G3 GNU best (O3+nosve) | G4 GNU best (O3+nosve) |
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[ 2.98 / 3 ] Architecture specific option -mcpu is used | [ 2.98 / 3 ] Architecture specific option -mcpu is used |
[ 2.98 / 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. | [ 2.98 / 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. |
[ 0 / 0 ] Fastmath not used Consider to add ffast-math to compilation flags (or replace -O3 with -Ofast) to unlock potential extra speedup by relaxing floating-point computation consistency. Warning: floating-point accuracy may be reduced and the compliance to IEEE/ISO rules/specifications for math functions will be relaxed, typically 'errno' will no longer be set after calling some math functions. | [ 0 / 0 ] Fastmath not used Consider to add ffast-math to compilation flags (or replace -O3 with -Ofast) to unlock potential extra speedup by relaxing floating-point computation consistency. Warning: floating-point accuracy may be reduced and the compliance to IEEE/ISO rules/specifications for math functions will be relaxed, typically 'errno' will no longer be set after calling some math functions. |
[ 2 / 2 ] Application is correctly profiled ("Others" category represents 2.45 % 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 | [ 2 / 2 ] Application is correctly profiled ("Others" category represents 1.35 % 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 |
[ 2.99 / 3 ] Optimization level option is correctly used | [ 2.99 / 3 ] Optimization level option is correctly used |
[ 4 / 4 ] Application profile is long enough (12124.63 s) To have good quality measurements, it is advised that the application profiling time is greater than 10 seconds. | [ 4 / 4 ] Application profile is long enough (7329.52 s) To have good quality measurements, it is advised that the application profiling time is greater than 10 seconds. |
G3 GNU best (O3+nosve) | G4 GNU best (O3+nosve) |
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[ 4 / 4 ] CPU activity is good CPU cores are active 91.45% of time | [ 3 / 4 ] CPU activity is below 90% (89.97%) CPU cores are idle more than 10% of time. Threads supposed to run on these cores are probably IO/sync waiting. Some hints: use faster filesystems to read/write data, improve parallel load balancing and/or scheduling. |
[ 4 / 4 ] Affinity is good (99.87%) Threads are not migrating to CPU cores: probably successfully pinned | [ 4 / 4 ] Affinity is good (99.98%) Threads are not migrating to CPU cores: probably successfully pinned |
[ 4 / 4 ] Enough time of the experiment time spent in analyzed loops (85.98%) If the time spent in analyzed loops is less than 30%, standard loop optimizations will have a limited impact on application performances. | [ 4 / 4 ] Enough time of the experiment time spent in analyzed loops (85.45%) If the time spent in analyzed loops is less than 30%, standard loop optimizations will have a limited impact on application performances. |
[ 3 / 3 ] Cumulative Outermost/In between loops coverage (4.75%) lower than cumulative innermost loop coverage (81.23%) Having cumulative Outermost/In between loops coverage greater than cumulative innermost loop coverage will make loop optimization more complex | [ 3 / 3 ] Cumulative Outermost/In between loops coverage (4.56%) lower than cumulative innermost loop coverage (80.89%) Having cumulative Outermost/In between loops coverage greater than cumulative innermost loop coverage will make loop optimization more complex |
[ 4 / 4 ] Threads activity is good On average, more than 91.43% of observed threads are actually active | [ 3 / 4 ] A significant amount of threads are idle (10.06%) On average, more than 10% of observed threads are idle. Such threads are probably IO/sync waiting. Some hints: use faster filesystems to read/write data, improve parallel load balancing and/or scheduling. |
[ 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. | [ 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. |
[ 4 / 4 ] Enough time of the experiment time spent in analyzed innermost loops (81.23%) 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. | [ 4 / 4 ] Enough time of the experiment time spent in analyzed innermost loops (80.89%) 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 ] Less than 10% (0.00%) is spend in BLAS1 operations It could be more efficient to inline by hand BLAS1 operations |
[ 2 / 2 ] Less than 10% (0.00%) is spend in Libm/SVML (special functions) | [ 2 / 2 ] Less than 10% (0.11%) is spend in Libm/SVML (special functions) |
[ 4 / 4 ] Loop profile is not flat At least one loop coverage is greater than 4% (5.10%), representing an hotspot for the application | [ 4 / 4 ] Loop profile is not flat At least one loop coverage is greater than 4% (4.39%), representing an hotspot for the application |
Analysis | r_1 | r_2 | |
---|---|---|---|
Loop Computation Issues | Presence of expensive FP instructions | 1 | 1 |
Less than 10% of the FP ADD/SUB/MUL arithmetic operations are performed using FMA | 10 | 9 | |
Presence of a large number of scalar integer instructions | 7 | 7 | |
Control Flow Issues | Presence of 2 to 4 paths | 2 | 3 |
Presence of more than 4 paths | 1 | 1 | |
Data Access Issues | Presence of constant non-unit stride data access | 6 | 6 |
Presence of indirect access | 3 | 4 | |
Vectorization Roadblocks | Presence of 2 to 4 paths | 2 | 3 |
Presence of more than 4 paths | 2 | 2 | |
Presence of constant non-unit stride data access | 6 | 6 | |
Presence of indirect access | 3 | 4 |