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Update ShiftAnalysis authored by Chris Cox's avatar Chris Cox
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ShiftAnalysis.md
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...@@ -485,7 +485,9 @@ number time per second test0 ...@@ -485,7 +485,9 @@ number time per second test0
54 "int64_t right shift zero" 49.89 sec 962.11 M 1.53 54 "int64_t right shift zero" 49.89 sec 962.11 M 1.53
55 "int64_t left shift zero" 49.54 sec 968.85 M 1.52 55 "int64_t left shift zero" 49.54 sec 968.85 M 1.52
``` ```
* * These are so slow it isn't easy to tell if any of them are being optimized at all.
* This is between 4x and 30x slower than LLVM generated code.
### Variable Shifts ### Variable Shifts
``` ```
...@@ -525,7 +527,8 @@ number time per second test0 ...@@ -525,7 +527,8 @@ number time per second test0
30 "int64_t variable left shift" 126.30 sec 380.05 M 2.49 30 "int64_t variable left shift" 126.30 sec 380.05 M 2.49
31 "int64_t repeated variable left shift" 174.56 sec 274.97 M 3.44 31 "int64_t repeated variable left shift" 174.56 sec 274.97 M 3.44
``` ```
* * Again incredibly slow and difficult to tell if anything is being optimized.
### Constant Mask Low ### Constant Mask Low
``` ```
...@@ -549,7 +552,7 @@ number time per second test0 ...@@ -549,7 +552,7 @@ number time per second test0
14 "int64_t constant mask low" 51.32 sec 935.27 M 2.40 14 "int64_t constant mask low" 51.32 sec 935.27 M 2.40
15 "int64_t constant mask low by shift" 51.40 sec 933.92 M 2.40 15 "int64_t constant mask low by shift" 51.40 sec 933.92 M 2.40
``` ```
* * Again incredibly slow and difficult to tell if anything is being optimized.
### Variable Mask Low ### Variable Mask Low
...@@ -574,7 +577,7 @@ number time per second test0 ...@@ -574,7 +577,7 @@ number time per second test0
14 "int64_t variable mask low" 86.08 sec 557.61 M 4.08 14 "int64_t variable mask low" 86.08 sec 557.61 M 4.08
15 "int64_t variable mask low by shift" 85.90 sec 558.78 M 4.07 15 "int64_t variable mask low by shift" 85.90 sec 558.78 M 4.07
``` ```
* * Again incredibly slow and difficult to tell if anything is being optimized.
### Constant Mask High ### Constant Mask High
...@@ -591,7 +594,7 @@ number time per second test0 ...@@ -591,7 +594,7 @@ number time per second test0
6 "uint64_t constant mask high" 49.59 sec 967.99 M 2.35 6 "uint64_t constant mask high" 49.59 sec 967.99 M 2.35
7 "uint64_t constant mask high by shift" 49.07 sec 978.24 M 2.33 7 "uint64_t constant mask high by shift" 49.07 sec 978.24 M 2.33
``` ```
* * Again incredibly slow and difficult to tell if anything is being optimized.
### Variable Mask High ### Variable Mask High
...@@ -608,8 +611,4 @@ number time per second test0 ...@@ -608,8 +611,4 @@ number time per second test0
6 "uint64_t variable mask high" 49.25 sec 974.53 M 2.42 6 "uint64_t variable mask high" 49.25 sec 974.53 M 2.42
7 "uint64_t variable mask high by shift" 49.34 sec 972.80 M 2.42 7 "uint64_t variable mask high by shift" 49.34 sec 972.80 M 2.42
``` ```
* * Again incredibly slow and difficult to tell if anything is being optimized.