OV - exec - Loop 156

	Loop Id: 156	Module: exec	Source: advec_mom.cpp:45-48 [...]	Coverage: 2.67%

0x429580 SEL	Z26.D, P1, Z5.D, Z19.D

0x429584 ADD	X10, X10, X8

0x429588 SDIVR	Z26.D, P0/M, Z26.D, Z25.D

0x42958c ADD	Z27.D, Z6.D, Z26.D

0x429590 MOVPRFX	Z28, Z25

0x429594 MLS	Z28.D, P0/M, Z26.D, Z5.D

0x429598 ADD	Z26.D, Z16.D, Z26.D

0x42959c ADD	Z25.D, Z25.D, Z18.D

0x4295a0 SXTW	Z27.D, P0/M, Z27.D

0x4295a4 SXTW	Z26.D, P0/M, Z26.D

0x4295a8 MOVPRFX	Z30, Z0

0x4295ac MUL	Z30.D, P0/M, Z30.D, Z27.D

0x4295b0 MUL	Z26.D, P0/M, Z26.D, Z1.D

0x4295b4 MOVPRFX	Z8, Z1

0x4295b8 MUL	Z8.D, P0/M, Z8.D, Z27.D

0x4295bc ADD	Z29.D, Z7.D, Z28.D

0x4295c0 ADD	Z28.D, Z17.D, Z28.D

0x4295c4 ADR	Z31.D, [Z20, Z29.D,SXTW #3]    [1]

0x4295c8 ADR	Z28.D, [Z23, Z28.D,SXTW #3]    [10]

0x4295cc ADR	Z30.D, [Z31, Z30.D,LSL #3]    [8]

0x4295d0 ADR	Z31.D, [Z21, Z29.D,SXTW #3]    [6]

0x4295d4 ADR	Z26.D, [Z31, Z26.D,LSL #3]    [7]

0x4295d8 LD1D	{Z30.D}, P1/Z, [V30.D]    [5]

0x4295dc LD1D	{Z26.D}, P1/Z, [V26.D]    [12]

0x4295e0 FADD	Z26.D, Z30.D, Z26.D

0x4295e4 ADR	Z30.D, [Z31, Z8.D,LSL #3]    [7]

0x4295e8 MOVPRFX	Z31, Z2

0x4295ec MUL	Z31.D, P0/M, Z31.D, Z27.D

0x4295f0 LD1D	{Z30.D}, P1/Z, [V30.D]    [4]

0x4295f4 FSUB	Z26.D, Z26.D, Z30.D

0x4295f8 ADR	Z30.D, [Z22, Z29.D,SXTW #3]    [9]

0x4295fc ADR	Z30.D, [Z30, Z31.D,LSL #3]    [3]

0x429600 ST1D	{Z26.D}, P1, [V30.D]    [2]

0x429604 MOVPRFX	Z30, Z3

0x429608 MUL	Z30.D, P0/M, Z30.D, Z27.D

0x42960c MUL	Z27.D, P0/M, Z27.D, Z4.D

0x429610 ADR	Z28.D, [Z28, Z30.D,LSL #3]    [17]

0x429614 LD1D	{Z28.D}, P1/Z, [V28.D]    [16]

0x429618 FADD	Z26.D, Z26.D, Z28.D

0x42961c ADR	Z28.D, [Z23, Z29.D,SXTW #3]    [10]

0x429620 ADR	Z28.D, [Z28, Z30.D,LSL #3]    [15]

0x429624 LD1D	{Z28.D}, P1/Z, [V28.D]    [14]

0x429628 FSUB	Z26.D, Z26.D, Z28.D

0x42962c ADR	Z28.D, [Z24, Z29.D,SXTW #3]    [11]

0x429630 ADR	Z27.D, [Z28, Z27.D,LSL #3]    [18]

0x429634 ST1D	{Z26.D}, P1, [V27.D]    [13]

0x429638 WHILELO	P1.D, X10, X9

0x42963c B.MI	429580

/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/context.h: 69 - 69

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

69:   T &operator()(size_t i, size_t j) const { return data[i + j * sizeX]; }

/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/advec_mom.cpp: 45 - 48

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

45:     for (int j = (y_min - 2 + 1); j < (y_max + 2 + 2); j++) {

46:       for (int i = (x_min - 2 + 1); i < (x_max + 2 + 2); i++) {

47:         post_vol(i, j) = volume(i, j) + vol_flux_y(i + 0, j + 1) - vol_flux_y(i, j);

48:         pre_vol(i, j) = post_vol(i, j) + vol_flux_x(i + 1, j + 0) - vol_flux_x(i, j);

Coverage (%)	Name	Module
►98.43+	__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	1.35 - 1.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	3.17 - 1.05
Bottlenecks	P6, P8,
Function	advec_mom_kernel(int, int, int, int, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer1D&, clover::Buffer1D&, int, int, int) [clone .omp_outlined]
Source	context.h:69-69,advec_mom.cpp:45-48
Source loop unroll info	not unrolled or unrolled with no peel/tail loop
Source loop unroll confidence level	max
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	19.00 - 20.00
CQA cycles if no scalar integer	19.00 - 20.00
CQA cycles if FP arith vectorized	19.00 - 20.00
CQA cycles if fully vectorized	14.13 - 20.00
Front-end cycles	6.00
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.25
P4 cycles	1.00
P5 cycles	0.25
P6 cycles	19.00
P7 cycles	19.00
P8 cycles	3.50
P9 cycles	3.50
P10 cycles	2.33
P11 cycles	2.33
P12 cycles	2.33
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	0.87 - 20.00
Inter-iter dependencies cycles	2
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	48.00
Nb uops	48.00
Nb loads	NA
Nb stores	2.00
Nb stack references	0.00
FLOP/cycle	0.84 - 0.80
Nb FLOP add-sub	16.00
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	11.28 - 11.88
Bytes prefetched	0.00
Bytes loaded	161.63
Bytes stored	64.00
Stride 0	0.00
Stride 1	0.00
Stride n	0.00
Stride unknown	13.00
Stride indirect	5.00
Vectorization ratio all	60.00
Vectorization ratio load	27.78
Vectorization ratio store	100.00
Vectorization ratio mul	100.00
Vectorization ratio add_sub	43.48
Vectorization ratio fma	NA
Vectorization ratio div_sqrt	100.00
Vectorization ratio other	37.50
Vector-efficiency ratio all	78.33
Vector-efficiency ratio load	45.83
Vector-efficiency ratio store	100.00
Vector-efficiency ratio mul	100.00
Vector-efficiency ratio add_sub	57.61
Vector-efficiency ratio fma	NA
Vector-efficiency ratio div_sqrt	100.00
Vector-efficiency ratio other	100.00

Metric	Value
CQA speedup if no scalar integer	1.00
CQA speedup if FP arith vectorized	1.00
CQA speedup if fully vectorized	1.35 - 1.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	3.17 - 1.05
Bottlenecks	P6, P8,
Function	advec_mom_kernel(int, int, int, int, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer1D&, clover::Buffer1D&, int, int, int) [clone .omp_outlined]
Source	context.h:69-69,advec_mom.cpp:45-48
Source loop unroll info	not unrolled or unrolled with no peel/tail loop
Source loop unroll confidence level	max
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	19.00 - 20.00
CQA cycles if no scalar integer	19.00 - 20.00
CQA cycles if FP arith vectorized	19.00 - 20.00
CQA cycles if fully vectorized	14.13 - 20.00
Front-end cycles	6.00
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.25
P4 cycles	1.00
P5 cycles	0.25
P6 cycles	19.00
P7 cycles	19.00
P8 cycles	3.50
P9 cycles	3.50
P10 cycles	2.33
P11 cycles	2.33
P12 cycles	2.33
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	0.87 - 20.00
Inter-iter dependencies cycles	2
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	48.00
Nb uops	48.00
Nb loads	NA
Nb stores	2.00
Nb stack references	0.00
FLOP/cycle	0.84 - 0.80
Nb FLOP add-sub	16.00
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	11.28 - 11.88
Bytes prefetched	0.00
Bytes loaded	161.63
Bytes stored	64.00
Stride 0	0.00
Stride 1	0.00
Stride n	0.00
Stride unknown	13.00
Stride indirect	5.00
Vectorization ratio all	60.00
Vectorization ratio load	27.78
Vectorization ratio store	100.00
Vectorization ratio mul	100.00
Vectorization ratio add_sub	43.48
Vectorization ratio fma	NA
Vectorization ratio div_sqrt	100.00
Vectorization ratio other	37.50
Vector-efficiency ratio all	78.33
Vector-efficiency ratio load	45.83
Vector-efficiency ratio store	100.00
Vector-efficiency ratio mul	100.00
Vector-efficiency ratio add_sub	57.61
Vector-efficiency ratio fma	NA
Vector-efficiency ratio div_sqrt	100.00
Vector-efficiency ratio other	100.00

Path /

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

Function	advec_mom_kernel(int, int, int, int, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer1D&, clover::Buffer1D&, int, int, int) [clone .omp_outlined]
Source file and lines	advec_mom.cpp:45-48
Module	exec

The loop is defined in:

/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/context.h:69
/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/advec_mom.cpp:45-48

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

gain
potential
hint
expert

Vectorization

Your loop is partially vectorized. Only 78% of vector register length is used (average across all VPU instructions).

Details

60% of VPU instructions are used in vector version (process two or more data elements in vector registers):

27% of VPU loads are used in vector version.
43% of VPU addition or subtraction instructions are used in vector version.
37% of VPU instructions that are not load, store, addition, subtraction nor multiply instructions are used in vector version.

Expensive FP math instructions/calls

Detected performance impact from expensive FP math instructions/calls. By removing/reexpressing them, you can lower the cost of an iteration from 20.00 to 18.50 cycles (1.08x speedup).

Slow data structures access

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

Details

Constant unknown stride: 13 occurrence(s)
Irregular (variable stride) or indirect: 5 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)
Try to remove indirect accesses. If applicable, precompute elements out of the innermost loop.

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

The binary loop is composed of 16 FP arithmetical operations:

16: addition or subtraction

The binary loop is loading 161 bytes. The binary loop is storing 64 bytes.

Arithmetic intensity

Arithmetic intensity is 0.07 FP operations per loaded or stored byte.

General properties

nb instructions	48
nb uops	48
loop length	192
used w registers	0
used x registers	3
used b registers	0
used h registers	0
used s registers	0
used d registers	0
used q registers	0
used v registers	4
used z registers	25
nb stack references	0

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	6.00 cycles
front end	6.00 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	0.50	0.50	0.50	0.25	1.00	0.25	19.00	19.00	3.50	3.50	2.33	2.33	2.33	0.00	0.00
cycles	0.50	0.50	0.50	0.25	1.00	0.25	19.00	19.00	3.50	3.50	2.33	2.33	2.33	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	0.87-20.00
Longest recurrence chain latency (RecMII)	2.00

Cycles summary

Front-end	6.00
Dispatch	19.00
DIV/SQRT	0.87-20.00
Data deps.	2.00
Overall L1	19.00-20.00

Vectorization ratios

INT

all	56%
load	27%
store	100%
mul	100%
add-sub	31%
fma	NA (no fma vectorizable/vectorized instructions)
other	44%

all	100%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	100%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	60%
load	27%
store	100%
mul	100%
add-sub	43%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	100%
other	37%

Vector efficiency ratios

INT

all	76%
load	45%
store	100%
mul	100%
add-sub	48%
fma	NA (no fma vectorizable/vectorized instructions)
other	100%

all	100%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	100%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	78%
load	45%
store	100%
mul	100%
add-sub	57%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	100%
other	100%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 20.00 cycles. At this rate:

8% of peak load performance is reached (8.08 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
6% of peak store performance is reached (3.20 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 429580

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput	Vectorization
SEL Z26.D, P1, Z5.D, Z19.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD X10, X10, X8	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25	N/A
SDIVR Z26.D, P0/M, Z26.D, Z25.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	7-20	0.87-20	vect (100.0%)
ADD Z27.D, Z6.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
MOVPRFX Z28, Z25	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MLS Z28.D, P0/M, Z26.D, Z5.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADD Z26.D, Z16.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD Z25.D, Z25.D, Z18.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
SXTW Z27.D, P0/M, Z27.D	1	0	0	0	0	0	0	0	1	0	0	0	0	0	2	1	vect (100.0%)
SXTW Z26.D, P0/M, Z26.D	1	0	0	0	0	0	0	0	1	0	0	0	0	0	2	1	vect (100.0%)
MOVPRFX Z30, Z0	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z30.D, P0/M, Z30.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MUL Z26.D, P0/M, Z26.D, Z1.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MOVPRFX Z8, Z1	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z8.D, P0/M, Z8.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADD Z29.D, Z7.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD Z28.D, Z17.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z31.D, [Z20, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z28.D, [Z23, Z28.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z30.D, [Z31, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z31.D, [Z21, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z26.D, [Z31, Z26.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z30.D}, P1/Z, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
LD1D {Z26.D}, P1/Z, [V26.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FADD Z26.D, Z30.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z30.D, [Z31, Z8.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
MOVPRFX Z31, Z2	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z31.D, P0/M, Z31.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
LD1D {Z30.D}, P1/Z, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FSUB Z26.D, Z26.D, Z30.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z30.D, [Z22, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z30.D, [Z30, Z31.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ST1D {Z26.D}, P1, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	6	2	vect (100.0%)
MOVPRFX Z30, Z3	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z30.D, P0/M, Z30.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MUL Z27.D, P0/M, Z27.D, Z4.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADR Z28.D, [Z28, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z28.D}, P1/Z, [V28.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FADD Z26.D, Z26.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z28.D, [Z23, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z28.D, [Z28, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z28.D}, P1/Z, [V28.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FSUB Z26.D, Z26.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z28.D, [Z24, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z27.D, [Z28, Z27.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ST1D {Z26.D}, P1, [V27.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	6	2	vect (100.0%)
WHILELO P1.D, X10, X9	1	0	0	0	0	1	0	0	0	0	0	0	0	0	3	2	N/A
B.MI 429580 <_Z16advec_mom_kerneliiiiRN6clover8Buffer2DIdEES2_S2_S2_S2_S2_S2_S2_S2_S2_S2_S2_S2_RNS_8Buffer1DIdEES5_iii.omp_outlined+0x150>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Function	advec_mom_kernel(int, int, int, int, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer1D&, clover::Buffer1D&, int, int, int) [clone .omp_outlined]
Source file and lines	advec_mom.cpp:45-48
Module	exec

The loop is defined in:

/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/context.h:69
/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/advec_mom.cpp:45-48

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

gain
potential
hint
expert

Vectorization

Your loop is partially vectorized. Only 78% of vector register length is used (average across all VPU instructions).

Details

60% of VPU instructions are used in vector version (process two or more data elements in vector registers):

27% of VPU loads are used in vector version.
43% of VPU addition or subtraction instructions are used in vector version.
37% of VPU instructions that are not load, store, addition, subtraction nor multiply instructions are used in vector version.

Expensive FP math instructions/calls

Detected performance impact from expensive FP math instructions/calls. By removing/reexpressing them, you can lower the cost of an iteration from 20.00 to 18.50 cycles (1.08x speedup).

Slow data structures access

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

Details

Constant unknown stride: 13 occurrence(s)
Irregular (variable stride) or indirect: 5 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)
Try to remove indirect accesses. If applicable, precompute elements out of the innermost loop.

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

The binary loop is composed of 16 FP arithmetical operations:

16: addition or subtraction

The binary loop is loading 161 bytes. The binary loop is storing 64 bytes.

Arithmetic intensity

Arithmetic intensity is 0.07 FP operations per loaded or stored byte.

General properties

nb instructions	48
nb uops	48
loop length	192
used w registers	0
used x registers	3
used b registers	0
used h registers	0
used s registers	0
used d registers	0
used q registers	0
used v registers	4
used z registers	25
nb stack references	0

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	6.00 cycles
front end	6.00 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	0.50	0.50	0.50	0.25	1.00	0.25	19.00	19.00	3.50	3.50	2.33	2.33	2.33	0.00	0.00
cycles	0.50	0.50	0.50	0.25	1.00	0.25	19.00	19.00	3.50	3.50	2.33	2.33	2.33	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	0.87-20.00
Longest recurrence chain latency (RecMII)	2.00

Cycles summary

Front-end	6.00
Dispatch	19.00
DIV/SQRT	0.87-20.00
Data deps.	2.00
Overall L1	19.00-20.00

Vectorization ratios

INT

all	56%
load	27%
store	100%
mul	100%
add-sub	31%
fma	NA (no fma vectorizable/vectorized instructions)
other	44%

all	100%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	100%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	60%
load	27%
store	100%
mul	100%
add-sub	43%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	100%
other	37%

Vector efficiency ratios

INT

all	76%
load	45%
store	100%
mul	100%
add-sub	48%
fma	NA (no fma vectorizable/vectorized instructions)
other	100%

all	100%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	100%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	NA (no div/sqrt vectorizable/vectorized instructions)
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	78%
load	45%
store	100%
mul	100%
add-sub	57%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	100%
other	100%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 20.00 cycles. At this rate:

8% of peak load performance is reached (8.08 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
6% of peak store performance is reached (3.20 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 429580

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput	Vectorization
SEL Z26.D, P1, Z5.D, Z19.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD X10, X10, X8	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25	N/A
SDIVR Z26.D, P0/M, Z26.D, Z25.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	7-20	0.87-20	vect (100.0%)
ADD Z27.D, Z6.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
MOVPRFX Z28, Z25	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MLS Z28.D, P0/M, Z26.D, Z5.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADD Z26.D, Z16.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD Z25.D, Z25.D, Z18.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
SXTW Z27.D, P0/M, Z27.D	1	0	0	0	0	0	0	0	1	0	0	0	0	0	2	1	vect (100.0%)
SXTW Z26.D, P0/M, Z26.D	1	0	0	0	0	0	0	0	1	0	0	0	0	0	2	1	vect (100.0%)
MOVPRFX Z30, Z0	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z30.D, P0/M, Z30.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MUL Z26.D, P0/M, Z26.D, Z1.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MOVPRFX Z8, Z1	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z8.D, P0/M, Z8.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADD Z29.D, Z7.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADD Z28.D, Z17.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z31.D, [Z20, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z28.D, [Z23, Z28.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z30.D, [Z31, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z31.D, [Z21, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z26.D, [Z31, Z26.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z30.D}, P1/Z, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
LD1D {Z26.D}, P1/Z, [V26.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FADD Z26.D, Z30.D, Z26.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z30.D, [Z31, Z8.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
MOVPRFX Z31, Z2	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z31.D, P0/M, Z31.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
LD1D {Z30.D}, P1/Z, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FSUB Z26.D, Z26.D, Z30.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z30.D, [Z22, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z30.D, [Z30, Z31.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ST1D {Z26.D}, P1, [V30.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	6	2	vect (100.0%)
MOVPRFX Z30, Z3	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (100.0%)
MUL Z30.D, P0/M, Z30.D, Z27.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
MUL Z27.D, P0/M, Z27.D, Z4.D	1	0	0	0	0	0	0	1	0	0	0	0	0	0	5	2	vect (100.0%)
ADR Z28.D, [Z28, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z28.D}, P1/Z, [V28.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FADD Z26.D, Z26.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z28.D, [Z23, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z28.D, [Z28, Z30.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
LD1D {Z28.D}, P1/Z, [V28.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.33	0.33	0.33	9	2	vect (100.0%)
FSUB Z26.D, Z26.D, Z28.D	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	vect (100.0%)
ADR Z28.D, [Z24, Z29.D,SXTW #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ADR Z27.D, [Z28, Z27.D,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0	0	0	2	0.50	scal (25.0%)
ST1D {Z26.D}, P1, [V27.D]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	6	2	vect (100.0%)
WHILELO P1.D, X10, X9	1	0	0	0	0	1	0	0	0	0	0	0	0	0	3	2	N/A
B.MI 429580 <_Z16advec_mom_kerneliiiiRN6clover8Buffer2DIdEES2_S2_S2_S2_S2_S2_S2_S2_S2_S2_S2_S2_RNS_8Buffer1DIdEES5_iii.omp_outlined+0x150>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Report Configuration

Vectorization

Details

Expensive FP math instructions/calls

Slow data structures access

Details

Workaround

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

Arithmetic intensity

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

Expensive FP math instructions/calls

Slow data structures access

Details

Workaround

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

Arithmetic intensity

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Vector efficiency ratios

Cycles and memory resources usage

Front-end bottlenecks

ASM code