OV - exec - Loop 25

    (23) 0x497320 CMP	X21, X26

    (23) 0x497324 B.GE	4973f8

    (23) 0x497328 LDR	X17, [X8, X21,LSL #3]

    (23) 0x49732c LDR	X18, [X19]

    (23) 0x497330 CBZ	X18, 497344

    (23) 0x497334 STR	X9, [X20, X21,LSL #3]

    (23) 0x497338 STR	XZR, [X10, X9,LSL #3]

    (23) 0x49733c STR	X21, [X11, X9,LSL #3]

    (23) 0x497340 ADD	X9, X9, #1

    (23) 0x497344 LDR	X18, [X12, X21,LSL #3]

    (23) 0x497348 ADD	X21, X21, #1

    (23) 0x49734c LDR	X4, [X12, X21,LSL #3]

    (23) 0x497350 CMP	X18, X4

    (23) 0x497354 B.GE	497320

  (24) 0x497358 LDR	X0, [X27]

  (24) 0x49735c LDR	X1, [X28]

  (24) 0x497360 B	497374

  (27) 0x497364 LDR	X4, [X12, X21,LSL #3]

  (24) 0x497368 ADD	X18, X18, #1

  (24) 0x49736c CMP	X18, X4

  (24) 0x497370 B.GE	497320

  (24) 0x497374 LDR	X2, [X13, X18,LSL #3]

  (24) 0x497378 LDR	X3, [X15, X2,LSL #3]

  (24) 0x49737c LDR	X5, [X16, X2,LSL #3]

  (24) 0x497380 CMP	X3, X5

  (24) 0x497384 B.GE	497368

0x497388 LDR	D0, [X14, X18,LSL #3]

0x49738c LDR	X4, [X22]

0x497390 LDR	X6, [X23]

0x497394 B	4973b8

0x4973a0 LDR	D2, [X4, X24,LSL #3]

0x4973a4 FMADD	D1, D0, D1, D2

0x4973a8 STR	D1, [X4, X24,LSL #3]

0x4973ac ADD	X3, X3, #1

0x4973b0 CMP	X3, X5

0x4973b4 B.GE	497364

  (26) 0x4973b8 LDR	X7, [X0, X3,LSL #3]

  (26) 0x4973bc LDR	D1, [X1, X3,LSL #3]

  (26) 0x4973c0 LDR	X24, [X20, X7,LSL #3]

  (26) 0x4973c4 CMP	X24, X17

  (26) 0x4973c8 B.GE	4973a0

  (26) 0x4973cc STR	X9, [X20, X7,LSL #3]

  (26) 0x4973d0 STR	X7, [X6, X9,LSL #3]

  (26) 0x4973d4 FMUL	D1, D0, D1

  (26) 0x4973d8 ADD	X9, X9, #1

  (26) 0x4973dc LDR	X5, [X20, X7,LSL #3]

  (26) 0x4973e0 STR	D1, [X4, X5,LSL #3]

  (26) 0x4973e4 LDR	X5, [X16, X2,LSL #3]

  (26) 0x4973e8 ADD	X3, X3, #1

  (26) 0x4973ec CMP	X3, X5

  (26) 0x4973f0 B.LT	4973b8

  (27) 0x4973f4 B	497364

/home/hbollore/qaas-runs/171-233-5044/intel/AMG/build/AMG/AMG/seq_mv/csr_matop.c: 272 - 298

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

272:    for (ic = ns; ic < ne; ic++)

273:    {

274:       row_start = C_i[ic];

275:       if (allsquare)

276:       {

277:          B_marker[ic] = counter;

278:          C_data[counter] = 0;

279:          C_j[counter] = ic;

280:          counter++;

281:       }

282:       for (ia = A_i[ic]; ia < A_i[ic+1]; ia++)

283:       {

284: 	 ja = A_j[ia];

285: 	 a_entry = A_data[ia];

286: 	 for (ib = B_i[ja]; ib < B_i[ja+1]; ib++)

287: 	 {

288: 	    jb = B_j[ib];

289: 	    b_entry = B_data[ib];

290: 	    if (B_marker[jb] < row_start)

291: 	    {

292: 		B_marker[jb] = counter;

293: 		C_j[B_marker[jb]] = jb;

294: 		C_data[B_marker[jb]] = a_entry*b_entry;

295: 		counter++;

296: 	    }

297: 	    else

298: 		C_data[B_marker[jb]] += a_entry*b_entry;

Coverage (%)	Name	Source Location	Module

Path /

Metric	Value
CQA speedup if no scalar integer	1.57
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	1.10
Bottlenecks	P10,
Function	.omp_outlined.#0x496ee0
Source	csr_matop.c:286-286,csr_matop.c:298-298
Source loop unroll info	NA
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	1.83
CQA cycles if no scalar integer	1.17
CQA cycles if FP arith vectorized	1.83
CQA cycles if fully vectorized	0.46
Front-end cycles	1.25
DIV/SQRT cycles	1.00
P0 cycles	1.00
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.50
P4 cycles	0.50
P5 cycles	0.50
P6 cycles	0.50
P7 cycles	0.50
P8 cycles	0.50
P9 cycles	1.83
P10 cycles	1.50
P11 cycles	1.67
P12 cycles	0.00
P13 cycles	0.00
P14 cycles	0.00
Inter-iter dependencies cycles	NA
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	10.00
Nb uops	10.00
Nb loads	NA
Nb stores	1.00
Nb stack references	0.00
FLOP/cycle	1.09
Nb FLOP add-sub	0.00
Nb FLOP mul	0.00
Nb FLOP fma	1.00
Nb FLOP div	0.00
Nb FLOP rcp	0.00
Nb FLOP sqrt	0.00
Nb FLOP rsqrt	0.00
Bytes/cycle	21.82
Bytes prefetched	0.00
Bytes loaded	32.00
Bytes stored	8.00
Stride 0	NA
Stride 1	NA
Stride n	NA
Stride unknown	NA
Stride indirect	NA
Vectorization ratio all	0.00
Vectorization ratio load	0.00
Vectorization ratio store	0.00
Vectorization ratio mul	NA
Vectorization ratio add_sub	NA
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	NA
Vector-efficiency ratio fma	NA
Vector-efficiency ratio div_sqrt	NA
Vector-efficiency ratio other	NA

Metric	Value
CQA speedup if no scalar integer	1.57
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	1.10
Bottlenecks	P10,
Function	.omp_outlined.#0x496ee0
Source	csr_matop.c:286-286,csr_matop.c:298-298
Source loop unroll info	NA
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	1.83
CQA cycles if no scalar integer	1.17
CQA cycles if FP arith vectorized	1.83
CQA cycles if fully vectorized	0.46
Front-end cycles	1.25
DIV/SQRT cycles	1.00
P0 cycles	1.00
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.50
P4 cycles	0.50
P5 cycles	0.50
P6 cycles	0.50
P7 cycles	0.50
P8 cycles	0.50
P9 cycles	1.83
P10 cycles	1.50
P11 cycles	1.67
P12 cycles	0.00
P13 cycles	0.00
P14 cycles	0.00
Inter-iter dependencies cycles	NA
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	10.00
Nb uops	10.00
Nb loads	NA
Nb stores	1.00
Nb stack references	0.00
FLOP/cycle	1.09
Nb FLOP add-sub	0.00
Nb FLOP mul	0.00
Nb FLOP fma	1.00
Nb FLOP div	0.00
Nb FLOP rcp	0.00
Nb FLOP sqrt	0.00
Nb FLOP rsqrt	0.00
Bytes/cycle	21.82
Bytes prefetched	0.00
Bytes loaded	32.00
Bytes stored	8.00
Stride 0	NA
Stride 1	NA
Stride n	NA
Stride unknown	NA
Stride indirect	NA
Vectorization ratio all	0.00
Vectorization ratio load	0.00
Vectorization ratio store	0.00
Vectorization ratio mul	NA
Vectorization ratio add_sub	NA
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	NA
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	.omp_outlined.#0x496ee0
Source file and lines	csr_matop.c:272-298
Module	exec

The loop is defined in /home/hbollore/qaas-runs/171-233-5044/intel/AMG/build/AMG/AMG/seq_mv/csr_matop.c:272-298.

Analyzed code is defined in /home/hbollore/qaas-runs/171-233-5044/intel/AMG/build/AMG/AMG/seq_mv/csr_matop.c:286,298.

Warnings:

Non-innermost loop: analyzing only self part (ignoring child loops).
Ignoring paths for analysis
Failed to get the number of paths
RecMII not computed since number of paths is unknown or > max_paths

gain
potential
hint
expert

Code clean check

Detected a slowdown caused by scalar integer instructions (typically used for address computation). By removing them, you can lower the cost of an iteration from 1.83 to 1.17 cycles (1.57x speedup).

Workaround

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

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 1.83 to 0.46 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
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)

FMA

Detected 1 FMA (fused multiply-add) operations.

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

The binary loop is composed of 2 FP arithmetical operations:

1: addition or subtraction (all inside FMA instructions)
1: multiply (all inside FMA instructions)

The binary loop is loading 32 bytes. The binary loop is storing 8 bytes.

Arithmetic intensity

Arithmetic intensity is 0.05 FP operations per loaded or stored byte.

General properties

nb instructions	10
loop length	40
nb stack references	0

Front-end

FIT IN UOP CACHE

front end

1.25 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	1.00	1.00	0.50	0.50	0.50	0.50	0.50	0.50	0.50	0.50	1.83	1.50	1.67	0.00	0.00
cycles	1.00	1.00	0.50	0.50	0.50	0.50	0.50	0.50	0.50	0.50	1.83	1.50	1.67	0.00	0.00

Execution ports to units layout:

P0:
P1:
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

Cycles summary

Front-end	1.25
Overall L1	1.83

Vectorization ratios

all	0%
load	0%
store	0%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	NA (no add-sub vectorizable/vectorized instructions)
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 1.83 cycles. At this rate:

18% of peak load performance is reached (17.45 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
9% of peak store performance is reached (4.36 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

ASM code

In the binary file, the address of the loop is: 4973a0

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput
LDR D0, [X14, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33
LDR X4, [X22]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33
LDR X6, [X23]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33
B 4973b8 <.omp_outlined.+0x4d8>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50
LDR D2, [X4, X24,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33
FMADD D1, D0, D1, D2	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25
STR D1, [X4, X24,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50
ADD X3, X3, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25
CMP X3, X5	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.33
B.GE 497364 <.omp_outlined.+0x484>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50

Function	.omp_outlined.#0x496ee0
Source file and lines	csr_matop.c:272-298
Module	exec

The loop is defined in /home/hbollore/qaas-runs/171-233-5044/intel/AMG/build/AMG/AMG/seq_mv/csr_matop.c:272-298.

Analyzed code is defined in /home/hbollore/qaas-runs/171-233-5044/intel/AMG/build/AMG/AMG/seq_mv/csr_matop.c:286,298.

Warnings:

Non-innermost loop: analyzing only self part (ignoring child loops).
Ignoring paths for analysis
Failed to get the number of paths
RecMII not computed since number of paths is unknown or > max_paths

gain
potential
hint
expert

Code clean check

Detected a slowdown caused by scalar integer instructions (typically used for address computation). By removing them, you can lower the cost of an iteration from 1.83 to 1.17 cycles (1.57x speedup).

Workaround

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

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 1.83 to 0.46 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
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)

FMA

Detected 1 FMA (fused multiply-add) operations.

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

The binary loop is composed of 2 FP arithmetical operations:

1: addition or subtraction (all inside FMA instructions)
1: multiply (all inside FMA instructions)

The binary loop is loading 32 bytes. The binary loop is storing 8 bytes.

Arithmetic intensity

Arithmetic intensity is 0.05 FP operations per loaded or stored byte.

General properties

nb instructions	10
loop length	40
nb stack references	0

Front-end

FIT IN UOP CACHE

front end

1.25 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	1.00	1.00	0.50	0.50	0.50	0.50	0.50	0.50	0.50	0.50	1.83	1.50	1.67	0.00	0.00
cycles	1.00	1.00	0.50	0.50	0.50	0.50	0.50	0.50	0.50	0.50	1.83	1.50	1.67	0.00	0.00

Execution ports to units layout:

P0:
P1:
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

Cycles summary

Front-end	1.25
Overall L1	1.83

Vectorization ratios

all	0%
load	0%
store	0%
mul	NA (no mul vectorizable/vectorized instructions)
add-sub	NA (no add-sub vectorizable/vectorized instructions)
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 1.83 cycles. At this rate:

18% of peak load performance is reached (17.45 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
9% of peak store performance is reached (4.36 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

ASM code

In the binary file, the address of the loop is: 4973a0

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput
LDR D0, [X14, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33
LDR X4, [X22]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33
LDR X6, [X23]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33
B 4973b8 <.omp_outlined.+0x4d8>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50
LDR D2, [X4, X24,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33
FMADD D1, D0, D1, D2	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25
STR D1, [X4, X24,LSL #3]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50
ADD X3, X3, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25
CMP X3, X5	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.33
B.GE 497364 <.omp_outlined.+0x484>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50

Report Configuration

Code clean check

Workaround

Vectorization

Details

Workaround

FMA

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

Arithmetic intensity

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Cycles and memory resources usage

ASM code

Code clean check

Workaround

Vectorization

Details

Workaround

FMA

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

Arithmetic intensity

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Cycles and memory resources usage

ASM code