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[ 4 / 4 ] Application profile is long enough (33.61 s)
To have good quality measurements, it is advised that the application profiling time is greater than 10 seconds.
[ 3 / 3 ] Optimization level option is correctly used
[ 2.40 / 3 ] Most of time spent in analyzed modules comes from functions compiled with -g
-g option gives access to debugging informations, such are source locations. Add -fno-omit-frame-pointer to improve the accuracy of callchains found during the application profiling
[ 3 / 3 ] Architecture specific option -march=skylake-avx512 is used
[ 2 / 2 ] Application is correctly profiled ("Others" category represents 0.19 % of the execution time)
To have a representative profiling, it is advised that the category "Others" represents less than 20% of the execution time in order to analyze as much as possible of the user code
[ 4 / 4 ] Enough time of the experiment time spent in analyzed loops (85.34%)
If the time spent in analyzed loops is less than 30%, standard loop optimizations will have a limited impact on application performances.
[ 4 / 4 ] Loop profile is not flat
At least one loop coverage is greater than 4% (85.29%), representing an hotspot for the application
[ 0 / 4 ] Too little time of the experiment time spent in analyzed innermost loops (0.01%)
If the time spent in analyzed innermost loops is less than 15%, standard innermost loop optimizations such as vectorisation will have a limited impact on application performances.
[ 3 / 3 ] Less than 10% (0.00%) is spend in BLAS1 operations
It could be more efficient to inline by hand BLAS1 operations
[ 0 / 3 ] Cumulative Outermost/In between loops coverage (85.33%) greater than cumulative innermost loop coverage (0.01%)
Having cumulative Outermost/In between loops coverage greater than cumulative innermost loop coverage will make loop optimization more complex
[ 2 / 2 ] Less than 10% (0.00%) is spend in Libm/SVML (special functions)
[ 2 / 2 ] Less than 10% (0.00%) is spend in BLAS2 operations
BLAS2 calls usually could make a poor cache usage and could benefit from inlining.
| Loop ID | Analysis | Penalty Score |
|---|---|---|
| ►Loop 1 - spmxv.exe | Execution Time: 85 % - Vectorization Ratio: 42.55 % - Vector Length Use: 21.28 % | |
| ►Loop Computation Issues | 2 | |
| ○ | [SA] Presence of a large number of scalar integer instructions - Simplify loop structure, perform loop splitting or perform unroll and jam. This issue costs 2 points. | 2 |
| ►Control Flow Issues | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 14 | |
| ► | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 2 issues (= instructions) costing 4 points each. | 8 |
| ○ | Number of YMM GATHER/SCATTER instructions: 2 | |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 6 issues (= instructions) costing 1 point each. | 6 |
| ○ | Number of INSERT/EXTRACT instructions: 3 Number of XMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 1 | |
| ►Vectorization Roadblocks | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Inefficient Vectorization | 14 | |
| ○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 2 issues (= instructions) costing 4 points each. | 8 |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 6 issues (= instructions) costing 1 point each. | 6 |
| ○ | Number of INSERT/EXTRACT instructions: 3 Number of XMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 1 | |
| ►Loop 2 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 9.38 % | |
| ►Control Flow Issues | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 2 | |
| ○ | [SA] More than 20% of the loads are accessing the stack - Perform loop splitting to decrease pressure on registers. This issue costs 2 points. | 2 |
| ►Vectorization Roadblocks | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Loop 95 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 11.70 % | |
| ►Loop Computation Issues | 2 | |
| ○ | [SA] Presence of a large number of scalar integer instructions - Simplify loop structure, perform loop splitting or perform unroll and jam. This issue costs 2 points. | 2 |
| ►Control Flow Issues | 4 | |
| ○ | [SA] Presence of calls - Inline either by compiler or by hand and use SVML for libm calls. There are 2 issues (= calls) costing 1 point each. | 2 |
| ○ | [SA] Several paths (2 paths) - Simplify control structure or force the compiler to use masked instructions. There are 2 issues ( = paths) costing 1 point each. | 2 |
| ►Data Access Issues | 8 | |
| ○ | [SA] Presence of constant non unit stride data access - Use array restructuring, perform loop interchange or use gather instructions to lower a bit the cost. There are 3 issues ( = data accesses) costing 2 point each. | 6 |
| ○ | [SA] More than 20% of the loads are accessing the stack - Perform loop splitting to decrease pressure on registers. This issue costs 2 points. | 2 |
| ►Vectorization Roadblocks | 10 | |
| ○ | [SA] Presence of calls - Inline either by compiler or by hand and use SVML for libm calls. There are 2 issues (= calls) costing 1 point each. | 2 |
| ○ | [SA] Several paths (2 paths) - Simplify control structure or force the compiler to use masked instructions. There are 2 issues ( = paths) costing 1 point each. | 2 |
| ○ | [SA] Presence of constant non unit stride data access - Use array restructuring, perform loop interchange or use gather instructions to lower a bit the cost. There are 3 issues ( = data accesses) costing 2 point each. | 6 |
| ►Loop 4 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 11.54 % - Vector Length Use: 14.18 % | |
| ►Loop Computation Issues | 2 | |
| ○ | [SA] Presence of a large number of scalar integer instructions - Simplify loop structure, perform loop splitting or perform unroll and jam. This issue costs 2 points. | 2 |
| ►Control Flow Issues | 34 | |
| ○ | [SA] Too many paths (28 paths) - Simplify control structure. There are 28 issues ( = paths) costing 1 point each with a malus of 4 points. | 32 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 2 | |
| ○ | [SA] More than 20% of the loads are accessing the stack - Perform loop splitting to decrease pressure on registers. This issue costs 2 points. | 2 |
| ►Vectorization Roadblocks | 34 | |
| ○ | [SA] Too many paths (28 paths) - Simplify control structure. There are 28 issues ( = paths) costing 1 point each with a malus of 4 points. | 32 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Loop 11 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 50.00 % - Vector Length Use: 22.50 % | |
| ►Loop Computation Issues | 2 | |
| ○ | [SA] Presence of a large number of scalar integer instructions - Simplify loop structure, perform loop splitting or perform unroll and jam. This issue costs 2 points. | 2 |
| ►Control Flow Issues | 2 | |
| ○ | [SA] Presence of calls - Inline either by compiler or by hand and use SVML for libm calls. There are 2 issues (= calls) costing 1 point each. | 2 |
| ►Data Access Issues | 2 | |
| ○ | [SA] More than 20% of the loads are accessing the stack - Perform loop splitting to decrease pressure on registers. This issue costs 2 points. | 2 |
| ►Vectorization Roadblocks | 2 | |
| ○ | [SA] Presence of calls - Inline either by compiler or by hand and use SVML for libm calls. There are 2 issues (= calls) costing 1 point each. | 2 |
| ►Loop 83 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 41.30 % - Vector Length Use: 21.20 % | |
| ►Loop Computation Issues | 2 | |
| ○ | [SA] Presence of a large number of scalar integer instructions - Simplify loop structure, perform loop splitting or perform unroll and jam. This issue costs 2 points. | 2 |
| ►Control Flow Issues | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 14 | |
| ► | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 2 issues (= instructions) costing 4 points each. | 8 |
| ○ | Number of YMM GATHER/SCATTER instructions: 2 | |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 6 issues (= instructions) costing 1 point each. | 6 |
| ○ | Number of INSERT/EXTRACT instructions: 3 Number of XMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 1 | |
| ►Vectorization Roadblocks | 38 | |
| ○ | [SA] Too many paths (32 paths) - Simplify control structure. There are 32 issues ( = paths) costing 1 point each with a malus of 4 points. | 36 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Inefficient Vectorization | 14 | |
| ○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 2 issues (= instructions) costing 4 points each. | 8 |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 6 issues (= instructions) costing 1 point each. | 6 |
| ○ | Number of INSERT/EXTRACT instructions: 3 Number of XMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 1 | |
| ►Loop 10 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 100.00 % - Vector Length Use: 100.00 % | |
| ►Loop Computation Issues | 0 | |
| ○ | [DA] Low iteration count (12 < 30) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. | 0 |
| ►Control Flow Issues | 0 | |
| ○ | [DA] Low iteration count (12 < 30) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. | 0 |
| ►Data Access Issues | 10 | |
| ○ | [SA] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 5 issues ( = arrays) costing 2 points each | 10 |