Help is available by moving the cursor above any symbol or by checking MAQAO website.
[ 4 / 4 ] Application profile is long enough (19.93 s)
To have good quality measurements, it is advised that the application profiling time is greater than 10 seconds.
[ 2.95 / 3 ] Optimization level option is correctly used
[ 2.95 / 3 ] Most of time spent in analyzed modules comes from functions compiled with -g and -fno-omit-frame-pointer
-g option gives access to debugging informations, such are source locations. -fno-omit-frame-pointer improve the accuracy of callchains found during the application profiling.
[ 2.95 / 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 (66.31%)
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% (26.99%), representing an hotspot for the application
[ 4 / 4 ] Enough time of the experiment time spent in analyzed innermost loops (57.41%)
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%) is spend in BLAS1 operations
It could be more efficient to inline by hand BLAS1 operations
[ 3 / 3 ] Cumulative Outermost/In between loops coverage (8.90%) lower than cumulative innermost loop coverage (57.41%)
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%) is spend in Libm/SVML (special functions)
[ 2 / 2 ] Less than 10% (0%) 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 3232 - exec | Execution Time: 26 % - Vectorization Ratio: 100.00 % - Vector Length Use: 43.75 % | |
►Data Access Issues | 14 | |
○ | [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] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 3 issues ( = arrays) costing 2 points each | 6 |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points 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 |
►Inefficient Vectorization | 4 | |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
►Loop 4309 - exec | Execution Time: 6 % - Vectorization Ratio: 100.00 % - Vector Length Use: 43.75 % | |
►Data Access Issues | 14 | |
○ | [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] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 3 issues ( = arrays) costing 2 points each | 6 |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points 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 |
►Inefficient Vectorization | 4 | |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
►Loop 4321 - exec | Execution Time: 6 % - Vectorization Ratio: 100.00 % - Vector Length Use: 43.75 % | |
►Data Access Issues | 14 | |
○ | [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] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 3 issues ( = arrays) costing 2 points each | 6 |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points 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 |
►Inefficient Vectorization | 4 | |
○ | [SA] Presence of expensive instructions (GATHER/SCATTER) - Use array restructuring. There are 1 issues (= instructions) costing 4 points each. | 4 |
►Loop 3231 - exec | Execution Time: 2 % - Vectorization Ratio: 0.00 % - Vector Length Use: 12.50 % | |
►Loop Computation Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
►Control Flow Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. 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 3228 - exec | Execution Time: 2 % - Vectorization Ratio: 28.57 % - Vector Length Use: 16.07 % | |
►Loop Computation Issues | 10 | |
○ | [SA] Presence of expensive FP instructions - Perform hoisting, change algorithm, use SVML or proper numerical library or perform value profiling (count the number of distinct input values). There are 1 issues (= instructions) costing 4 points each. | 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 |
○ | [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 | 23 | |
○ | [SA] Too many paths (17 paths) - Simplify control structure. There are 17 issues ( = paths) costing 1 point each with a malus of 4 points. | 21 |
○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
►Data Access Issues | 6 | |
○ | [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 4 issues (= instructions) costing 1 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 | 23 | |
○ | [SA] Too many paths (17 paths) - Simplify control structure. There are 17 issues ( = paths) costing 1 point each with a malus of 4 points. | 21 |
○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
►Inefficient Vectorization | 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 4 issues (= instructions) costing 1 point each. | 4 |
►Loop 4386 - exec | Execution Time: 1 % - Vectorization Ratio: 100.00 % - Vector Length Use: 50.00 % | |
►Data Access Issues | 4 | |
○ | [SA] Inefficient vectorization: more than 10% of the vector loads instructions are unaligned - When allocating arrays, don’t forget to align them. There are 2 issues ( = arrays) costing 2 points each | 4 |
►Loop 4348 - exec | Execution Time: 1 % - Vectorization Ratio: 0.00 % - Vector Length Use: 12.50 % | |
►Control Flow Issues | 11 | |
○ | [SA] Too many paths (5 paths) - Simplify control structure. There are 5 issues ( = paths) costing 1 point each with a malus of 4 points. | 9 |
○ | [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 | 11 | |
○ | [SA] Too many paths (5 paths) - Simplify control structure. There are 5 issues ( = paths) costing 1 point each with a malus of 4 points. | 9 |
○ | [SA] Non innermost loop (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
►Loop 4308 - exec | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 12.50 % | |
►Loop Computation Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
►Control Flow Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. 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 4301 - exec | Execution Time: 0 % - Vectorization Ratio: 16.23 % - Vector Length Use: 14.53 % | |
►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 (Outermost) - Collapse loop with innermost ones. This issue costs 2 points. | 2 |
►Data Access Issues | 13 | |
○ | [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 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 |
○ | [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 | 16 | |
○ | [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] Non innermost loop (Outermost) - 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 |
►Loop 4320 - exec | Execution Time: 0 % - Vectorization Ratio: 0.00 % - Vector Length Use: 12.50 % | |
►Loop Computation Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. Force compiler to use masked instructions. This issue costs 5 points. | 5 |
►Control Flow Issues | 5 | |
○ | [SA] Peel/tail loop, considered having a low iteration count - Perform full unroll. 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 |