OV - exec - Loop 70

0x415880 LDR	D0, [X13, W16,SXTW #3]    [1]

0x415884 SUBS	X15, X15, #1

0x415888 ADD	W16, W16, #1

0x41588c STR	D0, [X13, W17,SXTW #3]    [1]

0x415890 SUB	W17, W17, #1

0x415894 B.NE	415880

/home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp: 13 - 15

--------------------------------------------------------------------------------

13:     for (int kk = 0; kk < depth; ++kk) {

14:       int base = jj * x;

15:       buffer[base + (halo_depth - kk - 1)] = buffer[base + (halo_depth + kk)];

Coverage (%)	Name	Source Location	Module
►77.18+	__kmp_invoke_microtask		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec
►22.73+	__kmp_invoke_microtask		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:94	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►48.26+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►38.13+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec
►13.61+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:94	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►69.82+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►20.96+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec
►9.10+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:94	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►84.52+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►12.66+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec
►2.82+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:94	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►93.16+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►5.22+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec
►1.62+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:94	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►96.46+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►2.59+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►97.19+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►2.06+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►98.35+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►1.26+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►98.30+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►1.28+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Source Location	Module
►98.51+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_launch_thread		libomp.so
○	__kmp_launch_worker(void*)		libomp.so
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►1.12+	__kmp_invoke_microtask		libomp.so
○	__kmp_invoke_task_func		libomp.so
○	__kmp_fork_call		libomp.so
○	__kmpc_fork_call		libomp.so
○	update_face(int, int, int, int[...]	local_halos.cpp:73	exec
○	local_halos(int, int, int, int[...]	local_halos.cpp:103	exec
○	run_local_halos(Chunk*, Settin[...]	local_halos.cpp:114	exec
○	halo_update_driver(Chunk*, Set[...]	halo_update_driver.cpp:12	exec
○	cg_driver(Chunk*, Settings&, d[...]	cg_driver.cpp:20	exec
○	solve(Chunk*, Settings&, int, [...]	diffuse.cpp:45	exec
○	diffuse(Chunk*, Settings&)	diffuse.cpp:12	exec
○	main	main.cpp:169	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start		exec

Coverage (%)	Name	Module
►98.70+	__kmp_invoke_microtask	libomp.so
○	__kmp_invoke_task_func	libomp.so
○	__kmp_launch_thread	libomp.so
○	__kmp_launch_worker(void*)	libomp.so
○	start_thread	libc.so.6
○	thread_start	libc.so.6

min	med	avg	max

Percentile Index	10	20	30	40	50	60	70	80	90	100
Value

min	med	avg	max

Percentile Index	10	20	30	40	50	60	70	80	90	100
Value

Path /

Metric	Value
CQA speedup if no scalar integer	1.00
CQA speedup if FP arith vectorized	1.00
CQA speedup if fully vectorized	4.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.20
Bottlenecks
Function	update_left(int, int, int, int, double*, bool) [clone .omp_outlined]
Source	local_halos.cpp:13-15
Source loop unroll info	not unrolled or unrolled with no peel/tail loop
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	1.00
CQA cycles if no scalar integer	1.00
CQA cycles if FP arith vectorized	1.00
CQA cycles if fully vectorized	0.25
Front-end cycles	0.75
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.75
P3 cycles	0.75
P4 cycles	0.75
P5 cycles	0.75
P6 cycles	0.50
P7 cycles	0.50
P8 cycles	0.00
P9 cycles	0.00
P10 cycles	0.83
P11 cycles	0.50
P12 cycles	0.67
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	0.00
Inter-iter dependencies cycles	1
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	6.00
Nb uops	6.00
Nb loads	NA
Nb stores	1.00
Nb stack references	0.00
FLOP/cycle	0.00
Nb FLOP add-sub	0.00
Nb FLOP mul	0.00
Nb FLOP fma	0.00
Nb FLOP div	0.00
Nb FLOP rcp	0.00
Nb FLOP sqrt	0.00
Nb FLOP rsqrt	0.00
Bytes/cycle	0.00
Bytes prefetched	0.00
Bytes loaded	0.00
Bytes stored	0.00
Stride 0	0.00
Stride 1	0.00
Stride n	1.00
Stride unknown	0.00
Stride indirect	0.00
Vectorization ratio all	0.00
Vectorization ratio load	0.00
Vectorization ratio store	0.00
Vectorization ratio mul	NA
Vectorization ratio add_sub	0.00
Vectorization ratio fma	NA
Vectorization ratio div_sqrt	NA
Vectorization ratio other	NA
Vector-efficiency ratio all	25.00
Vector-efficiency ratio load	25.00
Vector-efficiency ratio store	25.00
Vector-efficiency ratio mul	NA
Vector-efficiency ratio add_sub	25.00
Vector-efficiency ratio fma	NA
Vector-efficiency ratio div_sqrt	NA
Vector-efficiency ratio other	NA

Metric	Value
CQA speedup if no scalar integer	1.00
CQA speedup if FP arith vectorized	1.00
CQA speedup if fully vectorized	4.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.20
Bottlenecks
Function	update_left(int, int, int, int, double*, bool) [clone .omp_outlined]
Source	local_halos.cpp:13-15
Source loop unroll info	not unrolled or unrolled with no peel/tail loop
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	1.00
CQA cycles if no scalar integer	1.00
CQA cycles if FP arith vectorized	1.00
CQA cycles if fully vectorized	0.25
Front-end cycles	0.75
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.75
P3 cycles	0.75
P4 cycles	0.75
P5 cycles	0.75
P6 cycles	0.50
P7 cycles	0.50
P8 cycles	0.00
P9 cycles	0.00
P10 cycles	0.83
P11 cycles	0.50
P12 cycles	0.67
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	0.00
Inter-iter dependencies cycles	1
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	6.00
Nb uops	6.00
Nb loads	NA
Nb stores	1.00
Nb stack references	0.00
FLOP/cycle	0.00
Nb FLOP add-sub	0.00
Nb FLOP mul	0.00
Nb FLOP fma	0.00
Nb FLOP div	0.00
Nb FLOP rcp	0.00
Nb FLOP sqrt	0.00
Nb FLOP rsqrt	0.00
Bytes/cycle	0.00
Bytes prefetched	0.00
Bytes loaded	0.00
Bytes stored	0.00
Stride 0	0.00
Stride 1	0.00
Stride n	1.00
Stride unknown	0.00
Stride indirect	0.00
Vectorization ratio all	0.00
Vectorization ratio load	0.00
Vectorization ratio store	0.00
Vectorization ratio mul	NA
Vectorization ratio add_sub	0.00
Vectorization ratio fma	NA
Vectorization ratio div_sqrt	NA
Vectorization ratio other	NA
Vector-efficiency ratio all	25.00
Vector-efficiency ratio load	25.00
Vector-efficiency ratio store	25.00
Vector-efficiency ratio mul	NA
Vector-efficiency ratio add_sub	25.00
Vector-efficiency ratio fma	NA
Vector-efficiency ratio div_sqrt	NA
Vector-efficiency ratio other	NA

Path /

Average path: Display a virtual path defined by average values of all real paths

Function	update_left(int, int, int, int, double*, bool) [clone .omp_outlined]
Source file and lines	local_halos.cpp:13-15
Module	exec

The loop is defined in /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:13-15.

The related source loop is not unrolled or unrolled with no peel/tail loop.

gain
potential
hint
expert

Vectorization

Your loop is not vectorized. 4 data elements could be processed at once in vector registers. By vectorizing your loop, you can lower the cost of an iteration from 1.00 to 0.25 cycles (4.00x speedup).

Details

All VPU instructions are used in scalar version (process only one data element in vector registers). Since your execution units are vector units, only a vectorized loop can use their full power.

Workaround

Try another compiler or update/tune your current one:
- recompile with ffast-math (included in Ofast) to extend loop vectorization to FP reductions.
Remove inter-iterations dependences from your loop and make it unit-stride:
- If your arrays have 2 or more dimensions, check whether elements are accessed contiguously and, otherwise, try to permute loops accordingly: C storage order is row-major: for(i) for(j) a[j][i] = b[j][i]; (slow, non stride 1) => for(i) for(j) a[i][j] = b[i][j]; (fast, stride 1)
- If your loop streams arrays of structures (AoS), try to use structures of arrays instead (SoA): for(i) a[i].x = b[i].x; (slow, non stride 1) => for(i) a.x[i] = b.x[i]; (fast, stride 1)

No data for this section

Slow data structures access

Detected data structures (typically arrays) that cannot be efficiently read/written

Details

Constant non-unit stride: 1 occurrence(s)

Non-unit stride (uncontiguous) accesses are not efficiently using data caches

Workaround

Try to reorganize arrays of structures to structures of arrays
Consider to permute loops (see vectorization gain report)

Matching between your loop (in the source code) and the binary loop

The binary loop does not contain any FP arithmetical operations. The binary loop does not load or store any data.

Unroll opportunity

Loop body is too small to efficiently use resources.

Workaround

Unroll your loop if trip count is significantly higher than target unroll factor. This can be done manually. Or with the unroll (resp. unroll_and_jam) directive on top of the inner (resp. surrounding) loop. You can enforce an unroll factor: #pragma unroll_and_jam N, unroll_and_jam(N), unroll N or unroll(N)

General properties

nb instructions	6
nb uops	6
loop length	24
used w registers	2
used x registers	2
used b registers	0
used h registers	0
used s registers	0
used d registers	1
used q registers	0
used v registers	0
used z registers	0
nb stack references	0

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	0.75 cycles
front end	0.75 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	0.50	0.50	0.75	0.75	0.75	0.75	0.50	0.50	0.00	0.00	0.83	0.50	0.67	0.00	0.00
cycles	0.50	0.50	0.75	0.75	0.75	0.75	0.50	0.50	0.00	0.00	0.83	0.50	0.67	0.00	0.00

Execution ports to units layout:

P0: BRU
P1: BRU
P2: ALU
P3: ALU
P4: ALU
P5: ALU
P6 (128 bits): VPU, FP store data, ALU, DIV/SQRT
P7 (128 bits): VPU, ALU, FP store data
P8 (128 bits): VPU, ALU, DIV/SQRT
P9 (128 bits): ALU, VPU
P10 (256 bits): store address, load
P11 (256 bits): store address, load
P12 (256 bits): load
P13 (64 bits): store data
P14 (64 bits): store data

Cycles executing div or sqrt instructions	NA
Longest recurrence chain latency (RecMII)	1.00

Cycles summary

Front-end	0.75
Dispatch	0.83
Data deps.	1.00
Overall L1	1.00

Vectorization ratios

all	0%
load	0%
store	0%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	0%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

Vector efficiency ratios

all	25%
load	25%
store	25%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	25%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 1.00 cycles.

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 415880

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P10	P11	P12	Latency	Recip. throughput	Vectorization
LDR D0, [X13, W16,SXTW #3]	1	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (25.0%)
SUBS X15, X15, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.33	scal (25.0%)
ADD W16, W16, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.25	N/A
STR D0, [X13, W17,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0.50	0.50	0	2	0.50	scal (25.0%)
SUB W17, W17, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.25	N/A
B.NE 415880 <_Z11update_leftiiiiPdb.omp_outlined+0xd4>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Function	update_left(int, int, int, int, double*, bool) [clone .omp_outlined]
Source file and lines	local_halos.cpp:13-15
Module	exec

The loop is defined in /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:13-15.

The related source loop is not unrolled or unrolled with no peel/tail loop.

gain
potential
hint
expert

Vectorization

Your loop is not vectorized. 4 data elements could be processed at once in vector registers. By vectorizing your loop, you can lower the cost of an iteration from 1.00 to 0.25 cycles (4.00x speedup).

Details

All VPU instructions are used in scalar version (process only one data element in vector registers). Since your execution units are vector units, only a vectorized loop can use their full power.

Workaround

Try another compiler or update/tune your current one:
- recompile with ffast-math (included in Ofast) to extend loop vectorization to FP reductions.
Remove inter-iterations dependences from your loop and make it unit-stride:
- If your arrays have 2 or more dimensions, check whether elements are accessed contiguously and, otherwise, try to permute loops accordingly: C storage order is row-major: for(i) for(j) a[j][i] = b[j][i]; (slow, non stride 1) => for(i) for(j) a[i][j] = b[i][j]; (fast, stride 1)
- If your loop streams arrays of structures (AoS), try to use structures of arrays instead (SoA): for(i) a[i].x = b[i].x; (slow, non stride 1) => for(i) a.x[i] = b.x[i]; (fast, stride 1)

No data for this section

Slow data structures access

Detected data structures (typically arrays) that cannot be efficiently read/written

Details

Constant non-unit stride: 1 occurrence(s)

Non-unit stride (uncontiguous) accesses are not efficiently using data caches

Workaround

Try to reorganize arrays of structures to structures of arrays
Consider to permute loops (see vectorization gain report)

Matching between your loop (in the source code) and the binary loop

The binary loop does not contain any FP arithmetical operations. The binary loop does not load or store any data.

Unroll opportunity

Loop body is too small to efficiently use resources.

Workaround

Unroll your loop if trip count is significantly higher than target unroll factor. This can be done manually. Or with the unroll (resp. unroll_and_jam) directive on top of the inner (resp. surrounding) loop. You can enforce an unroll factor: #pragma unroll_and_jam N, unroll_and_jam(N), unroll N or unroll(N)

General properties

nb instructions	6
nb uops	6
loop length	24
used w registers	2
used x registers	2
used b registers	0
used h registers	0
used s registers	0
used d registers	1
used q registers	0
used v registers	0
used z registers	0
nb stack references	0

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	0.75 cycles
front end	0.75 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	0.50	0.50	0.75	0.75	0.75	0.75	0.50	0.50	0.00	0.00	0.83	0.50	0.67	0.00	0.00
cycles	0.50	0.50	0.75	0.75	0.75	0.75	0.50	0.50	0.00	0.00	0.83	0.50	0.67	0.00	0.00

Execution ports to units layout:

P0: BRU
P1: BRU
P2: ALU
P3: ALU
P4: ALU
P5: ALU
P6 (128 bits): VPU, FP store data, ALU, DIV/SQRT
P7 (128 bits): VPU, ALU, FP store data
P8 (128 bits): VPU, ALU, DIV/SQRT
P9 (128 bits): ALU, VPU
P10 (256 bits): store address, load
P11 (256 bits): store address, load
P12 (256 bits): load
P13 (64 bits): store data
P14 (64 bits): store data

Cycles executing div or sqrt instructions	NA
Longest recurrence chain latency (RecMII)	1.00

Cycles summary

Front-end	0.75
Dispatch	0.83
Data deps.	1.00
Overall L1	1.00

Vectorization ratios

all	0%
load	0%
store	0%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	0%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

Vector efficiency ratios

all	25%
load	25%
store	25%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	25%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 1.00 cycles.

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 415880

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P10	P11	P12	Latency	Recip. throughput	Vectorization
LDR D0, [X13, W16,SXTW #3]	1	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (25.0%)
SUBS X15, X15, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.33	scal (25.0%)
ADD W16, W16, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.25	N/A
STR D0, [X13, W17,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0.50	0.50	0	2	0.50	scal (25.0%)
SUB W17, W17, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	1	0.25	N/A
B.NE 415880 <_Z11update_leftiiiiPdb.omp_outlined+0xd4>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	1	0.50	N/A

▶Scalability Runs Description

Run 1x1	Number processes: 1Number nodes: NARun Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_NUM_THREADS: 1OMP_PLACES: threads
Run 1x2	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 2OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x4	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 4OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x8	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 8OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x16	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 16OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x24	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 24OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x32	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 32OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x40	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 40OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x48	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 48OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x56	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 56OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads
Run 1x64	Number processes: 1Run Command: <executable>MPI Command: mpirun -n <number_processes> --bind-to core --map-by package:PE=64 --rank-by fill --report-bindings Dataset: Run Directory: /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/run/oneview_runs/multicore/armclang/oneview_run_1782430622OMP_NUM_THREADS: 64OMP_PROC_BIND: spreadOMP_DISPLAY_AFFINITY: TRUEOMP_AFFINITY_FORMAT: 'OMP: pid %P tid %i thread %n bound to OS proc set {%A}'OMP_DISPLAY_ENV: TRUEOMP_PLACES: threads

(1x1) Efficiency	(1x1) Potential Speed-Up (%)	(1x2) Efficiency	(1x2) Potential Speed-Up (%)	(1x4) Efficiency	(1x4) Potential Speed-Up (%)	(1x8) Efficiency	(1x8) Potential Speed-Up (%)	(1x16) Efficiency	(1x16) Potential Speed-Up (%)	(1x24) Efficiency	(1x24) Potential Speed-Up (%)	(1x32) Efficiency	(1x32) Potential Speed-Up (%)	(1x40) Efficiency	(1x40) Potential Speed-Up (%)	(1x48) Efficiency	(1x48) Potential Speed-Up (%)	(1x56) Efficiency	(1x56) Potential Speed-Up (%)	(1x64) Efficiency	(1x64) Potential Speed-Up (%)
1	0	1.28	0	1.36	0	0.97	0.01	0.83	0.02	0.72	0.03	0.71	0.03	0.49	0.05	0.69	0.02	0.85	0.01	0.98	0

Speed-Up and Efficiency

▶Detailed Speed-Up and Efficiency

Run	Number of threads	Efficiency (ideal is 1)	Speedup	Ideal Speedup	Time (s)	Coverage (%)
1x1	1	1	1	1	5.6750001907349	0.21820490062237
1x2	2	1.28	2.55	2	2.2999997138977	0.16947750747204
1x4	4	1.36	5.44	4	1.259999871254	0.15526942908764
1x8	8	0.97	7.77	8	0.90500003099442	0.1776502430439
1x16	16	0.83	13.35	16	0.5450000166893	0.12593126296997
1x24	24	0.72	17.24	24	0.47500005364418	0.10524490475655
1x32	32	0.71	22.66	32	0.38999998569489	0.087805762887001
1x40	40	0.49	19.69	40	0.77999997138977	0.1058058142662
1x48	48	0.69	33.14	48	0.25499999523163	0.063817642629147
1x56	56	0.85	47.32	56	0.19000001251698	0.044840127229691
1x64	64	0.98	62.83	64	0.14500001072884	0.033727716654539

Report Configuration

Vectorization

Details

Workaround

Slow data structures access

Details

Workaround

Matching between your loop (in the source code) and the binary loop

Unroll opportunity

Workaround

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Vector efficiency ratios

Cycles and memory resources usage

Front-end bottlenecks

ASM code

Vectorization

Details

Workaround

Slow data structures access

Details

Workaround

Matching between your loop (in the source code) and the binary loop

Unroll opportunity

Workaround

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Vector efficiency ratios

Cycles and memory resources usage

Front-end bottlenecks

ASM code

▶Scalability Runs Description

▼Columns Filter

Speed-Up and Efficiency

▶Detailed Speed-Up and Efficiency