OV - exec - Loop 157

	Loop Id: 157	Module: exec	Source: accelerate.cpp:43-53	Coverage: 7.32%

0x42b90c LDR	Q19, [X20, X0]    [7]

0x42b910 LDR	Q25, [X21, X0]    [9]

0x42b914 LDR	Q22, [X17, X0]    [20]

0x42b918 LDR	Q31, [X18, X0]    [22]

0x42b91c LDR	Q28, [X22, X0]    [11]

0x42b920 FMUL	V1.2D, V19.2D, V25.2D

0x42b924 LDR	Q2, [X23, X0]    [13]

0x42b928 LDR	Q0, [X15, X0]    [16]

0x42b92c FMUL	V4.2D, V22.2D, V31.2D

0x42b930 LDR	Q21, [X16, X0]    [18]

0x42b934 LDR	Q18, [X11, X0]    [8]

0x42b938 FMLA	V1.2D, V28.2D, V2.2D

0x42b93c LDR	Q17, [X6, X0]    [2]

0x42b940 FMLA	V4.2D, V0.2D, V21.2D

0x42b944 LDR	Q27, [X12, X0]    [10]

0x42b948 LDR	Q20, [X7, X0]    [3]

0x42b94c LDR	Q16, [X13, X0]    [12]

0x42b950 FSUB	V5.2D, V18.2D, V17.2D

0x42b954 LDR	Q6, [X14, X0]    [14]

0x42b958 FSUB	V23.2D, V27.2D, V20.2D

0x42b95c LDR	Q7, [X25, X0]    [17]

0x42b960 FADD	V24.2D, V4.2D, V1.2D

0x42b964 FMUL	V26.2D, V5.2D, V16.2D

0x42b968 FMLA	V26.2D, V23.2D, V6.2D

0x42b96c FDIV	V31.2D, V29.2D, V24.2D

0x42b970 FMLA	V7.2D, V26.2D, V31.2D

0x42b974 STR	Q7, [X2, X0]    [21]

0x42b978 LDR	Q3, [X7, X0]    [3]

0x42b97c LDR	Q19, [X6, X0]    [2]

0x42b980 LDR	Q25, [X12, X0]    [10]

0x42b984 LDR	Q22, [X11, X0]    [8]

0x42b988 LDR	Q28, [X5, X0]    [1]

0x42b98c FSUB	V2.2D, V3.2D, V19.2D

0x42b990 LDR	Q0, [X10, X0]    [6]

0x42b994 FSUB	V4.2D, V25.2D, V22.2D

0x42b998 LDR	Q1, [X24, X0]    [15]

0x42b99c FMUL	V21.2D, V2.2D, V28.2D

0x42b9a0 FMLA	V21.2D, V0.2D, V4.2D

0x42b9a4 FMLA	V1.2D, V31.2D, V21.2D

0x42b9a8 STR	Q1, [X1, X0]    [19]

0x42b9ac LDR	Q18, [X8, X0]    [4]

0x42b9b0 LDR	Q17, [X3, X0]    [23]

0x42b9b4 LDR	Q27, [X9, X0]    [5]

0x42b9b8 LDR	Q16, [X4, X0]    [24]

0x42b9bc LDR	Q20, [X13, X0]    [12]

0x42b9c0 FSUB	V5.2D, V18.2D, V17.2D

0x42b9c4 LDR	Q6, [X14, X0]    [14]

0x42b9c8 FSUB	V23.2D, V27.2D, V16.2D

0x42b9cc LDR	Q7, [X2, X0]    [21]

0x42b9d0 FMUL	V24.2D, V5.2D, V20.2D

0x42b9d4 FMLA	V24.2D, V6.2D, V23.2D

0x42b9d8 FMLA	V7.2D, V31.2D, V24.2D

0x42b9dc STR	Q7, [X2, X0]    [21]

0x42b9e0 LDR	Q26, [X1, X0]    [19]

0x42b9e4 LDR	Q3, [X4, X0]    [24]

0x42b9e8 LDR	Q19, [X3, X0]    [23]

0x42b9ec LDR	Q25, [X9, X0]    [5]

0x42b9f0 LDR	Q22, [X8, X0]    [4]

0x42b9f4 LDR	Q28, [X5, X0]    [1]

0x42b9f8 FSUB	V2.2D, V3.2D, V19.2D

0x42b9fc LDR	Q0, [X10, X0]    [6]

0x42ba00 FSUB	V4.2D, V25.2D, V22.2D

0x42ba04 FMUL	V1.2D, V2.2D, V28.2D

0x42ba08 FMLA	V1.2D, V0.2D, V4.2D

0x42ba0c FMLA	V26.2D, V31.2D, V1.2D

0x42ba10 STR	Q26, [X1, X0]    [19]

0x42ba14 ADD	X0, X0, #16

0x42ba18 CMP	X19, X0

0x42ba1c B.NE	42b90c

/home/eoseret/qaas/qaas_runs/178-219-7589/intel/CloverLeaf2.0-CXX/build/CloverLeaf2.0-CXX/src/omp/accelerate.cpp: 43 - 53

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

43:       double stepbymass_s = halfdt / ((density0(i - 1, j - 1) * volume(i - 1, j - 1) + density0(i - 1, j + 0) * volume(i - 1, j + 0) +

44:                                        density0(i, j) * volume(i, j) + density0(i + 0, j - 1) * volume(i + 0, j - 1)) *

45:                                       0.25);

46:       xvel1(i, j) = xvel0(i, j) - stepbymass_s * (xarea(i, j) * (pressure(i, j) - pressure(i - 1, j + 0)) +

47:                                                   xarea(i + 0, j - 1) * (pressure(i + 0, j - 1) - pressure(i - 1, j - 1)));

48:       yvel1(i, j) = yvel0(i, j) - stepbymass_s * (yarea(i, j) * (pressure(i, j) - pressure(i + 0, j - 1)) +

49:                                                   yarea(i - 1, j + 0) * (pressure(i - 1, j + 0) - pressure(i - 1, j - 1)));

50:       xvel1(i, j) = xvel1(i, j) - stepbymass_s * (xarea(i, j) * (viscosity(i, j) - viscosity(i - 1, j + 0)) +

51:                                                   xarea(i + 0, j - 1) * (viscosity(i + 0, j - 1) - viscosity(i - 1, j - 1)));

52:       yvel1(i, j) = yvel1(i, j) - stepbymass_s * (yarea(i, j) * (viscosity(i, j) - viscosity(i + 0, j - 1)) +

53:                                                   yarea(i - 1, j + 0) * (viscosity(i - 1, j + 0) - viscosity(i - 1, j - 1)));

Coverage (%)	Name	Source Location	Module
►98.43+	omp_fulfill_event		libgomp.so.1.0.0
○	start_thread		libc.so.6
○	thread_start		libc.so.6
►1.57+	GOMP_parallel		libgomp.so.1.0.0
○	accelerate(global_variables&)	accelerate.cpp:66	exec
○	hydro(global_variables&, paral[...]	hydro.cpp:68	exec
○	main	clover_leaf.cpp:209	exec
○	__libc_start_call_main		libc.so.6
○	__libc_start_main		libc.so.6
○	_start	clover_leaf.cpp:51	exec

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	2.00 - 1.91
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.55
Bottlenecks	P10, P11, P12,
Function	accelerate_kernel(int, int, int, int, double, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&) [clone ._omp_fn.0]
Source	accelerate.cpp:43-53
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	13.33
CQA cycles if no scalar integer	13.33
CQA cycles if FP arith vectorized	13.33
CQA cycles if fully vectorized	6.67 - 6.99
Front-end cycles	8.63
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.50
P4 cycles	0.50
P5 cycles	0.50
P6 cycles	7.50
P7 cycles	7.50
P8 cycles	7.50
P9 cycles	7.50
P10 cycles	13.33
P11 cycles	13.33
P12 cycles	13.33
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	3.50 - 6.99
Inter-iter dependencies cycles	1
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	69.00
Nb uops	69.00
Nb loads	NA
Nb stores	4.00
Nb stack references	0.00
FLOP/cycle	5.40
Nb FLOP add-sub	18.00
Nb FLOP mul	12.00
Nb FLOP fma	20.00
Nb FLOP div	2.00
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	24.00
Stride unknown	0.00
Stride indirect	0.00
Vectorization ratio all	100.00
Vectorization ratio load	100.00
Vectorization ratio store	100.00
Vectorization ratio mul	100.00
Vectorization ratio add_sub	100.00
Vectorization ratio fma	100.00
Vectorization ratio div_sqrt	100.00
Vectorization ratio other	NA
Vector-efficiency ratio all	50.00
Vector-efficiency ratio load	50.00
Vector-efficiency ratio store	50.00
Vector-efficiency ratio mul	50.00
Vector-efficiency ratio add_sub	50.00
Vector-efficiency ratio fma	50.00
Vector-efficiency ratio div_sqrt	50.00
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	2.00 - 1.91
CQA speedup if no inter-iteration dependency	NA
CQA speedup if next bottleneck killed	1.55
Bottlenecks	P10, P11, P12,
Function	accelerate_kernel(int, int, int, int, double, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&) [clone ._omp_fn.0]
Source	accelerate.cpp:43-53
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	13.33
CQA cycles if no scalar integer	13.33
CQA cycles if FP arith vectorized	13.33
CQA cycles if fully vectorized	6.67 - 6.99
Front-end cycles	8.63
P0 cycles	0.50
P1 cycles	0.50
P2 cycles	0.50
P3 cycles	0.50
P4 cycles	0.50
P5 cycles	0.50
P6 cycles	7.50
P7 cycles	7.50
P8 cycles	7.50
P9 cycles	7.50
P10 cycles	13.33
P11 cycles	13.33
P12 cycles	13.33
P13 cycles	0.00
P14 cycles	0.00
DIV/SQRT cycles	3.50 - 6.99
Inter-iter dependencies cycles	1
FE+BE cycles (UFS)	NA
Stall cycles (UFS)	NA
Nb insns	69.00
Nb uops	69.00
Nb loads	NA
Nb stores	4.00
Nb stack references	0.00
FLOP/cycle	5.40
Nb FLOP add-sub	18.00
Nb FLOP mul	12.00
Nb FLOP fma	20.00
Nb FLOP div	2.00
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	24.00
Stride unknown	0.00
Stride indirect	0.00
Vectorization ratio all	100.00
Vectorization ratio load	100.00
Vectorization ratio store	100.00
Vectorization ratio mul	100.00
Vectorization ratio add_sub	100.00
Vectorization ratio fma	100.00
Vectorization ratio div_sqrt	100.00
Vectorization ratio other	NA
Vector-efficiency ratio all	50.00
Vector-efficiency ratio load	50.00
Vector-efficiency ratio store	50.00
Vector-efficiency ratio mul	50.00
Vector-efficiency ratio add_sub	50.00
Vector-efficiency ratio fma	50.00
Vector-efficiency ratio div_sqrt	50.00
Vector-efficiency ratio other	NA

Path /

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

Function	accelerate_kernel(int, int, int, int, double, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&) [clone ._omp_fn.0]
Source file and lines	accelerate.cpp:43-53
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/accelerate.cpp:43-53.

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

gain
potential
hint
expert

Vectorization

Your loop is vectorized, but using only 128 out of 256 bits (SSE/AVX-128 instructions on AVX/AVX2 processors). By fully vectorizing your loop, you can lower the cost of an iteration from 13.33 to 6.99 cycles (1.91x speedup).

Details

All VPU instructions are used in vector version (process two or more data elements in vector registers). Since your execution units are vector units, only a fully vectorized loop can use their full power.

FMA

Detected 20 FMA (fused multiply-add) operations. Presence of both ADD/SUB and MUL operations.

Workaround

Try to change order in which elements are evaluated (using parentheses) in arithmetic expressions containing both ADD/SUB and MUL operations to enable your compiler to generate FMA instructions wherever possible. For instance a + b*c is a valid FMA (MUL then ADD). However (a+b)* c cannot be translated into an FMA (ADD then MUL).

Slow data structures access

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

Details

Constant non-unit stride: 24 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 is composed of 72 FP arithmetical operations:

38: addition or subtraction (20 inside FMA instructions)
32: multiply (20 inside FMA instructions)
2: divide

The binary loop does not load or store any data.

General properties

nb instructions	69
nb uops	69
loop length	276
used w registers	0
used x registers	26
used b registers	0
used h registers	0
used s registers	0
used d registers	0
used q registers	18
used v registers	23
used z registers	0
nb stack references	0
ADD-SUB / MUL ratio	1.50

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	8.63 cycles
front end	8.63 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	0.50	0.50	0.50	7.50	7.50	7.50	7.50	13.33	13.33	13.33	0.00	0.00
cycles	0.50	0.50	0.50	0.50	0.50	0.50	7.50	7.50	7.50	7.50	13.33	13.33	13.33	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	3.50-6.99
Longest recurrence chain latency (RecMII)	1.00

Cycles summary

Front-end	8.63
Dispatch	13.33
DIV/SQRT	3.50-6.99
Data deps.	1.00
Overall L1	13.33

Vectorization ratios

INT

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

INT+FP

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

Vector efficiency ratios

INT

all	50%
load	50%
store	50%
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	50%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	50%
add-sub	50%
fma	50%
div/sqrt	50%
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	50%
load	50%
store	50%
mul	50%
add-sub	50%
fma	50%
div/sqrt	50%
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 13.33 cycles.

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 42b90c

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput	Vectorization
LDR Q19, [X20, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X21, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X17, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q31, [X18, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X22, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V1.2D, V19.2D, V25.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
LDR Q2, [X23, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q0, [X15, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V4.2D, V22.2D, V31.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
LDR Q21, [X16, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q18, [X11, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMLA V1.2D, V28.2D, V2.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
LDR Q17, [X6, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMLA V4.2D, V0.2D, V21.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
LDR Q27, [X12, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q20, [X7, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q16, [X13, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V5.2D, V18.2D, V17.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q6, [X14, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V23.2D, V27.2D, V20.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q7, [X25, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FADD V24.2D, V4.2D, V1.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
FMUL V26.2D, V5.2D, V16.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V26.2D, V23.2D, V6.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FDIV V31.2D, V29.2D, V24.2D	1	0	0	0	0	0	0	0.50	0	0.50	0	0	0	0	7-15	3.50-6.99	vect (50.0%)
FMLA V7.2D, V26.2D, V31.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q7, [X2, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q3, [X7, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q19, [X6, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X12, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X11, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X5, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V2.2D, V3.2D, V19.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q0, [X10, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V4.2D, V25.2D, V22.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q1, [X24, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V21.2D, V2.2D, V28.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V21.2D, V0.2D, V4.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V1.2D, V31.2D, V21.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q1, [X1, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q18, [X8, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q17, [X3, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q27, [X9, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q16, [X4, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q20, [X13, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V5.2D, V18.2D, V17.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q6, [X14, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V23.2D, V27.2D, V16.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q7, [X2, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V24.2D, V5.2D, V20.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V24.2D, V6.2D, V23.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V7.2D, V31.2D, V24.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q7, [X2, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q26, [X1, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q3, [X4, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q19, [X3, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X9, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X8, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X5, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V2.2D, V3.2D, V19.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q0, [X10, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V4.2D, V25.2D, V22.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
FMUL V1.2D, V2.2D, V28.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V1.2D, V0.2D, V4.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V26.2D, V31.2D, V1.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q26, [X1, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
ADD X0, X0, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25	N/A
CMP X19, X0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.33	N/A
B.NE 42b90c <_Z17accelerate_kerneliiiidRN6clover8Buffer2DIdEES2_S2_S2_S2_S2_S2_S2_S2_S2_._omp_fn.0+0x34c>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Function	accelerate_kernel(int, int, int, int, double, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&, clover::Buffer2D&) [clone ._omp_fn.0]
Source file and lines	accelerate.cpp:43-53
Module	exec

gain
potential
hint
expert

Vectorization

Details

FMA

Detected 20 FMA (fused multiply-add) operations. Presence of both ADD/SUB and MUL operations.

Workaround

Slow data structures access

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

Details

Constant non-unit stride: 24 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 is composed of 72 FP arithmetical operations:

38: addition or subtraction (20 inside FMA instructions)
32: multiply (20 inside FMA instructions)
2: divide

The binary loop does not load or store any data.

General properties

nb instructions	69
nb uops	69
loop length	276
used w registers	0
used x registers	26
used b registers	0
used h registers	0
used s registers	0
used d registers	0
used q registers	18
used v registers	23
used z registers	0
nb stack references	0
ADD-SUB / MUL ratio	1.50

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	8.63 cycles
front end	8.63 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	0.50	0.50	0.50	7.50	7.50	7.50	7.50	13.33	13.33	13.33	0.00	0.00
cycles	0.50	0.50	0.50	0.50	0.50	0.50	7.50	7.50	7.50	7.50	13.33	13.33	13.33	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	3.50-6.99
Longest recurrence chain latency (RecMII)	1.00

Cycles summary

Front-end	8.63
Dispatch	13.33
DIV/SQRT	3.50-6.99
Data deps.	1.00
Overall L1	13.33

Vectorization ratios

INT

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

INT+FP

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

Vector efficiency ratios

INT

all	50%
load	50%
store	50%
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	50%
load	NA (no load vectorizable/vectorized instructions)
store	NA (no store vectorizable/vectorized instructions)
mul	50%
add-sub	50%
fma	50%
div/sqrt	50%
other	NA (no other vectorizable/vectorized instructions)

INT+FP

all	50%
load	50%
store	50%
mul	50%
add-sub	50%
fma	50%
div/sqrt	50%
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 13.33 cycles.

Front-end bottlenecks

Found no such bottlenecks.

ASM code

In the binary file, the address of the loop is: 42b90c

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	Latency	Recip. throughput	Vectorization
LDR Q19, [X20, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X21, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X17, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q31, [X18, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X22, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V1.2D, V19.2D, V25.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
LDR Q2, [X23, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q0, [X15, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V4.2D, V22.2D, V31.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
LDR Q21, [X16, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q18, [X11, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMLA V1.2D, V28.2D, V2.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
LDR Q17, [X6, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMLA V4.2D, V0.2D, V21.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
LDR Q27, [X12, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q20, [X7, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q16, [X13, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V5.2D, V18.2D, V17.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q6, [X14, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V23.2D, V27.2D, V20.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q7, [X25, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FADD V24.2D, V4.2D, V1.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
FMUL V26.2D, V5.2D, V16.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V26.2D, V23.2D, V6.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FDIV V31.2D, V29.2D, V24.2D	1	0	0	0	0	0	0	0.50	0	0.50	0	0	0	0	7-15	3.50-6.99	vect (50.0%)
FMLA V7.2D, V26.2D, V31.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q7, [X2, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q3, [X7, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q19, [X6, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X12, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X11, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X5, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V2.2D, V3.2D, V19.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q0, [X10, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V4.2D, V25.2D, V22.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q1, [X24, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V21.2D, V2.2D, V28.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V21.2D, V0.2D, V4.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V1.2D, V31.2D, V21.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q1, [X1, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q18, [X8, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q17, [X3, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q27, [X9, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q16, [X4, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q20, [X13, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V5.2D, V18.2D, V17.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q6, [X14, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V23.2D, V27.2D, V16.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q7, [X2, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FMUL V24.2D, V5.2D, V20.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V24.2D, V6.2D, V23.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V7.2D, V31.2D, V24.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q7, [X2, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
LDR Q26, [X1, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q3, [X4, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q19, [X3, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q25, [X9, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q22, [X8, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
LDR Q28, [X5, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V2.2D, V3.2D, V19.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
LDR Q0, [X10, X0]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	6	0.33	vect (50.0%)
FSUB V4.2D, V25.2D, V22.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	2	0.25	vect (50.0%)
FMUL V1.2D, V2.2D, V28.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	3	0.25	vect (50.0%)
FMLA V1.2D, V0.2D, V4.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
FMLA V26.2D, V31.2D, V1.2D	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0	0	0	4	0.25	vect (50.0%)
STR Q26, [X1, X0]	1	0	0	0	0	0	0	0.50	0.50	0	0	0.50	0.50	0	2	0.50	vect (50.0%)
ADD X0, X0, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.25	N/A
CMP X19, X0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	1	0.33	N/A
B.NE 42b90c <_Z17accelerate_kerneliiiidRN6clover8Buffer2DIdEES2_S2_S2_S2_S2_S2_S2_S2_S2_._omp_fn.0+0x34c>	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

FMA

Workaround

Slow data structures access

Details

Workaround

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

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

FMA

Workaround

Slow data structures access

Details

Workaround

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

General properties

Front-end

Back-end

Cycles summary

Vectorization ratios

Vector efficiency ratios

Cycles and memory resources usage

Front-end bottlenecks

ASM code