess up the compiler?

Also the memory for the object holding the pmin,pmax is freshly allcated by new.