Any ideas? Is this a known bug?
this error:
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff36b4069 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
Missing separate debuginfos, use: debuginfo-install glibc-2.14-5.x86_64 libX11-1.4.3-1.fc15.x86_64 libXau-1.0.6-2.fc15.x86_64 libXext-1.2.0-2.fc15.x86_64 libXinerama-1.1.1-2.fc15.x86_64 libgcc-4.6.1-9.fc15.x86_64 libgfortran-4.6.1-9.fc15.x86_64 libgomp-4.6.1-9.fc15.x86_64 libjpeg-turbo-1.1.1-1.fc15.x86_64 libpng-1.2.46-1.fc15.x86_64 libquadmath-4.6.1-9.fc15.x86_64 libstdc++-4.6.1-9.fc15.x86_64 libtiff-3.9.5-1.fc15.x86_64 libxcb-1.7-2.fc15.x86_64 numactl-2.0.7-1.fc15.x86_64 xorg-x11-drv-catalyst-libs-11.9-3.fc15.x86_64 zlib-1.2.5-3.fc15.x86_64
(gdb) bt
#0 0x00007ffff36b4069 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#1 0x00007ffff36b5c27 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#2 0x00007ffff36b6641 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#3 0x00007ffff3996e5f in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#4 0x00007ffff3e28950 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#5 0x00007ffff3e28a62 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#6 0x00007ffff3e28bf9 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#7 0x00007ffff320656b in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#8 0x00007ffff3208bc7 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#9 0x00007ffff3222f18 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#10 0x00007ffff324339f in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#11 0x00007ffff320d25d in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#12 0x00007ffff325f565 in ?? () from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#13 0x00007ffff320335d in clBuildProgram ()
from /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/lib/x86_64/libamdocl64.so
#14 0x00000000004038db in cl::Program::build (this=0xa2aec0,
devices=std::vector of length 1, capacity 1 = {...}, options=0x407ab9 "-I.", notifyFptr=0, data=0x0)
at /home/tesch/src/AMD-APP-SDK-v2.5-RC2-lnx64/include/CL/cl.hpp:2675
#15 0x0000000000402782 in clsetup (sourcecount=1) at Clutil.cpp:79
-----------
is cause by this code :
---------
//#define REAL_T_IS_FLOAT
#define REAL_T_IS_DOUBLE
#ifdef REAL_T_IS_FLOAT
typedef float real_t;
typedef float3 vec3_t;
#else
#pragma OPENCL EXTENSION cl_amd_fp64 : enable // subset of cl_khr_fp64
typedef double real_t;
typedef double3 vec3_t;
#endif
__kernel void
bloch_steps(int nsteps)
{
real_t T2i;
for (int i = 0; i < nsteps; i++) {
vec3_t b1;
real_t et2 = exp(-1 * T2i);
real_t theta;
theta = length(b1);
b1 *= 1. / theta;
}
}
----------
when compiling on this device (clinfo output):
[tesch@localhost mtsrc]$ ~/src/AMD-APP-SDK-v2.5-RC2-lnx64/bin/x86_64/clinfo
Number of platforms: 2
Platform Profile: FULL_PROFILE
Platform Version: OpenCL 1.1 AMD-APP-SDK-v2.5 (684.213)
Platform Name: AMD Accelerated Parallel Processing
Platform Vendor: Advanced Micro Devices, Inc.
Platform Extensions: cl_khr_icd cl_amd_event_callback cl_amd_offline_devices
Platform Profile: FULL_PROFILE
Platform Version: OpenCL 1.1 LINUX
Platform Name: Intel(R) OpenCL
Platform Vendor: Intel(R) Corporation
Platform Extensions: cl_khr_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_gl_sharing cl_khr_byte_addressable_store cl_intel_printf cl_ext_device_fission cl_khr_icd
Platform Name: AMD Accelerated Parallel Processing
Number of devices: 2
Device Type: CL_DEVICE_TYPE_GPU
Device ID: 4098
Device Topology: PCI[ B#1, D#0, F#0 ]
Max compute units: 18
Max work items dimensions: 3
Max work items[0]: 256
Max work items[1]: 256
Max work items[2]: 256
Max work group size: 256
Preferred vector width char: 16
Preferred vector width short: 8
Preferred vector width int: 4
Preferred vector width long: 2
Preferred vector width float: 4
Preferred vector width double: 2
Native vector width char: 16
Native vector width short: 8
Native vector width int: 4
Native vector width long: 2
Native vector width float: 4
Native vector width double: 2
Max clock frequency: 725Mhz
Address bits: 32
Max memory allocation: 134217728
Image support: Yes
Max number of images read arguments: 128
Max number of images write arguments: 8
Max image 2D width: 8192
Max image 2D height: 8192
Max image 3D width: 2048
Max image 3D height: 2048
Max image 3D depth: 2048
Max samplers within kernel: 16
Max size of kernel argument: 1024
Alignment (bits) of base address: 32768
Minimum alignment (bytes) for any datatype: 128
Single precision floating point capability
Denorms: No
Quiet NaNs: Yes
Round to nearest even: Yes
Round to zero: Yes
Round to +ve and infinity: Yes
IEEE754-2008 fused multiply-add: Yes
Cache type: None
Cache line size: 0
Cache size: 0
Global memory size: 536870912
Constant buffer size: 65536
Max number of constant args: 8
Local memory type: Scratchpad
Local memory size: 32768
Kernel Preferred work group size multiple: 64
Error correction support: 0
Unified memory for Host and Device: 0
Profiling timer resolution: 1
Device endianess: Little
Available: Yes
Compiler available: Yes
Execution capabilities:
Execute OpenCL kernels: Yes
Execute native function: No
Queue properties:
Out-of-Order: No
Profiling : Yes
Platform ID: 0x7f45fad3b060
Name: Cypress
Vendor: Advanced Micro Devices, Inc.
Device OpenCL C version: OpenCL C 1.1
Driver version: CAL 1.4.1546
Profile: FULL_PROFILE
Version: OpenCL 1.1 AMD-APP-SDK-v2.5 (684.213)
Extensions: cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_atomic_counters_32 cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_popcnt
-------------
but NOT when compiling for this device: (clinfo output continued)
-------------
Device Type: CL_DEVICE_TYPE_CPU
Device ID: 4098
Max compute units: 6
Max work items dimensions: 3
Max work items[0]: 1024
Max work items[1]: 1024
Max work items[2]: 1024
Max work group size: 1024
Preferred vector width char: 16
Preferred vector width short: 8
Preferred vector width int: 4
Preferred vector width long: 2
Preferred vector width float: 4
Preferred vector width double: 0
Native vector width char: 16
Native vector width short: 8
Native vector width int: 4
Native vector width long: 2
Native vector width float: 4
Native vector width double: 0
Max clock frequency: 800Mhz
Address bits: 64
Max memory allocation: 4215897088
Image support: Yes
Max number of images read arguments: 128
Max number of images write arguments: 8
Max image 2D width: 8192
Max image 2D height: 8192
Max image 3D width: 2048
Max image 3D height: 2048
Max image 3D depth: 2048
Max samplers within kernel: 16
Max size of kernel argument: 4096
Alignment (bits) of base address: 1024
Minimum alignment (bytes) for any datatype: 128
Single precision floating point capability
Denorms: Yes
Quiet NaNs: Yes
Round to nearest even: Yes
Round to zero: Yes
Round to +ve and infinity: Yes
IEEE754-2008 fused multiply-add: No
Cache type: Read/Write
Cache line size: 64
Cache size: 65536
Global memory size: 16863588352
Constant buffer size: 65536
Max number of constant args: 8
Local memory type: Global
Local memory size: 32768
Kernel Preferred work group size multiple: 1
Error correction support: 0
Unified memory for Host and Device: 1
Profiling timer resolution: 1
Device endianess: Little
Available: Yes
Compiler available: Yes
Execution capabilities:
Execute OpenCL kernels: Yes
Execute native function: Yes
Queue properties:
Out-of-Order: No
Profiling : Yes
Platform ID: 0x7f45fad3b060
Name: AMD Phenom(tm) II X6 1100T Processor
Vendor: AuthenticAMD
Device OpenCL C version: OpenCL C 1.1
Driver version: 2.0
Profile: FULL_PROFILE
Version: OpenCL 1.1 AMD-APP-SDK-v2.5 (684.213)
Extensions: cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_device_fission cl_amd_device_attribute_query cl_amd_vec3 cl_amd_media_ops cl_amd_popcnt cl_amd_printf
This looks a lot like a crash I've seen that Micah says is fixed in an upcoming release. I bet if you comment out the length that it won't crash.
Yep, commenting it out does stop the crash, also removing the for loop, and removing various other surrounding statements or declarations. I removed a ton of code from the original function to boil down the offending code to just this.
In the end my workaround is to compute the length with sqrt(a.x * a.x + a.y * a.y...) .. but still it would be much better if it just worked like it's supposed to, and I didn't spend any time at all finding workarounds for compiler bugs.