OV - exec - Function update_top(int, int, int, int, double*, bool) [clone ._omp

	Function: update_top(int, int, int, int, double*, bool) [clone ._omp_fn.0]	Module: exec	Source: local_halos.cpp:42-46	Coverage (incl. loops): 0.01% \| (excl. loops): 0.01%

/home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp: 42 - 46

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

42:   #pragma omp parallel for

43: #endif

44:     for (int kk = halo_depth; kk < x - halo_depth; ++kk) {

45:       int base = kk;

46:       buffer[base + (y - halo_depth + jj) * x] = buffer[base + (y - halo_depth - 1 - jj) * x];

0x414f40 STP	X29, X30, [SP, #976]!

0x414f44 ADD	X29, SP, #0

0x414f48 STP	X19, X20, [SP, #16]

0x414f4c ORR	X20, XZR, X0

0x414f50 STP	X21, X22, [SP, #32]

0x414f54 LDR	W22, [X0, #8]

0x414f58 LDR	W21, [X0, #16]

0x414f5c BL	410320

0x414f60 ORR	W19, WZR, W0

0x414f64 BL	4102b0

0x414f68 ORR	W1, WZR, W0

0x414f6c SUB	W2, W22, W21,LSL #1

0x414f70 SDIV	W5, W2, W19

0x414f74 MSUB	W2, W5, W19, W2

0x414f78 CMP	W0, W2

0x414f7c B.LT	415088

0x414f80 MUL	W1, W5, W1

0x414f84 ADD	W3, W2, W1

0x414f88 ADD	W6, W5, W3

0x414f8c CMP	W3, W6

0x414f90 B.GE	415078

0x414f94 LDR	W4, [X20, #12]

0x414f98 SBFM	X2, X2, #0, #31

0x414f9c ADD	X2, X2, W21,SXTW

0x414fa0 ADD	X1, X2, W1,SXTW

0x414fa4 LDR	W7, [X20, #20]

0x414fa8 LDR	X9, [X20]

0x414fac SUB	W0, W4, W21

0x414fb0 SUB	W4, W0, #1

0x414fb4 ADD	W2, W7, W0

0x414fb8 SUB	W4, W4, W7

0x414fbc MUL	W2, W2, W22

0x414fc0 MUL	W4, W4, W22

0x414fc4 SBFM	X2, X2, #0, #31

0x414fc8 ADD	X8, X2, X1

0x414fcc SBFM	X4, X4, #0, #31

0x414fd0 ADD	X1, X4, X1

0x414fd4 SUB	X0, X8, #1

0x414fd8 SUB	X0, X0, X1

0x414fdc UBFM	X0, X0, #61, #60

0x414fe0 CMP	X0, #16

0x414fe4 B.LS	4150ac

0x414fe8 SUB	W0, W5, #1

0x414fec CMP	W0, #2

0x414ff0 CCMP	W3, W6, #0, #8

0x414ff4 B.GE	4150d8

0x414ff8 ADD	X4, X9, X1,LSL #3

0x414ffc UBFM	W2, W5, #2, #31

0x415000 MOVZ	X0, #0

0x415004 ADD	X3, X9, X8,LSL #3

0x415008 UBFM	X2, X2, #59, #58

0x41500c ADD	X7, X4, #16

0x415010 ADD	X6, X3, #16

0x415014 HINT	#0

0x415018 HINT	#0

0x41501c HINT	#0

(91) 0x415020 LDR	Q30, [X4, X0]

(91) 0x415024 LDR	Q31, [X7, X0]

(91) 0x415028 STR	Q30, [X3, X0]

(91) 0x41502c STR	Q31, [X6, X0]

(91) 0x415030 ADD	X0, X0, #32

(91) 0x415034 CMP	X2, X0

(91) 0x415038 B.NE	415020

0x41503c AND	W0, W5, #0xfffffffc

0x415040 ANDS	XZR, X5, #0x3

0x415044 B.EQ	415078

0x415048 ORR	W2, WZR, W0

0x41504c SUB	W0, W5, W0

0x415050 WHILELO	P7.D, XZR, X0

0x415054 ADD	X8, X8, X2

0x415058 ADD	X1, X1, X2

0x41505c LD1D	{Z31.D}, P7/Z, [X9, X1,LSL #3]

0x415060 ADD	X8, X9, X8,LSL #3

0x415064 ST1D	{Z31.D}, P7, [X8, MUL VL]

0x415068 CNTD	X2, ALL

0x41506c ADD	X1, X9, X1,LSL #3

0x415070 WHILELO	P7.D, X2, X0

0x415074 B.NE	415094

0x415078 LDP	X19, X20, [SP, #16]

0x41507c LDP	X21, X22, [SP, #32]

0x415080 LDP	X29, X30, [SP], #48

0x415084 RET

0x415088 ADD	W5, W5, #1

0x41508c MOVZ	W2, #0

0x415090 B	414f80

0x415094 LD1D	{Z30.D}, P7/Z, [X1, #1, MUL VL]

0x415098 ST1D	{Z30.D}, P7, [X8, #1, MUL VL]

0x41509c LDP	X19, X20, [SP, #16]

0x4150a0 LDP	X21, X22, [SP, #32]

0x4150a4 LDP	X29, X30, [SP], #48

0x4150a8 RET

0x4150ac ADD	W0, W21, W3

0x4150b0 ADD	X4, X9, X4,LSL #3

0x4150b4 ADD	W6, W21, W6

0x4150b8 ADD	X2, X9, X2,LSL #3

0x4150bc SBFM	X0, X0, #0, #31

(90) 0x4150c0 LDR	D31, [X4, X0,LSL #3]

(90) 0x4150c4 STR	D31, [X2, X0,LSL #3]

(90) 0x4150c8 ADD	X0, X0, #1

(90) 0x4150cc CMP	W6, W0

(90) 0x4150d0 B.GT	4150c0

0x4150d4 B	415078

0x4150d8 MOVZ	W0, #0

0x4150dc B	415048

Coverage (%)	Name	Module
►97.63+	omp_fulfill_event	libgomp.so.1.0.0
○	start_thread	libc.so.6
○	thread_start	libc.so.6
►2.37+	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 /

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

The code analyzed by CQA in that panel excludes loops and represents 0.01% of application time for run gcc_0

Source file and lines	local_halos.cpp:42-46
Module	exec

The function is defined in /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42-46.

Warnings:
Ignoring paths for analysis

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 15.25 to 2.00 cycles (7.62x speedup).

Workaround

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

Vectorization

Your function is not vectorized. Only 34% of vector register length is used (average across all VPU instructions). By fully vectorizing your function, you can lower the cost of an iteration from 15.25 to 10.78 cycles (1.41x speedup).

Details

10% of VPU instructions are used in vector version (process two or more data elements in vector registers):

20% of VPU loads are used in vector version.
40% of VPU stores are used in vector version.
0% of VPU addition or subtraction instructions are used in vector version.
0% of VPU multiply instructions are used in vector version.
0% of VPU divide and square root instructions are used in vector version.
0% of VPU instructions that are not load, store, addition, subtraction nor multiply instructions are used in vector version.

Since your execution units are vector units, only a fully vectorized function can use their full power.

Workaround

Try another compiler or update/tune your current one
Make array accesses unit-stride:
- If your function 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

CALL instructions

Detected function call instructions.

Details

Calling (and then returning from) a function prevents many compiler optimizations (like vectorization), breaks control flow (which reduces pipeline performance) and executes extra instructions to save/restore the registers used inside it, which is very expensive (dozens of cycles). Consider to inline small functions.

unknown: 2 occurrences►
- /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42
- /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42

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

The binary function does not contain any FP arithmetical operations. The binary function is loading 76 bytes. The binary function is storing 64 bytes.

General properties

nb instructions	92
nb uops	89
loop length	368
used w registers	12
used x registers	17
used b registers	0
used h registers	0
used s registers	1
used d registers	0
used q registers	0
used v registers	0
used z registers	2
nb stack references	9

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	11.13 cycles
front end	11.13 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	6.50	6.50	15.25	15.25	15.25	15.25	0.50	0.50	0.50	0.50	6.17	5.83	6.00	1.50	1.50
cycles	6.50	6.50	15.25	15.25	15.25	15.25	0.50	0.50	0.50	0.50	6.17	5.83	6.00	1.50	1.50

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

5.00-12.50

Cycles summary

Front-end	11.13
Dispatch	15.25
DIV/SQRT	5.00-12.50
Overall L1	15.25

Vectorization ratios

all	10%
load	20%
store	40%
mul	0%
add-sub	0%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	0%
other	0%

Vector efficiency ratios

all	34%
load	45%
store	70%
mul	12%
add-sub	18%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	12%
other	26%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each call to the function takes 15.25 cycles. At this rate:

5% of peak load performance is reached (4.98 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
8% of peak store performance is reached (4.20 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 function is: 414f40

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	Latency	Recip. throughput	Vectorization
STP X29, X30, [SP, #976]!	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
ADD X29, SP, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
STP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
ORR X20, XZR, X0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
STP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
LDR W22, [X0, #8]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
LDR W21, [X0, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
BL 410320 <@plt_start@+0x300>	1	0.50	0.50	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W19, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
BL 4102b0 <@plt_start@+0x290>	1	0.50	0.50	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W1, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W2, W22, W21,LSL #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SDIV W5, W2, W19	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	5-12	5-12.50	scal (12.5%)
MSUB W2, W5, W19, W2	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	2	1	N/A
CMP W0, W2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
B.LT 415088 <_Z10update_topiiiiPdb._omp_fn.0+0x148>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
MUL W1, W5, W1	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
ADD W3, W2, W1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD W6, W5, W3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
CMP W3, W6	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
B.GE 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR W4, [X20, #12]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
SBFM X2, X2, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X2, X2, W21,SXTW	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
ADD X1, X2, W1,SXTW	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
LDR W7, [X20, #20]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
LDR X9, [X20]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	N/A
SUB W0, W4, W21	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W4, W0, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD W2, W7, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W4, W4, W7	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
MUL W2, W2, W22	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
MUL W4, W4, W22	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	scal (12.5%)
SBFM X2, X2, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X8, X2, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SBFM X4, X4, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (100.0%)
ADD X1, X4, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB X0, X8, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB X0, X0, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
UBFM X0, X0, #61, #60	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
CMP X0, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (25.0%)
B.LS 4150ac <_Z10update_topiiiiPdb._omp_fn.0+0x16c>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
SUB W0, W5, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
CMP W0, #2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
CCMP W3, W6, #0, #8	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
B.GE 4150d8 <_Z10update_topiiiiPdb._omp_fn.0+0x198>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X4, X9, X1,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
UBFM W2, W5, #2, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
MOVZ X0, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X3, X9, X8,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
UBFM X2, X2, #59, #58	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X7, X4, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
ADD X6, X3, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
HINT #0																			N/A
HINT #0																			N/A
HINT #0																			N/A
AND W0, W5, #0xfffffffc	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ANDS XZR, X5, #0x3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (25.0%)
B.EQ 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W2, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W0, W5, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
WHILELO P7.D, XZR, X0	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	3	2	N/A
ADD X8, X8, X2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X1, X1, X2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
LD1D {Z31.D}, P7/Z, [X9, X1,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0	6	0.50	vect (100.0%)
ADD X8, X9, X8,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ST1D {Z31.D}, P7, [X8, MUL VL]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	0	0	2	0.50	vect (100.0%)
CNTD X2, ALL	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	2	1	N/A
ADD X1, X9, X1,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
WHILELO P7.D, X2, X0	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	3	2	N/A
B.NE 415094 <_Z10update_topiiiiPdb._omp_fn.0+0x154>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	N/A
LDP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
LDP X29, X30, [SP], #48	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
RET	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD W5, W5, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
MOVZ W2, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 414f80 <_Z10update_topiiiiPdb._omp_fn.0+0x40>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LD1D {Z30.D}, P7/Z, [X1, #1, MUL VL]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0	6	0.50	vect (100.0%)
ST1D {Z30.D}, P7, [X8, #1, MUL VL]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	0	0	2	0.50	vect (100.0%)
LDP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	N/A
LDP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
LDP X29, X30, [SP], #48	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
RET	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD W0, W21, W3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X4, X9, X4,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
ADD W6, W21, W6	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD X2, X9, X2,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SBFM X0, X0, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
MOVZ W0, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 415048 <_Z10update_topiiiiPdb._omp_fn.0+0x108>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

The code analyzed by CQA in that panel excludes loops and represents 0.01% of application time for run gcc_0

Source file and lines	local_halos.cpp:42-46
Module	exec

The function is defined in /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42-46.

Warnings:
Ignoring paths for analysis

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 15.25 to 2.00 cycles (7.62x speedup).

Workaround

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

Vectorization

Details

10% of VPU instructions are used in vector version (process two or more data elements in vector registers):

20% of VPU loads are used in vector version.
40% of VPU stores are used in vector version.
0% of VPU addition or subtraction instructions are used in vector version.
0% of VPU multiply instructions are used in vector version.
0% of VPU divide and square root instructions are used in vector version.
0% of VPU instructions that are not load, store, addition, subtraction nor multiply instructions are used in vector version.

Since your execution units are vector units, only a fully vectorized function can use their full power.

Workaround

Try another compiler or update/tune your current one
Make array accesses unit-stride:
- If your function 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

CALL instructions

Detected function call instructions.

Details

unknown: 2 occurrences►
- /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42
- /home/eoseret/qaas/qaas_runs/178-237-4322/intel/TeaLeaf/build/TeaLeaf/src/omp/local_halos.cpp:42

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

The binary function does not contain any FP arithmetical operations. The binary function is loading 76 bytes. The binary function is storing 64 bytes.

General properties

nb instructions	92
nb uops	89
loop length	368
used w registers	12
used x registers	17
used b registers	0
used h registers	0
used s registers	1
used d registers	0
used q registers	0
used v registers	0
used z registers	2
nb stack references	9

Front-end

MACRO FUSION NOT POSSIBLE FIT IN UOP CACHE

micro-operation queue	11.13 cycles
front end	11.13 cycles

Back-end

	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14
uops	6.50	6.50	15.25	15.25	15.25	15.25	0.50	0.50	0.50	0.50	6.17	5.83	6.00	1.50	1.50
cycles	6.50	6.50	15.25	15.25	15.25	15.25	0.50	0.50	0.50	0.50	6.17	5.83	6.00	1.50	1.50

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

5.00-12.50

Cycles summary

Front-end	11.13
Dispatch	15.25
DIV/SQRT	5.00-12.50
Overall L1	15.25

Vectorization ratios

all	10%
load	20%
store	40%
mul	0%
add-sub	0%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	0%
other	0%

Vector efficiency ratios

all	34%
load	45%
store	70%
mul	12%
add-sub	18%
fma	NA (no fma vectorizable/vectorized instructions)
div/sqrt	12%
other	26%

Cycles and memory resources usage

Assuming all data fit into the L1 cache, each call to the function takes 15.25 cycles. At this rate:

5% of peak load performance is reached (4.98 out of 96.00 bytes loaded per cycle (GB/s @ 1GHz))
8% of peak store performance is reached (4.20 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 function is: 414f40

Instruction	Nb FU	P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11	P12	P13	P14	Latency	Recip. throughput	Vectorization
STP X29, X30, [SP, #976]!	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
ADD X29, SP, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
STP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
ORR X20, XZR, X0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
STP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0.50	0.50	1	0.50	scal (50.0%)
LDR W22, [X0, #8]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
LDR W21, [X0, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
BL 410320 <@plt_start@+0x300>	1	0.50	0.50	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W19, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
BL 4102b0 <@plt_start@+0x290>	1	0.50	0.50	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W1, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W2, W22, W21,LSL #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SDIV W5, W2, W19	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	5-12	5-12.50	scal (12.5%)
MSUB W2, W5, W19, W2	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	2	1	N/A
CMP W0, W2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
B.LT 415088 <_Z10update_topiiiiPdb._omp_fn.0+0x148>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
MUL W1, W5, W1	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
ADD W3, W2, W1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD W6, W5, W3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
CMP W3, W6	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
B.GE 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDR W4, [X20, #12]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
SBFM X2, X2, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X2, X2, W21,SXTW	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
ADD X1, X2, W1,SXTW	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
LDR W7, [X20, #20]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	scal (12.5%)
LDR X9, [X20]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	0.33	N/A
SUB W0, W4, W21	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W4, W0, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD W2, W7, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W4, W4, W7	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
MUL W2, W2, W22	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	N/A
MUL W4, W4, W22	1	0	0	0	0	0.50	0.50	0	0	0	0	0	0	0	0	0	2	0.50	scal (12.5%)
SBFM X2, X2, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X8, X2, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SBFM X4, X4, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (100.0%)
ADD X1, X4, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB X0, X8, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB X0, X0, X1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
UBFM X0, X0, #61, #60	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
CMP X0, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (25.0%)
B.LS 4150ac <_Z10update_topiiiiPdb._omp_fn.0+0x16c>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
SUB W0, W5, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
CMP W0, #2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (12.5%)
CCMP W3, W6, #0, #8	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
B.GE 4150d8 <_Z10update_topiiiiPdb._omp_fn.0+0x198>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD X4, X9, X1,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
UBFM W2, W5, #2, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
MOVZ X0, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X3, X9, X8,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
UBFM X2, X2, #59, #58	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X7, X4, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
ADD X6, X3, #16	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
HINT #0																			N/A
HINT #0																			N/A
HINT #0																			N/A
AND W0, W5, #0xfffffffc	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ANDS XZR, X5, #0x3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.33	scal (25.0%)
B.EQ 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ORR W2, WZR, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SUB W0, W5, W0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
WHILELO P7.D, XZR, X0	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	3	2	N/A
ADD X8, X8, X2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X1, X1, X2	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
LD1D {Z31.D}, P7/Z, [X9, X1,LSL #3]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0	6	0.50	vect (100.0%)
ADD X8, X9, X8,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ST1D {Z31.D}, P7, [X8, MUL VL]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	0	0	2	0.50	vect (100.0%)
CNTD X2, ALL	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	2	1	N/A
ADD X1, X9, X1,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
WHILELO P7.D, X2, X0	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	3	2	N/A
B.NE 415094 <_Z10update_topiiiiPdb._omp_fn.0+0x154>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LDP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	N/A
LDP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
LDP X29, X30, [SP], #48	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
RET	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD W5, W5, #1	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
MOVZ W2, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 414f80 <_Z10update_topiiiiPdb._omp_fn.0+0x40>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
LD1D {Z30.D}, P7/Z, [X1, #1, MUL VL]	1	0	0	0	0	0	0	0	0	0	0	0.50	0.50	0	0	0	6	0.50	vect (100.0%)
ST1D {Z30.D}, P7, [X8, #1, MUL VL]	1	0	0	0	0	0	0	0.25	0.25	0.25	0.25	0.50	0.50	0	0	0	2	0.50	vect (100.0%)
LDP X19, X20, [SP, #16]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	N/A
LDP X21, X22, [SP, #32]	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
LDP X29, X30, [SP], #48	1	0	0	0	0	0	0	0	0	0	0	0.33	0.33	0.33	0	0	4	1	scal (50.0%)
RET	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
ADD W0, W21, W3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
ADD X4, X9, X4,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (25.0%)
ADD W6, W21, W6	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	scal (12.5%)
ADD X2, X9, X2,LSL #3	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
SBFM X0, X0, #0, #31	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 415078 <_Z10update_topiiiiPdb._omp_fn.0+0x138>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A
MOVZ W0, #0	1	0	0	0.25	0.25	0.25	0.25	0	0	0	0	0	0	0	0	0	1	0.25	N/A
B 415048 <_Z10update_topiiiiPdb._omp_fn.0+0x108>	1	0.50	0.50	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0.50	N/A

Name	Coverage (%)	Time (s)
▼update_top(int, int, int, int, double*, bool) [clone ._omp_fn.0]–	0.01	0.04
○Loop 91 - local_halos.cpp:46-46 - exec	0.01	0.04
○Loop 90 - local_halos.cpp:46-46 - exec	0.00	0.00

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