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[ 4 / 4 ] Application profile is long enough (30.46 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=native is used
[ 2 / 2 ] Application is correctly profiled ("Others" category represents 0.06 % 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 (78.58%)
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% (51.77%), representing an hotspot for the application
[ 4 / 4 ] Enough time of the experiment time spent in analyzed innermost loops (69.60%)
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
[ 3 / 3 ] Cumulative Outermost/In between loops coverage (8.98%) lower than cumulative innermost loop coverage (69.60%)
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 5 - spmxv.exe | Execution Time: 51 % - Vectorization Ratio: 100.00 % - Vector Length Use: 37.50 % | |
| ►Loop Computation Issues | 5 | |
| ○ | [DA] Low iteration count (2.925 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Control Flow Issues | 5 | |
| ○ | [DA] Low iteration count (2.925 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Data Access Issues | 8 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ► | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
| ○ | Number of YMM GATHER/SCATTER instructions: 1 | |
| ►Vectorization Roadblocks | 4 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ►Inefficient Vectorization | 4 | |
| ○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
| ►Loop 4 - spmxv.exe | Execution Time: 17 % - Vectorization Ratio: 0.00 % - Vector Length Use: 12.50 % | |
| ►Loop Computation Issues | 5 | |
| ○ | [DA] Low iteration count (3 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Control Flow Issues | 5 | |
| ○ | [DA] Low iteration count (3 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Data Access Issues | 4 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ►Vectorization Roadblocks | 4 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ►Loop 3 - spmxv.exe | Execution Time: 8 % - Vectorization Ratio: 30.65 % - Vector Length Use: 15.87 % | |
| ►Loop Computation Issues | 6 | |
| ○ | [SA] Less than 10% of the FP ADD/SUB/MUL arithmetic operations are performed using FMA - Reorganize arithmetic expressions to exhibit potential for FMA. This issue costs 4 points. | 4 |
| ○ | [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 | 6 | |
| ○ | [SA] Several paths (4 paths) - Simplify control structure or force the compiler to use masked instructions. There are 4 issues ( = paths) costing 1 point each. | 4 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 17 | |
| ○ | [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 5 issues ( = data accesses) costing 2 point each. | 10 |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 1 issues (= instructions) costing 1 point each. | 1 |
| ○ | Number of INSERT/EXTRACT instructions: 0.5 Number of XMM SHUFFLE/PERM instructions: 0.5 | |
| ○ | [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 | 20 | |
| ○ | [SA] Several paths (4 paths) - Simplify control structure or force the compiler to use masked instructions. There are 4 issues ( = paths) costing 1 point each. | 4 |
| ○ | [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 5 issues ( = data accesses) costing 2 point each. | 10 |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ○ | [SA] Non innermost loop (InBetween) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Inefficient Vectorization | 1 | |
| ► | [SA] Presence of special instructions executing on a single port (INSERT/EXTRACT, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 1 issues (= instructions) costing 1 point each. | 1 |
| ○ | Number of INSERT/EXTRACT instructions: 0.5 Number of XMM SHUFFLE/PERM instructions: 0.5 | |
| ►Loop 2 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 7.69 % | |
| ►Control Flow Issues | 6 | |
| ○ | [SA] Several paths (4 paths) - Simplify control structure or force the compiler to use masked instructions. There are 4 issues ( = paths) costing 1 point each. | 4 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Data Access Issues | 6 | |
| ○ | [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 2 issues ( = data accesses) costing 2 point each. | 4 |
| ○ | [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] Several paths (4 paths) - Simplify control structure or force the compiler to use masked instructions. There are 4 issues ( = paths) costing 1 point each. | 4 |
| ○ | [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 2 issues ( = data accesses) costing 2 point each. | 4 |
| ○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
| ►Loop 78 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 10.82 % | |
| ►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 | 12 | |
| ○ | [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] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ○ | [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 | 14 | |
| ○ | [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 |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ►Loop 77 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 100.00 % - Vector Length Use: 37.50 % | |
| ►Loop Computation Issues | 5 | |
| ○ | [DA] Low iteration count (2.93 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Control Flow Issues | 5 | |
| ○ | [DA] Low iteration count (2.93 < 10) - Perform full unroll. Use compiler pragmas. Use PGO/FDO compiler options. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
| ►Data Access Issues | 8 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ► | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
| ○ | Number of YMM GATHER/SCATTER instructions: 1 | |
| ►Vectorization Roadblocks | 4 | |
| ○ | [SA] Presence of indirect accesses - Use array restructuring or gather instructions to lower the cost. There are 1 issues ( = indirect data accesses) costing 4 point each. | 4 |
| ►Inefficient Vectorization | 4 | |
| ○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
| ►Loop 71 - spmxv.exe | Execution Time: 0 % - Vectorization Ratio: 100.00 % - Vector Length Use: 40.00 % | |
| ►Loop Computation Issues | 4 | |
| ○ | [SA] Less than 10% of the FP ADD/SUB/MUL arithmetic operations are performed using FMA - Reorganize arithmetic expressions to exhibit potential for FMA. This issue costs 4 points. | 4 |
| ►Data Access Issues | 6 | |
| ○ | [SA] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 1 issues ( = arrays) costing 2 points each | 2 |
| ► | [SA] Presence of special instructions executing on a single port (BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 4 issues (= instructions) costing 1 point each. | 4 |
| ○ | Number of YMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 2 | |
| ►Inefficient Vectorization | 4 | |
| ► | [SA] Presence of special instructions executing on a single port (BLEND/MERGE, SHUFFLE/PERM) - Simplify data access and try to get stride 1 access. There are 4 issues (= instructions) costing 1 point each. | 4 |
| ○ | Number of YMM BLEND/MERGE instructions: 2 Number of YMM SHUFFLE/PERM instructions: 2 |