OV - exec - Loop 2587

	Loop Id: 2587	Module: exec	Source: ams.c:3532-3534	Coverage: 0.03%

0x4c31e8 LDR	X16, [X24, X0,LSL #3]    [2]

0x4c31ec LDR	D29, [X21, X16,LSL #3]    [1]

0x4c31f0 FCMPE	D29, #0

0x4c31f4 B.MI	4c3770

0x4c31f8 ADD	X0, X0, #1

0x4c31fc LDR	X17, [X24, X0,LSL #3]    [2]

0x4c3200 LDR	D1, [X21, X17,LSL #3]    [1]

0x4c3204 FCMPE	D1, #0

0x4c3208 B.MI	4c3760

0x4c320c ADD	X7, X0, #1

0x4c3210 LDR	X3, [X24, X7,LSL #3]    [2]

0x4c3214 LDR	D19, [X21, X3,LSL #3]    [1]

0x4c3218 FCMPE	D19, #0

0x4c321c B.MI	4c3750

0x4c3220 ADD	X15, X0, #2

0x4c3224 LDR	X12, [X24, X15,LSL #3]    [2]

0x4c3228 LDR	D5, [X21, X12,LSL #3]    [1]

0x4c322c FCMPE	D5, #0

0x4c3230 B.MI	4c3740

0x4c3234 ADD	X18, X0, #3

0x4c3238 LDR	X2, [X24, X18,LSL #3]    [2]

0x4c323c LDR	D17, [X21, X2,LSL #3]    [1]

0x4c3240 FCMPE	D17, #0

0x4c3244 B.MI	4c3730

0x4c3248 ADD	X11, X0, #4

0x4c324c LDR	X14, [X24, X11,LSL #3]    [2]

0x4c3250 LDR	D21, [X21, X14,LSL #3]    [1]

0x4c3254 FCMPE	D21, #0

0x4c3258 B.MI	4c3720

0x4c325c ADD	X30, X0, #5

0x4c3260 LDR	X16, [X24, X30,LSL #3]    [2]

0x4c3264 LDR	D25, [X21, X16,LSL #3]    [1]

0x4c3268 FCMPE	D25, #0

0x4c326c B.MI	4c3710

0x4c3270 ADD	X17, X0, #6

0x4c3274 LDR	X7, [X24, X17,LSL #3]    [2]

0x4c3278 LDR	D24, [X21, X7,LSL #3]    [1]

0x4c327c FCMPE	D24, #0

0x4c3280 B.MI	4c3700

0x4c3284 ADD	X0, X0, #7

0x4c3288 CMP	X0, X26

0x4c328c B.NE	4c31e8

0x4c3710 LDR	D22, [X19, X30,LSL #3]    [3]

0x4c3714 FNEG	D23, D22

0x4c3718 STR	D23, [X19, X30,LSL #3]    [3]

0x4c371c B	4c3270

0x4c3720 LDR	D27, [X19, X11,LSL #3]    [3]

0x4c3724 FNEG	D28, D27

0x4c3728 STR	D28, [X19, X11,LSL #3]    [3]

0x4c372c B	4c325c

0x4c3730 LDR	D18, [X19, X18,LSL #3]    [3]

0x4c3734 FNEG	D20, D18

0x4c3738 STR	D20, [X19, X18,LSL #3]    [3]

0x4c373c B	4c3248

0x4c3740 LDR	D7, [X19, X15,LSL #3]    [3]

0x4c3744 FNEG	D16, D7

0x4c3748 STR	D16, [X19, X15,LSL #3]    [3]

0x4c374c B	4c3234

0x4c3750 LDR	D3, [X19, X7,LSL #3]    [3]

0x4c3754 FNEG	D4, D3

0x4c3758 STR	D4, [X19, X7,LSL #3]    [3]

0x4c375c B	4c3220

0x4c3760 LDR	D31, [X19, X0,LSL #3]    [3]

0x4c3764 FNEG	D2, D31

0x4c3768 STR	D2, [X19, X0,LSL #3]    [3]

0x4c376c B	4c320c

0x4c3770 LDR	D6, [X19, X0,LSL #3]    [3]

0x4c3774 FNEG	D0, D6

0x4c3778 STR	D0, [X19, X0,LSL #3]    [3]

0x4c377c B	4c31f8

/home/hbollore/qaas/qaas-runs/174-161-6712/intel/AMG/build/AMG/AMG/parcsr_ls/ams.c: 3532 - 3534

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

3532:       for (i = ns; i < ne; i++)

3533:          if (A_diag_data[A_diag_I[i]] < 0)

3534:             l1_norm[i] = -l1_norm[i];

Coverage (%)	Name	Source Location	Module
►100.00+	gomp_thread_start	team.c:130	libgomp.so.1.0.0
○	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	1.36
CQA speedup if FP arith vectorized	1.00
CQA speedup if fully vectorized	2.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.02
Bottlenecks	P12,
Function	hypre_ParCSRComputeL1NormsThreads._omp_fn.0
Source	ams.c:3532-3534
Source loop unroll info	multi-versionned
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	10.17
CQA cycles if no scalar integer	7.50
CQA cycles if FP arith vectorized	10.17
CQA cycles if fully vectorized	5.08
Front-end cycles	8.75
P0 cycles	8.00
P1 cycles	8.00
P2 cycles	1.58
P3 cycles	1.58
P4 cycles	1.50
P5 cycles	1.50
P6 cycles	1.42
P7 cycles	1.42
P8 cycles	8.00
P9 cycles	7.00
P10 cycles	3.50
P11 cycles	3.50
P12 cycles	10.17
P13 cycles	9.83
P14 cycles	10.00
P15 cycles	0.00
P16 cycles	0.00
DIV/SQRT cycles	0.00
Inter-iter dependencies cycles	NA
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	70.00
Nb uops	70.00
Nb loads	NA
Nb stores	7.00
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	23.61
Bytes prefetched	0.00
Bytes loaded	184.00
Bytes stored	56.00
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	0.00
Vector-efficiency ratio all	50.00
Vector-efficiency ratio load	50.00
Vector-efficiency ratio store	50.00
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	50.00

Metric	Value
CQA speedup if no scalar integer	1.36
CQA speedup if FP arith vectorized	1.00
CQA speedup if fully vectorized	2.00
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.02
Bottlenecks	P12,
Function	hypre_ParCSRComputeL1NormsThreads._omp_fn.0
Source	ams.c:3532-3534
Source loop unroll info	multi-versionned
Source loop unroll confidence level	NA
Unroll/vectorization loop type	NA
Unroll factor	NA
CQA cycles	10.17
CQA cycles if no scalar integer	7.50
CQA cycles if FP arith vectorized	10.17
CQA cycles if fully vectorized	5.08
Front-end cycles	8.75
P0 cycles	8.00
P1 cycles	8.00
P2 cycles	1.58
P3 cycles	1.58
P4 cycles	1.50
P5 cycles	1.50
P6 cycles	1.42
P7 cycles	1.42
P8 cycles	8.00
P9 cycles	7.00
P10 cycles	3.50
P11 cycles	3.50
P12 cycles	10.17
P13 cycles	9.83
P14 cycles	10.00
P15 cycles	0.00
P16 cycles	0.00
DIV/SQRT cycles	0.00
Inter-iter dependencies cycles	NA
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	70.00
Nb uops	70.00
Nb loads	NA
Nb stores	7.00
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	23.61
Bytes prefetched	0.00
Bytes loaded	184.00
Bytes stored	56.00
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	0.00
Vector-efficiency ratio all	50.00
Vector-efficiency ratio load	50.00
Vector-efficiency ratio store	50.00
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	50.00

Path /

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

Function	hypre_ParCSRComputeL1NormsThreads._omp_fn.0
Source file and lines	ams.c:3532-3534
Module	exec

The loop is defined in /home/hbollore/qaas/qaas-runs/174-161-6712/intel/AMG/build/AMG/AMG/parcsr_ls/ams.c:3532-3534.

The related source loop is multi-versionned.
Warnings:

Ignoring paths for analysis
Failed to get the number of paths
RecMII not computed since number of paths is unknown or > max_paths
Streams not analyzed 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 10.17 to 7.50 cycles (1.36x 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. 2 data elements could be processed at once in vector registers. By vectorizing your loop, you can lower the cost of an iteration from 10.17 to 5.08 cycles (2.00x 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 fassociative-math (included in Ofast or ffast-math) 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

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 is loading 184 bytes. The binary loop is storing 56 bytes.

General properties

nb instructions	70
loop length	280
nb stack references	0

Front-end

FIT IN UOP CACHE

front end

8.75 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	P15	P16
uops	8.00	8.00	1.58	1.58	1.50	1.50	1.42	1.42	8.00	7.00	3.50	3.50	10.17	9.83	10.00	0.00	0.00
cycles	8.00	8.00	1.58	1.58	1.50	1.50	1.42	1.42	8.00	7.00	3.50	3.50	10.17	9.83	10.00	0.00	0.00

Execution ports to units layout:

P0: BRU
P1: BRU
P2: ALU
P3: ALU
P4: ALU
P5: ALU
P6: ALU
P7: ALU
P8 (128 bits): VPU, FP store data, ALU, DIV/SQRT
P9 (128 bits): VPU, ALU, FP store data
P10 (128 bits): VPU, ALU, DIV/SQRT
P11 (128 bits): ALU, VPU
P12 (256 bits): store address, load
P13 (256 bits): store address, load
P14 (256 bits): load
P15 (64 bits): store data
P16 (64 bits): store data

Cycles executing div or sqrt instructions

Cycles summary

Front-end	8.75
Overall L1	10.17

Vectorization ratios

INT

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)
other	NA (no other vectorizable/vectorized instructions)

all	0%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
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	0%

INT+FP

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	0%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 10.17 cycles. At this rate:

18% of peak load performance is reached (18.10 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
11% of peak store performance is reached (5.51 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

ASM code

In the binary file, the address of the loop is: 4c31e8

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	Latency	Recip. throughput	Vectorization
LDR X16, [X24, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D29, [X21, X16,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D29, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3770 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xaf0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X0, X0, #1	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X17, [X24, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D1, [X21, X17,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D1, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3760 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xae0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X7, X0, #1	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X3, [X24, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D19, [X21, X3,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D19, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3750 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xad0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X15, X0, #2	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X12, [X24, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D5, [X21, X12,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D5, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3740 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xac0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X18, X0, #3	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X2, [X24, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D17, [X21, X2,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D17, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3730 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xab0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X11, X0, #4	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X14, [X24, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D21, [X21, X14,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D21, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3720 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xaa0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X30, X0, #5	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X16, [X24, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D25, [X21, X16,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D25, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3710 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xa90>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X17, X0, #6	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X7, [X24, X17,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D24, [X21, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D24, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3700 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xa80>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X0, X0, #7	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
CMP X0, X26	1	0	0	0.25	0.25	0	0	0.25	0.25	0	0	0	0	0	0	0	1	0.33	N/A
B.NE 4c31e8 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x568>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D22, [X19, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D23, D22	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D23, [X19, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3270 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5f0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D27, [X19, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D28, D27	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D28, [X19, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c325c <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5dc>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D18, [X19, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D20, D18	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D20, [X19, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3248 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5c8>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D7, [X19, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D16, D7	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D16, [X19, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3234 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5b4>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D3, [X19, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D4, D3	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D4, [X19, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3220 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5a0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D31, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D2, D31	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D2, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c320c <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x58c>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D6, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D0, D6	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D0, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c31f8 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x578>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Function	hypre_ParCSRComputeL1NormsThreads._omp_fn.0
Source file and lines	ams.c:3532-3534
Module	exec

The loop is defined in /home/hbollore/qaas/qaas-runs/174-161-6712/intel/AMG/build/AMG/AMG/parcsr_ls/ams.c:3532-3534.

The related source loop is multi-versionned.
Warnings:

Ignoring paths for analysis
Failed to get the number of paths
RecMII not computed since number of paths is unknown or > max_paths
Streams not analyzed 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 10.17 to 7.50 cycles (1.36x speedup).

Workaround

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

Vectorization

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 fassociative-math (included in Ofast or ffast-math) 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

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 is loading 184 bytes. The binary loop is storing 56 bytes.

General properties

nb instructions	70
loop length	280
nb stack references	0

Front-end

FIT IN UOP CACHE

front end

8.75 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	P15	P16
uops	8.00	8.00	1.58	1.58	1.50	1.50	1.42	1.42	8.00	7.00	3.50	3.50	10.17	9.83	10.00	0.00	0.00
cycles	8.00	8.00	1.58	1.58	1.50	1.50	1.42	1.42	8.00	7.00	3.50	3.50	10.17	9.83	10.00	0.00	0.00

Execution ports to units layout:

P0: BRU
P1: BRU
P2: ALU
P3: ALU
P4: ALU
P5: ALU
P6: ALU
P7: ALU
P8 (128 bits): VPU, FP store data, ALU, DIV/SQRT
P9 (128 bits): VPU, ALU, FP store data
P10 (128 bits): VPU, ALU, DIV/SQRT
P11 (128 bits): ALU, VPU
P12 (256 bits): store address, load
P13 (256 bits): store address, load
P14 (256 bits): load
P15 (64 bits): store data
P16 (64 bits): store data

Cycles executing div or sqrt instructions

Cycles summary

Front-end	8.75
Overall L1	10.17

Vectorization ratios

INT

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)
other	NA (no other vectorizable/vectorized instructions)

all	0%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
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	0%

INT+FP

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	0%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each iteration of the binary loop takes 10.17 cycles. At this rate:

18% of peak load performance is reached (18.10 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
11% of peak store performance is reached (5.51 out of 48.00 bytes stored per cycle (GB/s @ 1GHz))

ASM code

In the binary file, the address of the loop is: 4c31e8

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	Latency	Recip. throughput	Vectorization
LDR X16, [X24, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D29, [X21, X16,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D29, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3770 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xaf0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X0, X0, #1	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X17, [X24, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D1, [X21, X17,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D1, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3760 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xae0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X7, X0, #1	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X3, [X24, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D19, [X21, X3,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D19, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3750 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xad0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X15, X0, #2	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X12, [X24, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D5, [X21, X12,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D5, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3740 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xac0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X18, X0, #3	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X2, [X24, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D17, [X21, X2,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D17, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3730 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xab0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X11, X0, #4	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X14, [X24, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D21, [X21, X14,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D21, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3720 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xaa0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X30, X0, #5	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X16, [X24, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D25, [X21, X16,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D25, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3710 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xa90>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X17, X0, #6	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
LDR X7, [X24, X17,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	4	0.33	N/A
LDR D24, [X21, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FCMPE D24, #0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	2	1	scal (50.0%)
B.MI 4c3700 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0xa80>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X0, X0, #7	1	0	0	0.17	0.17	0.17	0.17	0.17	0.17	0	0	0	0	0	0	0	1	0.17	N/A
CMP X0, X26	1	0	0	0.25	0.25	0	0	0.25	0.25	0	0	0	0	0	0	0	1	0.33	N/A
B.NE 4c31e8 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x568>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D22, [X19, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D23, D22	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D23, [X19, X30,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3270 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5f0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D27, [X19, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D28, D27	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D28, [X19, X11,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c325c <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5dc>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D18, [X19, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D20, D18	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D20, [X19, X18,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3248 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5c8>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D7, [X19, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D16, D7	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D16, [X19, X15,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3234 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5b4>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D3, [X19, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D4, D3	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D4, [X19, X7,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c3220 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x5a0>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D31, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D2, D31	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D2, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c320c <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x58c>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR D6, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	scal (50.0%)
FNEG D0, D6	1	0	0	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	scal (50.0%)
STR D0, [X19, X0,LSL #3]	1	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	scal (50.0%)
B 4c31f8 <hypre_ParCSRComputeL1NormsThreads._omp_fn.0+0x578>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Report Configuration

Code clean check

Workaround

Vectorization

Details

Workaround

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

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Cycles and memory resources usage

ASM code

Code clean check

Workaround

Vectorization

Details

Workaround

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

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Cycles and memory resources usage

ASM code